Skip to main content

rumdl_lib/rules/md013_line_length/
mod.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, ReflowLengthMode, blockquote_continuation_style, dominant_blockquote_prefix,
16    reflow_blockquote_content, split_into_sentences,
17};
18use pulldown_cmark::LinkType;
19use toml;
20
21mod block_builder;
22mod helpers;
23pub mod md013_config;
24use crate::utils::is_template_directive_only;
25use block_builder::{Block, BlockBuilder};
26use helpers::{
27    extract_list_marker_and_content, has_hard_break, is_github_alert_marker, is_horizontal_rule, is_html_only_line,
28    is_list_item, is_standalone_link_or_image_line, is_unwrappable_line, split_into_segments,
29    trim_preserving_hard_break,
30};
31pub use md013_config::MD013Config;
32use md013_config::{LengthMode, ReflowMode};
33
34#[cfg(test)]
35mod tests;
36use unicode_width::UnicodeWidthStr;
37
38#[derive(Clone, Default)]
39pub struct MD013LineLength {
40    pub(crate) config: MD013Config,
41}
42
43/// Blockquote paragraph line collected for reflow, with original line index for range computation.
44struct CollectedBlockquoteLine {
45    line_idx: usize,
46    data: BlockquoteLineData,
47}
48
49impl MD013LineLength {
50    pub fn new(line_length: usize, code_blocks: bool, tables: bool, headings: bool, strict: bool) -> Self {
51        Self {
52            config: MD013Config {
53                line_length: crate::types::LineLength::new(line_length),
54                code_blocks,
55                tables,
56                headings,
57                paragraphs: true,  // Default to true for backwards compatibility
58                blockquotes: true, // Default to true for backwards compatibility
59                strict,
60                stern: false,
61                heading_line_length: None,
62                code_block_line_length: None,
63                reflow: false,
64                reflow_mode: ReflowMode::default(),
65                length_mode: LengthMode::default(),
66                abbreviations: Vec::new(),
67                require_sentence_capital: true,
68            },
69        }
70    }
71
72    pub fn from_config_struct(config: MD013Config) -> Self {
73        Self { config }
74    }
75
76    /// Return a clone with code block checking disabled.
77    /// Used for doc comment linting where code blocks are Rust code managed by rustfmt.
78    pub fn with_code_blocks_disabled(&self) -> Self {
79        let mut clone = self.clone();
80        clone.config.code_blocks = false;
81        clone
82    }
83
84    /// Convert MD013 LengthMode to text_reflow ReflowLengthMode
85    fn reflow_length_mode(&self) -> ReflowLengthMode {
86        match self.config.length_mode {
87            LengthMode::Chars => ReflowLengthMode::Chars,
88            LengthMode::Visual => ReflowLengthMode::Visual,
89            LengthMode::Bytes => ReflowLengthMode::Bytes,
90        }
91    }
92
93    fn should_ignore_line(
94        &self,
95        line: &str,
96        _lines: &[&str],
97        current_line: usize,
98        ctx: &crate::lint_context::LintContext,
99    ) -> bool {
100        if self.config.strict {
101            return false;
102        }
103
104        // Quick check for common patterns before expensive regex
105        let trimmed = line.trim();
106
107        // Only skip if the entire line is a URL (quick check first)
108        if (trimmed.starts_with("http://") || trimmed.starts_with("https://")) && URL_PATTERN.is_match(trimmed) {
109            return true;
110        }
111
112        // Only skip if the entire line is an image reference (quick check first)
113        if trimmed.starts_with("![") && trimmed.ends_with(']') && IMAGE_REF_PATTERN.is_match(trimmed) {
114            return true;
115        }
116
117        // Note: link reference definitions are handled as always-exempt (even in strict mode)
118        // in the main check loop, so they don't need to be checked here.
119
120        // Code blocks with long strings (only check if in code block)
121        if ctx.line_info(current_line + 1).is_some_and(|info| info.in_code_block)
122            && !trimmed.is_empty()
123            && !line.contains(' ')
124            && !line.contains('\t')
125        {
126            return true;
127        }
128
129        false
130    }
131
132    /// Check if rule should skip based on provided config (used for inline config support)
133    fn should_skip_with_config(&self, ctx: &crate::lint_context::LintContext, config: &MD013Config) -> bool {
134        // Skip if content is empty
135        if ctx.content.is_empty() {
136            return true;
137        }
138
139        // For sentence-per-line, semantic-line-breaks, or normalize mode, never skip based on line length
140        if config.reflow
141            && (config.reflow_mode == ReflowMode::SentencePerLine
142                || config.reflow_mode == ReflowMode::SemanticLineBreaks
143                || config.reflow_mode == ReflowMode::Normalize)
144        {
145            return false;
146        }
147
148        // Use the smallest applicable budget across line/heading/code-block
149        // contexts so a stricter context-specific limit doesn't get masked by
150        // the document-wide budget.
151        let min_limit = config.min_effective_line_length();
152        if min_limit.is_unlimited() {
153            return true;
154        }
155        let min_limit_bytes = min_limit.get();
156
157        // Quick check: if total content is shorter than the smallest line limit,
158        // definitely skip.
159        if ctx.content.len() <= min_limit_bytes {
160            return true;
161        }
162
163        // Skip if no line exceeds the smallest applicable limit.
164        !ctx.lines.iter().any(|line| line.byte_len > min_limit_bytes)
165    }
166
167    fn normalize_mode_needs_reflow<'a, I>(&self, lines: I, config: &MD013Config) -> bool
168    where
169        I: IntoIterator<Item = &'a str>,
170    {
171        let mut line_count = 0;
172        let check_length = !config.line_length.is_unlimited();
173
174        for line in lines {
175            line_count += 1;
176            if check_length && self.calculate_effective_length(line) > config.line_length.get() {
177                return true;
178            }
179        }
180
181        line_count > 1
182    }
183}
184
185impl Rule for MD013LineLength {
186    fn name(&self) -> &'static str {
187        "MD013"
188    }
189
190    fn description(&self) -> &'static str {
191        "Line length should not be excessive"
192    }
193
194    fn check(&self, ctx: &crate::lint_context::LintContext) -> LintResult {
195        // Use pre-parsed inline config from LintContext
196        let config_override = ctx.inline_config().get_rule_config("MD013");
197
198        // Apply configuration override if present
199        let effective_config = if let Some(json_config) = config_override {
200            if let Some(obj) = json_config.as_object() {
201                let mut config = self.config.clone();
202                if let Some(line_length) = obj.get("line_length").and_then(serde_json::Value::as_u64) {
203                    config.line_length = crate::types::LineLength::new(line_length as usize);
204                }
205                if let Some(code_blocks) = obj.get("code_blocks").and_then(serde_json::Value::as_bool) {
206                    config.code_blocks = code_blocks;
207                }
208                if let Some(tables) = obj.get("tables").and_then(serde_json::Value::as_bool) {
209                    config.tables = tables;
210                }
211                if let Some(headings) = obj.get("headings").and_then(serde_json::Value::as_bool) {
212                    config.headings = headings;
213                }
214                if let Some(blockquotes) = obj.get("blockquotes").and_then(serde_json::Value::as_bool) {
215                    config.blockquotes = blockquotes;
216                }
217                if let Some(strict) = obj.get("strict").and_then(serde_json::Value::as_bool) {
218                    config.strict = strict;
219                }
220                if let Some(reflow) = obj.get("reflow").and_then(serde_json::Value::as_bool) {
221                    config.reflow = reflow;
222                }
223                if let Some(reflow_mode) = obj.get("reflow_mode").and_then(|v| v.as_str()) {
224                    config.reflow_mode = match reflow_mode {
225                        "default" => ReflowMode::Default,
226                        "normalize" => ReflowMode::Normalize,
227                        "sentence-per-line" => ReflowMode::SentencePerLine,
228                        "semantic-line-breaks" => ReflowMode::SemanticLineBreaks,
229                        _ => ReflowMode::default(),
230                    };
231                }
232                config
233            } else {
234                self.config.clone()
235            }
236        } else {
237            self.config.clone()
238        };
239
240        // Fast early return using should_skip with EFFECTIVE config (after inline overrides)
241        // But don't skip if we're in reflow mode with Normalize or SentencePerLine
242        if self.should_skip_with_config(ctx, &effective_config)
243            && !(effective_config.reflow
244                && (effective_config.reflow_mode == ReflowMode::Normalize
245                    || effective_config.reflow_mode == ReflowMode::SentencePerLine
246                    || effective_config.reflow_mode == ReflowMode::SemanticLineBreaks))
247        {
248            return Ok(Vec::new());
249        }
250
251        // Direct implementation without DocumentStructure
252        let mut warnings = Vec::new();
253
254        // Special handling: line_length = 0 means "no line length limit"
255        // Skip all line length checks, but still allow reflow if enabled
256        let skip_length_checks = effective_config.line_length.is_unlimited();
257
258        // Pre-filter lines that could be problematic to avoid processing all lines.
259        // Use the smallest applicable budget across line/heading/code-block contexts
260        // so candidates aren't dropped when a stricter context-specific budget applies.
261        let prefilter_limit = effective_config.min_effective_line_length();
262        let prefilter_skip = prefilter_limit.is_unlimited();
263        let mut candidate_lines = Vec::new();
264        if !skip_length_checks && !prefilter_skip {
265            for (line_idx, line_info) in ctx.lines.iter().enumerate() {
266                // Skip front matter - it should never be linted
267                if line_info.in_front_matter {
268                    continue;
269                }
270
271                // Quick length check first
272                if line_info.byte_len > prefilter_limit.get() {
273                    candidate_lines.push(line_idx);
274                }
275            }
276        }
277
278        // If no candidate lines and not in normalize or sentence-per-line mode, early return
279        if candidate_lines.is_empty()
280            && !(effective_config.reflow
281                && (effective_config.reflow_mode == ReflowMode::Normalize
282                    || effective_config.reflow_mode == ReflowMode::SentencePerLine
283                    || effective_config.reflow_mode == ReflowMode::SemanticLineBreaks))
284        {
285            return Ok(warnings);
286        }
287
288        let lines = ctx.raw_lines();
289
290        // Create a quick lookup set for heading lines
291        // We need this for both the heading skip check AND the paragraphs check
292        let heading_lines_set: std::collections::HashSet<usize> = ctx
293            .lines
294            .iter()
295            .enumerate()
296            .filter(|(_, line)| line.heading.is_some())
297            .map(|(idx, _)| idx + 1)
298            .collect();
299
300        // Use pre-computed table blocks from context
301        // We need this for both the table skip check AND the paragraphs check
302        let table_blocks = &ctx.table_blocks;
303        let mut table_lines_set = std::collections::HashSet::new();
304        for table in table_blocks {
305            table_lines_set.insert(table.header_line + 1);
306            table_lines_set.insert(table.delimiter_line + 1);
307            for &line in &table.content_lines {
308                table_lines_set.insert(line + 1);
309            }
310        }
311
312        // Process candidate lines for line length checks
313        'line_loop: for &line_idx in &candidate_lines {
314            let line_number = line_idx + 1;
315            let line = lines[line_idx];
316
317            // Calculate actual line length (used in warning messages)
318            let effective_length = self.calculate_effective_length(line);
319
320            // Pick the context-specific limit: heading > code-block > paragraph.
321            // Headings dominate over code-block context if a setext underline ever
322            // overlaps a fenced range (defensive — these are mutually exclusive in
323            // practice, but the explicit ordering documents intent).
324            let is_heading_line = heading_lines_set.contains(&line_number);
325            let in_code_block = ctx.line_info(line_number).is_some_and(|info| info.in_code_block);
326            let line_limit = if is_heading_line {
327                effective_config.effective_heading_line_length().get()
328            } else if in_code_block {
329                effective_config.effective_code_block_line_length().get()
330            } else {
331                effective_config.line_length.get()
332            };
333
334            // A context-specific limit of 0 means "unlimited for this context".
335            if line_limit == 0 {
336                continue;
337            }
338
339            // Stern mode: like default, but the trailing-token forgiveness is
340            // disabled — a line with whitespace that exceeds the limit is a
341            // violation even if the excess is the final token. The "unwrappable"
342            // line exemption (single token, optionally prefixed by # or >) is
343            // still honored. Strict overrides stern entirely.
344            if effective_config.stern && !effective_config.strict && is_unwrappable_line(line) {
345                continue;
346            }
347
348            // Trailing-token forgiveness: only in default mode (not strict, not stern).
349            // If the line only exceeds the limit because of a long token at the end
350            // (URL, link chain, identifier), it passes. This matches markdownlint's
351            // behavior: line.replace(/\S*$/u, "#")
352            let check_length = if effective_config.strict || effective_config.stern {
353                effective_length
354            } else {
355                match line.rfind(char::is_whitespace) {
356                    Some(pos) => {
357                        let ws_char = line[pos..].chars().next().unwrap();
358                        let prefix_end = pos + ws_char.len_utf8();
359                        self.calculate_string_length(&line[..prefix_end]) + 1
360                    }
361                    None => 1, // No whitespace — entire line is a single token
362                }
363            };
364
365            // Skip lines where the check length is within the limit
366            if check_length <= line_limit {
367                continue;
368            }
369
370            // Semantic link understanding: suppress when excess comes entirely from inline URLs
371            if !effective_config.strict {
372                let text_only_length = self.calculate_text_only_length(effective_length, line_number, ctx);
373                if text_only_length <= line_limit {
374                    continue;
375                }
376            }
377
378            // Skip mkdocstrings and pymdown blocks (already handled by LintContext)
379            if ctx.lines[line_idx].in_mkdocstrings || ctx.lines[line_idx].in_pymdown_block {
380                continue;
381            }
382
383            // Link reference definitions are always exempt, even in strict mode.
384            // There's no way to shorten them without breaking the URL.
385            // Also check after stripping list markers, since list items may
386            // contain link ref defs as their content.
387            {
388                let trimmed = line.trim();
389                if trimmed.starts_with('[') && trimmed.contains("]:") && LINK_REF_PATTERN.is_match(trimmed) {
390                    continue;
391                }
392                if is_list_item(trimmed) {
393                    let (_, content) = extract_list_marker_and_content(trimmed);
394                    let content_trimmed = content.trim();
395                    if content_trimmed.starts_with('[')
396                        && content_trimmed.contains("]:")
397                        && LINK_REF_PATTERN.is_match(content_trimmed)
398                    {
399                        continue;
400                    }
401                }
402            }
403
404            // Skip various block types efficiently
405            if !effective_config.strict {
406                // Lines whose only content is a link/image are exempt.
407                // After stripping list markers, blockquote markers, and emphasis,
408                // if only a link or image remains, there is no way to shorten it.
409                if is_standalone_link_or_image_line(line) {
410                    continue;
411                }
412
413                // Lines consisting entirely of HTML tags are exempt.
414                // Badge lines, images with attributes, and similar inline HTML
415                // are long due to URLs in attributes and can't be meaningfully shortened.
416                if is_html_only_line(line) {
417                    continue;
418                }
419
420                // Skip setext heading underlines
421                if !line.trim().is_empty() && line.trim().chars().all(|c| c == '=' || c == '-') {
422                    continue;
423                }
424
425                // Skip block elements according to config flags
426                // The flags mean: true = check these elements, false = skip these elements
427                // So we skip when the flag is FALSE and the line is in that element type
428                if (!effective_config.headings && heading_lines_set.contains(&line_number))
429                    || (!effective_config.code_blocks
430                        && ctx.line_info(line_number).is_some_and(|info| info.in_code_block))
431                    || (!effective_config.tables && table_lines_set.contains(&line_number))
432                    || ctx.line_info(line_number).is_some_and(|info| info.in_html_block)
433                    || ctx.line_info(line_number).is_some_and(|info| info.in_html_comment)
434                    || ctx.line_info(line_number).is_some_and(|info| info.in_esm_block)
435                    || ctx.line_info(line_number).is_some_and(|info| info.in_jsx_expression)
436                    || ctx.line_info(line_number).is_some_and(|info| info.in_jsx_block)
437                    || ctx.line_info(line_number).is_some_and(|info| info.in_mdx_comment)
438                    || ctx.line_info(line_number).is_some_and(|info| info.in_pymdown_block)
439                {
440                    continue;
441                }
442
443                // Check if this is a paragraph/regular text line
444                // If paragraphs = false, skip lines that are NOT in special blocks
445                // Blockquote content is treated as paragraph text, so it's not
446                // included in the special blocks list here.
447                if !effective_config.paragraphs {
448                    let is_special_block = heading_lines_set.contains(&line_number)
449                        || ctx.line_info(line_number).is_some_and(|info| info.in_code_block)
450                        || table_lines_set.contains(&line_number)
451                        || ctx.line_info(line_number).is_some_and(|info| info.in_html_block)
452                        || ctx.line_info(line_number).is_some_and(|info| info.in_html_comment)
453                        || ctx.line_info(line_number).is_some_and(|info| info.in_esm_block)
454                        || ctx.line_info(line_number).is_some_and(|info| info.in_jsx_expression)
455                        || ctx.line_info(line_number).is_some_and(|info| info.in_jsx_block)
456                        || ctx.line_info(line_number).is_some_and(|info| info.in_mdx_comment)
457                        || ctx
458                            .line_info(line_number)
459                            .is_some_and(super::super::lint_context::types::LineInfo::in_mkdocs_container);
460
461                    // Skip regular paragraph text when paragraphs = false
462                    if !is_special_block {
463                        continue;
464                    }
465                }
466
467                // Skip blockquote lines when blockquotes = false.
468                // Also skip lazy continuation lines that belong to a blockquote
469                // (lines without `>` prefix that follow a blockquote line).
470                if !effective_config.blockquotes {
471                    if ctx.lines[line_number - 1].blockquote.is_some() {
472                        continue;
473                    }
474                    // Check for lazy continuation: scan backwards through
475                    // non-blank lines to find if this paragraph started with
476                    // a blockquote marker
477                    if !line.trim().is_empty() {
478                        let mut scan = line_number.saturating_sub(2);
479                        loop {
480                            if ctx.lines[scan].blockquote.is_some() {
481                                // Found a blockquote ancestor — this is a lazy continuation
482                                continue 'line_loop;
483                            }
484                            if lines[scan].trim().is_empty() || scan == 0 {
485                                break;
486                            }
487                            scan -= 1;
488                        }
489                    }
490                }
491
492                // Skip lines that are only a URL, image ref, or link ref
493                if self.should_ignore_line(line, lines, line_idx, ctx) {
494                    continue;
495                }
496            }
497
498            // In sentence-per-line mode, check if this is a single long sentence
499            // If so, emit a warning without a fix (user must manually rephrase)
500            if effective_config.reflow_mode == ReflowMode::SentencePerLine {
501                let sentences = split_into_sentences(line.trim());
502                if sentences.len() == 1 {
503                    // Single sentence that's too long - warn but don't auto-fix
504                    let message = format!("Line length {effective_length} exceeds {line_limit} characters");
505
506                    let (start_line, start_col, end_line, end_col) =
507                        calculate_excess_range(line_number, line, line_limit);
508
509                    warnings.push(LintWarning {
510                        rule_name: Some(self.name().to_string()),
511                        message,
512                        line: start_line,
513                        column: start_col,
514                        end_line,
515                        end_column: end_col,
516                        severity: Severity::Warning,
517                        fix: None, // No auto-fix for long single sentences
518                    });
519                    continue;
520                }
521                // Multiple sentences will be handled by paragraph-based reflow
522                continue;
523            }
524
525            // In semantic-line-breaks mode, skip per-line checks —
526            // all reflow is handled at the paragraph level with cascading splits
527            if effective_config.reflow_mode == ReflowMode::SemanticLineBreaks {
528                continue;
529            }
530
531            // Don't provide fix for individual lines when reflow is enabled
532            // Paragraph-based fixes will be handled separately
533            let fix = None;
534
535            let message = format!("Line length {effective_length} exceeds {line_limit} characters");
536
537            // Calculate precise character range for the excess portion
538            let (start_line, start_col, end_line, end_col) = calculate_excess_range(line_number, line, line_limit);
539
540            warnings.push(LintWarning {
541                rule_name: Some(self.name().to_string()),
542                message,
543                line: start_line,
544                column: start_col,
545                end_line,
546                end_column: end_col,
547                severity: Severity::Warning,
548                fix,
549            });
550        }
551
552        // If reflow is enabled, generate paragraph-based fixes
553        if effective_config.reflow {
554            let paragraph_warnings = self.generate_paragraph_fixes(ctx, &effective_config, lines);
555            // Merge paragraph warnings with line warnings, removing duplicates
556            for pw in paragraph_warnings {
557                // Remove any line warnings that overlap with this paragraph
558                warnings.retain(|w| w.line < pw.line || w.line > pw.end_line);
559                warnings.push(pw);
560            }
561        }
562
563        Ok(warnings)
564    }
565
566    fn fix(&self, ctx: &crate::lint_context::LintContext) -> Result<String, LintError> {
567        // For CLI usage, apply fixes from warnings
568        // LSP will use the warning-based fixes directly
569        let warnings = self.check(ctx)?;
570        let warnings =
571            crate::utils::fix_utils::filter_warnings_by_inline_config(warnings, ctx.inline_config(), self.name());
572
573        // If there are no fixes, return content unchanged
574        if !warnings.iter().any(|w| w.fix.is_some()) {
575            return Ok(ctx.content.to_string());
576        }
577
578        // Apply warning-based fixes
579        crate::utils::fix_utils::apply_warning_fixes(ctx.content, &warnings)
580            .map_err(|e| LintError::FixFailed(format!("Failed to apply fixes: {e}")))
581    }
582
583    fn as_any(&self) -> &dyn std::any::Any {
584        self
585    }
586
587    fn category(&self) -> RuleCategory {
588        RuleCategory::Whitespace
589    }
590
591    fn should_skip(&self, ctx: &crate::lint_context::LintContext) -> bool {
592        self.should_skip_with_config(ctx, &self.config)
593    }
594
595    fn default_config_section(&self) -> Option<(String, toml::Value)> {
596        let table = crate::rule_config_serde::config_schema_table(&MD013Config::default())?;
597        if table.is_empty() {
598            None
599        } else {
600            Some((MD013Config::RULE_NAME.to_string(), toml::Value::Table(table)))
601        }
602    }
603
604    fn config_aliases(&self) -> Option<std::collections::HashMap<String, String>> {
605        let mut aliases = std::collections::HashMap::new();
606        aliases.insert("enable_reflow".to_string(), "reflow".to_string());
607        aliases.insert("strict_sentences".to_string(), "require-sentence-capital".to_string());
608        aliases.insert("strict-sentences".to_string(), "require-sentence-capital".to_string());
609        Some(aliases)
610    }
611
612    fn from_config(config: &crate::config::Config) -> Box<dyn Rule>
613    where
614        Self: Sized,
615    {
616        let mut rule_config = crate::rule_config_serde::load_rule_config::<MD013Config>(config);
617        // Use global line_length if rule-specific config still has default value
618        if rule_config.line_length.get() == 80 {
619            rule_config.line_length = config.global.line_length;
620        }
621        Box::new(Self::from_config_struct(rule_config))
622    }
623}
624
625impl MD013LineLength {
626    fn is_blockquote_content_boundary(
627        &self,
628        content: &str,
629        line_num: usize,
630        ctx: &crate::lint_context::LintContext,
631    ) -> bool {
632        let trimmed = content.trim();
633
634        trimmed.is_empty()
635            || ctx.line_info(line_num).is_some_and(|info| {
636                info.in_code_block
637                    || info.in_front_matter
638                    || info.in_html_block
639                    || info.in_html_comment
640                    || info.in_esm_block
641                    || info.in_jsx_expression
642                    || info.in_jsx_block
643                    || info.in_mdx_comment
644                    || info.in_mkdocstrings
645                    || info.in_pymdown_block
646                    || info.in_mkdocs_container()
647                    || info.is_div_marker
648            })
649            || trimmed.starts_with('#')
650            || trimmed.starts_with("```")
651            || trimmed.starts_with("~~~")
652            || trimmed.starts_with('>')
653            || TableUtils::is_potential_table_row(content)
654            || is_list_item(trimmed)
655            || is_horizontal_rule(content)
656            || (trimmed.starts_with('[') && content.contains("]:"))
657            || is_template_directive_only(content)
658            || is_standalone_attr_list(content)
659            || is_snippet_block_delimiter(content)
660            || is_github_alert_marker(trimmed)
661            || is_html_only_line(content)
662    }
663
664    fn generate_blockquote_paragraph_fix(
665        &self,
666        ctx: &crate::lint_context::LintContext,
667        config: &MD013Config,
668        lines: &[&str],
669        line_index: &LineIndex,
670        start_idx: usize,
671        line_ending: &str,
672    ) -> (Option<LintWarning>, usize) {
673        let Some(start_bq) = ctx.lines.get(start_idx).and_then(|line| line.blockquote.as_deref()) else {
674            return (None, start_idx + 1);
675        };
676        let target_level = start_bq.nesting_level;
677
678        let mut collected: Vec<CollectedBlockquoteLine> = Vec::new();
679        let mut i = start_idx;
680
681        while i < lines.len() {
682            if !collected.is_empty() && has_hard_break(&collected[collected.len() - 1].data.content) {
683                break;
684            }
685
686            let line_num = i + 1;
687            if line_num > ctx.lines.len() {
688                break;
689            }
690
691            if lines[i].trim().is_empty() {
692                break;
693            }
694
695            let line_bq = ctx.lines[i].blockquote.as_deref();
696            if let Some(bq) = line_bq {
697                if bq.nesting_level != target_level {
698                    break;
699                }
700
701                if self.is_blockquote_content_boundary(&bq.content, line_num, ctx) {
702                    break;
703                }
704
705                collected.push(CollectedBlockquoteLine {
706                    line_idx: i,
707                    data: BlockquoteLineData::explicit(trim_preserving_hard_break(&bq.content), bq.prefix.clone()),
708                });
709                i += 1;
710                continue;
711            }
712
713            let lazy_content = lines[i].trim_start();
714            if self.is_blockquote_content_boundary(lazy_content, line_num, ctx) {
715                break;
716            }
717
718            collected.push(CollectedBlockquoteLine {
719                line_idx: i,
720                data: BlockquoteLineData::lazy(trim_preserving_hard_break(lazy_content)),
721            });
722            i += 1;
723        }
724
725        if collected.is_empty() {
726            return (None, start_idx + 1);
727        }
728
729        let next_idx = i;
730        let paragraph_start = collected[0].line_idx;
731        let end_line = collected[collected.len() - 1].line_idx;
732        let line_data: Vec<BlockquoteLineData> = collected.iter().map(|l| l.data.clone()).collect();
733        let paragraph_text = line_data
734            .iter()
735            .map(|d| d.content.as_str())
736            .collect::<Vec<_>>()
737            .join(" ");
738
739        let contains_definition_list = line_data
740            .iter()
741            .any(|d| crate::utils::is_definition_list_item(&d.content));
742        if contains_definition_list {
743            return (None, next_idx);
744        }
745
746        let contains_snippets = line_data.iter().any(|d| is_snippet_block_delimiter(&d.content));
747        if contains_snippets {
748            return (None, next_idx);
749        }
750
751        let needs_reflow = match config.reflow_mode {
752            ReflowMode::Normalize => {
753                self.normalize_mode_needs_reflow(line_data.iter().map(|d| d.content.as_str()), config)
754            }
755            ReflowMode::SentencePerLine => {
756                let sentences = split_into_sentences(&paragraph_text);
757                sentences.len() > 1 || line_data.len() > 1
758            }
759            ReflowMode::SemanticLineBreaks => {
760                let sentences = split_into_sentences(&paragraph_text);
761                sentences.len() > 1
762                    || line_data.len() > 1
763                    || collected
764                        .iter()
765                        .any(|l| self.calculate_effective_length(lines[l.line_idx]) > config.line_length.get())
766            }
767            ReflowMode::Default => collected
768                .iter()
769                .any(|l| self.calculate_effective_length(lines[l.line_idx]) > config.line_length.get()),
770        };
771
772        if !needs_reflow {
773            return (None, next_idx);
774        }
775
776        let fallback_prefix = start_bq.prefix.clone();
777        let explicit_prefix = dominant_blockquote_prefix(&line_data, &fallback_prefix);
778        let continuation_style = blockquote_continuation_style(&line_data);
779
780        let reflow_line_length = if config.line_length.is_unlimited() {
781            usize::MAX
782        } else {
783            config
784                .line_length
785                .get()
786                .saturating_sub(self.calculate_string_length(&explicit_prefix))
787                .max(1)
788        };
789
790        let reflow_options = crate::utils::text_reflow::ReflowOptions {
791            line_length: reflow_line_length,
792            break_on_sentences: true,
793            preserve_breaks: false,
794            sentence_per_line: config.reflow_mode == ReflowMode::SentencePerLine,
795            semantic_line_breaks: config.reflow_mode == ReflowMode::SemanticLineBreaks,
796            abbreviations: config.abbreviations_for_reflow(),
797            length_mode: self.reflow_length_mode(),
798            attr_lists: ctx.flavor.supports_attr_lists(),
799            require_sentence_capital: config.require_sentence_capital,
800            max_list_continuation_indent: if ctx.flavor.requires_strict_list_indent() {
801                Some(4)
802            } else {
803                None
804            },
805        };
806
807        let reflowed_with_style =
808            reflow_blockquote_content(&line_data, &explicit_prefix, continuation_style, &reflow_options);
809
810        if reflowed_with_style.is_empty() {
811            return (None, next_idx);
812        }
813
814        let reflowed_text = reflowed_with_style.join(line_ending);
815
816        let start_range = line_index.whole_line_range(paragraph_start + 1);
817        let end_range = if end_line == lines.len() - 1 && !ctx.content.ends_with('\n') {
818            line_index.line_text_range(end_line + 1, 1, lines[end_line].len() + 1)
819        } else {
820            line_index.whole_line_range(end_line + 1)
821        };
822        let byte_range = start_range.start..end_range.end;
823
824        let replacement = if end_line < lines.len() - 1 || ctx.content.ends_with('\n') {
825            format!("{reflowed_text}{line_ending}")
826        } else {
827            reflowed_text
828        };
829
830        let original_text = &ctx.content[byte_range.clone()];
831        if original_text == replacement {
832            return (None, next_idx);
833        }
834
835        let (warning_line, warning_end_line) = match config.reflow_mode {
836            ReflowMode::Normalize => (paragraph_start + 1, end_line + 1),
837            ReflowMode::SentencePerLine | ReflowMode::SemanticLineBreaks => (paragraph_start + 1, end_line + 1),
838            ReflowMode::Default => {
839                let violating_line = collected
840                    .iter()
841                    .find(|line| self.calculate_effective_length(lines[line.line_idx]) > config.line_length.get())
842                    .map_or(paragraph_start + 1, |line| line.line_idx + 1);
843                (violating_line, violating_line)
844            }
845        };
846
847        let warning = LintWarning {
848            rule_name: Some(self.name().to_string()),
849            message: match config.reflow_mode {
850                ReflowMode::Normalize => format!(
851                    "Paragraph could be normalized to use line length of {} characters",
852                    config.line_length.get()
853                ),
854                ReflowMode::SentencePerLine => {
855                    let num_sentences = split_into_sentences(&paragraph_text).len();
856                    if line_data.len() == 1 {
857                        format!("Line contains {num_sentences} sentences (one sentence per line required)")
858                    } else {
859                        let num_lines = line_data.len();
860                        format!(
861                            "Paragraph should have one sentence per line (found {num_sentences} sentences across {num_lines} lines)"
862                        )
863                    }
864                }
865                ReflowMode::SemanticLineBreaks => {
866                    let num_sentences = split_into_sentences(&paragraph_text).len();
867                    format!("Paragraph should use semantic line breaks ({num_sentences} sentences)")
868                }
869                ReflowMode::Default => format!("Line length exceeds {} characters", config.line_length.get()),
870            },
871            line: warning_line,
872            column: 1,
873            end_line: warning_end_line,
874            end_column: lines[warning_end_line.saturating_sub(1)].len() + 1,
875            severity: Severity::Warning,
876            fix: Some(crate::rule::Fix::new(byte_range, replacement)),
877        };
878
879        (Some(warning), next_idx)
880    }
881
882    /// Generate paragraph-based fixes
883    fn generate_paragraph_fixes(
884        &self,
885        ctx: &crate::lint_context::LintContext,
886        config: &MD013Config,
887        lines: &[&str],
888    ) -> Vec<LintWarning> {
889        let mut warnings = Vec::new();
890        let line_index = LineIndex::new(ctx.content);
891
892        // Detect the content's line ending style to preserve it in replacements.
893        // The LSP receives content from editors which may use CRLF (Windows).
894        // Replacements must match the original line endings to avoid false positives.
895        let line_ending = crate::utils::line_ending::detect_line_ending(ctx.content);
896
897        let mut i = 0;
898        while i < lines.len() {
899            let line_num = i + 1;
900
901            // Handle blockquote paragraphs with style-preserving reflow.
902            // Skip blockquotes when blockquotes=false or paragraphs=false
903            if line_num > 0 && line_num <= ctx.lines.len() && ctx.lines[line_num - 1].blockquote.is_some() {
904                if !config.blockquotes || !config.paragraphs {
905                    // Skip past all blockquote lines (explicit and lazy continuations).
906                    // A lazy continuation is a non-blank line without `>` that follows
907                    // a blockquote line and isn't a structural element.
908                    let mut saw_explicit_bq = false;
909                    while i < lines.len() && i < ctx.lines.len() {
910                        if ctx.lines[i].blockquote.is_some() {
911                            saw_explicit_bq = true;
912                            i += 1;
913                        } else if saw_explicit_bq
914                            && !lines[i].trim().is_empty()
915                            && !lines[i].trim_start().starts_with('#')
916                            && !lines[i].trim_start().starts_with('>')
917                        {
918                            // Lazy continuation of preceding blockquote
919                            i += 1;
920                        } else {
921                            break;
922                        }
923                    }
924                    continue;
925                }
926                let (warning, next_idx) =
927                    self.generate_blockquote_paragraph_fix(ctx, config, lines, &line_index, i, line_ending);
928                if let Some(warning) = warning {
929                    warnings.push(warning);
930                }
931                i = next_idx;
932                continue;
933            }
934
935            // Skip special structures (but NOT MkDocs containers - those get special handling)
936            let should_skip_due_to_line_info = ctx.line_info(line_num).is_some_and(|info| {
937                info.in_code_block
938                    || info.in_front_matter
939                    || info.in_html_block
940                    || info.in_html_comment
941                    || info.in_esm_block
942                    || info.in_jsx_expression
943                    || info.in_jsx_block
944                    || info.in_mdx_comment
945                    || info.in_mkdocstrings
946                    || info.in_pymdown_block
947            });
948
949            // Skip link reference definitions but NOT footnote definitions.
950            // Footnote definitions (`[^id]: prose`) contain reflowable text,
951            // while link reference definitions (`[ref]: URL`) contain URLs
952            // that cannot be shortened.
953            let is_link_ref_def =
954                lines[i].trim().starts_with('[') && !lines[i].trim().starts_with("[^") && lines[i].contains("]:");
955
956            if should_skip_due_to_line_info
957                || lines[i].trim().starts_with('#')
958                || TableUtils::is_potential_table_row(lines[i])
959                || lines[i].trim().is_empty()
960                || is_horizontal_rule(lines[i])
961                || is_template_directive_only(lines[i])
962                || is_link_ref_def
963                || ctx.line_info(line_num).is_some_and(|info| info.is_div_marker)
964                || is_html_only_line(lines[i])
965            {
966                i += 1;
967                continue;
968            }
969
970            // Handle footnote definitions: `[^id]: prose text that can be reflowed`
971            // Supports multi-paragraph footnotes with code blocks, blockquotes,
972            // tables, and lists preserved verbatim.
973            // Validate structure: must start with `[^`, contain `]:`, and the ID
974            // must not contain `[` or `]` (prevents false matches on nested brackets)
975            if lines[i].trim().starts_with("[^") && lines[i].contains("]:") && {
976                let after_caret = &lines[i].trim()[2..];
977                after_caret
978                    .find("]:")
979                    .is_some_and(|pos| pos > 0 && !after_caret[..pos].contains(['[', ']']))
980            } {
981                let footnote_start = i;
982                let line = lines[i];
983
984                // Extract the prefix `[^id]:`
985                let Some(colon_pos) = line.find("]:") else {
986                    i += 1;
987                    continue;
988                };
989                let prefix_end = colon_pos + 2;
990                let prefix = &line[..prefix_end];
991
992                // Content starts after `]: ` (with optional space)
993                let content_start = if line[prefix_end..].starts_with(' ') {
994                    prefix_end + 1
995                } else {
996                    prefix_end
997                };
998                let first_content = &line[content_start..];
999
1000                // CommonMark footnotes use 4-space continuation indent
1001                const FN_INDENT: usize = 4;
1002
1003                // --- Line classification for footnote content ---
1004                #[derive(Debug, Clone)]
1005                enum FnLineType {
1006                    Content(String),
1007                    Verbatim(String, usize), // preserved text, original indent
1008                    Empty,
1009                }
1010
1011                // Helper: compute visual indent (tabs = 4 spaces)
1012                let visual_indent = |s: &str| -> usize {
1013                    s.chars()
1014                        .take_while(|c| c.is_whitespace())
1015                        .map(|c| if c == '\t' { 4 } else { 1 })
1016                        .sum::<usize>()
1017                };
1018
1019                // Helper: check if a trimmed line is a fence marker (homogeneous chars)
1020                let is_fence = |s: &str| -> bool {
1021                    let t = s.trim();
1022                    let fence_char = t.chars().next();
1023                    matches!(fence_char, Some('`') | Some('~'))
1024                        && t.chars().take_while(|&c| c == fence_char.unwrap()).count() >= 3
1025                };
1026
1027                // Helper: check if a trimmed line is a setext underline
1028                let is_setext_underline = |s: &str| -> bool {
1029                    let t = s.trim();
1030                    !t.is_empty()
1031                        && (t.chars().all(|c| c == '=' || c == ' ') || t.chars().all(|c| c == '-' || c == ' '))
1032                        && t.contains(['=', '-'])
1033                };
1034
1035                // Deferred body: `[^id]:\n    content` — first line has no content,
1036                // actual content starts on the next indented line
1037                let deferred_body = first_content.trim().is_empty();
1038
1039                // Collect all lines belonging to this footnote definition
1040                let mut fn_lines: Vec<FnLineType> = Vec::new();
1041                if !deferred_body {
1042                    fn_lines.push(FnLineType::Content(first_content.to_string()));
1043                }
1044                let mut last_consumed = i;
1045                i += 1;
1046
1047                // Strip only the footnote continuation indent, preserving
1048                // internal indentation (e.g., code block body indent)
1049                let strip_fn_indent = |s: &str| -> String {
1050                    let mut chars = s.chars();
1051                    let mut stripped = 0;
1052                    while stripped < FN_INDENT {
1053                        match chars.next() {
1054                            Some('\t') => stripped += 4,
1055                            Some(c) if c.is_whitespace() => stripped += 1,
1056                            _ => break,
1057                        }
1058                    }
1059                    chars.as_str().to_string()
1060                };
1061
1062                let mut in_fenced_code = false;
1063                let mut consecutive_blanks = 0u32;
1064
1065                while i < lines.len() {
1066                    let next = lines[i];
1067                    let next_trimmed = next.trim();
1068
1069                    // Blank line handling
1070                    if next_trimmed.is_empty() {
1071                        consecutive_blanks += 1;
1072                        // 2+ consecutive blanks terminate the footnote
1073                        if consecutive_blanks >= 2 {
1074                            break;
1075                        }
1076
1077                        // Inside a fenced code block, blank lines are part of the code
1078                        if in_fenced_code {
1079                            consecutive_blanks = 0; // Don't count blanks inside code blocks
1080                            fn_lines.push(FnLineType::Verbatim(String::new(), 0));
1081                            last_consumed = i;
1082                            i += 1;
1083                            continue;
1084                        }
1085
1086                        // Peek ahead: if next non-blank line is indented >= FN_INDENT,
1087                        // this blank is an internal paragraph separator
1088                        if i + 1 < lines.len() {
1089                            let peek = lines[i + 1];
1090                            let peek_indent = visual_indent(peek);
1091                            if !peek.trim().is_empty() && peek_indent >= FN_INDENT {
1092                                fn_lines.push(FnLineType::Empty);
1093                                last_consumed = i;
1094                                i += 1;
1095                                continue;
1096                            }
1097                        }
1098                        // No valid continuation after blank — end of footnote
1099                        break;
1100                    }
1101
1102                    consecutive_blanks = 0;
1103                    let indent = visual_indent(next);
1104
1105                    // Not indented enough — end of footnote
1106                    if indent < FN_INDENT {
1107                        break;
1108                    }
1109
1110                    // Inside a fenced code block: everything is verbatim until closing fence
1111                    if in_fenced_code {
1112                        fn_lines.push(FnLineType::Verbatim(strip_fn_indent(next), indent));
1113                        if is_fence(next_trimmed) {
1114                            in_fenced_code = false;
1115                        }
1116                        last_consumed = i;
1117                        i += 1;
1118                        continue;
1119                    }
1120
1121                    // Fence opener — start verbatim code block
1122                    if is_fence(next_trimmed) {
1123                        in_fenced_code = true;
1124                        fn_lines.push(FnLineType::Verbatim(strip_fn_indent(next), indent));
1125                        last_consumed = i;
1126                        i += 1;
1127                        continue;
1128                    }
1129
1130                    // Indented code block: indent >= FN_INDENT + 4 (= 8 spaces)
1131                    if indent >= FN_INDENT + 4 {
1132                        fn_lines.push(FnLineType::Verbatim(strip_fn_indent(next), indent));
1133                        last_consumed = i;
1134                        i += 1;
1135                        continue;
1136                    }
1137
1138                    // Structural content that must be preserved verbatim
1139                    if next_trimmed.starts_with('#')
1140                        || is_list_item(next_trimmed)
1141                        || next_trimmed.starts_with('>')
1142                        || TableUtils::is_potential_table_row(next_trimmed)
1143                        || is_setext_underline(next_trimmed)
1144                        || is_horizontal_rule(next_trimmed)
1145                        || crate::utils::mkdocs_footnotes::is_footnote_definition(next_trimmed)
1146                    {
1147                        // Preserve verbatim: blockquotes, tables, lists, setext
1148                        // underlines, and horizontal rules inside the footnote
1149                        if next_trimmed.starts_with('>')
1150                            || TableUtils::is_potential_table_row(next_trimmed)
1151                            || is_list_item(next_trimmed)
1152                            || is_setext_underline(next_trimmed)
1153                            || is_horizontal_rule(next_trimmed)
1154                        {
1155                            fn_lines.push(FnLineType::Verbatim(strip_fn_indent(next), indent));
1156                            last_consumed = i;
1157                            i += 1;
1158                            continue;
1159                        }
1160                        // Headings, new footnote defs, link refs — end the footnote
1161                        break;
1162                    }
1163
1164                    // Link reference definitions inside footnotes are not reflowable
1165                    if next_trimmed.starts_with('[')
1166                        && !next_trimmed.starts_with("[^")
1167                        && next_trimmed.contains("]:")
1168                        && LINK_REF_PATTERN.is_match(next_trimmed)
1169                    {
1170                        fn_lines.push(FnLineType::Verbatim(strip_fn_indent(next), indent));
1171                        last_consumed = i;
1172                        i += 1;
1173                        continue;
1174                    }
1175
1176                    // HTML-only lines inside footnotes are not reflowable
1177                    if is_html_only_line(next_trimmed) {
1178                        fn_lines.push(FnLineType::Verbatim(strip_fn_indent(next), indent));
1179                        last_consumed = i;
1180                        i += 1;
1181                        continue;
1182                    }
1183
1184                    // Regular prose content
1185                    fn_lines.push(FnLineType::Content(next_trimmed.to_string()));
1186                    last_consumed = i;
1187                    i += 1;
1188                }
1189
1190                // Nothing collected or only empty lines
1191                if fn_lines.iter().all(|l| matches!(l, FnLineType::Empty)) || fn_lines.is_empty() {
1192                    continue;
1193                }
1194
1195                // --- Group into blocks ---
1196                #[derive(Debug)]
1197                enum FnBlock {
1198                    Paragraph(Vec<String>),
1199                    Verbatim(Vec<(String, usize)>), // (content, indent) preserved as-is
1200                }
1201
1202                let mut blocks: Vec<FnBlock> = Vec::new();
1203                let mut current_para: Vec<String> = Vec::new();
1204                let mut current_verbatim: Vec<(String, usize)> = Vec::new();
1205
1206                for fl in &fn_lines {
1207                    match fl {
1208                        FnLineType::Content(s) => {
1209                            if !current_verbatim.is_empty() {
1210                                blocks.push(FnBlock::Verbatim(std::mem::take(&mut current_verbatim)));
1211                            }
1212                            current_para.push(s.clone());
1213                        }
1214                        FnLineType::Verbatim(s, indent) => {
1215                            if !current_para.is_empty() {
1216                                blocks.push(FnBlock::Paragraph(std::mem::take(&mut current_para)));
1217                            }
1218                            current_verbatim.push((s.clone(), *indent));
1219                        }
1220                        FnLineType::Empty => {
1221                            if !current_para.is_empty() {
1222                                blocks.push(FnBlock::Paragraph(std::mem::take(&mut current_para)));
1223                            }
1224                            if !current_verbatim.is_empty() {
1225                                blocks.push(FnBlock::Verbatim(std::mem::take(&mut current_verbatim)));
1226                            }
1227                        }
1228                    }
1229                }
1230                if !current_para.is_empty() {
1231                    blocks.push(FnBlock::Paragraph(current_para));
1232                }
1233                if !current_verbatim.is_empty() {
1234                    blocks.push(FnBlock::Verbatim(current_verbatim));
1235                }
1236
1237                // --- Reflow paragraphs and reconstruct ---
1238                let prefix_display_width = prefix.chars().count() + 1; // +1 for space
1239                let reflow_line_length = if config.line_length.is_unlimited() {
1240                    usize::MAX
1241                } else {
1242                    config
1243                        .line_length
1244                        .get()
1245                        .saturating_sub(FN_INDENT.max(prefix_display_width))
1246                        .max(20)
1247                };
1248                let reflow_options = crate::utils::text_reflow::ReflowOptions {
1249                    line_length: reflow_line_length,
1250                    break_on_sentences: true,
1251                    preserve_breaks: false,
1252                    sentence_per_line: config.reflow_mode == ReflowMode::SentencePerLine,
1253                    semantic_line_breaks: config.reflow_mode == ReflowMode::SemanticLineBreaks,
1254                    abbreviations: config.abbreviations_for_reflow(),
1255                    length_mode: self.reflow_length_mode(),
1256                    attr_lists: ctx.flavor.supports_attr_lists(),
1257                    require_sentence_capital: config.require_sentence_capital,
1258                    max_list_continuation_indent: None,
1259                };
1260
1261                let indent_str = " ".repeat(FN_INDENT);
1262                let mut result_lines: Vec<String> = Vec::new();
1263                let mut is_first_block = true;
1264
1265                for block in &blocks {
1266                    match block {
1267                        FnBlock::Paragraph(para_lines) => {
1268                            let paragraph_text = para_lines.join(" ");
1269                            let paragraph_text = paragraph_text.trim();
1270                            if paragraph_text.is_empty() {
1271                                continue;
1272                            }
1273
1274                            let reflowed = crate::utils::text_reflow::reflow_line(paragraph_text, &reflow_options);
1275                            if reflowed.is_empty() {
1276                                continue;
1277                            }
1278
1279                            // Blank line separator between blocks
1280                            if !result_lines.is_empty() {
1281                                result_lines.push(String::new());
1282                            }
1283
1284                            for (idx, rline) in reflowed.iter().enumerate() {
1285                                if is_first_block && idx == 0 {
1286                                    result_lines.push(format!("{prefix} {rline}"));
1287                                } else {
1288                                    result_lines.push(format!("{indent_str}{rline}"));
1289                                }
1290                            }
1291                            is_first_block = false;
1292                        }
1293                        FnBlock::Verbatim(verb_lines) => {
1294                            // Blank line separator between blocks
1295                            if !result_lines.is_empty() {
1296                                result_lines.push(String::new());
1297                            }
1298
1299                            if is_first_block {
1300                                // Verbatim as first block in a deferred-body footnote
1301                                if deferred_body {
1302                                    result_lines.push(prefix.to_string());
1303                                }
1304                                is_first_block = false;
1305                            }
1306                            for (content, _orig_indent) in verb_lines {
1307                                result_lines.push(format!("{indent_str}{content}"));
1308                            }
1309                        }
1310                    }
1311                }
1312
1313                // If nothing was produced, skip
1314                if result_lines.is_empty() {
1315                    continue;
1316                }
1317
1318                let reflowed_text = result_lines.join(line_ending);
1319
1320                // Calculate byte range using last_consumed
1321                let start_range = line_index.whole_line_range(footnote_start + 1);
1322                let end_range = if last_consumed == lines.len() - 1 && !ctx.content.ends_with('\n') {
1323                    line_index.line_text_range(last_consumed + 1, 1, lines[last_consumed].len() + 1)
1324                } else {
1325                    line_index.whole_line_range(last_consumed + 1)
1326                };
1327                let byte_range = start_range.start..end_range.end;
1328
1329                let replacement = if last_consumed < lines.len() - 1 || ctx.content.ends_with('\n') {
1330                    format!("{reflowed_text}{line_ending}")
1331                } else {
1332                    reflowed_text
1333                };
1334
1335                let original_text = &ctx.content[byte_range.clone()];
1336                let max_length = (footnote_start..=last_consumed)
1337                    .map(|idx| self.calculate_effective_length(lines[idx]))
1338                    .max()
1339                    .unwrap_or(0);
1340                let line_limit = if config.line_length.is_unlimited() {
1341                    usize::MAX
1342                } else {
1343                    config.line_length.get()
1344                };
1345                if original_text != replacement && max_length > line_limit {
1346                    warnings.push(LintWarning {
1347                        rule_name: Some(self.name().to_string()),
1348                        message: format!(
1349                            "Line length {} exceeds {} characters",
1350                            max_length,
1351                            config.line_length.get()
1352                        ),
1353                        line: footnote_start + 1,
1354                        column: 1,
1355                        end_line: last_consumed + 1,
1356                        end_column: lines[last_consumed].len() + 1,
1357                        severity: Severity::Warning,
1358                        fix: Some(crate::rule::Fix::new(byte_range, replacement)),
1359                    });
1360                }
1361                continue;
1362            }
1363
1364            // Handle MkDocs container content (admonitions and tabs) with indent-preserving reflow
1365            if ctx
1366                .line_info(line_num)
1367                .is_some_and(super::super::lint_context::types::LineInfo::in_mkdocs_container)
1368            {
1369                // Skip admonition/tab marker lines — only reflow their indented content
1370                let current_line = lines[i];
1371                if mkdocs_admonitions::is_admonition_start(current_line) || mkdocs_tabs::is_tab_marker(current_line) {
1372                    i += 1;
1373                    continue;
1374                }
1375
1376                let container_start = i;
1377
1378                // Detect the actual indent level from the first content line
1379                // (supports nested admonitions with 8+ spaces)
1380                let first_line = lines[i];
1381                let base_indent_len = first_line.len() - first_line.trim_start().len();
1382                let base_indent: String = " ".repeat(base_indent_len);
1383
1384                // Collect consecutive MkDocs container paragraph lines
1385                let mut container_lines: Vec<&str> = Vec::new();
1386                while i < lines.len() {
1387                    let current_line_num = i + 1;
1388                    let line_info = ctx.line_info(current_line_num);
1389
1390                    // Stop if we leave the MkDocs container
1391                    if !line_info.is_some_and(super::super::lint_context::types::LineInfo::in_mkdocs_container) {
1392                        break;
1393                    }
1394
1395                    let line = lines[i];
1396
1397                    // Stop at paragraph boundaries within the container
1398                    if line.trim().is_empty() {
1399                        break;
1400                    }
1401
1402                    // Skip list items, code blocks, headings, HTML-only lines within containers
1403                    if is_list_item(line.trim())
1404                        || line.trim().starts_with("```")
1405                        || line.trim().starts_with("~~~")
1406                        || line.trim().starts_with('#')
1407                        || is_html_only_line(line)
1408                    {
1409                        break;
1410                    }
1411
1412                    container_lines.push(line);
1413                    i += 1;
1414                }
1415
1416                if container_lines.is_empty() {
1417                    // Must advance i to avoid infinite loop when we encounter
1418                    // non-paragraph content (code block, list, heading, empty line)
1419                    // at the start of an MkDocs container
1420                    i += 1;
1421                    continue;
1422                }
1423
1424                // Strip the base indent from each line and join for reflow
1425                let stripped_lines: Vec<&str> = container_lines
1426                    .iter()
1427                    .map(|line| {
1428                        if line.starts_with(&base_indent) {
1429                            &line[base_indent_len..]
1430                        } else {
1431                            line.trim_start()
1432                        }
1433                    })
1434                    .collect();
1435                let paragraph_text = stripped_lines.join(" ");
1436
1437                // Check if reflow is needed
1438                let needs_reflow = match config.reflow_mode {
1439                    ReflowMode::Normalize => self.normalize_mode_needs_reflow(container_lines.iter().copied(), config),
1440                    ReflowMode::SentencePerLine => {
1441                        let sentences = split_into_sentences(&paragraph_text);
1442                        sentences.len() > 1 || container_lines.len() > 1
1443                    }
1444                    ReflowMode::SemanticLineBreaks => {
1445                        let sentences = split_into_sentences(&paragraph_text);
1446                        sentences.len() > 1
1447                            || container_lines.len() > 1
1448                            || container_lines
1449                                .iter()
1450                                .any(|line| self.calculate_effective_length(line) > config.line_length.get())
1451                    }
1452                    ReflowMode::Default => container_lines
1453                        .iter()
1454                        .any(|line| self.calculate_effective_length(line) > config.line_length.get()),
1455                };
1456
1457                if !needs_reflow {
1458                    continue;
1459                }
1460
1461                // Calculate byte range for this container paragraph
1462                let start_range = line_index.whole_line_range(container_start + 1);
1463                let end_line = container_start + container_lines.len() - 1;
1464                let end_range = if end_line == lines.len() - 1 && !ctx.content.ends_with('\n') {
1465                    line_index.line_text_range(end_line + 1, 1, lines[end_line].len() + 1)
1466                } else {
1467                    line_index.whole_line_range(end_line + 1)
1468                };
1469                let byte_range = start_range.start..end_range.end;
1470
1471                // Reflow with adjusted line length (accounting for the 4-space indent)
1472                let reflow_line_length = if config.line_length.is_unlimited() {
1473                    usize::MAX
1474                } else {
1475                    config.line_length.get().saturating_sub(base_indent_len).max(1)
1476                };
1477                let reflow_options = crate::utils::text_reflow::ReflowOptions {
1478                    line_length: reflow_line_length,
1479                    break_on_sentences: true,
1480                    preserve_breaks: false,
1481                    sentence_per_line: config.reflow_mode == ReflowMode::SentencePerLine,
1482                    semantic_line_breaks: config.reflow_mode == ReflowMode::SemanticLineBreaks,
1483                    abbreviations: config.abbreviations_for_reflow(),
1484                    length_mode: self.reflow_length_mode(),
1485                    attr_lists: ctx.flavor.supports_attr_lists(),
1486                    require_sentence_capital: config.require_sentence_capital,
1487                    max_list_continuation_indent: if ctx.flavor.requires_strict_list_indent() {
1488                        Some(4)
1489                    } else {
1490                        None
1491                    },
1492                };
1493                let reflowed = crate::utils::text_reflow::reflow_line(&paragraph_text, &reflow_options);
1494
1495                // Re-add the 4-space indent to each reflowed line
1496                let reflowed_with_indent: Vec<String> =
1497                    reflowed.iter().map(|line| format!("{base_indent}{line}")).collect();
1498                let reflowed_text = reflowed_with_indent.join(line_ending);
1499
1500                // Preserve trailing newline
1501                let replacement = if end_line < lines.len() - 1 || ctx.content.ends_with('\n') {
1502                    format!("{reflowed_text}{line_ending}")
1503                } else {
1504                    reflowed_text
1505                };
1506
1507                // Only generate a warning if the replacement is different
1508                let original_text = &ctx.content[byte_range.clone()];
1509                if original_text != replacement {
1510                    warnings.push(LintWarning {
1511                        rule_name: Some(self.name().to_string()),
1512                        message: format!(
1513                            "Line length {} exceeds {} characters (in MkDocs container)",
1514                            container_lines.iter().map(|l| l.len()).max().unwrap_or(0),
1515                            config.line_length.get()
1516                        ),
1517                        line: container_start + 1,
1518                        column: 1,
1519                        end_line: end_line + 1,
1520                        end_column: lines[end_line].len() + 1,
1521                        severity: Severity::Warning,
1522                        fix: Some(crate::rule::Fix::new(byte_range, replacement)),
1523                    });
1524                }
1525                continue;
1526            }
1527
1528            // Helper function to detect semantic line markers
1529            let is_semantic_line = |content: &str| -> bool {
1530                let trimmed = content.trim_start();
1531                let semantic_markers = [
1532                    "NOTE:",
1533                    "WARNING:",
1534                    "IMPORTANT:",
1535                    "CAUTION:",
1536                    "TIP:",
1537                    "DANGER:",
1538                    "HINT:",
1539                    "INFO:",
1540                ];
1541                semantic_markers.iter().any(|marker| trimmed.starts_with(marker))
1542            };
1543
1544            // Helper function to detect fence markers (opening or closing)
1545            let is_fence_marker = |content: &str| -> bool {
1546                let trimmed = content.trim_start();
1547                trimmed.starts_with("```") || trimmed.starts_with("~~~")
1548            };
1549
1550            // Check if this is a list item - handle it specially
1551            let trimmed = lines[i].trim();
1552            if is_list_item(trimmed) {
1553                // Collect the entire list item including continuation lines
1554                let list_start = i;
1555                let (marker, first_content) = extract_list_marker_and_content(lines[i]);
1556                let marker_len = marker.len();
1557
1558                // Checkbox ([ ]/[x]/[X]) is inline content, not part of the list marker.
1559                // Use the base bullet/number marker width for continuation recognition
1560                // so that continuation lines at 2+ spaces are collected for "- [ ] " items.
1561                let base_marker_len = if marker.contains("[ ] ") || marker.contains("[x] ") || marker.contains("[X] ") {
1562                    marker.find('[').unwrap_or(marker_len)
1563                } else {
1564                    marker_len
1565                };
1566
1567                // MkDocs flavor requires at least 4 spaces for list continuation
1568                // after a blank line (multi-paragraph list items). For non-blank
1569                // continuation (lines directly following the marker line), use
1570                // the natural marker width so that 2-space indent is recognized.
1571                let item_indent = ctx.lines[i].indent;
1572                let min_continuation_indent = if ctx.flavor.requires_strict_list_indent() {
1573                    // Use 4-space relative indent from the list item's nesting level
1574                    item_indent + (base_marker_len - item_indent).max(4)
1575                } else {
1576                    marker_len
1577                };
1578                let content_continuation_indent = base_marker_len;
1579
1580                // Track lines and their types (content, code block, fence, nested list)
1581                #[derive(Clone)]
1582                enum LineType {
1583                    Content(String),
1584                    CodeBlock(String, usize),         // content and original indent
1585                    SemanticLine(String), // Lines starting with NOTE:, WARNING:, etc that should stay separate
1586                    SnippetLine(String),  // MkDocs Snippets delimiters (-8<-) that must stay on their own line
1587                    DivMarker(String),    // Quarto/Pandoc div markers (::: opening or closing)
1588                    AdmonitionHeader(String, usize), // header text (e.g. "!!! note") and original indent
1589                    AdmonitionContent(String, usize), // body content text and original indent
1590                    Table(String, usize), // GFM table row, preserved verbatim with original indent
1591                    Empty,
1592                }
1593
1594                let mut list_item_lines: Vec<LineType> = vec![LineType::Content(first_content)];
1595                i += 1;
1596
1597                // Collect continuation lines using ctx.lines for metadata
1598                while i < lines.len() {
1599                    let line_info = &ctx.lines[i];
1600
1601                    // Use pre-computed is_blank from ctx
1602                    if line_info.is_blank {
1603                        // Empty line - check if next line is indented (part of list item)
1604                        if i + 1 < lines.len() {
1605                            let next_info = &ctx.lines[i + 1];
1606
1607                            // Check if next line is indented enough to be continuation
1608                            if !next_info.is_blank && next_info.indent >= min_continuation_indent {
1609                                // This blank line is between paragraphs/blocks in the list item
1610                                list_item_lines.push(LineType::Empty);
1611                                i += 1;
1612                                continue;
1613                            }
1614                        }
1615                        // No indented line after blank, end of list item
1616                        break;
1617                    }
1618
1619                    // Use pre-computed indent from ctx
1620                    let indent = line_info.indent;
1621
1622                    // Valid continuation must be indented at least content_continuation_indent.
1623                    // For non-blank continuation, use marker_len (e.g. 2 for "- ").
1624                    // MkDocs strict 4-space requirement applies only after blank lines.
1625                    if indent >= content_continuation_indent {
1626                        let trimmed = line_info.content(ctx.content).trim();
1627
1628                        // Check for MkDocs admonition lines inside list items BEFORE
1629                        // checking in_code_block. Lines inside code blocks within
1630                        // admonitions have both in_admonition and in_code_block set;
1631                        // admonition membership takes priority so the entire admonition
1632                        // structure (including embedded code blocks) is preserved.
1633                        if line_info.in_admonition {
1634                            let raw_content = line_info.content(ctx.content);
1635                            if mkdocs_admonitions::is_admonition_start(raw_content) {
1636                                let header_text = raw_content[indent..].trim_end().to_string();
1637                                list_item_lines.push(LineType::AdmonitionHeader(header_text, indent));
1638                            } else {
1639                                let body_text = raw_content[indent..].trim_end().to_string();
1640                                list_item_lines.push(LineType::AdmonitionContent(body_text, indent));
1641                            }
1642                            i += 1;
1643                            continue;
1644                        }
1645
1646                        // Use pre-computed in_code_block from ctx
1647                        if line_info.in_code_block {
1648                            list_item_lines.push(LineType::CodeBlock(
1649                                line_info.content(ctx.content)[indent..].to_string(),
1650                                indent,
1651                            ));
1652                            i += 1;
1653                            continue;
1654                        }
1655
1656                        // Check if this is a SIBLING list item (breaks parent)
1657                        // Nested lists are indented >= marker_len and are PART of the parent item
1658                        // Siblings are at indent < marker_len (at or before parent marker)
1659                        if is_list_item(trimmed) && indent < marker_len {
1660                            // This is a sibling item at same or higher level - end parent item
1661                            break;
1662                        }
1663
1664                        // Nested list items are always processed independently
1665                        // by the outer loop, so break when we encounter one.
1666                        // If a blank line was collected before this, uncollect it
1667                        // so the outer loop preserves the blank between parent and nested.
1668                        if is_list_item(trimmed) && indent >= marker_len {
1669                            if matches!(list_item_lines.last(), Some(LineType::Empty)) {
1670                                list_item_lines.pop();
1671                                i -= 1;
1672                            }
1673                            break;
1674                        }
1675
1676                        // Normal continuation vs indented code block.
1677                        // Use min_continuation_indent for the threshold since
1678                        // code blocks start 4 spaces beyond the expected content
1679                        // level (which is min_continuation_indent for MkDocs).
1680                        if indent <= min_continuation_indent + 3 {
1681                            // Extract content (remove indentation and trailing whitespace)
1682                            // Preserve hard breaks (2 trailing spaces) while removing excessive whitespace
1683                            // See: https://github.com/rvben/rumdl/issues/76
1684                            let content = trim_preserving_hard_break(&line_info.content(ctx.content)[indent..]);
1685
1686                            // Check if this is a div marker (::: opening or closing)
1687                            // These must be preserved on their own line, not merged into paragraphs
1688                            if line_info.is_div_marker {
1689                                list_item_lines.push(LineType::DivMarker(content));
1690                            }
1691                            // Check if this is a fence marker (opening or closing)
1692                            // These should be treated as code block lines, not paragraph content
1693                            else if is_fence_marker(&content) {
1694                                list_item_lines.push(LineType::CodeBlock(content, indent));
1695                            }
1696                            // Check if this is a semantic line (NOTE:, WARNING:, etc.)
1697                            else if is_semantic_line(&content) {
1698                                list_item_lines.push(LineType::SemanticLine(content));
1699                            }
1700                            // Check if this is a snippet block delimiter (-8<- or --8<--)
1701                            // These must be preserved on their own lines for MkDocs Snippets extension
1702                            else if is_snippet_block_delimiter(&content) {
1703                                list_item_lines.push(LineType::SnippetLine(content));
1704                            }
1705                            // Check if this is a GFM table row. Tables nested inside list
1706                            // items must be preserved verbatim — joining them with prose
1707                            // breaks the column structure.
1708                            //
1709                            // `is_potential_table_row` is intentionally permissive at the
1710                            // row level: any line with `|` and 2+ cells qualifies. To avoid
1711                            // misclassifying prose continuation lines that contain a literal
1712                            // pipe (e.g. "use grep | sort to ..."), require one of:
1713                            //   - the row is pipe-bordered (`| ... |`), the canonical form
1714                            //     for tables nested in lists; or
1715                            //   - the next line is a delimiter row (this is a header); or
1716                            //   - the previous classified line was already a Table (this is
1717                            //     a continuation row).
1718                            else if TableUtils::is_potential_table_row(&content) && {
1719                                let pipe_bordered = content.trim().starts_with('|') && content.trim().ends_with('|');
1720                                let next_is_delim = ctx
1721                                    .lines
1722                                    .get(i + 1)
1723                                    .is_some_and(|next| TableUtils::is_delimiter_row(next.content(ctx.content)));
1724                                let prev_was_table = matches!(list_item_lines.last(), Some(LineType::Table(..)));
1725                                pipe_bordered || next_is_delim || prev_was_table
1726                            } {
1727                                list_item_lines.push(LineType::Table(content, indent));
1728                            } else {
1729                                list_item_lines.push(LineType::Content(content));
1730                            }
1731                            i += 1;
1732                        } else {
1733                            // indent >= min_continuation_indent + 4: indented code block
1734                            list_item_lines.push(LineType::CodeBlock(
1735                                line_info.content(ctx.content)[indent..].to_string(),
1736                                indent,
1737                            ));
1738                            i += 1;
1739                        }
1740                    } else {
1741                        // Not indented enough, end of list item
1742                        break;
1743                    }
1744                }
1745
1746                // Determine the output continuation indent.
1747                // Normalize/Default modes canonicalize to min_continuation_indent
1748                // (fixing over-indented continuation). Semantic/SentencePerLine
1749                // modes preserve the user's actual indent since they only fix
1750                // line breaking, not indentation.
1751                let indent_size = match config.reflow_mode {
1752                    ReflowMode::SemanticLineBreaks | ReflowMode::SentencePerLine => {
1753                        // Find indent of the first plain text continuation line,
1754                        // skipping the marker line (index 0), nested list items,
1755                        // code blocks, and blank lines.
1756                        list_item_lines
1757                            .iter()
1758                            .enumerate()
1759                            .skip(1)
1760                            .find_map(|(k, lt)| {
1761                                if matches!(lt, LineType::Content(_)) {
1762                                    Some(ctx.lines[list_start + k].indent)
1763                                } else {
1764                                    None
1765                                }
1766                            })
1767                            .unwrap_or(min_continuation_indent)
1768                    }
1769                    _ => min_continuation_indent,
1770                };
1771                // For checkbox items in mkdocs flavor, enforce minimum indent so
1772                // continuation lines use the structural list indent (4), not the
1773                // content-aligned indent (6) which Python-Markdown doesn't support
1774                let has_checkbox = base_marker_len < marker_len;
1775                let indent_size = if has_checkbox && ctx.flavor.requires_strict_list_indent() {
1776                    indent_size.max(min_continuation_indent)
1777                } else {
1778                    indent_size
1779                };
1780                let expected_indent = " ".repeat(indent_size);
1781
1782                // Split list_item_lines into blocks (paragraphs, code blocks, nested lists, semantic lines, and HTML blocks)
1783                let mut builder = BlockBuilder::new();
1784                for line in &list_item_lines {
1785                    match line {
1786                        LineType::Empty => builder.feed_blank_line(),
1787                        LineType::Content(content) => builder.feed_content(content),
1788                        LineType::CodeBlock(content, indent) => builder.feed_code_line(content, *indent),
1789                        LineType::SemanticLine(content) => builder.feed_semantic_line(content),
1790                        LineType::SnippetLine(content) => builder.feed_snippet_line(content),
1791                        LineType::DivMarker(content) => builder.feed_div_marker(content),
1792                        LineType::AdmonitionHeader(header_text, indent) => {
1793                            builder.feed_admonition_header(header_text, *indent)
1794                        }
1795                        LineType::AdmonitionContent(content, indent) => {
1796                            builder.feed_admonition_content(content, *indent)
1797                        }
1798                        LineType::Table(content, indent) => builder.feed_table_line(content, *indent),
1799                    }
1800                }
1801                let blocks = builder.finalize();
1802
1803                // Helper: check if a line (raw source or stripped content) is exempt
1804                // from line-length checks. Link reference definitions are always exempt;
1805                // standalone link/image lines are exempt when strict mode is off.
1806                // Also checks content after stripping list markers, since list item
1807                // continuation lines may contain link ref defs.
1808                let is_exempt_line = |raw_line: &str| -> bool {
1809                    let trimmed = raw_line.trim();
1810                    // Link reference definitions: always exempt
1811                    if trimmed.starts_with('[') && trimmed.contains("]:") && LINK_REF_PATTERN.is_match(trimmed) {
1812                        return true;
1813                    }
1814                    // Also check after stripping list markers (for list item content)
1815                    if is_list_item(trimmed) {
1816                        let (_, content) = extract_list_marker_and_content(trimmed);
1817                        let content_trimmed = content.trim();
1818                        if content_trimmed.starts_with('[')
1819                            && content_trimmed.contains("]:")
1820                            && LINK_REF_PATTERN.is_match(content_trimmed)
1821                        {
1822                            return true;
1823                        }
1824                    }
1825                    // Standalone link/image lines: exempt when not strict
1826                    if !config.strict && is_standalone_link_or_image_line(raw_line) {
1827                        return true;
1828                    }
1829                    // HTML-only lines: exempt when not strict
1830                    if !config.strict && is_html_only_line(raw_line) {
1831                        return true;
1832                    }
1833                    false
1834                };
1835
1836                // Check if reflowing is needed (only for content paragraphs, not code blocks or nested lists)
1837                // Exclude link reference definitions and standalone link lines from content
1838                // so they don't pollute combined_content or trigger false reflow.
1839                let content_lines: Vec<String> = list_item_lines
1840                    .iter()
1841                    .filter_map(|line| {
1842                        if let LineType::Content(s) = line {
1843                            if is_exempt_line(s) {
1844                                return None;
1845                            }
1846                            Some(s.clone())
1847                        } else {
1848                            None
1849                        }
1850                    })
1851                    .collect();
1852
1853                // Check if we need to reflow this list item
1854                // We check the combined content to see if it exceeds length limits
1855                let combined_content = content_lines.join(" ").trim().to_string();
1856
1857                // Helper to check if we should reflow in normalize mode
1858                let should_normalize = || {
1859                    // Don't normalize if the list item only contains nested lists, code blocks, or semantic lines
1860                    // DO normalize if it has plain text content that spans multiple lines
1861                    let has_code_blocks = blocks.iter().any(|b| matches!(b, Block::Code { .. }));
1862                    let has_semantic_lines = blocks.iter().any(|b| matches!(b, Block::SemanticLine(_)));
1863                    let has_snippet_lines = blocks.iter().any(|b| matches!(b, Block::SnippetLine(_)));
1864                    let has_div_markers = blocks.iter().any(|b| matches!(b, Block::DivMarker(_)));
1865                    let has_admonitions = blocks.iter().any(|b| matches!(b, Block::Admonition { .. }));
1866                    let has_tables = blocks.iter().any(|b| matches!(b, Block::Table { .. }));
1867                    let has_paragraphs = blocks.iter().any(|b| matches!(b, Block::Paragraph(_)));
1868
1869                    // If we have structural blocks but no paragraphs, don't normalize
1870                    if (has_code_blocks
1871                        || has_semantic_lines
1872                        || has_snippet_lines
1873                        || has_div_markers
1874                        || has_admonitions
1875                        || has_tables)
1876                        && !has_paragraphs
1877                    {
1878                        return false;
1879                    }
1880
1881                    // If we have paragraphs, check if they span multiple lines or there are multiple blocks
1882                    if has_paragraphs {
1883                        // Count only paragraphs that contain at least one non-exempt line.
1884                        // Paragraphs consisting entirely of link ref defs or standalone links
1885                        // should not trigger normalization.
1886                        let paragraph_count = blocks
1887                            .iter()
1888                            .filter(|b| {
1889                                if let Block::Paragraph(para_lines) = b {
1890                                    !para_lines.iter().all(|line| is_exempt_line(line))
1891                                } else {
1892                                    false
1893                                }
1894                            })
1895                            .count();
1896                        if paragraph_count > 1 {
1897                            // Multiple non-exempt paragraph blocks should be normalized
1898                            return true;
1899                        }
1900
1901                        // Single paragraph block: normalize if it has multiple content lines
1902                        if content_lines.len() > 1 {
1903                            return true;
1904                        }
1905                    }
1906
1907                    false
1908                };
1909
1910                let needs_reflow = match config.reflow_mode {
1911                    ReflowMode::Normalize => {
1912                        // Only reflow if:
1913                        // 1. Any non-exempt paragraph, when joined, exceeds the limit, OR
1914                        // 2. Any admonition content line exceeds the limit, OR
1915                        // 3. The list item should be normalized (has multi-line plain text)
1916                        let any_paragraph_exceeds = blocks.iter().any(|block| match block {
1917                            Block::Paragraph(para_lines) => {
1918                                if para_lines.iter().all(|line| is_exempt_line(line)) {
1919                                    return false;
1920                                }
1921                                let joined = para_lines.join(" ");
1922                                let with_marker = format!("{}{}", " ".repeat(indent_size), joined.trim());
1923                                self.calculate_effective_length(&with_marker) > config.line_length.get()
1924                            }
1925                            Block::Admonition {
1926                                content_lines,
1927                                header_indent,
1928                                ..
1929                            } => content_lines.iter().any(|(content, indent)| {
1930                                if content.is_empty() {
1931                                    return false;
1932                                }
1933                                let with_indent = format!("{}{}", " ".repeat(*indent.max(header_indent)), content);
1934                                self.calculate_effective_length(&with_indent) > config.line_length.get()
1935                            }),
1936                            _ => false,
1937                        });
1938                        if any_paragraph_exceeds {
1939                            true
1940                        } else {
1941                            should_normalize()
1942                        }
1943                    }
1944                    ReflowMode::SentencePerLine => {
1945                        // Check if list item has multiple sentences
1946                        let sentences = split_into_sentences(&combined_content);
1947                        sentences.len() > 1
1948                    }
1949                    ReflowMode::SemanticLineBreaks => {
1950                        let sentences = split_into_sentences(&combined_content);
1951                        sentences.len() > 1
1952                            || (list_start..i).any(|line_idx| {
1953                                let line = lines[line_idx];
1954                                let trimmed = line.trim();
1955                                if trimmed.is_empty() || is_exempt_line(line) {
1956                                    return false;
1957                                }
1958                                self.calculate_effective_length(line) > config.line_length.get()
1959                            })
1960                    }
1961                    ReflowMode::Default => {
1962                        // In default mode, only reflow if any individual non-exempt line exceeds limit
1963                        (list_start..i).any(|line_idx| {
1964                            let line = lines[line_idx];
1965                            let trimmed = line.trim();
1966                            // Skip blank lines and exempt lines
1967                            if trimmed.is_empty() || is_exempt_line(line) {
1968                                return false;
1969                            }
1970                            self.calculate_effective_length(line) > config.line_length.get()
1971                        })
1972                    }
1973                };
1974
1975                if needs_reflow {
1976                    let start_range = line_index.whole_line_range(list_start + 1);
1977                    let end_line = i - 1;
1978                    let end_range = if end_line == lines.len() - 1 && !ctx.content.ends_with('\n') {
1979                        line_index.line_text_range(end_line + 1, 1, lines[end_line].len() + 1)
1980                    } else {
1981                        line_index.whole_line_range(end_line + 1)
1982                    };
1983                    let byte_range = start_range.start..end_range.end;
1984
1985                    // Reflow each block (paragraphs only, preserve code blocks)
1986                    // When line_length = 0 (no limit), use a very large value for reflow
1987                    let reflow_line_length = if config.line_length.is_unlimited() {
1988                        usize::MAX
1989                    } else {
1990                        config.line_length.get().saturating_sub(indent_size).max(1)
1991                    };
1992                    let reflow_options = crate::utils::text_reflow::ReflowOptions {
1993                        line_length: reflow_line_length,
1994                        break_on_sentences: true,
1995                        preserve_breaks: false,
1996                        sentence_per_line: config.reflow_mode == ReflowMode::SentencePerLine,
1997                        semantic_line_breaks: config.reflow_mode == ReflowMode::SemanticLineBreaks,
1998                        abbreviations: config.abbreviations_for_reflow(),
1999                        length_mode: self.reflow_length_mode(),
2000                        attr_lists: ctx.flavor.supports_attr_lists(),
2001                        require_sentence_capital: config.require_sentence_capital,
2002                        max_list_continuation_indent: if ctx.flavor.requires_strict_list_indent() {
2003                            Some(4)
2004                        } else {
2005                            None
2006                        },
2007                    };
2008
2009                    let mut result: Vec<String> = Vec::new();
2010                    let mut is_first_block = true;
2011
2012                    for (block_idx, block) in blocks.iter().enumerate() {
2013                        match block {
2014                            Block::Paragraph(para_lines) => {
2015                                // If every line in this paragraph is exempt (link ref defs,
2016                                // standalone links), preserve the paragraph verbatim instead
2017                                // of reflowing it. Reflowing would corrupt link ref defs.
2018                                let all_exempt = para_lines.iter().all(|line| is_exempt_line(line));
2019
2020                                if all_exempt {
2021                                    for (idx, line) in para_lines.iter().enumerate() {
2022                                        if is_first_block && idx == 0 {
2023                                            result.push(format!("{marker}{line}"));
2024                                            is_first_block = false;
2025                                        } else {
2026                                            result.push(format!("{expected_indent}{line}"));
2027                                        }
2028                                    }
2029                                } else {
2030                                    // Split the paragraph into segments at hard break boundaries
2031                                    // Each segment can be reflowed independently
2032                                    let segments = split_into_segments(para_lines);
2033
2034                                    for (segment_idx, segment) in segments.iter().enumerate() {
2035                                        // Check if this segment ends with a hard break and what type
2036                                        let hard_break_type = segment.last().and_then(|line| {
2037                                            let line = line.strip_suffix('\r').unwrap_or(line);
2038                                            if line.ends_with('\\') {
2039                                                Some("\\")
2040                                            } else if line.ends_with("  ") {
2041                                                Some("  ")
2042                                            } else {
2043                                                None
2044                                            }
2045                                        });
2046
2047                                        // Join and reflow the segment (removing the hard break marker for processing)
2048                                        let segment_for_reflow: Vec<String> = segment
2049                                            .iter()
2050                                            .map(|line| {
2051                                                // Strip hard break marker (2 spaces or backslash) for reflow processing
2052                                                if line.ends_with('\\') {
2053                                                    line[..line.len() - 1].trim_end().to_string()
2054                                                } else if line.ends_with("  ") {
2055                                                    line[..line.len() - 2].trim_end().to_string()
2056                                                } else {
2057                                                    line.clone()
2058                                                }
2059                                            })
2060                                            .collect();
2061
2062                                        let segment_text = segment_for_reflow.join(" ").trim().to_string();
2063                                        if !segment_text.is_empty() {
2064                                            let reflowed =
2065                                                crate::utils::text_reflow::reflow_line(&segment_text, &reflow_options);
2066
2067                                            if is_first_block && segment_idx == 0 {
2068                                                // First segment of first block starts with marker
2069                                                result.push(format!("{marker}{}", reflowed[0]));
2070                                                for line in reflowed.iter().skip(1) {
2071                                                    result.push(format!("{expected_indent}{line}"));
2072                                                }
2073                                                is_first_block = false;
2074                                            } else {
2075                                                // Subsequent segments
2076                                                for line in reflowed {
2077                                                    result.push(format!("{expected_indent}{line}"));
2078                                                }
2079                                            }
2080
2081                                            // If this segment had a hard break, add it back to the last line
2082                                            // Preserve the original hard break format (backslash or two spaces)
2083                                            if let Some(break_marker) = hard_break_type
2084                                                && let Some(last_line) = result.last_mut()
2085                                            {
2086                                                last_line.push_str(break_marker);
2087                                            }
2088                                        }
2089                                    }
2090                                }
2091
2092                                // Add blank line after paragraph block if there's a next block.
2093                                // Check if next block is a code block that doesn't want a preceding blank.
2094                                // Also don't add blank lines before snippet lines (they should stay tight).
2095                                // Only add if not already ending with one (avoids double blanks).
2096                                if block_idx < blocks.len() - 1 {
2097                                    let next_block = &blocks[block_idx + 1];
2098                                    let should_add_blank = match next_block {
2099                                        Block::Code {
2100                                            has_preceding_blank, ..
2101                                        } => *has_preceding_blank,
2102                                        Block::Table {
2103                                            has_preceding_blank, ..
2104                                        } => *has_preceding_blank,
2105                                        Block::SnippetLine(_) | Block::DivMarker(_) => false,
2106                                        _ => true, // For all other blocks, add blank line
2107                                    };
2108                                    if should_add_blank && result.last().is_none_or(|s: &String| !s.is_empty()) {
2109                                        result.push(String::new());
2110                                    }
2111                                }
2112                            }
2113                            Block::Code {
2114                                lines: code_lines,
2115                                has_preceding_blank: _,
2116                            } => {
2117                                // Preserve code blocks as-is with original indentation
2118                                // NOTE: Blank line before code block is handled by the previous block
2119                                // (see paragraph block's logic above)
2120
2121                                for (idx, (content, orig_indent)) in code_lines.iter().enumerate() {
2122                                    if is_first_block && idx == 0 {
2123                                        // First line of first block gets marker
2124                                        result.push(format!(
2125                                            "{marker}{}",
2126                                            " ".repeat(orig_indent - marker_len) + content
2127                                        ));
2128                                        is_first_block = false;
2129                                    } else if content.is_empty() {
2130                                        result.push(String::new());
2131                                    } else {
2132                                        result.push(format!("{}{}", " ".repeat(*orig_indent), content));
2133                                    }
2134                                }
2135                            }
2136                            Block::SemanticLine(content) => {
2137                                // Preserve semantic lines (NOTE:, WARNING:, etc.) as-is on their own line.
2138                                // Only add blank before if not already ending with one.
2139                                if !is_first_block && result.last().is_none_or(|s: &String| !s.is_empty()) {
2140                                    result.push(String::new());
2141                                }
2142
2143                                if is_first_block {
2144                                    // First block starts with marker
2145                                    result.push(format!("{marker}{content}"));
2146                                    is_first_block = false;
2147                                } else {
2148                                    // Subsequent blocks use expected indent
2149                                    result.push(format!("{expected_indent}{content}"));
2150                                }
2151
2152                                // Add blank line after semantic line if there's a next block.
2153                                // Only add if not already ending with one.
2154                                if block_idx < blocks.len() - 1 {
2155                                    let next_block = &blocks[block_idx + 1];
2156                                    let should_add_blank = match next_block {
2157                                        Block::Code {
2158                                            has_preceding_blank, ..
2159                                        } => *has_preceding_blank,
2160                                        Block::Table {
2161                                            has_preceding_blank, ..
2162                                        } => *has_preceding_blank,
2163                                        Block::SnippetLine(_) | Block::DivMarker(_) => false,
2164                                        _ => true, // For all other blocks, add blank line
2165                                    };
2166                                    if should_add_blank && result.last().is_none_or(|s: &String| !s.is_empty()) {
2167                                        result.push(String::new());
2168                                    }
2169                                }
2170                            }
2171                            Block::SnippetLine(content) => {
2172                                // Preserve snippet delimiters (-8<-) as-is on their own line
2173                                // Unlike semantic lines, snippet lines don't add extra blank lines
2174                                if is_first_block {
2175                                    // First block starts with marker
2176                                    result.push(format!("{marker}{content}"));
2177                                    is_first_block = false;
2178                                } else {
2179                                    // Subsequent blocks use expected indent
2180                                    result.push(format!("{expected_indent}{content}"));
2181                                }
2182                                // No blank lines added before or after snippet delimiters
2183                            }
2184                            Block::DivMarker(content) => {
2185                                // Preserve div markers (::: opening or closing) as-is on their own line
2186                                if is_first_block {
2187                                    result.push(format!("{marker}{content}"));
2188                                    is_first_block = false;
2189                                } else {
2190                                    result.push(format!("{expected_indent}{content}"));
2191                                }
2192                            }
2193                            Block::Html {
2194                                lines: html_lines,
2195                                has_preceding_blank: _,
2196                            } => {
2197                                // Preserve HTML blocks exactly as-is with original indentation
2198                                // NOTE: Blank line before HTML block is handled by the previous block
2199
2200                                for (idx, line) in html_lines.iter().enumerate() {
2201                                    if is_first_block && idx == 0 {
2202                                        // First line of first block gets marker
2203                                        result.push(format!("{marker}{line}"));
2204                                        is_first_block = false;
2205                                    } else if line.is_empty() {
2206                                        // Preserve blank lines inside HTML blocks
2207                                        result.push(String::new());
2208                                    } else {
2209                                        // Preserve lines with their original content (already includes indentation)
2210                                        result.push(format!("{expected_indent}{line}"));
2211                                    }
2212                                }
2213
2214                                // Add blank line after HTML block if there's a next block.
2215                                // Only add if not already ending with one (avoids double blanks
2216                                // when the HTML block itself contained a trailing blank line).
2217                                if block_idx < blocks.len() - 1 {
2218                                    let next_block = &blocks[block_idx + 1];
2219                                    let should_add_blank = match next_block {
2220                                        Block::Code {
2221                                            has_preceding_blank, ..
2222                                        } => *has_preceding_blank,
2223                                        Block::Html {
2224                                            has_preceding_blank, ..
2225                                        } => *has_preceding_blank,
2226                                        Block::Table {
2227                                            has_preceding_blank, ..
2228                                        } => *has_preceding_blank,
2229                                        Block::SnippetLine(_) | Block::DivMarker(_) => false,
2230                                        _ => true, // For all other blocks, add blank line
2231                                    };
2232                                    if should_add_blank && result.last().is_none_or(|s: &String| !s.is_empty()) {
2233                                        result.push(String::new());
2234                                    }
2235                                }
2236                            }
2237                            Block::Table {
2238                                lines: table_lines,
2239                                has_preceding_blank: _,
2240                            } => {
2241                                // Preserve table rows verbatim with their original indentation.
2242                                // Reflowing rows would corrupt column alignment and inject `|`
2243                                // characters mid-paragraph (issue #590).
2244                                // The leading blank line is emitted by the previous block.
2245                                for (idx, (content, orig_indent)) in table_lines.iter().enumerate() {
2246                                    if is_first_block && idx == 0 {
2247                                        // First line of first block gets the list marker
2248                                        result.push(format!(
2249                                            "{marker}{}",
2250                                            " ".repeat(orig_indent.saturating_sub(marker_len)) + content
2251                                        ));
2252                                        is_first_block = false;
2253                                    } else {
2254                                        result.push(format!("{}{}", " ".repeat(*orig_indent), content));
2255                                    }
2256                                }
2257
2258                                // Add blank line after table block if there's a next block.
2259                                if block_idx < blocks.len() - 1 {
2260                                    let next_block = &blocks[block_idx + 1];
2261                                    let should_add_blank = match next_block {
2262                                        Block::Code {
2263                                            has_preceding_blank, ..
2264                                        } => *has_preceding_blank,
2265                                        Block::Html {
2266                                            has_preceding_blank, ..
2267                                        } => *has_preceding_blank,
2268                                        Block::Table {
2269                                            has_preceding_blank, ..
2270                                        } => *has_preceding_blank,
2271                                        Block::SnippetLine(_) | Block::DivMarker(_) => false,
2272                                        _ => true,
2273                                    };
2274                                    if should_add_blank && result.last().is_none_or(|s: &String| !s.is_empty()) {
2275                                        result.push(String::new());
2276                                    }
2277                                }
2278                            }
2279                            Block::Admonition {
2280                                header,
2281                                header_indent,
2282                                content_lines: admon_lines,
2283                            } => {
2284                                // Reconstruct admonition block with header at original indent
2285                                // and body content reflowed to fit within the line length limit
2286
2287                                // Add blank line before admonition if not first block
2288                                if !is_first_block && result.last().is_none_or(|s: &String| !s.is_empty()) {
2289                                    result.push(String::new());
2290                                }
2291
2292                                // Output the header at its original indent
2293                                let header_indent_str = " ".repeat(*header_indent);
2294                                if is_first_block {
2295                                    result.push(format!(
2296                                        "{marker}{}",
2297                                        " ".repeat(header_indent.saturating_sub(marker_len)) + header
2298                                    ));
2299                                    is_first_block = false;
2300                                } else {
2301                                    result.push(format!("{header_indent_str}{header}"));
2302                                }
2303
2304                                // Derive body indent from the first non-empty content line's
2305                                // stored indent, falling back to header_indent + 4 for
2306                                // empty-body admonitions
2307                                let body_indent = admon_lines
2308                                    .iter()
2309                                    .find(|(content, _)| !content.is_empty())
2310                                    .map_or(header_indent + 4, |(_, indent)| *indent);
2311                                let body_indent_str = " ".repeat(body_indent);
2312
2313                                // Segment body content into code blocks (verbatim) and
2314                                // text paragraphs (reflowable), separated by blank lines.
2315                                // Code lines store (content, orig_indent) to reconstruct
2316                                // internal indentation relative to body_indent.
2317                                enum AdmonSegment {
2318                                    Text(Vec<String>),
2319                                    Code(Vec<(String, usize)>),
2320                                }
2321
2322                                let mut segments: Vec<AdmonSegment> = Vec::new();
2323                                let mut current_text: Vec<String> = Vec::new();
2324                                let mut current_code: Vec<(String, usize)> = Vec::new();
2325                                let mut in_admon_code = false;
2326                                // Track the opening fence character so closing fences
2327                                // must match (backticks close backticks, tildes close tildes)
2328                                let mut fence_char: char = '`';
2329
2330                                // Opening fences: ``` or ~~~ followed by optional info string
2331                                let get_opening_fence = |s: &str| -> Option<(char, usize)> {
2332                                    let t = s.trim_start();
2333                                    if t.starts_with("```") {
2334                                        Some(('`', t.bytes().take_while(|&b| b == b'`').count()))
2335                                    } else if t.starts_with("~~~") {
2336                                        Some(('~', t.bytes().take_while(|&b| b == b'~').count()))
2337                                    } else {
2338                                        None
2339                                    }
2340                                };
2341                                // Closing fences: ONLY fence chars + optional trailing spaces
2342                                let get_closing_fence = |s: &str| -> Option<(char, usize)> {
2343                                    let t = s.trim();
2344                                    if t.starts_with("```") && t.bytes().all(|b| b == b'`') {
2345                                        Some(('`', t.len()))
2346                                    } else if t.starts_with("~~~") && t.bytes().all(|b| b == b'~') {
2347                                        Some(('~', t.len()))
2348                                    } else {
2349                                        None
2350                                    }
2351                                };
2352                                let mut fence_len: usize = 3;
2353
2354                                for (content, orig_indent) in admon_lines {
2355                                    if in_admon_code {
2356                                        // Closing fence must use the same character, be
2357                                        // at least as long, and have no info string
2358                                        if let Some((ch, len)) = get_closing_fence(content)
2359                                            && ch == fence_char
2360                                            && len >= fence_len
2361                                        {
2362                                            current_code.push((content.clone(), *orig_indent));
2363                                            in_admon_code = false;
2364                                            segments.push(AdmonSegment::Code(std::mem::take(&mut current_code)));
2365                                            continue;
2366                                        }
2367                                        current_code.push((content.clone(), *orig_indent));
2368                                    } else if let Some((ch, len)) = get_opening_fence(content) {
2369                                        if !current_text.is_empty() {
2370                                            segments.push(AdmonSegment::Text(std::mem::take(&mut current_text)));
2371                                        }
2372                                        in_admon_code = true;
2373                                        fence_char = ch;
2374                                        fence_len = len;
2375                                        current_code.push((content.clone(), *orig_indent));
2376                                    } else if content.is_empty() {
2377                                        if !current_text.is_empty() {
2378                                            segments.push(AdmonSegment::Text(std::mem::take(&mut current_text)));
2379                                        }
2380                                    } else {
2381                                        current_text.push(content.clone());
2382                                    }
2383                                }
2384                                if in_admon_code && !current_code.is_empty() {
2385                                    segments.push(AdmonSegment::Code(std::mem::take(&mut current_code)));
2386                                }
2387                                if !current_text.is_empty() {
2388                                    segments.push(AdmonSegment::Text(std::mem::take(&mut current_text)));
2389                                }
2390
2391                                // Build reflow options once for all text segments
2392                                let admon_reflow_length = if config.line_length.is_unlimited() {
2393                                    usize::MAX
2394                                } else {
2395                                    config.line_length.get().saturating_sub(body_indent).max(1)
2396                                };
2397
2398                                let admon_reflow_options = crate::utils::text_reflow::ReflowOptions {
2399                                    line_length: admon_reflow_length,
2400                                    break_on_sentences: true,
2401                                    preserve_breaks: false,
2402                                    sentence_per_line: config.reflow_mode == ReflowMode::SentencePerLine,
2403                                    semantic_line_breaks: config.reflow_mode == ReflowMode::SemanticLineBreaks,
2404                                    abbreviations: config.abbreviations_for_reflow(),
2405                                    length_mode: self.reflow_length_mode(),
2406                                    attr_lists: ctx.flavor.supports_attr_lists(),
2407                                    require_sentence_capital: config.require_sentence_capital,
2408                                    max_list_continuation_indent: if ctx.flavor.requires_strict_list_indent() {
2409                                        Some(4)
2410                                    } else {
2411                                        None
2412                                    },
2413                                };
2414
2415                                // Output each segment
2416                                for segment in &segments {
2417                                    // Blank line before each segment (after the header or previous segment)
2418                                    result.push(String::new());
2419
2420                                    match segment {
2421                                        AdmonSegment::Code(lines) => {
2422                                            for (line, orig_indent) in lines {
2423                                                if line.is_empty() {
2424                                                    // Preserve blank lines inside code blocks
2425                                                    result.push(String::new());
2426                                                } else {
2427                                                    // Reconstruct with body_indent + any extra
2428                                                    // indentation the line had beyond body_indent
2429                                                    let extra = orig_indent.saturating_sub(body_indent);
2430                                                    let indent_str = " ".repeat(body_indent + extra);
2431                                                    result.push(format!("{indent_str}{line}"));
2432                                                }
2433                                            }
2434                                        }
2435                                        AdmonSegment::Text(lines) => {
2436                                            let paragraph_text = lines.join(" ").trim().to_string();
2437                                            if paragraph_text.is_empty() {
2438                                                continue;
2439                                            }
2440                                            let reflowed = crate::utils::text_reflow::reflow_line(
2441                                                &paragraph_text,
2442                                                &admon_reflow_options,
2443                                            );
2444                                            for line in &reflowed {
2445                                                result.push(format!("{body_indent_str}{line}"));
2446                                            }
2447                                        }
2448                                    }
2449                                }
2450
2451                                // Add blank line after admonition if there's a next block
2452                                if block_idx < blocks.len() - 1 {
2453                                    let next_block = &blocks[block_idx + 1];
2454                                    let should_add_blank = match next_block {
2455                                        Block::Code {
2456                                            has_preceding_blank, ..
2457                                        } => *has_preceding_blank,
2458                                        Block::Table {
2459                                            has_preceding_blank, ..
2460                                        } => *has_preceding_blank,
2461                                        Block::SnippetLine(_) | Block::DivMarker(_) => false,
2462                                        _ => true,
2463                                    };
2464                                    if should_add_blank && result.last().is_none_or(|s: &String| !s.is_empty()) {
2465                                        result.push(String::new());
2466                                    }
2467                                }
2468                            }
2469                        }
2470                    }
2471
2472                    let reflowed_text = result.join(line_ending);
2473
2474                    // Preserve trailing newline
2475                    let replacement = if end_line < lines.len() - 1 || ctx.content.ends_with('\n') {
2476                        format!("{reflowed_text}{line_ending}")
2477                    } else {
2478                        reflowed_text
2479                    };
2480
2481                    // Get the original text to compare
2482                    let original_text = &ctx.content[byte_range.clone()];
2483
2484                    // Physical-line-length scan, shared by the Normalize-mode gate and its
2485                    // message. The list-item reflow preserves code blocks, HTML blocks,
2486                    // admonition headers, fence markers, semantic markers, and snippet/div
2487                    // markers verbatim; only paragraph content and admonition bodies are
2488                    // restructured. Only those lines drive the length warning, so that
2489                    // preserved-but-overlong content does not keep the paragraph-level
2490                    // warning alive when the reflow would not fix that line.
2491                    let should_count_for_length = |line_idx: usize| -> bool {
2492                        let line = lines[line_idx];
2493                        let trimmed = line.trim();
2494                        if trimmed.is_empty() || is_exempt_line(line) {
2495                            return false;
2496                        }
2497                        let info = &ctx.lines[line_idx];
2498                        if info.in_code_block || info.in_html_block {
2499                            return false;
2500                        }
2501                        if info.in_admonition && mkdocs_admonitions::is_admonition_start(line) {
2502                            return false;
2503                        }
2504                        if is_fence_marker(line) || is_semantic_line(line) {
2505                            return false;
2506                        }
2507                        if is_snippet_block_delimiter(line) {
2508                            return false;
2509                        }
2510                        if line.trim_start().starts_with(":::") {
2511                            return false;
2512                        }
2513                        true
2514                    };
2515                    let max_physical_length = (list_start..i)
2516                        .filter(|&idx| should_count_for_length(idx))
2517                        .map(|idx| self.calculate_effective_length(lines[idx]))
2518                        .max()
2519                        .unwrap_or(0);
2520                    // `line-length = 0` means "no limit" — never emit a length warning in
2521                    // that configuration, even when the reflow would restructure content.
2522                    let any_paragraph_line_over =
2523                        !config.line_length.is_unlimited() && max_physical_length > config.line_length.get();
2524
2525                    // Only generate a warning if the replacement is different from the original.
2526                    // For Normalize mode, additionally require that at least one physical
2527                    // content line exceeds the limit — otherwise the reflow is a cosmetic
2528                    // change (continuation-indent normalization or joining/splitting
2529                    // already-fitting multi-line paragraphs) and should not be reported as
2530                    // a length violation. SentencePerLine and SemanticLineBreaks modes warn
2531                    // on sentence structure, not length, so they ignore this gate.
2532                    let gate_ok = match config.reflow_mode {
2533                        ReflowMode::Normalize => original_text != replacement && any_paragraph_line_over,
2534                        _ => original_text != replacement,
2535                    };
2536                    if gate_ok {
2537                        // Generate an appropriate message based on why reflow is needed
2538                        let message = match config.reflow_mode {
2539                            ReflowMode::SentencePerLine => {
2540                                let num_sentences = split_into_sentences(&combined_content).len();
2541                                let num_lines = content_lines.len();
2542                                if num_lines == 1 {
2543                                    // Single line with multiple sentences
2544                                    format!("Line contains {num_sentences} sentences (one sentence per line required)")
2545                                } else {
2546                                    // Multiple lines - could be split sentences or mixed
2547                                    format!(
2548                                        "Paragraph should have one sentence per line (found {num_sentences} sentences across {num_lines} lines)"
2549                                    )
2550                                }
2551                            }
2552                            ReflowMode::SemanticLineBreaks => {
2553                                let num_sentences = split_into_sentences(&combined_content).len();
2554                                format!("Paragraph should use semantic line breaks ({num_sentences} sentences)")
2555                            }
2556                            ReflowMode::Normalize => {
2557                                // Report the physical line length of the longest over-limit
2558                                // content line. The gate above guarantees at least one.
2559                                format!(
2560                                    "Line length {} exceeds {} characters",
2561                                    max_physical_length,
2562                                    config.line_length.get()
2563                                )
2564                            }
2565                            ReflowMode::Default => {
2566                                // Report the actual longest non-exempt line, not the combined content
2567                                let max_length = (list_start..i)
2568                                    .filter(|&line_idx| {
2569                                        let line = lines[line_idx];
2570                                        let trimmed = line.trim();
2571                                        !trimmed.is_empty() && !is_exempt_line(line)
2572                                    })
2573                                    .map(|line_idx| self.calculate_effective_length(lines[line_idx]))
2574                                    .max()
2575                                    .unwrap_or(0);
2576                                format!(
2577                                    "Line length {} exceeds {} characters",
2578                                    max_length,
2579                                    config.line_length.get()
2580                                )
2581                            }
2582                        };
2583
2584                        warnings.push(LintWarning {
2585                            rule_name: Some(self.name().to_string()),
2586                            message,
2587                            line: list_start + 1,
2588                            column: 1,
2589                            end_line: end_line + 1,
2590                            end_column: lines[end_line].len() + 1,
2591                            severity: Severity::Warning,
2592                            fix: Some(crate::rule::Fix::new(byte_range, replacement)),
2593                        });
2594                    }
2595                }
2596                continue;
2597            }
2598
2599            // Found start of a paragraph - collect all lines in it
2600            let paragraph_start = i;
2601            let mut paragraph_lines = vec![lines[i]];
2602            i += 1;
2603
2604            while i < lines.len() {
2605                let next_line = lines[i];
2606                let next_line_num = i + 1;
2607                let next_trimmed = next_line.trim();
2608
2609                // Stop at paragraph boundaries
2610                if next_trimmed.is_empty()
2611                    || ctx.line_info(next_line_num).is_some_and(|info| info.in_code_block)
2612                    || ctx.line_info(next_line_num).is_some_and(|info| info.in_front_matter)
2613                    || ctx.line_info(next_line_num).is_some_and(|info| info.in_html_block)
2614                    || ctx.line_info(next_line_num).is_some_and(|info| info.in_html_comment)
2615                    || ctx.line_info(next_line_num).is_some_and(|info| info.in_esm_block)
2616                    || ctx.line_info(next_line_num).is_some_and(|info| info.in_jsx_expression)
2617                    || ctx.line_info(next_line_num).is_some_and(|info| info.in_jsx_block)
2618                    || ctx.line_info(next_line_num).is_some_and(|info| info.in_mdx_comment)
2619                    || ctx
2620                        .line_info(next_line_num)
2621                        .is_some_and(super::super::lint_context::types::LineInfo::in_mkdocs_container)
2622                    || (next_line_num > 0
2623                        && next_line_num <= ctx.lines.len()
2624                        && ctx.lines[next_line_num - 1].blockquote.is_some())
2625                    || next_trimmed.starts_with('#')
2626                    || TableUtils::is_potential_table_row(next_line)
2627                    || is_list_item(next_trimmed)
2628                    || is_horizontal_rule(next_line)
2629                    || (next_trimmed.starts_with('[') && next_line.contains("]:"))
2630                    || is_template_directive_only(next_line)
2631                    || is_standalone_attr_list(next_line)
2632                    || is_snippet_block_delimiter(next_line)
2633                    || ctx.line_info(next_line_num).is_some_and(|info| info.is_div_marker)
2634                    || is_html_only_line(next_line)
2635                {
2636                    break;
2637                }
2638
2639                // Check if the previous line ends with a hard break (2+ spaces or backslash)
2640                if i > 0 && has_hard_break(lines[i - 1]) {
2641                    // Don't include lines after hard breaks in the same paragraph
2642                    break;
2643                }
2644
2645                paragraph_lines.push(next_line);
2646                i += 1;
2647            }
2648
2649            // Compute the common leading indent of all non-empty paragraph lines,
2650            // but only when those lines are structurally inside a list block.
2651            // Indented continuation lines that follow a nested list arrive here
2652            // with their structural indentation intact (e.g. 2 spaces for a
2653            // top-level list item). Stripping the indent before reflow and
2654            // re-applying it afterward prevents the fixer from moving those
2655            // lines to column 0.
2656            //
2657            // The list-block guard is essential: top-level paragraphs that happen
2658            // to start with spaces (insignificant in Markdown) must NOT have those
2659            // spaces preserved or injected by the fixer.
2660            let common_indent: String = if ctx.is_in_list_block(paragraph_start + 1) {
2661                let min_len = paragraph_lines
2662                    .iter()
2663                    .filter(|l| !l.trim().is_empty())
2664                    .map(|l| l.len() - l.trim_start().len())
2665                    .min()
2666                    .unwrap_or(0);
2667                paragraph_lines
2668                    .iter()
2669                    .find(|l| !l.trim().is_empty())
2670                    .map(|l| l[..min_len].to_string())
2671                    .unwrap_or_default()
2672            } else {
2673                String::new()
2674            };
2675
2676            // Combine paragraph lines into a single string for processing.
2677            // This must be done BEFORE the needs_reflow check for sentence-per-line mode.
2678            let paragraph_text = if common_indent.is_empty() {
2679                paragraph_lines.join(" ")
2680            } else {
2681                paragraph_lines
2682                    .iter()
2683                    .map(|l| {
2684                        if l.starts_with(common_indent.as_str()) {
2685                            &l[common_indent.len()..]
2686                        } else {
2687                            l.trim_start()
2688                        }
2689                    })
2690                    .collect::<Vec<_>>()
2691                    .join(" ")
2692            };
2693
2694            // Skip reflowing if this paragraph contains definition list items
2695            // Definition lists are multi-line structures that should not be joined
2696            let contains_definition_list = paragraph_lines
2697                .iter()
2698                .any(|line| crate::utils::is_definition_list_item(line));
2699
2700            if contains_definition_list {
2701                // Don't reflow definition lists - skip this paragraph
2702                i = paragraph_start + paragraph_lines.len();
2703                continue;
2704            }
2705
2706            // Skip reflowing if this paragraph contains MkDocs Snippets markers
2707            // Snippets blocks (-8<- ... -8<-) should be preserved exactly
2708            let contains_snippets = paragraph_lines.iter().any(|line| is_snippet_block_delimiter(line));
2709
2710            if contains_snippets {
2711                // Don't reflow Snippets blocks - skip this paragraph
2712                i = paragraph_start + paragraph_lines.len();
2713                continue;
2714            }
2715
2716            // Check if this paragraph needs reflowing
2717            let needs_reflow = match config.reflow_mode {
2718                ReflowMode::Normalize => self.normalize_mode_needs_reflow(paragraph_lines.iter().copied(), config),
2719                ReflowMode::SentencePerLine => {
2720                    // In sentence-per-line mode, check if the JOINED paragraph has multiple sentences
2721                    // Note: we check the joined text because sentences can span multiple lines
2722                    let sentences = split_into_sentences(&paragraph_text);
2723
2724                    // Always reflow if multiple sentences on one line
2725                    if sentences.len() > 1 {
2726                        true
2727                    } else if paragraph_lines.len() > 1 {
2728                        // For single-sentence paragraphs spanning multiple lines:
2729                        // Reflow if they COULD fit on one line (respecting line-length constraint)
2730                        if config.line_length.is_unlimited() {
2731                            // No line-length constraint - always join single sentences
2732                            true
2733                        } else {
2734                            // Only join if it fits within line-length.
2735                            // paragraph_text has the common indent stripped, so add it
2736                            // back to get the true output length before comparing.
2737                            let effective_length =
2738                                self.calculate_effective_length(&paragraph_text) + common_indent.len();
2739                            effective_length <= config.line_length.get()
2740                        }
2741                    } else {
2742                        false
2743                    }
2744                }
2745                ReflowMode::SemanticLineBreaks => {
2746                    let sentences = split_into_sentences(&paragraph_text);
2747                    // Reflow if multiple sentences, multiple lines, or any line exceeds limit
2748                    sentences.len() > 1
2749                        || paragraph_lines.len() > 1
2750                        || paragraph_lines
2751                            .iter()
2752                            .any(|line| self.calculate_effective_length(line) > config.line_length.get())
2753                }
2754                ReflowMode::Default => {
2755                    // In default mode, only reflow if lines exceed limit
2756                    paragraph_lines
2757                        .iter()
2758                        .any(|line| self.calculate_effective_length(line) > config.line_length.get())
2759                }
2760            };
2761
2762            if needs_reflow {
2763                // Calculate byte range for this paragraph
2764                // Use whole_line_range for each line and combine
2765                let start_range = line_index.whole_line_range(paragraph_start + 1);
2766                let end_line = paragraph_start + paragraph_lines.len() - 1;
2767
2768                // For the last line, we want to preserve any trailing newline
2769                let end_range = if end_line == lines.len() - 1 && !ctx.content.ends_with('\n') {
2770                    // Last line without trailing newline - use line_text_range
2771                    line_index.line_text_range(end_line + 1, 1, lines[end_line].len() + 1)
2772                } else {
2773                    // Not the last line or has trailing newline - use whole_line_range
2774                    line_index.whole_line_range(end_line + 1)
2775                };
2776
2777                let byte_range = start_range.start..end_range.end;
2778
2779                // Check if the paragraph ends with a hard break and what type
2780                let hard_break_type = paragraph_lines.last().and_then(|line| {
2781                    let line = line.strip_suffix('\r').unwrap_or(line);
2782                    if line.ends_with('\\') {
2783                        Some("\\")
2784                    } else if line.ends_with("  ") {
2785                        Some("  ")
2786                    } else {
2787                        None
2788                    }
2789                });
2790
2791                // Reflow the paragraph
2792                // When line_length = 0 (no limit), use a very large value for reflow
2793                let reflow_line_length = if config.line_length.is_unlimited() {
2794                    usize::MAX
2795                } else {
2796                    config.line_length.get()
2797                };
2798                let reflow_options = crate::utils::text_reflow::ReflowOptions {
2799                    line_length: reflow_line_length,
2800                    break_on_sentences: true,
2801                    preserve_breaks: false,
2802                    sentence_per_line: config.reflow_mode == ReflowMode::SentencePerLine,
2803                    semantic_line_breaks: config.reflow_mode == ReflowMode::SemanticLineBreaks,
2804                    abbreviations: config.abbreviations_for_reflow(),
2805                    length_mode: self.reflow_length_mode(),
2806                    attr_lists: ctx.flavor.supports_attr_lists(),
2807                    require_sentence_capital: config.require_sentence_capital,
2808                    max_list_continuation_indent: if ctx.flavor.requires_strict_list_indent() {
2809                        Some(4)
2810                    } else {
2811                        None
2812                    },
2813                };
2814                let mut reflowed = crate::utils::text_reflow::reflow_line(&paragraph_text, &reflow_options);
2815
2816                // Re-apply the common indent to each non-empty reflowed line so
2817                // that the replacement preserves the original structural indentation.
2818                if !common_indent.is_empty() {
2819                    for line in &mut reflowed {
2820                        if !line.is_empty() {
2821                            *line = format!("{common_indent}{line}");
2822                        }
2823                    }
2824                }
2825
2826                // If the original paragraph ended with a hard break, preserve it
2827                // Preserve the original hard break format (backslash or two spaces)
2828                if let Some(break_marker) = hard_break_type
2829                    && !reflowed.is_empty()
2830                {
2831                    let last_idx = reflowed.len() - 1;
2832                    if !has_hard_break(&reflowed[last_idx]) {
2833                        reflowed[last_idx].push_str(break_marker);
2834                    }
2835                }
2836
2837                let reflowed_text = reflowed.join(line_ending);
2838
2839                // Preserve trailing newline if the original paragraph had one
2840                let replacement = if end_line < lines.len() - 1 || ctx.content.ends_with('\n') {
2841                    format!("{reflowed_text}{line_ending}")
2842                } else {
2843                    reflowed_text
2844                };
2845
2846                // Get the original text to compare
2847                let original_text = &ctx.content[byte_range.clone()];
2848
2849                // Only generate a warning if the replacement is different from the original
2850                if original_text != replacement {
2851                    // Create warning with actual fix
2852                    // In default mode, report the specific line that violates
2853                    // In normalize mode, report the whole paragraph
2854                    // In sentence-per-line mode, report the entire paragraph
2855                    let (warning_line, warning_end_line) = match config.reflow_mode {
2856                        ReflowMode::Normalize => (paragraph_start + 1, end_line + 1),
2857                        ReflowMode::SentencePerLine | ReflowMode::SemanticLineBreaks => {
2858                            // Highlight the entire paragraph that needs reformatting
2859                            (paragraph_start + 1, paragraph_start + paragraph_lines.len())
2860                        }
2861                        ReflowMode::Default => {
2862                            // Find the first line that exceeds the limit
2863                            let mut violating_line = paragraph_start;
2864                            for (idx, line) in paragraph_lines.iter().enumerate() {
2865                                if self.calculate_effective_length(line) > config.line_length.get() {
2866                                    violating_line = paragraph_start + idx;
2867                                    break;
2868                                }
2869                            }
2870                            (violating_line + 1, violating_line + 1)
2871                        }
2872                    };
2873
2874                    warnings.push(LintWarning {
2875                        rule_name: Some(self.name().to_string()),
2876                        message: match config.reflow_mode {
2877                            ReflowMode::Normalize => format!(
2878                                "Paragraph could be normalized to use line length of {} characters",
2879                                config.line_length.get()
2880                            ),
2881                            ReflowMode::SentencePerLine => {
2882                                let num_sentences = split_into_sentences(&paragraph_text).len();
2883                                if paragraph_lines.len() == 1 {
2884                                    // Single line with multiple sentences
2885                                    format!("Line contains {num_sentences} sentences (one sentence per line required)")
2886                                } else {
2887                                    let num_lines = paragraph_lines.len();
2888                                    // Multiple lines - could be split sentences or mixed
2889                                    format!("Paragraph should have one sentence per line (found {num_sentences} sentences across {num_lines} lines)")
2890                                }
2891                            },
2892                            ReflowMode::SemanticLineBreaks => {
2893                                let num_sentences = split_into_sentences(&paragraph_text).len();
2894                                format!(
2895                                    "Paragraph should use semantic line breaks ({num_sentences} sentences)"
2896                                )
2897                            },
2898                            ReflowMode::Default => format!("Line length exceeds {} characters", config.line_length.get()),
2899                        },
2900                        line: warning_line,
2901                        column: 1,
2902                        end_line: warning_end_line,
2903                        end_column: lines[warning_end_line.saturating_sub(1)].len() + 1,
2904                        severity: Severity::Warning,
2905                        fix: Some(crate::rule::Fix::new(byte_range, replacement)),
2906                    });
2907                }
2908            }
2909        }
2910
2911        warnings
2912    }
2913
2914    /// Calculate string length based on the configured length mode
2915    fn calculate_string_length(&self, s: &str) -> usize {
2916        match self.config.length_mode {
2917            LengthMode::Chars => s.chars().count(),
2918            LengthMode::Visual => s.width(),
2919            LengthMode::Bytes => s.len(),
2920        }
2921    }
2922
2923    /// Calculate effective line length
2924    ///
2925    /// Returns the actual display length of the line using the configured length mode.
2926    fn calculate_effective_length(&self, line: &str) -> usize {
2927        self.calculate_string_length(line)
2928    }
2929
2930    /// Calculate line length with inline link/image URLs removed.
2931    ///
2932    /// For each inline link `[text](url)` or image `![alt](url)` on the line,
2933    /// computes the "savings" from removing the URL portion (keeping only `[text]`
2934    /// or `![alt]`). Returns `effective_length - total_savings`.
2935    ///
2936    /// Handles nested constructs (e.g., `[![img](url)](url)`) by only counting the
2937    /// outermost construct to avoid double-counting.
2938    fn calculate_text_only_length(
2939        &self,
2940        effective_length: usize,
2941        line_number: usize,
2942        ctx: &crate::lint_context::LintContext,
2943    ) -> usize {
2944        let line_range = ctx.line_index.line_content_range(line_number);
2945        let line_byte_end = line_range.end;
2946
2947        // Collect inline links/images on this line: (byte_offset, byte_end, text_only_display_len)
2948        let mut constructs: Vec<(usize, usize, usize)> = Vec::new();
2949
2950        // Binary search: links are sorted by byte_offset, so link.line is non-decreasing
2951        let link_start = ctx.links.partition_point(|l| l.line < line_number);
2952        for link in &ctx.links[link_start..] {
2953            if link.line != line_number {
2954                break;
2955            }
2956            if link.is_reference {
2957                continue;
2958            }
2959            if !matches!(link.link_type, LinkType::Inline) {
2960                continue;
2961            }
2962            if link.byte_end > line_byte_end {
2963                continue;
2964            }
2965            let text_only_len = 2 + self.calculate_string_length(&link.text);
2966            constructs.push((link.byte_offset, link.byte_end, text_only_len));
2967        }
2968
2969        let img_start = ctx.images.partition_point(|i| i.line < line_number);
2970        for image in &ctx.images[img_start..] {
2971            if image.line != line_number {
2972                break;
2973            }
2974            if image.is_reference {
2975                continue;
2976            }
2977            if !matches!(image.link_type, LinkType::Inline) {
2978                continue;
2979            }
2980            if image.byte_end > line_byte_end {
2981                continue;
2982            }
2983            let text_only_len = 3 + self.calculate_string_length(&image.alt_text);
2984            constructs.push((image.byte_offset, image.byte_end, text_only_len));
2985        }
2986
2987        if constructs.is_empty() {
2988            return effective_length;
2989        }
2990
2991        // Sort by byte offset to handle overlapping/nested constructs
2992        constructs.sort_by_key(|&(start, _, _)| start);
2993
2994        let mut total_savings: usize = 0;
2995        let mut last_end: usize = 0;
2996
2997        for (start, end, text_only_len) in &constructs {
2998            // Skip constructs nested inside a previously counted one
2999            if *start < last_end {
3000                continue;
3001            }
3002            // Full construct length in configured length mode
3003            let full_source = &ctx.content[*start..*end];
3004            let full_len = self.calculate_string_length(full_source);
3005            total_savings += full_len.saturating_sub(*text_only_len);
3006            last_end = *end;
3007        }
3008
3009        effective_length.saturating_sub(total_savings)
3010    }
3011}