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rumdl_lib/rules/
md013_line_length.rs

1/// Rule MD013: Line length
2///
3/// See [docs/md013.md](../../docs/md013.md) for full documentation, configuration, and examples.
4use crate::rule::{LintError, LintResult, LintWarning, Rule, RuleCategory, Severity};
5use crate::rule_config_serde::RuleConfig;
6use crate::utils::mkdocs_admonitions;
7use crate::utils::mkdocs_attr_list::is_standalone_attr_list;
8use crate::utils::mkdocs_snippets::is_snippet_block_delimiter;
9use crate::utils::mkdocs_tabs;
10use crate::utils::range_utils::LineIndex;
11use crate::utils::range_utils::calculate_excess_range;
12use crate::utils::regex_cache::{IMAGE_REF_PATTERN, LINK_REF_PATTERN, URL_PATTERN};
13use crate::utils::table_utils::TableUtils;
14use crate::utils::text_reflow::{
15    BlockquoteLineData, blockquote_continuation_style, dominant_blockquote_prefix, reflow_blockquote_content,
16    split_into_sentences,
17};
18use pulldown_cmark::LinkType;
19use toml;
20
21mod block_builder;
22mod helpers;
23pub mod md013_config;
24use crate::rules::md030_list_marker_space::MD030Config;
25use crate::utils::is_template_directive_only;
26use block_builder::{Block, BlockBuilder};
27use helpers::{
28    extract_list_marker_and_content, has_hard_break, is_github_alert_marker, is_horizontal_rule, is_html_only_line,
29    is_list_item, is_standalone_link_or_image_line, is_unwrappable_line, split_into_segments,
30    trim_preserving_hard_break,
31};
32pub use md013_config::MD013Config;
33use md013_config::{LengthMode, ReflowMode};
34
35#[cfg(test)]
36mod tests;
37use unicode_width::UnicodeWidthStr;
38
39#[derive(Clone, Default)]
40pub struct MD013LineLength {
41    pub(crate) config: MD013Config,
42    /// MD030 list-marker spacing, applied when reflowing list items so the rewrite
43    /// uses the configured post-marker spacing rather than a hard-coded single
44    /// space. Defaults to MD030's defaults (a single space everywhere), which
45    /// reproduces the previous behaviour exactly. See [`MD030Config::expected_spaces`].
46    pub(crate) list_spacing: MD030Config,
47}
48
49/// Blockquote paragraph line collected for reflow, with original line index for range computation.
50struct CollectedBlockquoteLine {
51    line_idx: usize,
52    data: BlockquoteLineData,
53}
54
55impl MD013LineLength {
56    pub fn new(line_length: usize, code_blocks: bool, tables: bool, headings: bool, strict: bool) -> Self {
57        Self {
58            config: MD013Config {
59                line_length: crate::types::LineLength::new(line_length),
60                code_blocks,
61                code_spans: true,
62                tables,
63                headings,
64                paragraphs: true,  // Default to true for backwards compatibility
65                blockquotes: true, // Default to true for backwards compatibility
66                strict,
67                stern: false,
68                heading_line_length: None,
69                code_block_line_length: None,
70                reflow: false,
71                reflow_mode: ReflowMode::default(),
72                length_mode: LengthMode::default(),
73                abbreviations: Vec::new(),
74                require_sentence_capital: true,
75                ignore_link_urls: true,
76            },
77            list_spacing: MD030Config::default(),
78        }
79    }
80
81    pub fn from_config_struct(config: MD013Config) -> Self {
82        Self {
83            config,
84            list_spacing: MD030Config::default(),
85        }
86    }
87
88    /// Return a clone with code block checking disabled.
89    /// Used for doc comment linting where code blocks are Rust code managed by rustfmt.
90    pub fn with_code_blocks_disabled(&self) -> Self {
91        let mut clone = self.clone();
92        clone.config.code_blocks = false;
93        clone
94    }
95
96    /// Convert MD013 LengthMode to text_reflow ReflowLengthMode
97    /// Normalized set of reference labels defined in the document.
98    ///
99    /// Passed to reflow so a bare shortcut reference (`[text]`) is treated as an
100    /// atomic link only when its label is actually defined; an undefined
101    /// bracketed run reflows as literal prose.
102    fn defined_reference_labels(ctx: &crate::lint_context::LintContext) -> std::collections::HashSet<String> {
103        ctx.reference_defs
104            .iter()
105            .map(|d| crate::utils::text_reflow::normalize_reference_label(&d.id))
106            .collect()
107    }
108
109    /// Build the reflow options shared by every MD013 fix path.
110    ///
111    /// `line_length` varies per call site (some subtract a list-marker or
112    /// blockquote prefix); every other field is derived uniformly from the
113    /// effective config and the document flavor. Callers that need a different
114    /// `max_list_continuation_indent` override it via struct update.
115    fn reflow_options(
116        ctx: &crate::lint_context::LintContext,
117        config: &MD013Config,
118        line_length: usize,
119    ) -> crate::utils::text_reflow::ReflowOptions {
120        crate::utils::text_reflow::ReflowOptions {
121            line_length,
122            break_on_sentences: true,
123            preserve_breaks: false,
124            sentence_per_line: config.reflow_mode == ReflowMode::SentencePerLine,
125            semantic_line_breaks: config.reflow_mode == ReflowMode::SemanticLineBreaks,
126            abbreviations: config.abbreviations_for_reflow(),
127            length_mode: config.reflow_length_mode(),
128            attr_lists: ctx.flavor.supports_attr_lists(),
129            myst_roles: ctx.flavor.supports_myst_roles(),
130            require_sentence_capital: config.require_sentence_capital,
131            max_list_continuation_indent: if ctx.flavor.requires_strict_list_indent() {
132                Some(4)
133            } else {
134                None
135            },
136            defined_references: Some(Self::defined_reference_labels(ctx)),
137        }
138    }
139
140    fn should_ignore_line(
141        &self,
142        line: &str,
143        _lines: &[&str],
144        current_line: usize,
145        ctx: &crate::lint_context::LintContext,
146    ) -> bool {
147        if self.config.strict {
148            return false;
149        }
150
151        // Quick check for common patterns before expensive regex
152        let trimmed = line.trim();
153
154        // Only skip if the entire line is a URL (quick check first)
155        if (trimmed.starts_with("http://") || trimmed.starts_with("https://")) && URL_PATTERN.is_match(trimmed) {
156            return true;
157        }
158
159        // Only skip if the entire line is an image reference (quick check first)
160        if trimmed.starts_with("![") && trimmed.ends_with(']') && IMAGE_REF_PATTERN.is_match(trimmed) {
161            return true;
162        }
163
164        // Note: link reference definitions are handled as always-exempt (even in strict mode)
165        // in the main check loop, so they don't need to be checked here.
166
167        // Code blocks with long strings (only check if in code block)
168        if ctx.line_info(current_line + 1).is_some_and(|info| info.in_code_block)
169            && !trimmed.is_empty()
170            && !line.contains(' ')
171            && !line.contains('\t')
172        {
173            return true;
174        }
175
176        false
177    }
178
179    /// Check if rule should skip based on provided config (used for inline config support)
180    fn should_skip_with_config(&self, ctx: &crate::lint_context::LintContext, config: &MD013Config) -> bool {
181        // Skip if content is empty
182        if ctx.content.is_empty() {
183            return true;
184        }
185
186        // For sentence-per-line, semantic-line-breaks, or normalize mode, never skip based on line length
187        if config.reflow
188            && (config.reflow_mode == ReflowMode::SentencePerLine
189                || config.reflow_mode == ReflowMode::SemanticLineBreaks
190                || config.reflow_mode == ReflowMode::Normalize)
191        {
192            return false;
193        }
194
195        // Use the smallest applicable budget across line/heading/code-block
196        // contexts so a stricter context-specific limit doesn't get masked by
197        // the document-wide budget.
198        let min_limit = config.min_effective_line_length();
199        if min_limit.is_unlimited() {
200            return true;
201        }
202        let min_limit_bytes = min_limit.get();
203
204        // Quick check: if total content is shorter than the smallest line limit,
205        // definitely skip.
206        if ctx.content.len() <= min_limit_bytes {
207            return true;
208        }
209
210        // Skip if no line exceeds the smallest applicable limit.
211        !ctx.lines.iter().any(|line| line.byte_len > min_limit_bytes)
212    }
213
214    fn normalize_mode_needs_reflow<'a, I>(&self, lines: I, config: &MD013Config) -> bool
215    where
216        I: IntoIterator<Item = &'a str>,
217    {
218        let mut line_count = 0;
219        let check_length = !config.line_length.is_unlimited();
220
221        for line in lines {
222            line_count += 1;
223            if check_length && self.calculate_effective_length(line) > config.line_length.get() {
224                return true;
225            }
226        }
227
228        line_count > 1
229    }
230}
231
232impl Rule for MD013LineLength {
233    fn name(&self) -> &'static str {
234        "MD013"
235    }
236
237    fn description(&self) -> &'static str {
238        "Line length should not be excessive"
239    }
240
241    fn check(&self, ctx: &crate::lint_context::LintContext) -> LintResult {
242        // Use pre-parsed inline config from LintContext
243        let config_override = ctx.inline_config().get_rule_config("MD013");
244
245        // Apply configuration override if present
246        let effective_config = if let Some(json_config) = config_override {
247            if let Some(obj) = json_config.as_object() {
248                let mut config = self.config.clone();
249                if let Some(line_length) = obj.get("line_length").and_then(serde_json::Value::as_u64) {
250                    config.line_length = crate::types::LineLength::new(line_length as usize);
251                }
252                if let Some(code_blocks) = obj.get("code_blocks").and_then(serde_json::Value::as_bool) {
253                    config.code_blocks = code_blocks;
254                }
255                if let Some(code_spans) = obj.get("code_spans").and_then(serde_json::Value::as_bool) {
256                    config.code_spans = code_spans;
257                }
258                if let Some(tables) = obj.get("tables").and_then(serde_json::Value::as_bool) {
259                    config.tables = tables;
260                }
261                if let Some(headings) = obj.get("headings").and_then(serde_json::Value::as_bool) {
262                    config.headings = headings;
263                }
264                if let Some(blockquotes) = obj.get("blockquotes").and_then(serde_json::Value::as_bool) {
265                    config.blockquotes = blockquotes;
266                }
267                if let Some(strict) = obj.get("strict").and_then(serde_json::Value::as_bool) {
268                    config.strict = strict;
269                }
270                if let Some(stern) = obj.get("stern").and_then(serde_json::Value::as_bool) {
271                    config.stern = stern;
272                }
273                if let Some(v) = obj
274                    .get("ignore_link_urls")
275                    .or_else(|| obj.get("ignore-link-urls"))
276                    .or_else(|| obj.get("semantic_link_understanding"))
277                    .or_else(|| obj.get("semantic-link-understanding"))
278                    .and_then(serde_json::Value::as_bool)
279                {
280                    config.ignore_link_urls = v;
281                }
282                if let Some(reflow) = obj.get("reflow").and_then(serde_json::Value::as_bool) {
283                    config.reflow = reflow;
284                }
285                if let Some(reflow_mode) = obj.get("reflow_mode").and_then(|v| v.as_str()) {
286                    config.reflow_mode = match reflow_mode {
287                        "default" => ReflowMode::Default,
288                        "normalize" => ReflowMode::Normalize,
289                        "sentence-per-line" => ReflowMode::SentencePerLine,
290                        "semantic-line-breaks" => ReflowMode::SemanticLineBreaks,
291                        _ => ReflowMode::default(),
292                    };
293                }
294                config
295            } else {
296                self.config.clone()
297            }
298        } else {
299            self.config.clone()
300        };
301
302        // Fast early return using should_skip with EFFECTIVE config (after inline overrides)
303        // But don't skip if we're in reflow mode with Normalize or SentencePerLine
304        if self.should_skip_with_config(ctx, &effective_config)
305            && !(effective_config.reflow
306                && (effective_config.reflow_mode == ReflowMode::Normalize
307                    || effective_config.reflow_mode == ReflowMode::SentencePerLine
308                    || effective_config.reflow_mode == ReflowMode::SemanticLineBreaks))
309        {
310            return Ok(Vec::new());
311        }
312
313        // Direct implementation without DocumentStructure
314        let mut warnings = Vec::new();
315
316        // Special handling: line_length = 0 means "no line length limit"
317        // Skip all line length checks, but still allow reflow if enabled
318        let skip_length_checks = effective_config.line_length.is_unlimited();
319
320        // Pre-filter lines that could be problematic to avoid processing all lines.
321        // Use the smallest applicable budget across line/heading/code-block contexts
322        // so candidates aren't dropped when a stricter context-specific budget applies.
323        let prefilter_limit = effective_config.min_effective_line_length();
324        let prefilter_skip = prefilter_limit.is_unlimited();
325        let mut candidate_lines = Vec::new();
326        if !skip_length_checks && !prefilter_skip {
327            for (line_idx, line_info) in ctx.lines.iter().enumerate() {
328                // Skip front matter - it should never be linted
329                if line_info.in_front_matter {
330                    continue;
331                }
332
333                // Quick length check first
334                if line_info.byte_len > prefilter_limit.get() {
335                    candidate_lines.push(line_idx);
336                }
337            }
338        }
339
340        // If no candidate lines and not in normalize or sentence-per-line mode, early return
341        if candidate_lines.is_empty()
342            && !(effective_config.reflow
343                && (effective_config.reflow_mode == ReflowMode::Normalize
344                    || effective_config.reflow_mode == ReflowMode::SentencePerLine
345                    || effective_config.reflow_mode == ReflowMode::SemanticLineBreaks))
346        {
347            return Ok(warnings);
348        }
349
350        let lines = ctx.raw_lines();
351
352        // Create a quick lookup set for heading lines
353        // We need this for both the heading skip check AND the paragraphs check
354        let heading_lines_set: std::collections::HashSet<usize> = ctx
355            .lines
356            .iter()
357            .enumerate()
358            .filter(|(_, line)| line.heading.is_some())
359            .map(|(idx, _)| idx + 1)
360            .collect();
361
362        // Use pre-computed table blocks from context
363        // We need this for both the table skip check AND the paragraphs check
364        let table_blocks = &ctx.table_blocks;
365        let mut table_lines_set = std::collections::HashSet::new();
366        for table in table_blocks {
367            table_lines_set.insert(table.header_line + 1);
368            table_lines_set.insert(table.delimiter_line + 1);
369            for &line in &table.content_lines {
370                table_lines_set.insert(line + 1);
371            }
372        }
373
374        // Process candidate lines for line length checks
375        'line_loop: for &line_idx in &candidate_lines {
376            let line_number = line_idx + 1;
377            let line = lines[line_idx];
378
379            // Calculate actual line length (used in warning messages)
380            let effective_length = self.calculate_effective_length(line);
381
382            // Pick the context-specific limit: heading > code-block > paragraph.
383            // Headings dominate over code-block context if a setext underline ever
384            // overlaps a fenced range (defensive — these are mutually exclusive in
385            // practice, but the explicit ordering documents intent).
386            let is_heading_line = heading_lines_set.contains(&line_number);
387            let in_code_block = ctx.line_info(line_number).is_some_and(|info| info.in_code_block);
388            let line_limit = if is_heading_line {
389                effective_config.effective_heading_line_length().get()
390            } else if in_code_block {
391                effective_config.effective_code_block_line_length().get()
392            } else {
393                effective_config.line_length.get()
394            };
395
396            // A context-specific limit of 0 means "unlimited for this context".
397            if line_limit == 0 {
398                continue;
399            }
400
401            // Stern mode: like default, but the trailing-token forgiveness is
402            // disabled — a line with whitespace that exceeds the limit is a
403            // violation even if the excess is the final token. The "unwrappable"
404            // line exemption (single token, optionally prefixed by # or >) is
405            // still honored. Strict overrides stern entirely.
406            if effective_config.stern && !effective_config.strict && is_unwrappable_line(line) {
407                continue;
408            }
409
410            // Trailing-token forgiveness: only in default mode (not strict, not stern).
411            // If the line only exceeds the limit because of a long token at the end
412            // (URL, link chain, identifier), it passes. This matches markdownlint's
413            // behavior: line.replace(/\S*$/u, "#")
414            let check_length = if effective_config.strict || effective_config.stern {
415                effective_length
416            } else {
417                match line.rfind(char::is_whitespace) {
418                    Some(pos) => {
419                        let ws_char = line[pos..].chars().next().unwrap();
420                        let prefix_end = pos + ws_char.len_utf8();
421                        self.calculate_string_length(&line[..prefix_end]) + 1
422                    }
423                    None => 1, // No whitespace — entire line is a single token
424                }
425            };
426
427            // Skip lines where the check length is within the limit
428            if check_length <= line_limit {
429                continue;
430            }
431
432            // Ignore inline link/image URLs: suppress when excess comes entirely from inline URLs.
433            // Disabled by `strict` (all forgiveness off) and by `ignore_link_urls = false`
434            // (count link/image URLs toward the line length so such lines are flagged).
435            if !effective_config.strict && effective_config.ignore_link_urls {
436                let length_without_urls = self.length_without_inline_link_urls(effective_length, line_number, ctx);
437                if length_without_urls <= line_limit {
438                    continue;
439                }
440            }
441
442            // Inline code spans cannot be wrapped, so reflow cannot shorten a line
443            // whose excess length is one. When code-span checking is disabled,
444            // suppress a violation that would fit once inline code spans are excluded.
445            if !effective_config.code_spans {
446                let code_span_width: usize = ctx
447                    .code_spans()
448                    .iter()
449                    .filter(|span| span.line == line_number && span.end_line == line_number)
450                    .map(|span| self.calculate_string_length(&ctx.content[span.byte_offset..span.byte_end]))
451                    .sum();
452                if effective_length.saturating_sub(code_span_width) <= line_limit {
453                    continue;
454                }
455            }
456
457            // Skip mkdocstrings and pymdown blocks (already handled by LintContext)
458            if ctx.lines[line_idx].in_mkdocstrings || ctx.lines[line_idx].in_pymdown_block {
459                continue;
460            }
461
462            // Skip MyST comments (% comment) — structural lines, not prose
463            if ctx.lines[line_idx].is_myst_comment {
464                continue;
465            }
466
467            // Link reference definitions are always exempt, even in strict mode.
468            // There's no way to shorten them without breaking the URL.
469            // Also check after stripping list markers, since list items may
470            // contain link ref defs as their content.
471            {
472                let trimmed = line.trim();
473                if trimmed.starts_with('[') && trimmed.contains("]:") && LINK_REF_PATTERN.is_match(trimmed) {
474                    continue;
475                }
476                if is_list_item(trimmed) {
477                    let (_, content) = extract_list_marker_and_content(trimmed);
478                    let content_trimmed = content.trim();
479                    if content_trimmed.starts_with('[')
480                        && content_trimmed.contains("]:")
481                        && LINK_REF_PATTERN.is_match(content_trimmed)
482                    {
483                        continue;
484                    }
485                }
486            }
487
488            // Skip various block types efficiently
489            if !effective_config.strict {
490                // Lines whose only content is a link/image are exempt.
491                // After stripping list markers, blockquote markers, and emphasis,
492                // if only a link or image remains, there is no way to shorten it.
493                if is_standalone_link_or_image_line(line) {
494                    continue;
495                }
496
497                // Lines consisting entirely of HTML tags are exempt.
498                // Badge lines, images with attributes, and similar inline HTML
499                // are long due to URLs in attributes and can't be meaningfully shortened.
500                if is_html_only_line(line) {
501                    continue;
502                }
503
504                // Skip setext heading underlines
505                if !line.trim().is_empty() && line.trim().chars().all(|c| c == '=' || c == '-') {
506                    continue;
507                }
508
509                // Skip block elements according to config flags
510                // The flags mean: true = check these elements, false = skip these elements
511                // So we skip when the flag is FALSE and the line is in that element type
512                if (!effective_config.headings && heading_lines_set.contains(&line_number))
513                    || (!effective_config.code_blocks
514                        && ctx.line_info(line_number).is_some_and(|info| info.in_code_block))
515                    || (!effective_config.tables && table_lines_set.contains(&line_number))
516                    || ctx.line_info(line_number).is_some_and(|info| info.in_html_block)
517                    || ctx.line_info(line_number).is_some_and(|info| info.in_html_comment)
518                    || ctx.line_info(line_number).is_some_and(|info| info.in_esm_block)
519                    || ctx.line_info(line_number).is_some_and(|info| info.in_jsx_expression)
520                    || ctx.line_info(line_number).is_some_and(|info| info.in_jsx_block)
521                    || ctx.line_info(line_number).is_some_and(|info| info.in_mdx_comment)
522                    || ctx.line_info(line_number).is_some_and(|info| info.in_pymdown_block)
523                {
524                    continue;
525                }
526
527                // Check if this is a paragraph/regular text line
528                // If paragraphs = false, skip lines that are NOT in special blocks
529                // Blockquote content is treated as paragraph text, so it's not
530                // included in the special blocks list here.
531                if !effective_config.paragraphs {
532                    let is_special_block = heading_lines_set.contains(&line_number)
533                        || ctx.line_info(line_number).is_some_and(|info| info.in_code_block)
534                        || table_lines_set.contains(&line_number)
535                        || ctx.line_info(line_number).is_some_and(|info| info.in_html_block)
536                        || ctx.line_info(line_number).is_some_and(|info| info.in_html_comment)
537                        || ctx.line_info(line_number).is_some_and(|info| info.in_esm_block)
538                        || ctx.line_info(line_number).is_some_and(|info| info.in_jsx_expression)
539                        || ctx.line_info(line_number).is_some_and(|info| info.in_jsx_block)
540                        || ctx.line_info(line_number).is_some_and(|info| info.in_mdx_comment)
541                        || ctx
542                            .line_info(line_number)
543                            .is_some_and(super::super::lint_context::types::LineInfo::in_mkdocs_container);
544
545                    // Skip regular paragraph text when paragraphs = false
546                    if !is_special_block {
547                        continue;
548                    }
549                }
550
551                // Skip blockquote lines when blockquotes = false.
552                // Also skip lazy continuation lines that belong to a blockquote
553                // (lines without `>` prefix that follow a blockquote line).
554                if !effective_config.blockquotes {
555                    if ctx.lines[line_number - 1].blockquote.is_some() {
556                        continue;
557                    }
558                    // Check for lazy continuation: scan backwards through
559                    // non-blank lines to find if this paragraph started with
560                    // a blockquote marker
561                    if !line.trim().is_empty() {
562                        let mut scan = line_number.saturating_sub(2);
563                        loop {
564                            if ctx.lines[scan].blockquote.is_some() {
565                                // Found a blockquote ancestor — this is a lazy continuation
566                                continue 'line_loop;
567                            }
568                            if lines[scan].trim().is_empty() || scan == 0 {
569                                break;
570                            }
571                            scan -= 1;
572                        }
573                    }
574                }
575
576                // Skip lines that are only a URL, image ref, or link ref
577                if self.should_ignore_line(line, lines, line_idx, ctx) {
578                    continue;
579                }
580            }
581
582            // In sentence-per-line mode, check if this is a single long sentence
583            // If so, emit a warning without a fix (user must manually rephrase)
584            if effective_config.reflow_mode == ReflowMode::SentencePerLine {
585                let sentences = split_into_sentences(line.trim());
586                if sentences.len() == 1 {
587                    // Single sentence that's too long - warn but don't auto-fix
588                    let message = format!("Line length {effective_length} exceeds {line_limit} characters");
589
590                    let (start_line, start_col, end_line, end_col) =
591                        calculate_excess_range(line_number, line, line_limit);
592
593                    warnings.push(LintWarning {
594                        rule_name: Some(self.name().to_string()),
595                        message,
596                        line: start_line,
597                        column: start_col,
598                        end_line,
599                        end_column: end_col,
600                        severity: Severity::Warning,
601                        fix: None, // No auto-fix for long single sentences
602                    });
603                    continue;
604                }
605                // Multiple sentences will be handled by paragraph-based reflow
606                continue;
607            }
608
609            // In semantic-line-breaks mode, skip per-line checks —
610            // all reflow is handled at the paragraph level with cascading splits
611            if effective_config.reflow_mode == ReflowMode::SemanticLineBreaks {
612                continue;
613            }
614
615            // Don't provide fix for individual lines when reflow is enabled
616            // Paragraph-based fixes will be handled separately
617            let fix = None;
618
619            let message = format!("Line length {effective_length} exceeds {line_limit} characters");
620
621            // Calculate precise character range for the excess portion
622            let (start_line, start_col, end_line, end_col) = calculate_excess_range(line_number, line, line_limit);
623
624            warnings.push(LintWarning {
625                rule_name: Some(self.name().to_string()),
626                message,
627                line: start_line,
628                column: start_col,
629                end_line,
630                end_column: end_col,
631                severity: Severity::Warning,
632                fix,
633            });
634        }
635
636        // If reflow is enabled, generate paragraph-based fixes
637        if effective_config.reflow {
638            let paragraph_warnings = self.generate_paragraph_fixes(ctx, &effective_config, lines);
639            // Merge paragraph warnings with line warnings, removing duplicates
640            for pw in paragraph_warnings {
641                // Remove any line warnings that overlap with this paragraph
642                warnings.retain(|w| w.line < pw.line || w.line > pw.end_line);
643                warnings.push(pw);
644            }
645        }
646
647        Ok(warnings)
648    }
649
650    fn fix(&self, ctx: &crate::lint_context::LintContext) -> Result<String, LintError> {
651        // For CLI usage, apply fixes from warnings
652        // LSP will use the warning-based fixes directly
653        let warnings = self.check(ctx)?;
654        let warnings =
655            crate::utils::fix_utils::filter_warnings_by_inline_config(warnings, ctx.inline_config(), self.name());
656
657        // If there are no fixes, return content unchanged
658        if !warnings.iter().any(|w| w.fix.is_some()) {
659            return Ok(ctx.content.to_string());
660        }
661
662        // Apply warning-based fixes
663        crate::utils::fix_utils::apply_warning_fixes(ctx.content, &warnings)
664            .map_err(|e| LintError::FixFailed(format!("Failed to apply fixes: {e}")))
665    }
666
667    fn as_any(&self) -> &dyn std::any::Any {
668        self
669    }
670
671    fn category(&self) -> RuleCategory {
672        RuleCategory::Whitespace
673    }
674
675    fn should_skip(&self, ctx: &crate::lint_context::LintContext) -> bool {
676        self.should_skip_with_config(ctx, &self.config)
677    }
678
679    fn default_config_section(&self) -> Option<(String, toml::Value)> {
680        let table = crate::rule_config_serde::config_schema_table(&MD013Config::default())?;
681        if table.is_empty() {
682            None
683        } else {
684            Some((MD013Config::RULE_NAME.to_string(), toml::Value::Table(table)))
685        }
686    }
687
688    fn config_aliases(&self) -> Option<std::collections::HashMap<String, String>> {
689        let mut aliases = std::collections::HashMap::new();
690        aliases.insert("enable_reflow".to_string(), "reflow".to_string());
691        aliases.insert("strict_sentences".to_string(), "require-sentence-capital".to_string());
692        aliases.insert("strict-sentences".to_string(), "require-sentence-capital".to_string());
693        Some(aliases)
694    }
695
696    fn from_config(config: &crate::config::Config) -> Box<dyn Rule>
697    where
698        Self: Sized,
699    {
700        let mut rule_config = crate::rule_config_serde::load_rule_config::<MD013Config>(config);
701        // Use global line_length if rule-specific config still has default value
702        if rule_config.line_length.get() == 80 {
703            rule_config.line_length = config.global.line_length;
704        }
705        let mut rule = Self::from_config_struct(rule_config);
706        // Pull list-marker spacing from MD030 (via the shared serde config loader)
707        // so reflow rewrites list items with the configured spacing rather than a
708        // hard-coded single space.
709        rule.list_spacing = crate::rule_config_serde::load_rule_config::<MD030Config>(config);
710        Box::new(rule)
711    }
712}
713
714impl MD013LineLength {
715    /// True when `line_num` (1-based) sits inside a structure whose lines must be
716    /// preserved verbatim (code block, front matter, HTML/JSX/MDX block, MkDocs
717    /// container, div marker, ...). Used to keep blockquote reflow from touching
718    /// quoted-looking text embedded in such structures.
719    fn line_in_verbatim_context(&self, line_num: usize, ctx: &crate::lint_context::LintContext) -> bool {
720        ctx.line_info(line_num).is_some_and(|info| {
721            info.in_code_block
722                || info.in_front_matter
723                || info.in_html_block
724                || info.in_html_comment
725                || info.in_esm_block
726                || info.in_jsx_expression
727                || info.in_jsx_block
728                || info.in_mdx_comment
729                || info.in_mkdocstrings
730                || info.in_pymdown_block
731                || info.in_mkdocs_container()
732                || info.is_div_marker
733        })
734    }
735
736    fn is_blockquote_content_boundary(
737        &self,
738        content: &str,
739        line_num: usize,
740        ctx: &crate::lint_context::LintContext,
741        strict: bool,
742    ) -> bool {
743        let trimmed = content.trim();
744
745        trimmed.is_empty()
746            || self.line_in_verbatim_context(line_num, ctx)
747            || trimmed.starts_with('#')
748            || trimmed.starts_with("```")
749            || trimmed.starts_with("~~~")
750            || trimmed.starts_with('>')
751            || TableUtils::is_potential_table_row(content)
752            || is_list_item(trimmed)
753            || is_horizontal_rule(content)
754            || (trimmed.starts_with('[') && content.contains("]:"))
755            || is_template_directive_only(content)
756            || is_standalone_attr_list(content)
757            || is_snippet_block_delimiter(content)
758            || is_github_alert_marker(trimmed)
759            || is_html_only_line(content)
760            // A standalone link/image line is exempt from MD013 (non-strict mode),
761            // so it must end the blockquote paragraph rather than be absorbed into
762            // it, mirroring the top-level paragraph reflow boundary.
763            || (!strict && is_standalone_link_or_image_line(content))
764    }
765
766    #[allow(clippy::too_many_arguments)]
767    fn generate_blockquote_paragraph_fix(
768        &self,
769        ctx: &crate::lint_context::LintContext,
770        config: &MD013Config,
771        lines: &[&str],
772        line_index: &LineIndex,
773        start_idx: usize,
774        line_ending: &str,
775        // Extra indent (spaces) to prepend to the emitted `>` prefix so a blockquote
776        // nested in a list item moves with its parent's widened marker. Zero unless a
777        // non-default MD030 widened an ancestor list item.
778        ancestor_shift: isize,
779    ) -> (Option<LintWarning>, usize) {
780        let Some(start_bq) = ctx.lines.get(start_idx).and_then(|line| line.blockquote.as_deref()) else {
781            return (None, start_idx + 1);
782        };
783        let target_level = start_bq.nesting_level;
784
785        let mut collected: Vec<CollectedBlockquoteLine> = Vec::new();
786        let mut i = start_idx;
787
788        while i < lines.len() {
789            if !collected.is_empty() && has_hard_break(&collected[collected.len() - 1].data.content) {
790                break;
791            }
792
793            let line_num = i + 1;
794            if line_num > ctx.lines.len() {
795                break;
796            }
797
798            if lines[i].trim().is_empty() {
799                break;
800            }
801
802            let line_bq = ctx.lines[i].blockquote.as_deref();
803            if let Some(bq) = line_bq {
804                if bq.nesting_level != target_level {
805                    break;
806                }
807
808                if self.is_blockquote_content_boundary(&bq.content, line_num, ctx, config.strict) {
809                    break;
810                }
811
812                collected.push(CollectedBlockquoteLine {
813                    line_idx: i,
814                    data: BlockquoteLineData::explicit(trim_preserving_hard_break(&bq.content), bq.prefix.clone()),
815                });
816                i += 1;
817                continue;
818            }
819
820            let lazy_content = lines[i].trim_start();
821            if self.is_blockquote_content_boundary(lazy_content, line_num, ctx, config.strict) {
822                break;
823            }
824
825            collected.push(CollectedBlockquoteLine {
826                line_idx: i,
827                data: BlockquoteLineData::lazy(trim_preserving_hard_break(lazy_content)),
828            });
829            i += 1;
830        }
831
832        if collected.is_empty() {
833            return (None, start_idx + 1);
834        }
835
836        let next_idx = i;
837        let paragraph_start = collected[0].line_idx;
838        let end_line = collected[collected.len() - 1].line_idx;
839        let line_data: Vec<BlockquoteLineData> = collected.iter().map(|l| l.data.clone()).collect();
840        let paragraph_text = line_data
841            .iter()
842            .map(|d| d.content.as_str())
843            .collect::<Vec<_>>()
844            .join(" ");
845
846        let contains_definition_list = line_data
847            .iter()
848            .any(|d| crate::utils::is_definition_list_item(&d.content));
849        if contains_definition_list {
850            return (None, next_idx);
851        }
852
853        let contains_snippets = line_data.iter().any(|d| is_snippet_block_delimiter(&d.content));
854        if contains_snippets {
855            return (None, next_idx);
856        }
857
858        let needs_reflow = match config.reflow_mode {
859            ReflowMode::Normalize => {
860                self.normalize_mode_needs_reflow(line_data.iter().map(|d| d.content.as_str()), config)
861            }
862            ReflowMode::SentencePerLine => {
863                let sentences = split_into_sentences(&paragraph_text);
864                sentences.len() > 1 || line_data.len() > 1
865            }
866            ReflowMode::SemanticLineBreaks => {
867                let sentences = split_into_sentences(&paragraph_text);
868                sentences.len() > 1
869                    || line_data.len() > 1
870                    || collected
871                        .iter()
872                        .any(|l| self.calculate_effective_length(lines[l.line_idx]) > config.line_length.get())
873            }
874            ReflowMode::Default => collected
875                .iter()
876                .any(|l| self.calculate_effective_length(lines[l.line_idx]) > config.line_length.get()),
877        };
878
879        if !needs_reflow {
880            return (None, next_idx);
881        }
882
883        let fallback_prefix = start_bq.prefix.clone();
884        let explicit_prefix = dominant_blockquote_prefix(&line_data, &fallback_prefix);
885        // Shift the whole quote right to track a widened parent list item's content
886        // column (only widening matters for nesting; a narrowed parent leaves the quote
887        // harmlessly over-indented, which MD027/MD030 tidy).
888        let explicit_prefix = if ancestor_shift > 0 {
889            format!("{}{explicit_prefix}", " ".repeat(ancestor_shift as usize))
890        } else {
891            explicit_prefix
892        };
893        let continuation_style = blockquote_continuation_style(&line_data);
894
895        let reflow_line_length = if config.line_length.is_unlimited() {
896            usize::MAX
897        } else {
898            config
899                .line_length
900                .get()
901                .saturating_sub(self.calculate_string_length(&explicit_prefix))
902                .max(1)
903        };
904
905        let reflow_options = Self::reflow_options(ctx, config, reflow_line_length);
906
907        let reflowed_with_style =
908            reflow_blockquote_content(&line_data, &explicit_prefix, continuation_style, &reflow_options);
909
910        if reflowed_with_style.is_empty() {
911            return (None, next_idx);
912        }
913
914        let reflowed_text = reflowed_with_style.join(line_ending);
915
916        let start_range = line_index.whole_line_range(paragraph_start + 1);
917        let end_range = if end_line == lines.len() - 1 && !ctx.content.ends_with('\n') {
918            line_index.line_text_range(end_line + 1, 1, lines[end_line].len() + 1)
919        } else {
920            line_index.whole_line_range(end_line + 1)
921        };
922        let byte_range = start_range.start..end_range.end;
923
924        let replacement = if end_line < lines.len() - 1 || ctx.content.ends_with('\n') {
925            format!("{reflowed_text}{line_ending}")
926        } else {
927            reflowed_text
928        };
929
930        let original_text = &ctx.content[byte_range.clone()];
931        if original_text == replacement {
932            return (None, next_idx);
933        }
934
935        let (warning_line, warning_end_line) = match config.reflow_mode {
936            ReflowMode::Normalize => (paragraph_start + 1, end_line + 1),
937            ReflowMode::SentencePerLine | ReflowMode::SemanticLineBreaks => (paragraph_start + 1, end_line + 1),
938            ReflowMode::Default => {
939                let violating_line = collected
940                    .iter()
941                    .find(|line| self.calculate_effective_length(lines[line.line_idx]) > config.line_length.get())
942                    .map_or(paragraph_start + 1, |line| line.line_idx + 1);
943                (violating_line, violating_line)
944            }
945        };
946
947        let warning = LintWarning {
948            rule_name: Some(self.name().to_string()),
949            message: match config.reflow_mode {
950                ReflowMode::Normalize => format!(
951                    "Paragraph could be normalized to use line length of {} characters",
952                    config.line_length.get()
953                ),
954                ReflowMode::SentencePerLine => {
955                    let num_sentences = split_into_sentences(&paragraph_text).len();
956                    if line_data.len() == 1 {
957                        format!("Line contains {num_sentences} sentences (one sentence per line required)")
958                    } else {
959                        let num_lines = line_data.len();
960                        format!(
961                            "Paragraph should have one sentence per line (found {num_sentences} sentences across {num_lines} lines)"
962                        )
963                    }
964                }
965                ReflowMode::SemanticLineBreaks => {
966                    let num_sentences = split_into_sentences(&paragraph_text).len();
967                    format!("Paragraph should use semantic line breaks ({num_sentences} sentences)")
968                }
969                ReflowMode::Default => format!("Line length exceeds {} characters", config.line_length.get()),
970            },
971            line: warning_line,
972            column: 1,
973            end_line: warning_end_line,
974            end_column: lines[warning_end_line.saturating_sub(1)].chars().count() + 1,
975            severity: Severity::Warning,
976            fix: Some(crate::rule::Fix::new(byte_range, replacement)),
977        };
978
979        (Some(warning), next_idx)
980    }
981
982    /// Reflow a single list item that lives inside a blockquote.
983    ///
984    /// The blockquote paragraph reflow treats a list marker as a content boundary,
985    /// so `> - long item ...` is never wrapped even though the identical top-level
986    /// item is. This handles that case: it collects one tight, prose-only list item
987    /// at the starting blockquote level, reflows the item body to the configured
988    /// width, and re-emits it with the blockquote prefix preserved and continuation
989    /// lines aligned under the list content.
990    ///
991    /// Sibling and nested list items end collection and are reflowed independently
992    /// by the caller's outer loop (a nested item carries its indent folded into the
993    /// blockquote prefix, so it reflows correctly on its own). Items that are not
994    /// simple tight prose - those embedding a code block, table, fence, or hard
995    /// break - are left untouched (`None`) and the cursor still advances past the
996    /// whole item so its inner lines are never reprocessed as loose prose.
997    #[allow(clippy::too_many_arguments)]
998    fn generate_blockquote_list_item_fix(
999        &self,
1000        ctx: &crate::lint_context::LintContext,
1001        config: &MD013Config,
1002        lines: &[&str],
1003        line_index: &LineIndex,
1004        start_idx: usize,
1005        line_ending: &str,
1006        // Extra indent (spaces) to prepend to the emitted `>` prefix when this quoted
1007        // list lives inside a list item whose marker widened. Zero unless a non-default
1008        // MD030 widened an ancestor list item.
1009        ancestor_shift: isize,
1010    ) -> (Option<LintWarning>, usize) {
1011        use crate::utils::blockquote::effective_indent_in_blockquote;
1012
1013        let Some(start_bq) = ctx.lines.get(start_idx).and_then(|line| line.blockquote.as_deref()) else {
1014            return (None, start_idx + 1);
1015        };
1016
1017        // A `>`-prefixed line can be marked as a blockquote even inside a fenced code
1018        // block (or other verbatim structure); such content must never be reflowed.
1019        if self.line_in_verbatim_context(start_idx + 1, ctx) {
1020            return (None, start_idx + 1);
1021        }
1022
1023        let target_level = start_bq.nesting_level;
1024
1025        // The marker line carries the canonical blockquote prefix: its content begins
1026        // with the list marker, so no list indent has been folded into the prefix.
1027        // Track a widened parent list item's content column so the quote stays nested
1028        // (only widening can detach it; narrowing just over-indents).
1029        let bq_prefix = if ancestor_shift > 0 {
1030            format!("{}{}", " ".repeat(ancestor_shift as usize), start_bq.prefix)
1031        } else {
1032            start_bq.prefix.clone()
1033        };
1034
1035        let (marker, first_body) = extract_list_marker_and_content(&start_bq.content);
1036        if marker.is_empty() {
1037            return (None, start_idx + 1);
1038        }
1039        let marker_width = marker.chars().count();
1040
1041        // Continuation lines of a checkbox item align under the bullet+checkbox, but
1042        // are recognized from the bullet width, matching the top-level list reflow.
1043        let base_marker_width = ["[ ] ", "[x] ", "[X] "]
1044            .iter()
1045            .find_map(|cb| marker.find(*cb))
1046            .unwrap_or(marker_width);
1047
1048        // Collect the item: the marker line plus its tight prose continuation lines.
1049        // `end_idx` always tracks the last consumed line so the cursor advances past
1050        // the entire item, even when it turns out to be too complex to reflow safely.
1051        let first_piece = trim_preserving_hard_break(&first_body);
1052        let mut simple = !has_hard_break(&first_piece);
1053        let mut body_pieces: Vec<String> = vec![first_piece];
1054        let mut end_idx = start_idx;
1055        let mut i = start_idx + 1;
1056
1057        while i < lines.len() {
1058            let Some(bq) = ctx.lines[i].blockquote.as_deref() else {
1059                // A blank line ends the item.
1060                if lines[i].trim().is_empty() {
1061                    break;
1062                }
1063                // A lazy continuation (no `>` marker) is too ambiguous to reflow
1064                // safely. Consume the whole lazy run into this item's span and leave
1065                // the item untouched, so the caller does not reflow the continuation
1066                // in isolation and leave the marker line partially fixed.
1067                simple = false;
1068                while i < lines.len() && ctx.lines[i].blockquote.is_none() && !lines[i].trim().is_empty() {
1069                    end_idx = i;
1070                    i += 1;
1071                }
1072                break;
1073            };
1074            if bq.nesting_level != target_level {
1075                break;
1076            }
1077
1078            let content = bq.content.as_str();
1079            if content.trim().is_empty() {
1080                // Blank quoted line ends the tight paragraph. A following indented
1081                // paragraph (loose item) is reflowed on its own by the prose path.
1082                break;
1083            }
1084
1085            let eff_indent = effective_indent_in_blockquote(lines[i], target_level, 0);
1086            if eff_indent < base_marker_width {
1087                // Dedented: a sibling list item or text outside this item. Stop here
1088                // and let the outer loop classify it.
1089                break;
1090            }
1091            if is_list_item(content) {
1092                // A nested list item: its own item, handled independently.
1093                break;
1094            }
1095
1096            // An embedded structure (code block, table, fence, nested quote, ...)
1097            // means the item is not simple prose: keep consuming so the cursor clears
1098            // the whole structure, but do not produce a fix.
1099            if self.is_blockquote_content_boundary(content, i + 1, ctx, config.strict) {
1100                simple = false;
1101            }
1102
1103            let piece = trim_preserving_hard_break(content);
1104            if has_hard_break(&piece) {
1105                simple = false;
1106            }
1107            body_pieces.push(piece);
1108            end_idx = i;
1109            i += 1;
1110        }
1111
1112        let next_idx = end_idx + 1;
1113
1114        if !simple {
1115            return (None, next_idx);
1116        }
1117
1118        let exceeds_limit =
1119            || (start_idx..=end_idx).any(|idx| self.calculate_effective_length(lines[idx]) > config.line_length.get());
1120        let body_text = body_pieces.join(" ");
1121        let body_text = body_text.trim();
1122
1123        // Some bodies cannot be shortened and must stay verbatim, matching the
1124        // exemptions the top-level list reflow applies: link reference definitions
1125        // always, and (in non-strict mode) standalone links/images and HTML-only
1126        // lines. Reflowing a link reference definition would split it after the
1127        // colon/URL and break the definition.
1128        let is_link_ref_def =
1129            body_text.starts_with('[') && body_text.contains("]:") && LINK_REF_PATTERN.is_match(body_text);
1130        let raw_marker_line = lines[start_idx];
1131        let body_is_unwrappable = is_link_ref_def
1132            || (!config.strict && is_standalone_link_or_image_line(raw_marker_line))
1133            || (!config.strict && is_html_only_line(raw_marker_line));
1134        if body_is_unwrappable {
1135            return (None, next_idx);
1136        }
1137
1138        let needs_reflow = match config.reflow_mode {
1139            ReflowMode::Normalize => body_pieces.len() > 1 || exceeds_limit(),
1140            ReflowMode::Default => exceeds_limit(),
1141            ReflowMode::SentencePerLine => split_into_sentences(body_text).len() > 1 || body_pieces.len() > 1,
1142            ReflowMode::SemanticLineBreaks => split_into_sentences(body_text).len() > 1 || exceeds_limit(),
1143        };
1144        if !needs_reflow {
1145            return (None, next_idx);
1146        }
1147
1148        // Apply MD030 list-marker spacing in the spacing-normalizing modes, mirroring
1149        // the top-level list reflow: derive the post-marker spacing from MD030 and let
1150        // the continuation indent follow the resulting content width. Default MD030 (a
1151        // single space) leaves the marker unchanged. MkDocs keeps its rigid indent.
1152        let (marker, marker_width) = if matches!(config.reflow_mode, ReflowMode::Default | ReflowMode::Normalize)
1153            && !ctx.flavor.requires_strict_list_indent()
1154        {
1155            let is_ordered = marker.starts_with(|c: char| c.is_ascii_digit());
1156            // Bullet/number portion only (e.g. `-`, `1.`); the checkbox is content.
1157            let bullet = marker.split(' ').next().unwrap_or("");
1158            let bullet_len = bullet.chars().count();
1159            let checkbox_tail = &marker[base_marker_width..];
1160            // Decide single- vs multi-line spacing from the rewritten shape. This path
1161            // only handles a single tight prose paragraph (structural or multi-paragraph
1162            // items set `simple = false` and bail out above), so the emitted item stays
1163            // multi-line solely when the joined body wraps past one line. A multi-line
1164            // *source* that collapses onto the marker line must use MD030's single-line
1165            // spacing, matching the top-level reflow. The wrap test measures at the
1166            // single-line content column so it does not depend on the spacing chosen here.
1167            let single_col = self.calculate_string_length(&bq_prefix)
1168                + bullet_len
1169                + self.list_spacing.expected_spaces(is_ordered, false, bullet_len)
1170                + checkbox_tail.chars().count();
1171            let is_multi = !body_text.is_empty()
1172                && self.calculate_effective_length(&format!("{}{body_text}", " ".repeat(single_col)))
1173                    > config.line_length.effective_limit();
1174            let spaces = self.list_spacing.expected_spaces(is_ordered, is_multi, bullet_len);
1175            let new_marker = format!("{bullet}{}{checkbox_tail}", " ".repeat(spaces));
1176            let width = new_marker.chars().count();
1177            (new_marker, width)
1178        } else {
1179            (marker, marker_width)
1180        };
1181
1182        let prefix_width = self.calculate_string_length(&bq_prefix) + self.calculate_string_length(&marker);
1183        let reflow_line_length = if config.line_length.is_unlimited() {
1184            usize::MAX
1185        } else {
1186            config.line_length.get().saturating_sub(prefix_width).max(1)
1187        };
1188
1189        let reflow_options = Self::reflow_options(ctx, config, reflow_line_length);
1190
1191        let reflowed = crate::utils::text_reflow::reflow_line(body_text, &reflow_options);
1192        if reflowed.is_empty() {
1193            return (None, next_idx);
1194        }
1195
1196        let continuation_indent = " ".repeat(marker_width);
1197        let reflowed_text = reflowed
1198            .iter()
1199            .enumerate()
1200            .map(|(idx, line)| {
1201                if idx == 0 {
1202                    format!("{bq_prefix}{marker}{line}")
1203                } else {
1204                    format!("{bq_prefix}{continuation_indent}{line}")
1205                }
1206            })
1207            .collect::<Vec<_>>()
1208            .join(line_ending);
1209
1210        let start_range = line_index.whole_line_range(start_idx + 1);
1211        let end_range = if end_idx == lines.len() - 1 && !ctx.content.ends_with('\n') {
1212            line_index.line_text_range(end_idx + 1, 1, lines[end_idx].len() + 1)
1213        } else {
1214            line_index.whole_line_range(end_idx + 1)
1215        };
1216        let byte_range = start_range.start..end_range.end;
1217
1218        let replacement = if end_idx < lines.len() - 1 || ctx.content.ends_with('\n') {
1219            format!("{reflowed_text}{line_ending}")
1220        } else {
1221            reflowed_text
1222        };
1223
1224        let original_text = &ctx.content[byte_range.clone()];
1225        if original_text == replacement {
1226            return (None, next_idx);
1227        }
1228
1229        let message = match config.reflow_mode {
1230            ReflowMode::Normalize => format!(
1231                "Paragraph could be normalized to use line length of {} characters",
1232                config.line_length.get()
1233            ),
1234            ReflowMode::SentencePerLine => {
1235                let num_sentences = split_into_sentences(body_text).len();
1236                format!("List item should have one sentence per line (found {num_sentences} sentences)")
1237            }
1238            ReflowMode::SemanticLineBreaks => {
1239                let num_sentences = split_into_sentences(body_text).len();
1240                format!("List item should use semantic line breaks ({num_sentences} sentences)")
1241            }
1242            ReflowMode::Default => format!("Line length exceeds {} characters", config.line_length.get()),
1243        };
1244
1245        let warning = LintWarning {
1246            rule_name: Some(self.name().to_string()),
1247            message,
1248            line: start_idx + 1,
1249            column: 1,
1250            end_line: end_idx + 1,
1251            end_column: lines[end_idx].chars().count() + 1,
1252            severity: Severity::Warning,
1253            fix: Some(crate::rule::Fix::new(byte_range, replacement)),
1254        };
1255
1256        (Some(warning), next_idx)
1257    }
1258
1259    /// Generate paragraph-based fixes
1260    fn generate_paragraph_fixes(
1261        &self,
1262        ctx: &crate::lint_context::LintContext,
1263        config: &MD013Config,
1264        lines: &[&str],
1265    ) -> Vec<LintWarning> {
1266        let mut warnings = Vec::new();
1267        let line_index = LineIndex::new(ctx.content);
1268
1269        // Detect the content's line ending style to preserve it in replacements.
1270        // The LSP receives content from editors which may use CRLF (Windows).
1271        // Replacements must match the original line endings to avoid false positives.
1272        let line_ending = crate::utils::line_ending::detect_line_ending(ctx.content);
1273
1274        // Ancestor list-item indent shifts, innermost last. When a reflowed parent's
1275        // marker widens under a non-default MD030 (e.g. ul-multi = 3 moves the parent's
1276        // content from column 2 to 4), its nested list/blockquote children are reflowed
1277        // independently and would otherwise keep their original indent — leaving them
1278        // under the parent's new content column, where a CommonMark parser reparses them
1279        // as siblings rather than children. Each frame is (source content column,
1280        // cumulative shift applied to that item's content column); a descendant adds its
1281        // innermost open ancestor's shift to its own indent so the whole subtree moves
1282        // together. With default MD030 every shift is 0, so this is inert and the output
1283        // is byte-identical.
1284        let mut list_shift_stack: Vec<(usize, isize)> = Vec::new();
1285
1286        let mut i = 0;
1287        while i < lines.len() {
1288            let line_num = i + 1;
1289
1290            // Close ancestor frames whose list item has ended at this line: a non-blank
1291            // line indented less than the frame's source content column is no longer
1292            // inside that item. Blank lines alone don't close a (loose) list item.
1293            if !list_shift_stack.is_empty()
1294                && let Some(info) = ctx.lines.get(i)
1295                && !info.is_blank
1296            {
1297                while let Some(&(content_column, _)) = list_shift_stack.last() {
1298                    if info.indent < content_column {
1299                        list_shift_stack.pop();
1300                    } else {
1301                        break;
1302                    }
1303                }
1304            }
1305
1306            // Handle blockquote paragraphs with style-preserving reflow.
1307            // Skip blockquotes when blockquotes=false or paragraphs=false
1308            if line_num > 0 && line_num <= ctx.lines.len() && ctx.lines[line_num - 1].blockquote.is_some() {
1309                if !config.blockquotes || !config.paragraphs {
1310                    // Skip past all blockquote lines (explicit and lazy continuations).
1311                    // A lazy continuation is a non-blank line without `>` that follows
1312                    // a blockquote line and isn't a structural element.
1313                    let mut saw_explicit_bq = false;
1314                    while i < lines.len() && i < ctx.lines.len() {
1315                        if ctx.lines[i].blockquote.is_some() {
1316                            saw_explicit_bq = true;
1317                            i += 1;
1318                        } else if saw_explicit_bq
1319                            && !lines[i].trim().is_empty()
1320                            && !lines[i].trim_start().starts_with('#')
1321                            && !lines[i].trim_start().starts_with('>')
1322                        {
1323                            // Lazy continuation of preceding blockquote
1324                            i += 1;
1325                        } else {
1326                            break;
1327                        }
1328                    }
1329                    continue;
1330                }
1331                // A blockquote nested in a list item moves with its parent when the
1332                // parent's marker widens (see `list_shift_stack`); pass that shift so the
1333                // emitted `>` prefix lands under the parent's new content column instead
1334                // of detaching into a sibling.
1335                let ancestor_shift = list_shift_stack.last().map_or(0isize, |&(_, shift)| shift);
1336                // A list item inside the blockquote needs list-aware reflow (marker +
1337                // continuation indent); plain prose goes through the paragraph path.
1338                let is_bq_list_item = ctx.lines[i]
1339                    .blockquote
1340                    .as_deref()
1341                    .is_some_and(|bq| is_list_item(&bq.content));
1342                let (warning, next_idx) = if is_bq_list_item {
1343                    self.generate_blockquote_list_item_fix(
1344                        ctx,
1345                        config,
1346                        lines,
1347                        &line_index,
1348                        i,
1349                        line_ending,
1350                        ancestor_shift,
1351                    )
1352                } else {
1353                    self.generate_blockquote_paragraph_fix(
1354                        ctx,
1355                        config,
1356                        lines,
1357                        &line_index,
1358                        i,
1359                        line_ending,
1360                        ancestor_shift,
1361                    )
1362                };
1363                if let Some(warning) = warning {
1364                    warnings.push(warning);
1365                }
1366                i = next_idx;
1367                continue;
1368            }
1369
1370            // Skip special structures (but NOT MkDocs containers - those get special handling)
1371            let should_skip_due_to_line_info = ctx.line_info(line_num).is_some_and(|info| {
1372                info.in_code_block
1373                    || info.in_front_matter
1374                    || info.in_html_block
1375                    || info.in_html_comment
1376                    || info.in_esm_block
1377                    || info.in_jsx_expression
1378                    || info.in_jsx_block
1379                    || info.in_mdx_comment
1380                    || info.in_mkdocstrings
1381                    || info.in_pymdown_block
1382            });
1383
1384            // Skip link reference definitions but NOT footnote definitions.
1385            // Footnote definitions (`[^id]: prose`) contain reflowable text,
1386            // while link reference definitions (`[ref]: URL`) contain URLs
1387            // that cannot be shortened.
1388            let is_link_ref_def =
1389                lines[i].trim().starts_with('[') && !lines[i].trim().starts_with("[^") && lines[i].contains("]:");
1390
1391            if should_skip_due_to_line_info
1392                || lines[i].trim().starts_with('#')
1393                || TableUtils::is_potential_table_row(lines[i])
1394                || lines[i].trim().is_empty()
1395                || is_horizontal_rule(lines[i])
1396                || is_template_directive_only(lines[i])
1397                || is_link_ref_def
1398                || ctx.line_info(line_num).is_some_and(|info| info.is_div_marker)
1399                || is_html_only_line(lines[i])
1400                || (!config.strict && is_standalone_link_or_image_line(lines[i]))
1401            {
1402                i += 1;
1403                continue;
1404            }
1405
1406            // Handle footnote definitions: `[^id]: prose text that can be reflowed`
1407            // Supports multi-paragraph footnotes with code blocks, blockquotes,
1408            // tables, and lists preserved verbatim.
1409            // Validate structure: must start with `[^`, contain `]:`, and the ID
1410            // must not contain `[` or `]` (prevents false matches on nested brackets)
1411            if lines[i].trim().starts_with("[^") && lines[i].contains("]:") && {
1412                let after_caret = &lines[i].trim()[2..];
1413                after_caret
1414                    .find("]:")
1415                    .is_some_and(|pos| pos > 0 && !after_caret[..pos].contains(['[', ']']))
1416            } {
1417                let footnote_start = i;
1418                let line = lines[i];
1419
1420                // Extract the prefix `[^id]:`
1421                let Some(colon_pos) = line.find("]:") else {
1422                    i += 1;
1423                    continue;
1424                };
1425                let prefix_end = colon_pos + 2;
1426                let prefix = &line[..prefix_end];
1427
1428                // Content starts after `]: ` (with optional space)
1429                let content_start = if line[prefix_end..].starts_with(' ') {
1430                    prefix_end + 1
1431                } else {
1432                    prefix_end
1433                };
1434                let first_content = &line[content_start..];
1435
1436                // CommonMark footnotes use 4-space continuation indent
1437                const FN_INDENT: usize = 4;
1438
1439                // --- Line classification for footnote content ---
1440                #[derive(Debug, Clone)]
1441                enum FnLineType {
1442                    Content(String),
1443                    Verbatim(String, usize), // preserved text, original indent
1444                    Empty,
1445                }
1446
1447                // Helper: compute visual indent (tabs = 4 spaces)
1448                let visual_indent = |s: &str| -> usize {
1449                    s.chars()
1450                        .take_while(|c| c.is_whitespace())
1451                        .map(|c| if c == '\t' { 4 } else { 1 })
1452                        .sum::<usize>()
1453                };
1454
1455                // Helper: check if a trimmed line is a fence marker (homogeneous chars)
1456                let is_fence = |s: &str| -> bool {
1457                    let t = s.trim();
1458                    let fence_char = t.chars().next();
1459                    matches!(fence_char, Some('`') | Some('~'))
1460                        && t.chars().take_while(|&c| c == fence_char.unwrap()).count() >= 3
1461                };
1462
1463                // Helper: check if a trimmed line is a setext underline
1464                let is_setext_underline = |s: &str| -> bool {
1465                    let t = s.trim();
1466                    !t.is_empty()
1467                        && (t.chars().all(|c| c == '=' || c == ' ') || t.chars().all(|c| c == '-' || c == ' '))
1468                        && t.contains(['=', '-'])
1469                };
1470
1471                // Deferred body: `[^id]:\n    content` — first line has no content,
1472                // actual content starts on the next indented line
1473                let deferred_body = first_content.trim().is_empty();
1474
1475                // Collect all lines belonging to this footnote definition
1476                let mut fn_lines: Vec<FnLineType> = Vec::new();
1477                if !deferred_body {
1478                    fn_lines.push(FnLineType::Content(first_content.to_string()));
1479                }
1480                let mut last_consumed = i;
1481                i += 1;
1482
1483                // Strip only the footnote continuation indent, preserving
1484                // internal indentation (e.g., code block body indent)
1485                let strip_fn_indent = |s: &str| -> String {
1486                    let mut chars = s.chars();
1487                    let mut stripped = 0;
1488                    while stripped < FN_INDENT {
1489                        match chars.next() {
1490                            Some('\t') => stripped += 4,
1491                            Some(c) if c.is_whitespace() => stripped += 1,
1492                            _ => break,
1493                        }
1494                    }
1495                    chars.as_str().to_string()
1496                };
1497
1498                let mut in_fenced_code = false;
1499                let mut consecutive_blanks = 0u32;
1500
1501                while i < lines.len() {
1502                    let next = lines[i];
1503                    let next_trimmed = next.trim();
1504
1505                    // Blank line handling
1506                    if next_trimmed.is_empty() {
1507                        consecutive_blanks += 1;
1508                        // 2+ consecutive blanks terminate the footnote
1509                        if consecutive_blanks >= 2 {
1510                            break;
1511                        }
1512
1513                        // Inside a fenced code block, blank lines are part of the code
1514                        if in_fenced_code {
1515                            consecutive_blanks = 0; // Don't count blanks inside code blocks
1516                            fn_lines.push(FnLineType::Verbatim(String::new(), 0));
1517                            last_consumed = i;
1518                            i += 1;
1519                            continue;
1520                        }
1521
1522                        // Peek ahead: if next non-blank line is indented >= FN_INDENT,
1523                        // this blank is an internal paragraph separator
1524                        if i + 1 < lines.len() {
1525                            let peek = lines[i + 1];
1526                            let peek_indent = visual_indent(peek);
1527                            if !peek.trim().is_empty() && peek_indent >= FN_INDENT {
1528                                fn_lines.push(FnLineType::Empty);
1529                                last_consumed = i;
1530                                i += 1;
1531                                continue;
1532                            }
1533                        }
1534                        // No valid continuation after blank — end of footnote
1535                        break;
1536                    }
1537
1538                    consecutive_blanks = 0;
1539                    let indent = visual_indent(next);
1540
1541                    // Not indented enough — end of footnote
1542                    if indent < FN_INDENT {
1543                        break;
1544                    }
1545
1546                    // Inside a fenced code block: everything is verbatim until closing fence
1547                    if in_fenced_code {
1548                        fn_lines.push(FnLineType::Verbatim(strip_fn_indent(next), indent));
1549                        if is_fence(next_trimmed) {
1550                            in_fenced_code = false;
1551                        }
1552                        last_consumed = i;
1553                        i += 1;
1554                        continue;
1555                    }
1556
1557                    // Fence opener — start verbatim code block
1558                    if is_fence(next_trimmed) {
1559                        in_fenced_code = true;
1560                        fn_lines.push(FnLineType::Verbatim(strip_fn_indent(next), indent));
1561                        last_consumed = i;
1562                        i += 1;
1563                        continue;
1564                    }
1565
1566                    // Indented code block: indent >= FN_INDENT + 4 (= 8 spaces)
1567                    if indent >= FN_INDENT + 4 {
1568                        fn_lines.push(FnLineType::Verbatim(strip_fn_indent(next), indent));
1569                        last_consumed = i;
1570                        i += 1;
1571                        continue;
1572                    }
1573
1574                    // Structural content that must be preserved verbatim
1575                    if next_trimmed.starts_with('#')
1576                        || is_list_item(next_trimmed)
1577                        || next_trimmed.starts_with('>')
1578                        || TableUtils::is_potential_table_row(next_trimmed)
1579                        || is_setext_underline(next_trimmed)
1580                        || is_horizontal_rule(next_trimmed)
1581                        || crate::utils::mkdocs_footnotes::is_footnote_definition(next_trimmed)
1582                    {
1583                        // Preserve verbatim: blockquotes, tables, lists, setext
1584                        // underlines, and horizontal rules inside the footnote
1585                        if next_trimmed.starts_with('>')
1586                            || TableUtils::is_potential_table_row(next_trimmed)
1587                            || is_list_item(next_trimmed)
1588                            || is_setext_underline(next_trimmed)
1589                            || is_horizontal_rule(next_trimmed)
1590                        {
1591                            fn_lines.push(FnLineType::Verbatim(strip_fn_indent(next), indent));
1592                            last_consumed = i;
1593                            i += 1;
1594                            continue;
1595                        }
1596                        // Headings, new footnote defs, link refs — end the footnote
1597                        break;
1598                    }
1599
1600                    // Link reference definitions inside footnotes are not reflowable
1601                    if next_trimmed.starts_with('[')
1602                        && !next_trimmed.starts_with("[^")
1603                        && next_trimmed.contains("]:")
1604                        && LINK_REF_PATTERN.is_match(next_trimmed)
1605                    {
1606                        fn_lines.push(FnLineType::Verbatim(strip_fn_indent(next), indent));
1607                        last_consumed = i;
1608                        i += 1;
1609                        continue;
1610                    }
1611
1612                    // HTML-only lines inside footnotes are not reflowable
1613                    if is_html_only_line(next_trimmed) {
1614                        fn_lines.push(FnLineType::Verbatim(strip_fn_indent(next), indent));
1615                        last_consumed = i;
1616                        i += 1;
1617                        continue;
1618                    }
1619
1620                    // Regular prose content
1621                    fn_lines.push(FnLineType::Content(next_trimmed.to_string()));
1622                    last_consumed = i;
1623                    i += 1;
1624                }
1625
1626                // Nothing collected or only empty lines
1627                if fn_lines.iter().all(|l| matches!(l, FnLineType::Empty)) || fn_lines.is_empty() {
1628                    continue;
1629                }
1630
1631                // --- Group into blocks ---
1632                #[derive(Debug)]
1633                enum FnBlock {
1634                    Paragraph(Vec<String>),
1635                    Verbatim(Vec<(String, usize)>), // (content, indent) preserved as-is
1636                }
1637
1638                let mut blocks: Vec<FnBlock> = Vec::new();
1639                let mut current_para: Vec<String> = Vec::new();
1640                let mut current_verbatim: Vec<(String, usize)> = Vec::new();
1641
1642                for fl in &fn_lines {
1643                    match fl {
1644                        FnLineType::Content(s) => {
1645                            if !current_verbatim.is_empty() {
1646                                blocks.push(FnBlock::Verbatim(std::mem::take(&mut current_verbatim)));
1647                            }
1648                            current_para.push(s.clone());
1649                        }
1650                        FnLineType::Verbatim(s, indent) => {
1651                            if !current_para.is_empty() {
1652                                blocks.push(FnBlock::Paragraph(std::mem::take(&mut current_para)));
1653                            }
1654                            current_verbatim.push((s.clone(), *indent));
1655                        }
1656                        FnLineType::Empty => {
1657                            if !current_para.is_empty() {
1658                                blocks.push(FnBlock::Paragraph(std::mem::take(&mut current_para)));
1659                            }
1660                            if !current_verbatim.is_empty() {
1661                                blocks.push(FnBlock::Verbatim(std::mem::take(&mut current_verbatim)));
1662                            }
1663                        }
1664                    }
1665                }
1666                if !current_para.is_empty() {
1667                    blocks.push(FnBlock::Paragraph(current_para));
1668                }
1669                if !current_verbatim.is_empty() {
1670                    blocks.push(FnBlock::Verbatim(current_verbatim));
1671                }
1672
1673                // --- Reflow paragraphs and reconstruct ---
1674                let prefix_display_width = prefix.chars().count() + 1; // +1 for space
1675                let reflow_line_length = if config.line_length.is_unlimited() {
1676                    usize::MAX
1677                } else {
1678                    config
1679                        .line_length
1680                        .get()
1681                        .saturating_sub(FN_INDENT.max(prefix_display_width))
1682                        .max(20)
1683                };
1684                // Footnote continuation uses a fixed 4-space indent, so list
1685                // continuation capping does not apply here.
1686                let reflow_options = crate::utils::text_reflow::ReflowOptions {
1687                    max_list_continuation_indent: None,
1688                    ..Self::reflow_options(ctx, config, reflow_line_length)
1689                };
1690
1691                let indent_str = " ".repeat(FN_INDENT);
1692                let mut result_lines: Vec<String> = Vec::new();
1693                let mut is_first_block = true;
1694
1695                for block in &blocks {
1696                    match block {
1697                        FnBlock::Paragraph(para_lines) => {
1698                            let paragraph_text = para_lines.join(" ");
1699                            let paragraph_text = paragraph_text.trim();
1700                            if paragraph_text.is_empty() {
1701                                continue;
1702                            }
1703
1704                            let reflowed = crate::utils::text_reflow::reflow_line(paragraph_text, &reflow_options);
1705                            if reflowed.is_empty() {
1706                                continue;
1707                            }
1708
1709                            // Blank line separator between blocks
1710                            if !result_lines.is_empty() {
1711                                result_lines.push(String::new());
1712                            }
1713
1714                            for (idx, rline) in reflowed.iter().enumerate() {
1715                                if is_first_block && idx == 0 {
1716                                    result_lines.push(format!("{prefix} {rline}"));
1717                                } else {
1718                                    result_lines.push(format!("{indent_str}{rline}"));
1719                                }
1720                            }
1721                            is_first_block = false;
1722                        }
1723                        FnBlock::Verbatim(verb_lines) => {
1724                            // Blank line separator between blocks
1725                            if !result_lines.is_empty() {
1726                                result_lines.push(String::new());
1727                            }
1728
1729                            if is_first_block {
1730                                // Verbatim as first block in a deferred-body footnote
1731                                if deferred_body {
1732                                    result_lines.push(prefix.to_string());
1733                                }
1734                                is_first_block = false;
1735                            }
1736                            for (content, _orig_indent) in verb_lines {
1737                                result_lines.push(format!("{indent_str}{content}"));
1738                            }
1739                        }
1740                    }
1741                }
1742
1743                // If nothing was produced, skip
1744                if result_lines.is_empty() {
1745                    continue;
1746                }
1747
1748                let reflowed_text = result_lines.join(line_ending);
1749
1750                // Calculate byte range using last_consumed
1751                let start_range = line_index.whole_line_range(footnote_start + 1);
1752                let end_range = if last_consumed == lines.len() - 1 && !ctx.content.ends_with('\n') {
1753                    line_index.line_text_range(last_consumed + 1, 1, lines[last_consumed].len() + 1)
1754                } else {
1755                    line_index.whole_line_range(last_consumed + 1)
1756                };
1757                let byte_range = start_range.start..end_range.end;
1758
1759                let replacement = if last_consumed < lines.len() - 1 || ctx.content.ends_with('\n') {
1760                    format!("{reflowed_text}{line_ending}")
1761                } else {
1762                    reflowed_text
1763                };
1764
1765                let original_text = &ctx.content[byte_range.clone()];
1766                let max_length = (footnote_start..=last_consumed)
1767                    .map(|idx| self.calculate_effective_length(lines[idx]))
1768                    .max()
1769                    .unwrap_or(0);
1770                let line_limit = if config.line_length.is_unlimited() {
1771                    usize::MAX
1772                } else {
1773                    config.line_length.get()
1774                };
1775                if original_text != replacement && max_length > line_limit {
1776                    warnings.push(LintWarning {
1777                        rule_name: Some(self.name().to_string()),
1778                        message: format!(
1779                            "Line length {} exceeds {} characters",
1780                            max_length,
1781                            config.line_length.get()
1782                        ),
1783                        line: footnote_start + 1,
1784                        column: 1,
1785                        end_line: last_consumed + 1,
1786                        end_column: lines[last_consumed].chars().count() + 1,
1787                        severity: Severity::Warning,
1788                        fix: Some(crate::rule::Fix::new(byte_range, replacement)),
1789                    });
1790                }
1791                continue;
1792            }
1793
1794            // Handle MkDocs container content (admonitions and tabs) with indent-preserving reflow
1795            if ctx
1796                .line_info(line_num)
1797                .is_some_and(super::super::lint_context::types::LineInfo::in_mkdocs_container)
1798            {
1799                // Skip admonition/tab marker lines — only reflow their indented content
1800                let current_line = lines[i];
1801                if mkdocs_admonitions::is_admonition_start(current_line) || mkdocs_tabs::is_tab_marker(current_line) {
1802                    i += 1;
1803                    continue;
1804                }
1805
1806                let container_start = i;
1807
1808                // Detect the actual indent level from the first content line
1809                // (supports nested admonitions with 8+ spaces)
1810                let first_line = lines[i];
1811                let base_indent_len = first_line.len() - first_line.trim_start().len();
1812                let base_indent: String = " ".repeat(base_indent_len);
1813
1814                // Collect consecutive MkDocs container paragraph lines
1815                let mut container_lines: Vec<&str> = Vec::new();
1816                while i < lines.len() {
1817                    let current_line_num = i + 1;
1818                    let line_info = ctx.line_info(current_line_num);
1819
1820                    // Stop if we leave the MkDocs container
1821                    if !line_info.is_some_and(super::super::lint_context::types::LineInfo::in_mkdocs_container) {
1822                        break;
1823                    }
1824
1825                    let line = lines[i];
1826
1827                    // Stop at paragraph boundaries within the container
1828                    if line.trim().is_empty() {
1829                        break;
1830                    }
1831
1832                    // Skip list items, code blocks, headings, HTML-only lines within containers
1833                    if is_list_item(line.trim())
1834                        || line.trim().starts_with("```")
1835                        || line.trim().starts_with("~~~")
1836                        || line.trim().starts_with('#')
1837                        || is_html_only_line(line)
1838                    {
1839                        break;
1840                    }
1841
1842                    container_lines.push(line);
1843                    i += 1;
1844                }
1845
1846                if container_lines.is_empty() {
1847                    // Must advance i to avoid infinite loop when we encounter
1848                    // non-paragraph content (code block, list, heading, empty line)
1849                    // at the start of an MkDocs container
1850                    i += 1;
1851                    continue;
1852                }
1853
1854                // Strip the base indent from each line and join for reflow
1855                let stripped_lines: Vec<&str> = container_lines
1856                    .iter()
1857                    .map(|line| {
1858                        if line.starts_with(&base_indent) {
1859                            &line[base_indent_len..]
1860                        } else {
1861                            line.trim_start()
1862                        }
1863                    })
1864                    .collect();
1865                let paragraph_text = stripped_lines.join(" ");
1866
1867                // Check if reflow is needed
1868                let needs_reflow = match config.reflow_mode {
1869                    ReflowMode::Normalize => self.normalize_mode_needs_reflow(container_lines.iter().copied(), config),
1870                    ReflowMode::SentencePerLine => {
1871                        let sentences = split_into_sentences(&paragraph_text);
1872                        sentences.len() > 1 || container_lines.len() > 1
1873                    }
1874                    ReflowMode::SemanticLineBreaks => {
1875                        let sentences = split_into_sentences(&paragraph_text);
1876                        sentences.len() > 1
1877                            || container_lines.len() > 1
1878                            || container_lines
1879                                .iter()
1880                                .any(|line| self.calculate_effective_length(line) > config.line_length.get())
1881                    }
1882                    ReflowMode::Default => container_lines
1883                        .iter()
1884                        .any(|line| self.calculate_effective_length(line) > config.line_length.get()),
1885                };
1886
1887                if !needs_reflow {
1888                    continue;
1889                }
1890
1891                // Calculate byte range for this container paragraph
1892                let start_range = line_index.whole_line_range(container_start + 1);
1893                let end_line = container_start + container_lines.len() - 1;
1894                let end_range = if end_line == lines.len() - 1 && !ctx.content.ends_with('\n') {
1895                    line_index.line_text_range(end_line + 1, 1, lines[end_line].len() + 1)
1896                } else {
1897                    line_index.whole_line_range(end_line + 1)
1898                };
1899                let byte_range = start_range.start..end_range.end;
1900
1901                // Reflow with adjusted line length (accounting for the 4-space indent)
1902                let reflow_line_length = if config.line_length.is_unlimited() {
1903                    usize::MAX
1904                } else {
1905                    config.line_length.get().saturating_sub(base_indent_len).max(1)
1906                };
1907                let reflow_options = Self::reflow_options(ctx, config, reflow_line_length);
1908                let reflowed = crate::utils::text_reflow::reflow_line(&paragraph_text, &reflow_options);
1909
1910                // Re-add the 4-space indent to each reflowed line
1911                let reflowed_with_indent: Vec<String> =
1912                    reflowed.iter().map(|line| format!("{base_indent}{line}")).collect();
1913                let reflowed_text = reflowed_with_indent.join(line_ending);
1914
1915                // Preserve trailing newline
1916                let replacement = if end_line < lines.len() - 1 || ctx.content.ends_with('\n') {
1917                    format!("{reflowed_text}{line_ending}")
1918                } else {
1919                    reflowed_text
1920                };
1921
1922                // Only generate a warning if the replacement is different
1923                let original_text = &ctx.content[byte_range.clone()];
1924                if original_text != replacement {
1925                    warnings.push(LintWarning {
1926                        rule_name: Some(self.name().to_string()),
1927                        message: format!(
1928                            "Line length {} exceeds {} characters (in MkDocs container)",
1929                            container_lines.iter().map(|l| l.len()).max().unwrap_or(0),
1930                            config.line_length.get()
1931                        ),
1932                        line: container_start + 1,
1933                        column: 1,
1934                        end_line: end_line + 1,
1935                        end_column: lines[end_line].chars().count() + 1,
1936                        severity: Severity::Warning,
1937                        fix: Some(crate::rule::Fix::new(byte_range, replacement)),
1938                    });
1939                }
1940                continue;
1941            }
1942
1943            // Helper function to detect semantic line markers
1944            let is_semantic_line = |content: &str| -> bool {
1945                let trimmed = content.trim_start();
1946                let semantic_markers = [
1947                    "NOTE:",
1948                    "WARNING:",
1949                    "IMPORTANT:",
1950                    "CAUTION:",
1951                    "TIP:",
1952                    "DANGER:",
1953                    "HINT:",
1954                    "INFO:",
1955                ];
1956                semantic_markers.iter().any(|marker| trimmed.starts_with(marker))
1957            };
1958
1959            // Helper function to detect fence markers (opening or closing)
1960            let is_fence_marker = |content: &str| -> bool {
1961                let trimmed = content.trim_start();
1962                trimmed.starts_with("```") || trimmed.starts_with("~~~")
1963            };
1964
1965            // Check if this is a list item - handle it specially
1966            let trimmed = lines[i].trim();
1967            if is_list_item(trimmed) {
1968                // Collect the entire list item including continuation lines
1969                let list_start = i;
1970                let (marker, first_content) = extract_list_marker_and_content(lines[i]);
1971                let marker_len = marker.len();
1972
1973                // Checkbox ([ ]/[x]/[X]) is inline content, not part of the list marker.
1974                // Use the base bullet/number marker width for continuation recognition
1975                // so that continuation lines at 2+ spaces are collected for "- [ ] " items.
1976                let base_marker_len = if marker.contains("[ ] ") || marker.contains("[x] ") || marker.contains("[X] ") {
1977                    marker.find('[').unwrap_or(marker_len)
1978                } else {
1979                    marker_len
1980                };
1981
1982                // MkDocs flavor requires at least 4 spaces for list continuation
1983                // after a blank line (multi-paragraph list items). For non-blank
1984                // continuation (lines directly following the marker line), use
1985                // the natural marker width so that 2-space indent is recognized.
1986                let item_indent = ctx.lines[i].indent;
1987                let min_continuation_indent = if ctx.flavor.requires_strict_list_indent() {
1988                    // Use 4-space relative indent from the list item's nesting level
1989                    item_indent + (base_marker_len - item_indent).max(4)
1990                } else {
1991                    marker_len
1992                };
1993                let content_continuation_indent = base_marker_len;
1994
1995                // Track lines and their types (content, code block, fence, nested list)
1996                #[derive(Clone)]
1997                enum LineType {
1998                    Content(String),
1999                    CodeBlock(String, usize),         // content and original indent
2000                    SemanticLine(String), // Lines starting with NOTE:, WARNING:, etc that should stay separate
2001                    SnippetLine(String),  // MkDocs Snippets delimiters (-8<-) that must stay on their own line
2002                    DivMarker(String),    // Quarto/Pandoc div markers (::: opening or closing)
2003                    AdmonitionHeader(String, usize), // header text (e.g. "!!! note") and original indent
2004                    AdmonitionContent(String, usize), // body content text and original indent
2005                    Table(String, usize), // GFM table row, preserved verbatim with original indent
2006                    Empty,
2007                }
2008
2009                let mut list_item_lines: Vec<LineType> = vec![LineType::Content(first_content)];
2010                // Set when collection stops at a nested list item or a nested
2011                // blockquote that belongs to this item. Such structure is reflowed
2012                // independently and is therefore absent from `list_item_lines`/`blocks`,
2013                // but it still keeps the emitted item spanning multiple physical lines,
2014                // which the MD030 multi-line spacing decision below must account for.
2015                let mut has_trailing_nested_structure = false;
2016                i += 1;
2017
2018                // Collect continuation lines using ctx.lines for metadata
2019                while i < lines.len() {
2020                    let line_info = &ctx.lines[i];
2021
2022                    // Use pre-computed is_blank from ctx
2023                    if line_info.is_blank {
2024                        // Empty line - check if next line is indented (part of list item)
2025                        if i + 1 < lines.len() {
2026                            let next_info = &ctx.lines[i + 1];
2027
2028                            // Check if next line is indented enough to be continuation
2029                            if !next_info.is_blank && next_info.indent >= min_continuation_indent {
2030                                // This blank line is between paragraphs/blocks in the list item
2031                                list_item_lines.push(LineType::Empty);
2032                                i += 1;
2033                                continue;
2034                            }
2035                        }
2036                        // No indented line after blank, end of list item
2037                        break;
2038                    }
2039
2040                    // Use pre-computed indent from ctx
2041                    let indent = line_info.indent;
2042
2043                    // Valid continuation must be indented at least content_continuation_indent.
2044                    // For non-blank continuation, use marker_len (e.g. 2 for "- ").
2045                    // MkDocs strict 4-space requirement applies only after blank lines.
2046                    if indent >= content_continuation_indent {
2047                        let trimmed = line_info.content(ctx.content).trim();
2048
2049                        // Check for MkDocs admonition lines inside list items BEFORE
2050                        // checking in_code_block. Lines inside code blocks within
2051                        // admonitions have both in_admonition and in_code_block set;
2052                        // admonition membership takes priority so the entire admonition
2053                        // structure (including embedded code blocks) is preserved.
2054                        if line_info.in_admonition {
2055                            let raw_content = line_info.content(ctx.content);
2056                            if mkdocs_admonitions::is_admonition_start(raw_content) {
2057                                let header_text = raw_content[indent..].trim_end().to_string();
2058                                list_item_lines.push(LineType::AdmonitionHeader(header_text, indent));
2059                            } else {
2060                                let body_text = raw_content[indent..].trim_end().to_string();
2061                                list_item_lines.push(LineType::AdmonitionContent(body_text, indent));
2062                            }
2063                            i += 1;
2064                            continue;
2065                        }
2066
2067                        // Use pre-computed in_code_block from ctx
2068                        if line_info.in_code_block {
2069                            list_item_lines.push(LineType::CodeBlock(
2070                                line_info.content(ctx.content)[indent..].to_string(),
2071                                indent,
2072                            ));
2073                            i += 1;
2074                            continue;
2075                        }
2076
2077                        // A blockquote nested inside the list item is reflowed by the
2078                        // blockquote-aware path (it preserves the `>` prefix, including the
2079                        // list indent), not as list-item prose. Collecting it as Content
2080                        // would strip the markers and reflow `>` as words, collapsing the
2081                        // blank `>` line and dropping `>` from wrapped continuations. End
2082                        // the item here so the outer loop routes the blockquote line to
2083                        // generate_blockquote_paragraph_fix. Uncollect a pending blank so
2084                        // the separator between the list prose and the blockquote survives.
2085                        if line_info.blockquote.is_some() {
2086                            has_trailing_nested_structure = true;
2087                            if matches!(list_item_lines.last(), Some(LineType::Empty)) {
2088                                list_item_lines.pop();
2089                                i -= 1;
2090                            }
2091                            break;
2092                        }
2093
2094                        // Check if this is a SIBLING list item (breaks parent)
2095                        // Nested lists are indented >= marker_len and are PART of the parent item
2096                        // Siblings are at indent < marker_len (at or before parent marker)
2097                        if is_list_item(trimmed) && indent < marker_len {
2098                            // This is a sibling item at same or higher level - end parent item
2099                            break;
2100                        }
2101
2102                        // Nested list items are always processed independently
2103                        // by the outer loop, so break when we encounter one.
2104                        // If a blank line was collected before this, uncollect it
2105                        // so the outer loop preserves the blank between parent and nested.
2106                        if is_list_item(trimmed) && indent >= marker_len {
2107                            has_trailing_nested_structure = true;
2108                            if matches!(list_item_lines.last(), Some(LineType::Empty)) {
2109                                list_item_lines.pop();
2110                                i -= 1;
2111                            }
2112                            break;
2113                        }
2114
2115                        // Normal continuation vs indented code block.
2116                        // Use min_continuation_indent for the threshold since
2117                        // code blocks start 4 spaces beyond the expected content
2118                        // level (which is min_continuation_indent for MkDocs).
2119                        if indent <= min_continuation_indent + 3 {
2120                            // Extract content (remove indentation and trailing whitespace)
2121                            // Preserve hard breaks (2 trailing spaces) while removing excessive whitespace
2122                            // See: https://github.com/rvben/rumdl/issues/76
2123                            let content = trim_preserving_hard_break(&line_info.content(ctx.content)[indent..]);
2124
2125                            // Check if this is a div marker (::: opening or closing)
2126                            // These must be preserved on their own line, not merged into paragraphs
2127                            if line_info.is_div_marker {
2128                                list_item_lines.push(LineType::DivMarker(content));
2129                            }
2130                            // Check if this is a fence marker (opening or closing)
2131                            // These should be treated as code block lines, not paragraph content
2132                            else if is_fence_marker(&content) {
2133                                list_item_lines.push(LineType::CodeBlock(content, indent));
2134                            }
2135                            // Check if this is a semantic line (NOTE:, WARNING:, etc.)
2136                            else if is_semantic_line(&content) {
2137                                list_item_lines.push(LineType::SemanticLine(content));
2138                            }
2139                            // Check if this is a snippet block delimiter (-8<- or --8<--)
2140                            // These must be preserved on their own lines for MkDocs Snippets extension
2141                            else if is_snippet_block_delimiter(&content) {
2142                                list_item_lines.push(LineType::SnippetLine(content));
2143                            }
2144                            // Check if this is a GFM table row. Tables nested inside list
2145                            // items must be preserved verbatim — joining them with prose
2146                            // breaks the column structure.
2147                            //
2148                            // `is_potential_table_row` is intentionally permissive at the
2149                            // row level: any line with `|` and 2+ cells qualifies. To avoid
2150                            // misclassifying prose continuation lines that contain a literal
2151                            // pipe (e.g. "use grep | sort to ..."), require one of:
2152                            //   - the row is pipe-bordered (`| ... |`), the canonical form
2153                            //     for tables nested in lists; or
2154                            //   - the next line is a delimiter row (this is a header); or
2155                            //   - the previous classified line was already a Table (this is
2156                            //     a continuation row).
2157                            else if TableUtils::is_potential_table_row(&content) && {
2158                                let pipe_bordered = content.trim().starts_with('|') && content.trim().ends_with('|');
2159                                let next_is_delim = ctx
2160                                    .lines
2161                                    .get(i + 1)
2162                                    .is_some_and(|next| TableUtils::is_delimiter_row(next.content(ctx.content)));
2163                                let prev_was_table = matches!(list_item_lines.last(), Some(LineType::Table(..)));
2164                                pipe_bordered || next_is_delim || prev_was_table
2165                            } {
2166                                list_item_lines.push(LineType::Table(content, indent));
2167                            } else {
2168                                list_item_lines.push(LineType::Content(content));
2169                            }
2170                            i += 1;
2171                        } else {
2172                            // indent >= min_continuation_indent + 4: indented code block
2173                            list_item_lines.push(LineType::CodeBlock(
2174                                line_info.content(ctx.content)[indent..].to_string(),
2175                                indent,
2176                            ));
2177                            i += 1;
2178                        }
2179                    } else {
2180                        // Not indented enough, end of list item
2181                        break;
2182                    }
2183                }
2184
2185                // Determine the output continuation indent.
2186                // Normalize/Default modes canonicalize to min_continuation_indent
2187                // (fixing over-indented continuation). Semantic/SentencePerLine
2188                // modes preserve the user's actual indent since they only fix
2189                // line breaking, not indentation.
2190                let indent_size = match config.reflow_mode {
2191                    ReflowMode::SemanticLineBreaks | ReflowMode::SentencePerLine => {
2192                        // Find indent of the first plain text continuation line,
2193                        // skipping the marker line (index 0), nested list items,
2194                        // code blocks, and blank lines.
2195                        list_item_lines
2196                            .iter()
2197                            .enumerate()
2198                            .skip(1)
2199                            .find_map(|(k, lt)| {
2200                                if matches!(lt, LineType::Content(_)) {
2201                                    Some(ctx.lines[list_start + k].indent)
2202                                } else {
2203                                    None
2204                                }
2205                            })
2206                            .unwrap_or(min_continuation_indent)
2207                    }
2208                    _ => min_continuation_indent,
2209                };
2210                // For checkbox items in mkdocs flavor, enforce minimum indent so
2211                // continuation lines use the structural list indent (4), not the
2212                // content-aligned indent (6) which Python-Markdown doesn't support
2213                let has_checkbox = base_marker_len < marker_len;
2214                let indent_size = if has_checkbox && ctx.flavor.requires_strict_list_indent() {
2215                    indent_size.max(min_continuation_indent)
2216                } else {
2217                    indent_size
2218                };
2219
2220                // Split list_item_lines into blocks (paragraphs, code blocks, nested lists, semantic lines, and HTML blocks)
2221                let mut builder = BlockBuilder::new();
2222                for line in &list_item_lines {
2223                    match line {
2224                        LineType::Empty => builder.feed_blank_line(),
2225                        LineType::Content(content) => builder.feed_content(content),
2226                        LineType::CodeBlock(content, indent) => builder.feed_code_line(content, *indent),
2227                        LineType::SemanticLine(content) => builder.feed_semantic_line(content),
2228                        LineType::SnippetLine(content) => builder.feed_snippet_line(content),
2229                        LineType::DivMarker(content) => builder.feed_div_marker(content),
2230                        LineType::AdmonitionHeader(header_text, indent) => {
2231                            builder.feed_admonition_header(header_text, *indent)
2232                        }
2233                        LineType::AdmonitionContent(content, indent) => {
2234                            builder.feed_admonition_content(content, *indent)
2235                        }
2236                        LineType::Table(content, indent) => builder.feed_table_line(content, *indent),
2237                    }
2238                }
2239                let blocks = builder.finalize();
2240
2241                // Helper: check if a line (raw source or stripped content) is exempt
2242                // from line-length checks. Link reference definitions are always exempt;
2243                // standalone link/image lines are exempt when strict mode is off.
2244                // Also checks content after stripping list markers, since list item
2245                // continuation lines may contain link ref defs.
2246                let is_exempt_line = |raw_line: &str| -> bool {
2247                    let trimmed = raw_line.trim();
2248                    // Link reference definitions: always exempt
2249                    if trimmed.starts_with('[') && trimmed.contains("]:") && LINK_REF_PATTERN.is_match(trimmed) {
2250                        return true;
2251                    }
2252                    // Also check after stripping list markers (for list item content)
2253                    if is_list_item(trimmed) {
2254                        let (_, content) = extract_list_marker_and_content(trimmed);
2255                        let content_trimmed = content.trim();
2256                        if content_trimmed.starts_with('[')
2257                            && content_trimmed.contains("]:")
2258                            && LINK_REF_PATTERN.is_match(content_trimmed)
2259                        {
2260                            return true;
2261                        }
2262                    }
2263                    // Standalone link/image lines: exempt when not strict
2264                    if !config.strict && is_standalone_link_or_image_line(raw_line) {
2265                        return true;
2266                    }
2267                    // HTML-only lines: exempt when not strict
2268                    if !config.strict && is_html_only_line(raw_line) {
2269                        return true;
2270                    }
2271                    false
2272                };
2273
2274                // Check if reflowing is needed (only for content paragraphs, not code blocks or nested lists)
2275                // Exclude link reference definitions and standalone link lines from content
2276                // so they don't pollute combined_content or trigger false reflow.
2277                let content_lines: Vec<String> = list_item_lines
2278                    .iter()
2279                    .filter_map(|line| {
2280                        if let LineType::Content(s) = line {
2281                            if is_exempt_line(s) {
2282                                return None;
2283                            }
2284                            Some(s.clone())
2285                        } else {
2286                            None
2287                        }
2288                    })
2289                    .collect();
2290
2291                // Check if we need to reflow this list item
2292                // We check the combined content to see if it exceeds length limits
2293                let combined_content = content_lines.join(" ").trim().to_string();
2294
2295                // Helper to check if we should reflow in normalize mode
2296                let should_normalize = || {
2297                    // Don't normalize if the list item only contains nested lists, code blocks, or semantic lines
2298                    // DO normalize if it has plain text content that spans multiple lines
2299                    let has_code_blocks = blocks.iter().any(|b| matches!(b, Block::Code { .. }));
2300                    let has_semantic_lines = blocks.iter().any(|b| matches!(b, Block::SemanticLine(_)));
2301                    let has_snippet_lines = blocks.iter().any(|b| matches!(b, Block::SnippetLine(_)));
2302                    let has_div_markers = blocks.iter().any(|b| matches!(b, Block::DivMarker(_)));
2303                    let has_admonitions = blocks.iter().any(|b| matches!(b, Block::Admonition { .. }));
2304                    let has_tables = blocks.iter().any(|b| matches!(b, Block::Table { .. }));
2305                    let has_paragraphs = blocks.iter().any(|b| matches!(b, Block::Paragraph(_)));
2306
2307                    // If we have structural blocks but no paragraphs, don't normalize
2308                    if (has_code_blocks
2309                        || has_semantic_lines
2310                        || has_snippet_lines
2311                        || has_div_markers
2312                        || has_admonitions
2313                        || has_tables)
2314                        && !has_paragraphs
2315                    {
2316                        return false;
2317                    }
2318
2319                    // If we have paragraphs, check if they span multiple lines or there are multiple blocks
2320                    if has_paragraphs {
2321                        // Count only paragraphs that contain at least one non-exempt line.
2322                        // Paragraphs consisting entirely of link ref defs or standalone links
2323                        // should not trigger normalization.
2324                        let paragraph_count = blocks
2325                            .iter()
2326                            .filter(|b| {
2327                                if let Block::Paragraph(para_lines) = b {
2328                                    !para_lines.iter().all(|line| is_exempt_line(line))
2329                                } else {
2330                                    false
2331                                }
2332                            })
2333                            .count();
2334                        if paragraph_count > 1 {
2335                            // Multiple non-exempt paragraph blocks should be normalized
2336                            return true;
2337                        }
2338
2339                        // Single paragraph block: normalize if it has multiple content lines
2340                        if content_lines.len() > 1 {
2341                            return true;
2342                        }
2343                    }
2344
2345                    false
2346                };
2347
2348                // Integrate MD030 list-marker spacing (and MD007's text-aligned
2349                // continuation). In Default/Normalize modes — the modes that already
2350                // canonicalize spacing/indent — derive the number of spaces after the
2351                // marker from the configured MD030 values instead of forcing a single
2352                // space, then align continuation lines to the resulting content column.
2353                // Sentence/Semantic modes only adjust line breaks, so they keep the
2354                // marker spacing and indentation already present in the source.
2355                //
2356                // With default MD030 (a single space everywhere) the rebuilt marker is
2357                // byte-identical to the source marker, so this is a no-op and existing
2358                // behaviour is preserved; only a non-default MD030 changes the output.
2359                // The MkDocs flavor enforces a rigid structural indent (4 spaces,
2360                // capped via max_list_continuation_indent) that Python-Markdown
2361                // requires; leave its specialized handling untouched.
2362                let (marker, indent_size, code_indent_shift) =
2363                    if matches!(config.reflow_mode, ReflowMode::Default | ReflowMode::Normalize)
2364                        && !ctx.flavor.requires_strict_list_indent()
2365                        && let Some(li) = ctx.lines[list_start].list_item.as_deref()
2366                    {
2367                        let bullet_len = li.marker.len();
2368                        // The checkbox (e.g. `[ ] `) is content, not part of the list
2369                        // marker MD030 governs; carry it over verbatim after the spacing.
2370                        let checkbox_tail = marker[base_marker_len..].to_string();
2371                        // Shift this item right by its ancestors' cumulative marker
2372                        // widening so a nested item stays under its parent's (widened)
2373                        // content column. Zero for top-level items and for the whole
2374                        // tree under default MD030, where the source indent is preserved
2375                        // verbatim (byte-identical output).
2376                        let ancestor_shift = list_shift_stack.last().map_or(0isize, |&(_, shift)| shift);
2377                        let shifted_indent = (item_indent as isize + ancestor_shift).max(0) as usize;
2378                        let indent_prefix = if ancestor_shift == 0 {
2379                            marker[..item_indent].to_string()
2380                        } else {
2381                            " ".repeat(shifted_indent)
2382                        };
2383
2384                        // Decide single- vs multi-line spacing from the *rewritten* shape,
2385                        // not the source. A multi-line source is not enough: plain prose
2386                        // continuation collapses onto the marker line during reflow, so a
2387                        // two-line bullet that fits becomes a single physical line and must
2388                        // use MD030's single-line spacing (otherwise MD013 emits a result
2389                        // that MD030 immediately rewrites). The emitted item stays
2390                        // multi-line only when reflow cannot collapse it:
2391                        //   - the prose wraps past the line length, or
2392                        //   - a structural block remains (code, table, admonition, semantic
2393                        //     line, snippet, div marker, HTML) that is not joinable prose, or
2394                        //   - more than one paragraph remains (blank-separated), or
2395                        //   - a nested list/blockquote follows (reflowed independently, so it
2396                        //     is absent from `blocks` but still keeps the item multi-line).
2397                        // The wrap test uses the single-line content column so it is
2398                        // independent of the spacing we are about to choose (avoiding a
2399                        // circular result). `ol-align-column` ignores this flag entirely in
2400                        // expected_spaces(), so ordered lists are unaffected.
2401                        //
2402                        // This is the rewritten-shape counterpart of MD030's
2403                        // `is_multi_line_list_item` (which keys off the *source*). The two
2404                        // are related but technically distinct and intentionally separate;
2405                        // if the notion of "multi-line" changes in one, revisit the other.
2406                        let single_col = shifted_indent
2407                            + bullet_len
2408                            + self.list_spacing.expected_spaces(li.is_ordered, false, bullet_len)
2409                            + checkbox_tail.len();
2410                        let prose_wraps = !combined_content.is_empty()
2411                            && self
2412                                .calculate_effective_length(&format!("{}{combined_content}", " ".repeat(single_col)))
2413                                > config.line_length.effective_limit();
2414                        let has_structural_block = blocks.iter().any(|b| !matches!(b, Block::Paragraph(_)));
2415                        let multiple_paragraphs =
2416                            blocks.iter().filter(|b| matches!(b, Block::Paragraph(_))).count() > 1;
2417                        let is_multi =
2418                            prose_wraps || has_structural_block || multiple_paragraphs || has_trailing_nested_structure;
2419
2420                        let spaces = self.list_spacing.expected_spaces(li.is_ordered, is_multi, bullet_len);
2421                        let new_marker = format!("{indent_prefix}{}{}{checkbox_tail}", li.marker, " ".repeat(spaces));
2422                        let new_col = new_marker.chars().count();
2423                        let shift = new_col as isize - marker_len as isize;
2424                        (new_marker, new_col, shift)
2425                    } else {
2426                        (marker, indent_size, 0isize)
2427                    };
2428                let expected_indent = " ".repeat(indent_size);
2429
2430                let needs_reflow = match config.reflow_mode {
2431                    ReflowMode::Normalize => {
2432                        // Only reflow if:
2433                        // 1. Any non-exempt paragraph, when joined, exceeds the limit, OR
2434                        // 2. Any admonition content line exceeds the limit, OR
2435                        // 3. The list item should be normalized (has multi-line plain text)
2436                        let any_paragraph_exceeds = blocks.iter().any(|block| match block {
2437                            Block::Paragraph(para_lines) => {
2438                                if para_lines.iter().all(|line| is_exempt_line(line)) {
2439                                    return false;
2440                                }
2441                                let joined = para_lines.join(" ");
2442                                let with_marker = format!("{}{}", " ".repeat(indent_size), joined.trim());
2443                                self.calculate_effective_length(&with_marker) > config.line_length.get()
2444                            }
2445                            Block::Admonition {
2446                                content_lines,
2447                                header_indent,
2448                                ..
2449                            } => content_lines.iter().any(|(content, indent)| {
2450                                if content.is_empty() {
2451                                    return false;
2452                                }
2453                                let with_indent = format!("{}{}", " ".repeat(*indent.max(header_indent)), content);
2454                                self.calculate_effective_length(&with_indent) > config.line_length.get()
2455                            }),
2456                            _ => false,
2457                        });
2458                        if any_paragraph_exceeds {
2459                            true
2460                        } else {
2461                            should_normalize()
2462                        }
2463                    }
2464                    ReflowMode::SentencePerLine => {
2465                        // Check if list item has multiple sentences
2466                        let sentences = split_into_sentences(&combined_content);
2467                        sentences.len() > 1
2468                    }
2469                    ReflowMode::SemanticLineBreaks => {
2470                        let sentences = split_into_sentences(&combined_content);
2471                        sentences.len() > 1
2472                            || (list_start..i).any(|line_idx| {
2473                                let line = lines[line_idx];
2474                                let trimmed = line.trim();
2475                                if trimmed.is_empty() || is_exempt_line(line) {
2476                                    return false;
2477                                }
2478                                self.calculate_effective_length(line) > config.line_length.get()
2479                            })
2480                    }
2481                    ReflowMode::Default => {
2482                        // In default mode, only reflow if any individual non-exempt line exceeds limit
2483                        (list_start..i).any(|line_idx| {
2484                            let line = lines[line_idx];
2485                            let trimmed = line.trim();
2486                            // Skip blank lines and exempt lines
2487                            if trimmed.is_empty() || is_exempt_line(line) {
2488                                return false;
2489                            }
2490                            self.calculate_effective_length(line) > config.line_length.get()
2491                        })
2492                    }
2493                };
2494
2495                // Record this item's frame so its nested children inherit the shift.
2496                // Only a reflowed item's marker actually moves; an unreflowed one keeps
2497                // its source position and so contributes no shift to its children. The
2498                // source content column (`marker_len`) is the threshold that decides
2499                // which following lines are inside this item.
2500                list_shift_stack.push((marker_len, if needs_reflow { code_indent_shift } else { 0 }));
2501
2502                if needs_reflow {
2503                    let start_range = line_index.whole_line_range(list_start + 1);
2504                    let end_line = i - 1;
2505                    let end_range = if end_line == lines.len() - 1 && !ctx.content.ends_with('\n') {
2506                        line_index.line_text_range(end_line + 1, 1, lines[end_line].len() + 1)
2507                    } else {
2508                        line_index.whole_line_range(end_line + 1)
2509                    };
2510                    let byte_range = start_range.start..end_range.end;
2511
2512                    // Reflow each block (paragraphs only, preserve code blocks)
2513                    // When line_length = 0 (no limit), use a very large value for reflow
2514                    let reflow_line_length = if config.line_length.is_unlimited() {
2515                        usize::MAX
2516                    } else {
2517                        config.line_length.get().saturating_sub(indent_size).max(1)
2518                    };
2519                    let reflow_options = Self::reflow_options(ctx, config, reflow_line_length);
2520
2521                    let mut result: Vec<String> = Vec::new();
2522                    let mut is_first_block = true;
2523
2524                    for (block_idx, block) in blocks.iter().enumerate() {
2525                        match block {
2526                            Block::Paragraph(para_lines) => {
2527                                // If every line in this paragraph is exempt (link ref defs,
2528                                // standalone links), preserve the paragraph verbatim instead
2529                                // of reflowing it. Reflowing would corrupt link ref defs.
2530                                let all_exempt = para_lines.iter().all(|line| is_exempt_line(line));
2531
2532                                if all_exempt {
2533                                    for (idx, line) in para_lines.iter().enumerate() {
2534                                        if is_first_block && idx == 0 {
2535                                            result.push(format!("{marker}{line}"));
2536                                            is_first_block = false;
2537                                        } else {
2538                                            result.push(format!("{expected_indent}{line}"));
2539                                        }
2540                                    }
2541                                } else {
2542                                    // Split the paragraph into segments at hard break boundaries
2543                                    // Each segment can be reflowed independently
2544                                    let segments = split_into_segments(para_lines);
2545
2546                                    for (segment_idx, segment) in segments.iter().enumerate() {
2547                                        // Check if this segment ends with a hard break and what type
2548                                        let hard_break_type = segment.last().and_then(|line| {
2549                                            let line = line.strip_suffix('\r').unwrap_or(line);
2550                                            if line.ends_with('\\') {
2551                                                Some("\\")
2552                                            } else if line.ends_with("  ") {
2553                                                Some("  ")
2554                                            } else {
2555                                                None
2556                                            }
2557                                        });
2558
2559                                        // Join and reflow the segment (removing the hard break marker for processing)
2560                                        let segment_for_reflow: Vec<String> = segment
2561                                            .iter()
2562                                            .map(|line| {
2563                                                // Strip hard break marker (2 spaces or backslash) for reflow processing
2564                                                if line.ends_with('\\') {
2565                                                    line[..line.len() - 1].trim_end().to_string()
2566                                                } else if line.ends_with("  ") {
2567                                                    line[..line.len() - 2].trim_end().to_string()
2568                                                } else {
2569                                                    line.clone()
2570                                                }
2571                                            })
2572                                            .collect();
2573
2574                                        let segment_text = segment_for_reflow.join(" ").trim().to_string();
2575                                        if !segment_text.is_empty() {
2576                                            let reflowed =
2577                                                crate::utils::text_reflow::reflow_line(&segment_text, &reflow_options);
2578
2579                                            if is_first_block && segment_idx == 0 {
2580                                                // First segment of first block starts with marker
2581                                                result.push(format!("{marker}{}", reflowed[0]));
2582                                                for line in reflowed.iter().skip(1) {
2583                                                    result.push(format!("{expected_indent}{line}"));
2584                                                }
2585                                                is_first_block = false;
2586                                            } else {
2587                                                // Subsequent segments
2588                                                for line in reflowed {
2589                                                    result.push(format!("{expected_indent}{line}"));
2590                                                }
2591                                            }
2592
2593                                            // If this segment had a hard break, add it back to the last line
2594                                            // Preserve the original hard break format (backslash or two spaces)
2595                                            if let Some(break_marker) = hard_break_type
2596                                                && let Some(last_line) = result.last_mut()
2597                                            {
2598                                                last_line.push_str(break_marker);
2599                                            }
2600                                        }
2601                                    }
2602                                }
2603
2604                                // Add blank line after paragraph block if there's a next block.
2605                                // Check if next block is a code block that doesn't want a preceding blank.
2606                                // Also don't add blank lines before snippet lines (they should stay tight).
2607                                // Only add if not already ending with one (avoids double blanks).
2608                                if block_idx < blocks.len() - 1 {
2609                                    let next_block = &blocks[block_idx + 1];
2610                                    let should_add_blank = match next_block {
2611                                        Block::Code {
2612                                            has_preceding_blank, ..
2613                                        } => *has_preceding_blank,
2614                                        Block::Table {
2615                                            has_preceding_blank, ..
2616                                        } => *has_preceding_blank,
2617                                        Block::SnippetLine(_) | Block::DivMarker(_) => false,
2618                                        _ => true, // For all other blocks, add blank line
2619                                    };
2620                                    if should_add_blank && result.last().is_none_or(|s: &String| !s.is_empty()) {
2621                                        result.push(String::new());
2622                                    }
2623                                }
2624                            }
2625                            Block::Code {
2626                                lines: code_lines,
2627                                has_preceding_blank: _,
2628                            } => {
2629                                // Preserve code blocks as-is with original indentation
2630                                // NOTE: Blank line before code block is handled by the previous block
2631                                // (see paragraph block's logic above)
2632
2633                                for (idx, (content, orig_indent)) in code_lines.iter().enumerate() {
2634                                    if is_first_block && idx == 0 {
2635                                        // First line of first block gets marker
2636                                        result.push(format!(
2637                                            "{marker}{}",
2638                                            " ".repeat(orig_indent - marker_len) + content
2639                                        ));
2640                                        is_first_block = false;
2641                                    } else if content.is_empty() {
2642                                        result.push(String::new());
2643                                    } else {
2644                                        // Shift nested code with the marker so it stays
2645                                        // aligned under content when MD030 widens spacing.
2646                                        result.push(format!(
2647                                            "{}{}",
2648                                            " ".repeat((*orig_indent as isize + code_indent_shift).max(0) as usize),
2649                                            content
2650                                        ));
2651                                    }
2652                                }
2653                            }
2654                            Block::SemanticLine(content) => {
2655                                // Preserve semantic lines (NOTE:, WARNING:, etc.) as-is on their own line.
2656                                // Only add blank before if not already ending with one.
2657                                if !is_first_block && result.last().is_none_or(|s: &String| !s.is_empty()) {
2658                                    result.push(String::new());
2659                                }
2660
2661                                if is_first_block {
2662                                    // First block starts with marker
2663                                    result.push(format!("{marker}{content}"));
2664                                    is_first_block = false;
2665                                } else {
2666                                    // Subsequent blocks use expected indent
2667                                    result.push(format!("{expected_indent}{content}"));
2668                                }
2669
2670                                // Add blank line after semantic line if there's a next block.
2671                                // Only add if not already ending with one.
2672                                if block_idx < blocks.len() - 1 {
2673                                    let next_block = &blocks[block_idx + 1];
2674                                    let should_add_blank = match next_block {
2675                                        Block::Code {
2676                                            has_preceding_blank, ..
2677                                        } => *has_preceding_blank,
2678                                        Block::Table {
2679                                            has_preceding_blank, ..
2680                                        } => *has_preceding_blank,
2681                                        Block::SnippetLine(_) | Block::DivMarker(_) => false,
2682                                        _ => true, // For all other blocks, add blank line
2683                                    };
2684                                    if should_add_blank && result.last().is_none_or(|s: &String| !s.is_empty()) {
2685                                        result.push(String::new());
2686                                    }
2687                                }
2688                            }
2689                            Block::SnippetLine(content) => {
2690                                // Preserve snippet delimiters (-8<-) as-is on their own line
2691                                // Unlike semantic lines, snippet lines don't add extra blank lines
2692                                if is_first_block {
2693                                    // First block starts with marker
2694                                    result.push(format!("{marker}{content}"));
2695                                    is_first_block = false;
2696                                } else {
2697                                    // Subsequent blocks use expected indent
2698                                    result.push(format!("{expected_indent}{content}"));
2699                                }
2700                                // No blank lines added before or after snippet delimiters
2701                            }
2702                            Block::DivMarker(content) => {
2703                                // Preserve div markers (::: opening or closing) as-is on their own line
2704                                if is_first_block {
2705                                    result.push(format!("{marker}{content}"));
2706                                    is_first_block = false;
2707                                } else {
2708                                    result.push(format!("{expected_indent}{content}"));
2709                                }
2710                            }
2711                            Block::Html {
2712                                lines: html_lines,
2713                                has_preceding_blank: _,
2714                            } => {
2715                                // Preserve HTML blocks exactly as-is with original indentation
2716                                // NOTE: Blank line before HTML block is handled by the previous block
2717
2718                                for (idx, line) in html_lines.iter().enumerate() {
2719                                    if is_first_block && idx == 0 {
2720                                        // First line of first block gets marker
2721                                        result.push(format!("{marker}{line}"));
2722                                        is_first_block = false;
2723                                    } else if line.is_empty() {
2724                                        // Preserve blank lines inside HTML blocks
2725                                        result.push(String::new());
2726                                    } else {
2727                                        // Preserve lines with their original content (already includes indentation)
2728                                        result.push(format!("{expected_indent}{line}"));
2729                                    }
2730                                }
2731
2732                                // Add blank line after HTML block if there's a next block.
2733                                // Only add if not already ending with one (avoids double blanks
2734                                // when the HTML block itself contained a trailing blank line).
2735                                if block_idx < blocks.len() - 1 {
2736                                    let next_block = &blocks[block_idx + 1];
2737                                    let should_add_blank = match next_block {
2738                                        Block::Code {
2739                                            has_preceding_blank, ..
2740                                        } => *has_preceding_blank,
2741                                        Block::Html {
2742                                            has_preceding_blank, ..
2743                                        } => *has_preceding_blank,
2744                                        Block::Table {
2745                                            has_preceding_blank, ..
2746                                        } => *has_preceding_blank,
2747                                        Block::SnippetLine(_) | Block::DivMarker(_) => false,
2748                                        _ => true, // For all other blocks, add blank line
2749                                    };
2750                                    if should_add_blank && result.last().is_none_or(|s: &String| !s.is_empty()) {
2751                                        result.push(String::new());
2752                                    }
2753                                }
2754                            }
2755                            Block::Table {
2756                                lines: table_lines,
2757                                has_preceding_blank: _,
2758                            } => {
2759                                // Preserve table rows verbatim with their original indentation.
2760                                // Reflowing rows would corrupt column alignment and inject `|`
2761                                // characters mid-paragraph (issue #590).
2762                                // The leading blank line is emitted by the previous block.
2763                                for (idx, (content, orig_indent)) in table_lines.iter().enumerate() {
2764                                    if is_first_block && idx == 0 {
2765                                        // First line of first block gets the list marker
2766                                        result.push(format!(
2767                                            "{marker}{}",
2768                                            " ".repeat(orig_indent.saturating_sub(marker_len)) + content
2769                                        ));
2770                                        is_first_block = false;
2771                                    } else {
2772                                        // Shift nested table rows with the marker so they
2773                                        // stay aligned when MD030 widens marker spacing.
2774                                        result.push(format!(
2775                                            "{}{}",
2776                                            " ".repeat((*orig_indent as isize + code_indent_shift).max(0) as usize),
2777                                            content
2778                                        ));
2779                                    }
2780                                }
2781
2782                                // Add blank line after table block if there's a next block.
2783                                if block_idx < blocks.len() - 1 {
2784                                    let next_block = &blocks[block_idx + 1];
2785                                    let should_add_blank = match next_block {
2786                                        Block::Code {
2787                                            has_preceding_blank, ..
2788                                        } => *has_preceding_blank,
2789                                        Block::Html {
2790                                            has_preceding_blank, ..
2791                                        } => *has_preceding_blank,
2792                                        Block::Table {
2793                                            has_preceding_blank, ..
2794                                        } => *has_preceding_blank,
2795                                        Block::SnippetLine(_) | Block::DivMarker(_) => false,
2796                                        _ => true,
2797                                    };
2798                                    if should_add_blank && result.last().is_none_or(|s: &String| !s.is_empty()) {
2799                                        result.push(String::new());
2800                                    }
2801                                }
2802                            }
2803                            Block::Admonition {
2804                                header,
2805                                header_indent,
2806                                content_lines: admon_lines,
2807                            } => {
2808                                // Reconstruct admonition block with header at original indent
2809                                // and body content reflowed to fit within the line length limit
2810
2811                                // Add blank line before admonition if not first block
2812                                if !is_first_block && result.last().is_none_or(|s: &String| !s.is_empty()) {
2813                                    result.push(String::new());
2814                                }
2815
2816                                // Output the header at its original indent
2817                                let header_indent_str = " ".repeat(*header_indent);
2818                                if is_first_block {
2819                                    result.push(format!(
2820                                        "{marker}{}",
2821                                        " ".repeat(header_indent.saturating_sub(marker_len)) + header
2822                                    ));
2823                                    is_first_block = false;
2824                                } else {
2825                                    result.push(format!("{header_indent_str}{header}"));
2826                                }
2827
2828                                // Derive body indent from the first non-empty content line's
2829                                // stored indent, falling back to header_indent + 4 for
2830                                // empty-body admonitions
2831                                let body_indent = admon_lines
2832                                    .iter()
2833                                    .find(|(content, _)| !content.is_empty())
2834                                    .map_or(header_indent + 4, |(_, indent)| *indent);
2835                                let body_indent_str = " ".repeat(body_indent);
2836
2837                                // Segment body content into code blocks (verbatim) and
2838                                // text paragraphs (reflowable), separated by blank lines.
2839                                // Code lines store (content, orig_indent) to reconstruct
2840                                // internal indentation relative to body_indent.
2841                                enum AdmonSegment {
2842                                    Text(Vec<String>),
2843                                    Code(Vec<(String, usize)>),
2844                                }
2845
2846                                let mut segments: Vec<AdmonSegment> = Vec::new();
2847                                let mut current_text: Vec<String> = Vec::new();
2848                                let mut current_code: Vec<(String, usize)> = Vec::new();
2849                                let mut in_admon_code = false;
2850                                // Track the opening fence character so closing fences
2851                                // must match (backticks close backticks, tildes close tildes)
2852                                let mut fence_char: char = '`';
2853
2854                                // Opening fences: ``` or ~~~ followed by optional info string
2855                                let get_opening_fence = |s: &str| -> Option<(char, usize)> {
2856                                    let t = s.trim_start();
2857                                    if t.starts_with("```") {
2858                                        Some(('`', t.bytes().take_while(|&b| b == b'`').count()))
2859                                    } else if t.starts_with("~~~") {
2860                                        Some(('~', t.bytes().take_while(|&b| b == b'~').count()))
2861                                    } else {
2862                                        None
2863                                    }
2864                                };
2865                                // Closing fences: ONLY fence chars + optional trailing spaces
2866                                let get_closing_fence = |s: &str| -> Option<(char, usize)> {
2867                                    let t = s.trim();
2868                                    if t.starts_with("```") && t.bytes().all(|b| b == b'`') {
2869                                        Some(('`', t.len()))
2870                                    } else if t.starts_with("~~~") && t.bytes().all(|b| b == b'~') {
2871                                        Some(('~', t.len()))
2872                                    } else {
2873                                        None
2874                                    }
2875                                };
2876                                let mut fence_len: usize = 3;
2877
2878                                for (content, orig_indent) in admon_lines {
2879                                    if in_admon_code {
2880                                        // Closing fence must use the same character, be
2881                                        // at least as long, and have no info string
2882                                        if let Some((ch, len)) = get_closing_fence(content)
2883                                            && ch == fence_char
2884                                            && len >= fence_len
2885                                        {
2886                                            current_code.push((content.clone(), *orig_indent));
2887                                            in_admon_code = false;
2888                                            segments.push(AdmonSegment::Code(std::mem::take(&mut current_code)));
2889                                            continue;
2890                                        }
2891                                        current_code.push((content.clone(), *orig_indent));
2892                                    } else if let Some((ch, len)) = get_opening_fence(content) {
2893                                        if !current_text.is_empty() {
2894                                            segments.push(AdmonSegment::Text(std::mem::take(&mut current_text)));
2895                                        }
2896                                        in_admon_code = true;
2897                                        fence_char = ch;
2898                                        fence_len = len;
2899                                        current_code.push((content.clone(), *orig_indent));
2900                                    } else if content.is_empty() {
2901                                        if !current_text.is_empty() {
2902                                            segments.push(AdmonSegment::Text(std::mem::take(&mut current_text)));
2903                                        }
2904                                    } else {
2905                                        current_text.push(content.clone());
2906                                    }
2907                                }
2908                                if in_admon_code && !current_code.is_empty() {
2909                                    segments.push(AdmonSegment::Code(std::mem::take(&mut current_code)));
2910                                }
2911                                if !current_text.is_empty() {
2912                                    segments.push(AdmonSegment::Text(std::mem::take(&mut current_text)));
2913                                }
2914
2915                                // Build reflow options once for all text segments
2916                                let admon_reflow_length = if config.line_length.is_unlimited() {
2917                                    usize::MAX
2918                                } else {
2919                                    config.line_length.get().saturating_sub(body_indent).max(1)
2920                                };
2921
2922                                let admon_reflow_options = Self::reflow_options(ctx, config, admon_reflow_length);
2923
2924                                // Output each segment
2925                                for segment in &segments {
2926                                    // Blank line before each segment (after the header or previous segment)
2927                                    result.push(String::new());
2928
2929                                    match segment {
2930                                        AdmonSegment::Code(lines) => {
2931                                            for (line, orig_indent) in lines {
2932                                                if line.is_empty() {
2933                                                    // Preserve blank lines inside code blocks
2934                                                    result.push(String::new());
2935                                                } else {
2936                                                    // Reconstruct with body_indent + any extra
2937                                                    // indentation the line had beyond body_indent
2938                                                    let extra = orig_indent.saturating_sub(body_indent);
2939                                                    let indent_str = " ".repeat(body_indent + extra);
2940                                                    result.push(format!("{indent_str}{line}"));
2941                                                }
2942                                            }
2943                                        }
2944                                        AdmonSegment::Text(lines) => {
2945                                            let paragraph_text = lines.join(" ").trim().to_string();
2946                                            if paragraph_text.is_empty() {
2947                                                continue;
2948                                            }
2949                                            let reflowed = crate::utils::text_reflow::reflow_line(
2950                                                &paragraph_text,
2951                                                &admon_reflow_options,
2952                                            );
2953                                            for line in &reflowed {
2954                                                result.push(format!("{body_indent_str}{line}"));
2955                                            }
2956                                        }
2957                                    }
2958                                }
2959
2960                                // Add blank line after admonition if there's a next block
2961                                if block_idx < blocks.len() - 1 {
2962                                    let next_block = &blocks[block_idx + 1];
2963                                    let should_add_blank = match next_block {
2964                                        Block::Code {
2965                                            has_preceding_blank, ..
2966                                        } => *has_preceding_blank,
2967                                        Block::Table {
2968                                            has_preceding_blank, ..
2969                                        } => *has_preceding_blank,
2970                                        Block::SnippetLine(_) | Block::DivMarker(_) => false,
2971                                        _ => true,
2972                                    };
2973                                    if should_add_blank && result.last().is_none_or(|s: &String| !s.is_empty()) {
2974                                        result.push(String::new());
2975                                    }
2976                                }
2977                            }
2978                        }
2979                    }
2980
2981                    let reflowed_text = result.join(line_ending);
2982
2983                    // Preserve trailing newline
2984                    let replacement = if end_line < lines.len() - 1 || ctx.content.ends_with('\n') {
2985                        format!("{reflowed_text}{line_ending}")
2986                    } else {
2987                        reflowed_text
2988                    };
2989
2990                    // Get the original text to compare
2991                    let original_text = &ctx.content[byte_range.clone()];
2992
2993                    // Physical-line-length scan, shared by the Normalize-mode gate and its
2994                    // message. The list-item reflow preserves code blocks, HTML blocks,
2995                    // admonition headers, fence markers, semantic markers, and snippet/div
2996                    // markers verbatim; only paragraph content and admonition bodies are
2997                    // restructured. Only those lines drive the length warning, so that
2998                    // preserved-but-overlong content does not keep the paragraph-level
2999                    // warning alive when the reflow would not fix that line.
3000                    let should_count_for_length = |line_idx: usize| -> bool {
3001                        let line = lines[line_idx];
3002                        let trimmed = line.trim();
3003                        if trimmed.is_empty() || is_exempt_line(line) {
3004                            return false;
3005                        }
3006                        let info = &ctx.lines[line_idx];
3007                        if info.in_code_block || info.in_html_block {
3008                            return false;
3009                        }
3010                        if info.in_admonition && mkdocs_admonitions::is_admonition_start(line) {
3011                            return false;
3012                        }
3013                        if is_fence_marker(line) || is_semantic_line(line) {
3014                            return false;
3015                        }
3016                        if is_snippet_block_delimiter(line) {
3017                            return false;
3018                        }
3019                        if line.trim_start().starts_with(":::") {
3020                            return false;
3021                        }
3022                        true
3023                    };
3024                    let max_physical_length = (list_start..i)
3025                        .filter(|&idx| should_count_for_length(idx))
3026                        .map(|idx| self.calculate_effective_length(lines[idx]))
3027                        .max()
3028                        .unwrap_or(0);
3029                    // `line-length = 0` means "no limit", so no physical line can be
3030                    // "over"; the message below then describes a structural join rather
3031                    // than a length violation.
3032                    let any_paragraph_line_over =
3033                        !config.line_length.is_unlimited() && max_physical_length > config.line_length.get();
3034
3035                    // Normalize mode reflows list-item prose just like paragraphs:
3036                    // joining continuation lines and re-wrapping to `line-length`.
3037                    // `prose_changed` is true only when the reflow alters the words or
3038                    // line breaks, not when it would merely re-indent continuation
3039                    // lines or trim trailing whitespace. Comparing the texts with each
3040                    // line's leading and trailing whitespace removed isolates "did the
3041                    // words/line breaks change" from "did the surrounding whitespace
3042                    // change". Continuation indentation is MD077's responsibility and
3043                    // trailing whitespace is MD009's; an MD013 warning for either would
3044                    // both duplicate those rules and resurface a persistent advisory on
3045                    // already-fitting items that users disable MD013 fixing to avoid.
3046                    let prose_changed = {
3047                        let stripped = |text: &str| text.lines().map(str::trim).collect::<Vec<_>>().join("\n");
3048                        stripped(original_text) != stripped(&replacement)
3049                    };
3050                    // Warn when the reflow rewraps prose (the normalize feature for
3051                    // list items), or when a physical line genuinely exceeds the limit
3052                    // and the reflow can change something (a true length violation,
3053                    // even if all that changes is the continuation indent). A line that
3054                    // is already optimal in both respects produces no warning.
3055                    let gate_ok = prose_changed || (any_paragraph_line_over && original_text != replacement);
3056                    if gate_ok {
3057                        // Generate an appropriate message based on why reflow is needed
3058                        let message = match config.reflow_mode {
3059                            ReflowMode::SentencePerLine => {
3060                                let num_sentences = split_into_sentences(&combined_content).len();
3061                                let num_lines = content_lines.len();
3062                                if num_lines == 1 {
3063                                    // Single line with multiple sentences
3064                                    format!("Line contains {num_sentences} sentences (one sentence per line required)")
3065                                } else {
3066                                    // Multiple lines - could be split sentences or mixed
3067                                    format!(
3068                                        "Paragraph should have one sentence per line (found {num_sentences} sentences across {num_lines} lines)"
3069                                    )
3070                                }
3071                            }
3072                            ReflowMode::SemanticLineBreaks => {
3073                                let num_sentences = split_into_sentences(&combined_content).len();
3074                                format!("Paragraph should use semantic line breaks ({num_sentences} sentences)")
3075                            }
3076                            ReflowMode::Normalize => {
3077                                // When a physical line genuinely exceeds the limit, report
3078                                // it as a length violation. Otherwise the reflow is a
3079                                // structural normalization (joining/re-wrapping multi-line
3080                                // content that already fits), mirroring the paragraph path.
3081                                if any_paragraph_line_over {
3082                                    format!(
3083                                        "Line length {} exceeds {} characters",
3084                                        max_physical_length,
3085                                        config.line_length.get()
3086                                    )
3087                                } else {
3088                                    format!(
3089                                        "List item could be normalized to use line length of {} characters",
3090                                        config.line_length.get()
3091                                    )
3092                                }
3093                            }
3094                            ReflowMode::Default => {
3095                                // Report the actual longest non-exempt line, not the combined content
3096                                let max_length = (list_start..i)
3097                                    .filter(|&line_idx| {
3098                                        let line = lines[line_idx];
3099                                        let trimmed = line.trim();
3100                                        !trimmed.is_empty() && !is_exempt_line(line)
3101                                    })
3102                                    .map(|line_idx| self.calculate_effective_length(lines[line_idx]))
3103                                    .max()
3104                                    .unwrap_or(0);
3105                                format!(
3106                                    "Line length {} exceeds {} characters",
3107                                    max_length,
3108                                    config.line_length.get()
3109                                )
3110                            }
3111                        };
3112
3113                        warnings.push(LintWarning {
3114                            rule_name: Some(self.name().to_string()),
3115                            message,
3116                            line: list_start + 1,
3117                            column: 1,
3118                            end_line: end_line + 1,
3119                            end_column: lines[end_line].chars().count() + 1,
3120                            severity: Severity::Warning,
3121                            fix: Some(crate::rule::Fix::new(byte_range, replacement)),
3122                        });
3123                    }
3124                }
3125                continue;
3126            }
3127
3128            // Found start of a paragraph - collect all lines in it
3129            let paragraph_start = i;
3130            let mut paragraph_lines = vec![lines[i]];
3131            i += 1;
3132
3133            while i < lines.len() {
3134                let next_line = lines[i];
3135                let next_line_num = i + 1;
3136                let next_trimmed = next_line.trim();
3137
3138                // Stop at paragraph boundaries
3139                if next_trimmed.is_empty()
3140                    || ctx.line_info(next_line_num).is_some_and(|info| info.in_code_block)
3141                    || ctx.line_info(next_line_num).is_some_and(|info| info.in_front_matter)
3142                    || ctx.line_info(next_line_num).is_some_and(|info| info.in_html_block)
3143                    || ctx.line_info(next_line_num).is_some_and(|info| info.in_html_comment)
3144                    || ctx.line_info(next_line_num).is_some_and(|info| info.in_esm_block)
3145                    || ctx.line_info(next_line_num).is_some_and(|info| info.in_jsx_expression)
3146                    || ctx.line_info(next_line_num).is_some_and(|info| info.in_jsx_block)
3147                    || ctx.line_info(next_line_num).is_some_and(|info| info.in_mdx_comment)
3148                    || ctx
3149                        .line_info(next_line_num)
3150                        .is_some_and(super::super::lint_context::types::LineInfo::in_mkdocs_container)
3151                    || (next_line_num > 0
3152                        && next_line_num <= ctx.lines.len()
3153                        && ctx.lines[next_line_num - 1].blockquote.is_some())
3154                    || next_trimmed.starts_with('#')
3155                    || TableUtils::is_potential_table_row(next_line)
3156                    || is_list_item(next_trimmed)
3157                    || is_horizontal_rule(next_line)
3158                    || (next_trimmed.starts_with('[') && next_line.contains("]:"))
3159                    || is_template_directive_only(next_line)
3160                    || is_standalone_attr_list(next_line)
3161                    || is_snippet_block_delimiter(next_line)
3162                    || ctx.line_info(next_line_num).is_some_and(|info| info.is_div_marker)
3163                    || is_html_only_line(next_line)
3164                    || (!config.strict && is_standalone_link_or_image_line(next_line))
3165                {
3166                    break;
3167                }
3168
3169                // Check if the previous line ends with a hard break (2+ spaces or backslash)
3170                if i > 0 && has_hard_break(lines[i - 1]) {
3171                    // Don't include lines after hard breaks in the same paragraph
3172                    break;
3173                }
3174
3175                paragraph_lines.push(next_line);
3176                i += 1;
3177            }
3178
3179            // Compute the common leading indent of all non-empty paragraph lines,
3180            // but only when those lines are structurally inside a list block.
3181            // Indented continuation lines that follow a nested list arrive here
3182            // with their structural indentation intact (e.g. 2 spaces for a
3183            // top-level list item). Stripping the indent before reflow and
3184            // re-applying it afterward prevents the fixer from moving those
3185            // lines to column 0.
3186            //
3187            // The list-block guard is essential: top-level paragraphs that happen
3188            // to start with spaces (insignificant in Markdown) must NOT have those
3189            // spaces preserved or injected by the fixer.
3190            let common_indent: String = if ctx.is_in_list_block(paragraph_start + 1) {
3191                let min_len = paragraph_lines
3192                    .iter()
3193                    .filter(|l| !l.trim().is_empty())
3194                    .map(|l| l.len() - l.trim_start().len())
3195                    .min()
3196                    .unwrap_or(0);
3197                paragraph_lines
3198                    .iter()
3199                    .find(|l| !l.trim().is_empty())
3200                    .map(|l| l[..min_len].to_string())
3201                    .unwrap_or_default()
3202            } else {
3203                String::new()
3204            };
3205
3206            // Combine paragraph lines into a single string for processing.
3207            // This must be done BEFORE the needs_reflow check for sentence-per-line mode.
3208            let paragraph_text = if common_indent.is_empty() {
3209                paragraph_lines.join(" ")
3210            } else {
3211                paragraph_lines
3212                    .iter()
3213                    .map(|l| {
3214                        if l.starts_with(common_indent.as_str()) {
3215                            &l[common_indent.len()..]
3216                        } else {
3217                            l.trim_start()
3218                        }
3219                    })
3220                    .collect::<Vec<_>>()
3221                    .join(" ")
3222            };
3223
3224            // Skip reflowing if this paragraph contains definition list items
3225            // Definition lists are multi-line structures that should not be joined
3226            let contains_definition_list = paragraph_lines
3227                .iter()
3228                .any(|line| crate::utils::is_definition_list_item(line));
3229
3230            if contains_definition_list {
3231                // Don't reflow definition lists - skip this paragraph
3232                i = paragraph_start + paragraph_lines.len();
3233                continue;
3234            }
3235
3236            // Skip reflowing if this paragraph contains MkDocs Snippets markers
3237            // Snippets blocks (-8<- ... -8<-) should be preserved exactly
3238            let contains_snippets = paragraph_lines.iter().any(|line| is_snippet_block_delimiter(line));
3239
3240            if contains_snippets {
3241                // Don't reflow Snippets blocks - skip this paragraph
3242                i = paragraph_start + paragraph_lines.len();
3243                continue;
3244            }
3245
3246            // Check if this paragraph needs reflowing
3247            let needs_reflow = match config.reflow_mode {
3248                ReflowMode::Normalize => self.normalize_mode_needs_reflow(paragraph_lines.iter().copied(), config),
3249                ReflowMode::SentencePerLine => {
3250                    // In sentence-per-line mode, check if the JOINED paragraph has multiple sentences
3251                    // Note: we check the joined text because sentences can span multiple lines
3252                    let sentences = split_into_sentences(&paragraph_text);
3253
3254                    // Always reflow if multiple sentences on one line
3255                    if sentences.len() > 1 {
3256                        true
3257                    } else if paragraph_lines.len() > 1 {
3258                        // For single-sentence paragraphs spanning multiple lines:
3259                        // Reflow if they COULD fit on one line (respecting line-length constraint)
3260                        if config.line_length.is_unlimited() {
3261                            // No line-length constraint - always join single sentences
3262                            true
3263                        } else {
3264                            // Only join if it fits within line-length.
3265                            // paragraph_text has the common indent stripped, so add it
3266                            // back to get the true output length before comparing.
3267                            let effective_length =
3268                                self.calculate_effective_length(&paragraph_text) + common_indent.len();
3269                            effective_length <= config.line_length.get()
3270                        }
3271                    } else {
3272                        false
3273                    }
3274                }
3275                ReflowMode::SemanticLineBreaks => {
3276                    let sentences = split_into_sentences(&paragraph_text);
3277                    // Reflow if multiple sentences, multiple lines, or any line exceeds limit
3278                    sentences.len() > 1
3279                        || paragraph_lines.len() > 1
3280                        || paragraph_lines
3281                            .iter()
3282                            .any(|line| self.calculate_effective_length(line) > config.line_length.get())
3283                }
3284                ReflowMode::Default => {
3285                    // In default mode, only reflow if lines exceed limit
3286                    paragraph_lines
3287                        .iter()
3288                        .any(|line| self.calculate_effective_length(line) > config.line_length.get())
3289                }
3290            };
3291
3292            if needs_reflow {
3293                // Calculate byte range for this paragraph
3294                // Use whole_line_range for each line and combine
3295                let start_range = line_index.whole_line_range(paragraph_start + 1);
3296                let end_line = paragraph_start + paragraph_lines.len() - 1;
3297
3298                // For the last line, we want to preserve any trailing newline
3299                let end_range = if end_line == lines.len() - 1 && !ctx.content.ends_with('\n') {
3300                    // Last line without trailing newline - use line_text_range
3301                    line_index.line_text_range(end_line + 1, 1, lines[end_line].len() + 1)
3302                } else {
3303                    // Not the last line or has trailing newline - use whole_line_range
3304                    line_index.whole_line_range(end_line + 1)
3305                };
3306
3307                let byte_range = start_range.start..end_range.end;
3308
3309                // Check if the paragraph ends with a hard break and what type
3310                let hard_break_type = paragraph_lines.last().and_then(|line| {
3311                    let line = line.strip_suffix('\r').unwrap_or(line);
3312                    if line.ends_with('\\') {
3313                        Some("\\")
3314                    } else if line.ends_with("  ") {
3315                        Some("  ")
3316                    } else {
3317                        None
3318                    }
3319                });
3320
3321                // Reflow the paragraph
3322                // When line_length = 0 (no limit), use a very large value for reflow
3323                let reflow_line_length = if config.line_length.is_unlimited() {
3324                    usize::MAX
3325                } else {
3326                    config.line_length.get()
3327                };
3328                let reflow_options = Self::reflow_options(ctx, config, reflow_line_length);
3329                let mut reflowed = crate::utils::text_reflow::reflow_line(&paragraph_text, &reflow_options);
3330
3331                // Re-apply the common indent to each non-empty reflowed line so
3332                // that the replacement preserves the original structural indentation.
3333                if !common_indent.is_empty() {
3334                    for line in &mut reflowed {
3335                        if !line.is_empty() {
3336                            *line = format!("{common_indent}{line}");
3337                        }
3338                    }
3339                }
3340
3341                // If the original paragraph ended with a hard break, preserve it
3342                // Preserve the original hard break format (backslash or two spaces)
3343                if let Some(break_marker) = hard_break_type
3344                    && !reflowed.is_empty()
3345                {
3346                    let last_idx = reflowed.len() - 1;
3347                    if !has_hard_break(&reflowed[last_idx]) {
3348                        reflowed[last_idx].push_str(break_marker);
3349                    }
3350                }
3351
3352                let reflowed_text = reflowed.join(line_ending);
3353
3354                // Preserve trailing newline if the original paragraph had one
3355                let replacement = if end_line < lines.len() - 1 || ctx.content.ends_with('\n') {
3356                    format!("{reflowed_text}{line_ending}")
3357                } else {
3358                    reflowed_text
3359                };
3360
3361                // Get the original text to compare
3362                let original_text = &ctx.content[byte_range.clone()];
3363
3364                // Only generate a warning if the replacement is different from the original
3365                if original_text != replacement {
3366                    // Determine which line ranges and messages to report based on the reflow mode.
3367                    let warnings_to_report: Vec<(usize, usize, String)> = match config.reflow_mode {
3368                        ReflowMode::Default => {
3369                            // In default mode, report a warning for *every* line in the paragraph
3370                            // that exceeds the limit. Each warning will carry the same paragraph-level
3371                            // fix, making all of them auto-fixable.
3372                            paragraph_lines
3373                                .iter()
3374                                .enumerate()
3375                                .filter(|(_, line)| self.calculate_effective_length(line) > config.line_length.get())
3376                                .map(|(idx, _)| {
3377                                    let violating_line = paragraph_start + idx + 1;
3378                                    (
3379                                        violating_line,
3380                                        violating_line,
3381                                        format!("Line length exceeds {} characters", config.line_length.get()),
3382                                    )
3383                                })
3384                                .collect()
3385                        }
3386                        ReflowMode::Normalize => {
3387                            // In normalize mode, report the whole paragraph as needing normalization.
3388                            vec![(
3389                                paragraph_start + 1,
3390                                end_line + 1,
3391                                format!(
3392                                    "Paragraph could be normalized to use line length of {} characters",
3393                                    config.line_length.get()
3394                                ),
3395                            )]
3396                        }
3397                        ReflowMode::SentencePerLine => {
3398                            // In sentence-per-line mode, highlight the entire paragraph that needs reformatting.
3399                            let num_sentences = split_into_sentences(&paragraph_text).len();
3400                            let message = if paragraph_lines.len() == 1 {
3401                                // Single line with multiple sentences
3402                                format!("Line contains {num_sentences} sentences (one sentence per line required)")
3403                            } else {
3404                                // Multiple lines - could be split sentences or mixed
3405                                let num_lines = paragraph_lines.len();
3406                                format!(
3407                                    "Paragraph should have one sentence per line (found {num_sentences} sentences across {num_lines} lines)"
3408                                )
3409                            };
3410                            vec![(paragraph_start + 1, paragraph_start + paragraph_lines.len(), message)]
3411                        }
3412                        ReflowMode::SemanticLineBreaks => {
3413                            // In semantic-line-breaks mode, highlight the entire paragraph.
3414                            let num_sentences = split_into_sentences(&paragraph_text).len();
3415                            vec![(
3416                                paragraph_start + 1,
3417                                paragraph_start + paragraph_lines.len(),
3418                                format!("Paragraph should use semantic line breaks ({num_sentences} sentences)"),
3419                            )]
3420                        }
3421                    };
3422
3423                    // Generate the actual lint warnings. All warnings for this paragraph
3424                    // share the same paragraph-level fix.
3425                    for (w_start, w_end, msg) in warnings_to_report {
3426                        warnings.push(LintWarning {
3427                            rule_name: Some(self.name().to_string()),
3428                            message: msg,
3429                            line: w_start,
3430                            column: 1,
3431                            end_line: w_end,
3432                            end_column: lines[w_end.saturating_sub(1)].chars().count() + 1,
3433                            severity: Severity::Warning,
3434                            fix: Some(crate::rule::Fix::new(byte_range.clone(), replacement.clone())),
3435                        });
3436                    }
3437                }
3438            }
3439        }
3440
3441        warnings
3442    }
3443
3444    /// Calculate string length based on the configured length mode
3445    fn calculate_string_length(&self, s: &str) -> usize {
3446        match self.config.length_mode {
3447            LengthMode::Chars => s.chars().count(),
3448            LengthMode::Visual => s.width(),
3449            LengthMode::Bytes => s.len(),
3450        }
3451    }
3452
3453    /// Calculate effective line length
3454    ///
3455    /// Returns the actual display length of the line using the configured length mode.
3456    fn calculate_effective_length(&self, line: &str) -> usize {
3457        self.calculate_string_length(line)
3458    }
3459
3460    /// Calculate line length with inline link/image URLs removed.
3461    ///
3462    /// For each inline link `[text](url)` or image `![alt](url)` on the line,
3463    /// computes the "savings" from removing the URL portion (keeping only `[text]`
3464    /// or `![alt]`). Returns `effective_length - total_savings`.
3465    ///
3466    /// Handles nested constructs (e.g., `[![img](url)](url)`) by only counting the
3467    /// outermost construct to avoid double-counting.
3468    fn length_without_inline_link_urls(
3469        &self,
3470        effective_length: usize,
3471        line_number: usize,
3472        ctx: &crate::lint_context::LintContext,
3473    ) -> usize {
3474        let line_range = ctx.line_index.line_content_range(line_number);
3475        let line_byte_end = line_range.end;
3476
3477        // Collect inline links/images on this line: (byte_offset, byte_end, text_only_display_len)
3478        let mut constructs: Vec<(usize, usize, usize)> = Vec::new();
3479
3480        // Binary search: links are sorted by byte_offset, so link.line is non-decreasing
3481        let link_start = ctx.links.partition_point(|l| l.line < line_number);
3482        for link in &ctx.links[link_start..] {
3483            if link.line != line_number {
3484                break;
3485            }
3486            if link.is_reference {
3487                continue;
3488            }
3489            if !matches!(link.link_type, LinkType::Inline) {
3490                continue;
3491            }
3492            if link.byte_end > line_byte_end {
3493                continue;
3494            }
3495            let text_only_len = 2 + self.calculate_string_length(&link.text);
3496            constructs.push((link.byte_offset, link.byte_end, text_only_len));
3497        }
3498
3499        let img_start = ctx.images.partition_point(|i| i.line < line_number);
3500        for image in &ctx.images[img_start..] {
3501            if image.line != line_number {
3502                break;
3503            }
3504            if image.is_reference {
3505                continue;
3506            }
3507            if !matches!(image.link_type, LinkType::Inline) {
3508                continue;
3509            }
3510            if image.byte_end > line_byte_end {
3511                continue;
3512            }
3513            let text_only_len = 3 + self.calculate_string_length(&image.alt_text);
3514            constructs.push((image.byte_offset, image.byte_end, text_only_len));
3515        }
3516
3517        if constructs.is_empty() {
3518            return effective_length;
3519        }
3520
3521        // Sort by byte offset to handle overlapping/nested constructs
3522        constructs.sort_by_key(|&(start, _, _)| start);
3523
3524        let mut total_savings: usize = 0;
3525        let mut last_end: usize = 0;
3526
3527        for (start, end, text_only_len) in &constructs {
3528            // Skip constructs nested inside a previously counted one
3529            if *start < last_end {
3530                continue;
3531            }
3532            // Full construct length in configured length mode
3533            let full_source = &ctx.content[*start..*end];
3534            let full_len = self.calculate_string_length(full_source);
3535            total_savings += full_len.saturating_sub(*text_only_len);
3536            last_end = *end;
3537        }
3538
3539        effective_length.saturating_sub(total_savings)
3540    }
3541}