panache-parser 0.1.0

use std::collections::HashMap;
use std::env;
use std::fs;
use std::io;
use std::path::{Path, PathBuf};

use globset::GlobBuilder;
use serde::{Deserialize, Deserializer, Serialize};

mod formatter_presets;
pub use formatter_presets::FormatterPresetMetadata;

/// The flavor of Markdown to parse and format.
/// Each flavor has a different set of default extensions enabled.
#[derive(Debug, Clone, Copy, Deserialize, PartialEq, Eq, Default)]
#[serde(rename_all = "kebab-case")]
pub enum Flavor {
    /// Standard Pandoc Markdown (default extensions enabled)
    #[default]
    Pandoc,
    /// Quarto (Pandoc + Quarto-specific extensions)
    Quarto,
    /// R Markdown (Pandoc + R-specific extensions)
    #[serde(rename = "rmarkdown")]
    RMarkdown,
    /// GitHub Flavored Markdown
    Gfm,
    /// CommonMark
    CommonMark,
    /// MultiMarkdown
    #[serde(rename = "multimarkdown")]
    MultiMarkdown,
}

/// Pandoc/Markdown extensions configuration.
/// Each field represents a specific Pandoc extension.
/// Extensions marked with a comment indicate implementation status.
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
#[serde(default)]
#[serde(rename_all = "kebab-case")]
pub struct Extensions {
    // ===== Block-level extensions =====

    // Headings
    /// Require blank line before headers (default: enabled)
    #[serde(alias = "blank_before_header")]
    pub blank_before_header: bool,
    /// Full attribute syntax on headers {#id .class key=value}
    #[serde(alias = "header_attributes")]
    pub header_attributes: bool,
    /// Auto-generate identifiers from headings
    pub auto_identifiers: bool,
    /// Use GitHub's algorithm for auto-generated heading identifiers
    pub gfm_auto_identifiers: bool,
    /// Implicit header references ([Heading] links to header)
    pub implicit_header_references: bool,

    // Block quotes
    /// Require blank line before blockquotes (default: enabled)
    #[serde(alias = "blank_before_blockquote")]
    pub blank_before_blockquote: bool,

    // Lists
    /// Fancy list markers (roman numerals, letters, etc.)
    #[serde(alias = "fancy_lists")]
    pub fancy_lists: bool,
    /// Start ordered lists at arbitrary numbers
    pub startnum: bool,
    /// Example lists with (@) markers
    #[serde(alias = "example_lists")]
    pub example_lists: bool,
    /// GitHub-style task lists - [ ] and - [x]
    #[serde(alias = "task_lists")]
    pub task_lists: bool,
    /// Term/definition syntax
    #[serde(alias = "definition_lists")]
    pub definition_lists: bool,

    // Code blocks
    /// Fenced code blocks with backticks
    #[serde(alias = "backtick_code_blocks")]
    pub backtick_code_blocks: bool,
    /// Fenced code blocks with tildes
    #[serde(alias = "fenced_code_blocks")]
    pub fenced_code_blocks: bool,
    /// Attributes on fenced code blocks {.language #id}
    #[serde(alias = "fenced_code_attributes")]
    pub fenced_code_attributes: bool,
    /// Executable code syntax (currently fenced chunks like ```{r} / ```{python})
    pub executable_code: bool,
    /// R Markdown inline executable code (`...`r ...)
    pub rmarkdown_inline_code: bool,
    /// Quarto inline executable code (`...`{r} ...)
    pub quarto_inline_code: bool,
    /// Attributes on inline code
    #[serde(alias = "inline_code_attributes")]
    pub inline_code_attributes: bool,

    // Tables
    /// Simple table syntax
    #[serde(alias = "simple_tables")]
    pub simple_tables: bool,
    /// Multiline cell content in tables
    #[serde(alias = "multiline_tables")]
    pub multiline_tables: bool,
    /// Grid-style tables
    #[serde(alias = "grid_tables")]
    pub grid_tables: bool,
    /// Pipe tables (GitHub/PHP Markdown style)
    #[serde(alias = "pipe_tables")]
    pub pipe_tables: bool,
    /// Table captions
    #[serde(alias = "table_captions")]
    pub table_captions: bool,

    // Divs
    /// Fenced divs ::: {.class}
    #[serde(alias = "fenced_divs")]
    pub fenced_divs: bool,
    /// HTML <div> elements
    #[serde(alias = "native_divs")]
    pub native_divs: bool,

    // Other block elements
    /// Line blocks for poetry | prefix
    #[serde(alias = "line_blocks")]
    pub line_blocks: bool,

    // ===== Inline elements =====

    // Emphasis
    /// Underscores don't trigger emphasis in snake_case
    #[serde(alias = "intraword_underscores")]
    pub intraword_underscores: bool,
    /// Strikethrough ~~text~~
    pub strikeout: bool,
    /// Superscript and subscript ^super^ ~sub~
    pub superscript: bool,
    pub subscript: bool,

    // Links
    /// Inline links [text](url)
    #[serde(alias = "inline_links")]
    pub inline_links: bool,
    /// Reference links [text][ref]
    #[serde(alias = "reference_links")]
    pub reference_links: bool,
    /// Shortcut reference links [ref] without second []
    #[serde(alias = "shortcut_reference_links")]
    pub shortcut_reference_links: bool,
    /// Attributes on links [text](url){.class}
    #[serde(alias = "link_attributes")]
    pub link_attributes: bool,
    /// Automatic links <http://example.com>
    pub autolinks: bool,

    // Images
    /// Inline images ![alt](url)
    #[serde(alias = "inline_images")]
    pub inline_images: bool,
    /// Paragraph with just image becomes figure
    #[serde(alias = "implicit_figures")]
    pub implicit_figures: bool,

    // Math
    /// Dollar-delimited math $x$ and $$equation$$
    #[serde(alias = "tex_math_dollars")]
    pub tex_math_dollars: bool,
    /// [NON-DEFAULT] GFM math: inline $`...`$ and fenced ``` math blocks
    #[serde(alias = "tex_math_gfm")]
    pub tex_math_gfm: bool,
    /// [NON-DEFAULT] Single backslash math \(...\) and \[...\] (RMarkdown default)
    #[serde(alias = "tex_math_single_backslash")]
    pub tex_math_single_backslash: bool,
    /// [NON-DEFAULT] Double backslash math \\(...\\) and \\[...\\]
    #[serde(alias = "tex_math_double_backslash")]
    pub tex_math_double_backslash: bool,

    // Footnotes
    /// Inline footnotes ^[text]
    #[serde(alias = "inline_footnotes")]
    pub inline_footnotes: bool,
    /// Reference footnotes `[^1]` (requires footnote parsing)
    pub footnotes: bool,

    // Citations
    /// Citation syntax [@cite]
    pub citations: bool,

    // Spans
    /// Bracketed spans [text]{.class}
    #[serde(alias = "bracketed_spans")]
    pub bracketed_spans: bool,
    /// HTML <span> elements
    #[serde(alias = "native_spans")]
    pub native_spans: bool,

    // ===== Metadata =====
    /// YAML metadata block
    #[serde(alias = "yaml_metadata_block")]
    pub yaml_metadata_block: bool,
    /// Pandoc title block (Title/Author/Date)
    #[serde(alias = "pandoc_title_block")]
    pub pandoc_title_block: bool,
    /// [NON-DEFAULT] MultiMarkdown metadata/title block (Key: Value ...)
    pub mmd_title_block: bool,

    // ===== Raw content =====
    /// Raw HTML blocks and inline
    #[serde(alias = "raw_html")]
    pub raw_html: bool,
    /// Markdown inside HTML blocks
    #[serde(alias = "markdown_in_html_blocks")]
    pub markdown_in_html_blocks: bool,
    /// LaTeX commands and environments
    #[serde(alias = "raw_tex")]
    pub raw_tex: bool,
    /// Generic raw blocks with {=format} syntax
    #[serde(alias = "raw_attribute")]
    pub raw_attribute: bool,

    // ===== Escapes and special characters =====
    /// Backslash escapes any symbol
    #[serde(alias = "all_symbols_escapable")]
    pub all_symbols_escapable: bool,
    /// Backslash at line end = hard line break
    #[serde(alias = "escaped_line_breaks")]
    pub escaped_line_breaks: bool,

    // ===== NON-DEFAULT EXTENSIONS =====
    // These are disabled by default in Pandoc
    /// [NON-DEFAULT] Bare URLs become links
    #[serde(alias = "autolink_bare_uris")]
    pub autolink_bare_uris: bool,
    /// [NON-DEFAULT] Newline = <br>
    #[serde(alias = "hard_line_breaks")]
    pub hard_line_breaks: bool,
    /// [NON-DEFAULT] MultiMarkdown style heading identifiers [my-id]
    pub mmd_header_identifiers: bool,
    /// [NON-DEFAULT] MultiMarkdown key=value attributes on reference defs
    pub mmd_link_attributes: bool,
    /// [NON-DEFAULT] GitHub/CommonMark alerts in blockquotes (`> [!NOTE]`)
    pub alerts: bool,
    /// [NON-DEFAULT] :emoji: syntax
    pub emoji: bool,
    /// [NON-DEFAULT] Highlighted ==text==
    pub mark: bool,

    // ===== Quarto-specific extensions =====
    /// Quarto callout blocks (.callout-note, etc.)
    #[serde(alias = "quarto_callouts")]
    pub quarto_callouts: bool,
    /// Quarto cross-references @fig-id, @tbl-id
    #[serde(alias = "quarto_crossrefs")]
    pub quarto_crossrefs: bool,
    /// Quarto shortcodes {{< name args >}}
    #[serde(alias = "quarto_shortcodes")]
    pub quarto_shortcodes: bool,
    /// Bookdown references \@ref(label) and (\#label)
    pub bookdown_references: bool,
    /// Bookdown equation references in LaTeX math blocks (\#eq:label)
    pub bookdown_equation_references: bool,
}

impl Default for Extensions {
    fn default() -> Self {
        Self::for_flavor(Flavor::default())
    }
}

impl Extensions {
    fn none_defaults() -> Self {
        Self {
            alerts: false,
            all_symbols_escapable: false,
            auto_identifiers: false,
            autolink_bare_uris: false,
            autolinks: false,
            backtick_code_blocks: false,
            blank_before_blockquote: false,
            blank_before_header: false,
            bookdown_references: false,
            bookdown_equation_references: false,
            bracketed_spans: false,
            citations: false,
            definition_lists: false,
            emoji: false,
            escaped_line_breaks: false,
            example_lists: false,
            executable_code: false,
            rmarkdown_inline_code: false,
            quarto_inline_code: false,
            fancy_lists: false,
            fenced_code_attributes: false,
            fenced_code_blocks: false,
            fenced_divs: false,
            footnotes: false,
            gfm_auto_identifiers: false,
            grid_tables: false,
            hard_line_breaks: false,
            header_attributes: false,
            implicit_figures: false,
            implicit_header_references: false,
            inline_code_attributes: false,
            inline_footnotes: false,
            inline_images: false,
            inline_links: false,
            intraword_underscores: false,
            line_blocks: false,
            link_attributes: false,
            mark: false,
            markdown_in_html_blocks: false,
            mmd_header_identifiers: false,
            mmd_link_attributes: false,
            mmd_title_block: false,
            multiline_tables: false,
            native_divs: false,
            native_spans: false,
            pandoc_title_block: false,
            pipe_tables: false,
            quarto_callouts: false,
            quarto_crossrefs: false,
            quarto_shortcodes: false,
            raw_attribute: false,
            raw_html: false,
            raw_tex: false,
            reference_links: false,
            shortcut_reference_links: false,
            simple_tables: false,
            startnum: false,
            strikeout: false,
            subscript: false,
            superscript: false,
            table_captions: false,
            task_lists: false,
            tex_math_dollars: false,
            tex_math_double_backslash: false,
            tex_math_gfm: false,
            tex_math_single_backslash: false,
            yaml_metadata_block: false,
        }
    }

    /// Get the default extension set for a given flavor.
    pub fn for_flavor(flavor: Flavor) -> Self {
        match flavor {
            Flavor::Pandoc => Self::pandoc_defaults(),
            Flavor::Quarto => Self::quarto_defaults(),
            Flavor::RMarkdown => Self::rmarkdown_defaults(),
            Flavor::Gfm => Self::gfm_defaults(),
            Flavor::CommonMark => Self::commonmark_defaults(),
            Flavor::MultiMarkdown => Self::multimarkdown_defaults(),
        }
    }

    fn pandoc_defaults() -> Self {
        Self {
            // Block-level - enabled by default in Pandoc
            auto_identifiers: true,
            blank_before_blockquote: true,
            blank_before_header: true,
            gfm_auto_identifiers: false,
            header_attributes: true,
            implicit_header_references: true,

            // Lists
            definition_lists: true,
            example_lists: true,
            fancy_lists: true,
            startnum: true,
            task_lists: true,

            // Code
            backtick_code_blocks: true,
            executable_code: false,
            rmarkdown_inline_code: false,
            quarto_inline_code: false,
            fenced_code_attributes: true,
            fenced_code_blocks: true,
            inline_code_attributes: true,

            // Tables
            grid_tables: true,
            multiline_tables: true,
            pipe_tables: true,
            simple_tables: true,
            table_captions: true,

            // Divs
            fenced_divs: true,
            native_divs: true,

            // Other blocks
            line_blocks: true,

            // Inline
            intraword_underscores: true,
            strikeout: true,
            subscript: true,
            superscript: true,

            // Links
            autolinks: true,
            inline_links: true,
            link_attributes: true,
            reference_links: true,
            shortcut_reference_links: true,

            // Images
            implicit_figures: true,
            inline_images: true,

            // Math
            tex_math_dollars: true,
            tex_math_double_backslash: false,
            tex_math_gfm: false,
            tex_math_single_backslash: false,

            // Footnotes
            footnotes: true,
            inline_footnotes: true,

            // Citations
            citations: true,

            // Spans
            bracketed_spans: true,
            native_spans: true,

            // Metadata
            mmd_title_block: false,
            pandoc_title_block: true,
            yaml_metadata_block: true,

            // Raw
            markdown_in_html_blocks: false,
            raw_attribute: true,
            raw_html: true,
            raw_tex: true,

            // Escapes
            all_symbols_escapable: true,
            escaped_line_breaks: true,

            // Non-default
            alerts: false,
            autolink_bare_uris: false,
            emoji: false,
            hard_line_breaks: false,
            mark: false,
            mmd_header_identifiers: false,
            mmd_link_attributes: false,

            // Quarto/Bookdown-specific
            bookdown_references: false,
            bookdown_equation_references: false,
            quarto_callouts: false,
            quarto_crossrefs: false,
            quarto_shortcodes: false,
        }
    }

    fn quarto_defaults() -> Self {
        let mut ext = Self::pandoc_defaults();

        ext.executable_code = true;
        ext.rmarkdown_inline_code = true;
        ext.quarto_inline_code = true;
        ext.quarto_callouts = true;
        ext.quarto_crossrefs = true;
        ext.quarto_shortcodes = true;

        ext
    }

    fn rmarkdown_defaults() -> Self {
        let mut ext = Self::pandoc_defaults();

        ext.bookdown_references = true;
        ext.bookdown_equation_references = true;
        ext.executable_code = true;
        ext.rmarkdown_inline_code = true;
        ext.quarto_inline_code = false;
        ext.tex_math_dollars = true;
        ext.tex_math_single_backslash = true;

        ext
    }

    fn gfm_defaults() -> Self {
        let mut ext = Self::none_defaults();

        ext.alerts = true;
        ext.auto_identifiers = true;
        ext.autolink_bare_uris = true;
        ext.backtick_code_blocks = true;
        ext.emoji = true;
        ext.fenced_code_blocks = true;
        ext.footnotes = true;
        ext.gfm_auto_identifiers = true;
        ext.pipe_tables = true;
        ext.raw_html = true;
        ext.strikeout = true;
        ext.task_lists = true;
        ext.tex_math_dollars = true;
        ext.tex_math_gfm = true;
        ext.yaml_metadata_block = true;

        ext
    }

    fn commonmark_defaults() -> Self {
        let mut ext = Self::none_defaults();
        ext.raw_html = true;
        ext
    }

    fn multimarkdown_defaults() -> Self {
        let mut ext = Self::none_defaults();

        ext.all_symbols_escapable = true;
        ext.auto_identifiers = true;
        ext.backtick_code_blocks = true;
        ext.definition_lists = true;
        ext.footnotes = true;
        ext.implicit_figures = true;
        ext.implicit_header_references = true;
        ext.intraword_underscores = true;
        ext.mmd_header_identifiers = true;
        ext.mmd_link_attributes = true;
        ext.mmd_title_block = true;
        ext.pipe_tables = true;
        ext.raw_attribute = true;
        ext.raw_html = true;
        ext.reference_links = true;
        ext.shortcut_reference_links = true;
        ext.subscript = true;
        ext.superscript = true;
        ext.tex_math_dollars = true;
        ext.tex_math_double_backslash = true;

        ext
    }

    /// Merge user-specified extension overrides with flavor defaults.
    ///
    /// This is used to support partial extension overrides in config files.
    /// For example, if a user specifies `flavor = "quarto"` and then sets
    /// `[extensions] quarto-crossrefs = false`, we want all other extensions
    /// to use Quarto defaults, not Pandoc defaults.
    ///
    /// # Arguments
    /// * `user_overrides` - Map of extension names to their user-specified values
    /// * `flavor` - The flavor to use for default values
    ///
    /// # Returns
    /// A new Extensions struct with flavor defaults merged with user overrides
    pub fn merge_with_flavor(user_overrides: HashMap<String, bool>, flavor: Flavor) -> Self {
        let defaults = Self::for_flavor(flavor);
        Self::merge_overrides(defaults, user_overrides)
    }

    fn merge_overrides(base: Extensions, user_overrides: HashMap<String, bool>) -> Self {
        use serde_json::{Map, Value};

        let defaults_value =
            serde_json::to_value(&base).expect("Failed to serialize extension defaults");

        let mut merged = if let Value::Object(obj) = defaults_value {
            obj
        } else {
            Map::new()
        };

        // Apply user overrides (normalize snake_case to kebab-case for consistency)
        for (key, value) in user_overrides {
            // Normalize: convert snake_case to kebab-case
            let normalized_key = key.replace('_', "-");
            merged.insert(normalized_key, Value::Bool(value));
        }

        // Deserialize back to Extensions
        serde_json::from_value(Value::Object(merged))
            .expect("Failed to deserialize merged extensions")
    }
}

/// Configuration for an external code formatter.
#[derive(Debug, Clone, PartialEq)]
pub struct FormatterConfig {
    /// Command to execute (e.g., "black", "air", "rustfmt")
    pub cmd: String,
    /// Arguments to pass to the command (e.g., ["-", "--line-length=80"])
    pub args: Vec<String>,
    /// Whether this formatter is enabled (deprecated, kept for backwards compatibility)
    pub enabled: bool,
    /// Whether the formatter reads from stdin (true) or requires a file path (false)
    pub stdin: bool,
}

/// NEW: Language → Formatter mapping value (single formatter or chain)
#[derive(Debug, Clone, Deserialize, PartialEq)]
#[serde(untagged)]
pub enum FormatterValue {
    /// Single formatter: r = "air"
    Single(String),
    /// Multiple formatters (sequential): python = ["isort", "black"]
    Multiple(Vec<String>),
}

/// NEW: Named formatter definition (formatters.NAME sections in new format)
/// OLD: Language-specific formatter config (formatters.LANG sections in old format)
///
/// In new format, if the definition name matches a built-in preset, unspecified fields
/// will inherit from that preset. This allows partial overrides like:
///
/// ```toml
/// [formatters.air]
/// args = ["format", "--custom"]  # Overrides args, inherits cmd/stdin from built-in "air"
/// ```
///
/// Additionally, you can modify arguments incrementally using `prepend-args` and `append-args`:
///
/// ```toml
/// [formatters.air]
/// append-args = ["-i", "2"]  # Adds args to end: ["format", "{}", "-i", "2"]
/// ```
#[derive(Debug, Clone, Deserialize, PartialEq, Default)]
#[serde(default)]
#[serde(rename_all = "kebab-case")]
pub struct FormatterDefinition {
    /// Reference to a built-in preset (e.g., "air", "black") - OLD FORMAT ONLY
    /// In new format, presets are referenced directly in [formatters] mapping
    pub preset: Option<String>,
    /// Custom command to execute (None = inherit from preset if name matches)
    pub cmd: Option<String>,
    /// Arguments to pass (None = inherit from preset if name matches)
    pub args: Option<Vec<String>>,
    /// Arguments to prepend to base args (from preset or explicit args)
    #[serde(alias = "prepend_args")]
    pub prepend_args: Option<Vec<String>>,
    /// Arguments to append to base args (from preset or explicit args)
    #[serde(alias = "append_args")]
    pub append_args: Option<Vec<String>>,
    /// Whether the formatter reads from stdin (None = inherit from preset if name matches)
    pub stdin: Option<bool>,
    /// DEPRECATED: Whether formatter is enabled (old format only)
    pub enabled: Option<bool>,
}

/// Internal struct for deserializing FormatterConfig with preset support.
#[derive(Debug, Deserialize)]
#[serde(default)]
struct RawFormatterConfig {
    /// Preset name (e.g., "air", "ruff") - mutually exclusive with cmd
    preset: Option<String>,
    /// Command to execute
    cmd: Option<String>,
    /// Arguments to pass to the command
    args: Option<Vec<String>>,
    /// Whether this formatter is enabled
    enabled: bool,
    /// Whether the formatter reads from stdin
    stdin: bool,
}

impl Default for RawFormatterConfig {
    fn default() -> Self {
        Self {
            preset: None,
            cmd: None,
            args: None,
            enabled: true,
            stdin: true,
        }
    }
}

impl<'de> Deserialize<'de> for FormatterConfig {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        let raw = RawFormatterConfig::deserialize(deserializer)?;

        // Check mutual exclusivity of preset and cmd
        if raw.preset.is_some() && raw.cmd.is_some() {
            return Err(serde::de::Error::custom(
                "FormatterConfig: 'preset' and 'cmd' are mutually exclusive - use one or the other",
            ));
        }

        // If preset is specified, resolve it
        if let Some(preset_name) = raw.preset {
            let preset = get_formatter_preset(&preset_name).ok_or_else(|| {
                let available = formatter_preset_names().join(", ");
                serde::de::Error::custom(format!(
                    "Unknown formatter preset: '{}'. Available presets: {}",
                    preset_name, available
                ))
            })?;

            // Return the preset, but respect enabled field if explicitly set
            Ok(FormatterConfig {
                cmd: preset.cmd,
                args: preset.args,
                enabled: raw.enabled,
                stdin: preset.stdin,
            })
        } else if let Some(cmd) = raw.cmd {
            // Custom configuration
            Ok(FormatterConfig {
                cmd,
                args: raw.args.unwrap_or_default(),
                enabled: raw.enabled,
                stdin: raw.stdin,
            })
        } else {
            // No preset and no cmd - return empty config
            // This can happen with Default::default()
            Ok(FormatterConfig {
                cmd: String::new(),
                args: raw.args.unwrap_or_default(),
                enabled: raw.enabled,
                stdin: raw.stdin,
            })
        }
    }
}

impl Default for FormatterConfig {
    fn default() -> Self {
        Self {
            cmd: String::new(),
            args: Vec::new(),
            enabled: true,
            stdin: true,
        }
    }
}

/// Get a built-in formatter preset by name.
/// Returns None if the preset doesn't exist.
pub fn get_formatter_preset(name: &str) -> Option<FormatterConfig> {
    formatter_presets::get_formatter_preset(name)
}

/// Canonical built-in formatter preset names used for docs and diagnostics.
pub fn formatter_preset_names() -> &'static [&'static str] {
    formatter_presets::formatter_preset_names()
}

pub fn formatter_preset_supported_languages(name: &str) -> Option<&'static [&'static str]> {
    formatter_presets::formatter_preset_supported_languages(name)
}

pub fn formatter_preset_metadata(name: &str) -> Option<&'static FormatterPresetMetadata> {
    formatter_presets::formatter_preset_metadata(name)
}

pub fn all_formatter_preset_metadata() -> &'static [FormatterPresetMetadata] {
    formatter_presets::all_formatter_preset_metadata()
}

pub fn formatter_presets_for_language(language: &str) -> Vec<&'static FormatterPresetMetadata> {
    formatter_presets::formatter_presets_for_language(language)
}

fn normalize_formatter_language(language: &str) -> String {
    language.trim().to_ascii_lowercase().replace('_', "-")
}

fn validate_formatter_language_for_preset(lang: &str, formatter_name: &str) -> Result<(), String> {
    let Some(supported) = formatter_preset_supported_languages(formatter_name) else {
        return Ok(()); // custom formatter or unknown preset handled elsewhere
    };

    let normalized_lang = normalize_formatter_language(lang);
    let matches = supported
        .iter()
        .any(|supported_lang| *supported_lang == normalized_lang);

    if matches {
        return Ok(());
    }

    Err(format!(
        "Language '{}': formatter '{}' does not support this language. Supported languages: {}",
        lang,
        formatter_name,
        supported.join(", ")
    ))
}

/// Get the default formatters HashMap with built-in presets.
/// Currently includes R (air) and Python (ruff).
pub fn default_formatters() -> HashMap<String, FormatterConfig> {
    let mut map = HashMap::new();
    map.insert("r".to_string(), get_formatter_preset("air").unwrap());
    map.insert("python".to_string(), get_formatter_preset("ruff").unwrap());
    map
}

/// Style for formatting math delimiters
#[derive(Debug, Clone, Copy, Deserialize, PartialEq, Eq, Default)]
#[serde(rename_all = "kebab-case")]
pub enum MathDelimiterStyle {
    /// Preserve original delimiter style (\(...\) stays \(...\), $...$ stays $...$)
    #[default]
    Preserve,
    /// Normalize all to dollar syntax ($...$ and $$...$$)
    Dollars,
    /// Normalize all to backslash syntax (\(...\) and \[...\])
    Backslash,
}

/// Tab stop handling for formatter output.
#[derive(Debug, Clone, Copy, Deserialize, PartialEq, Eq, Default)]
#[serde(rename_all = "kebab-case")]
pub enum TabStopMode {
    /// Normalize tabs to spaces (4-column tab stop).
    #[default]
    Normalize,
    /// Preserve tabs in literal code spans/blocks.
    Preserve,
}

/// Formatting style configuration.
/// Groups all style-related settings together.
#[derive(Debug, Clone, Deserialize, PartialEq)]
#[serde(default)]
#[serde(rename_all = "kebab-case")]
pub struct StyleConfig {
    /// Text wrapping mode
    pub wrap: Option<WrapMode>,
    /// Blank line handling between blocks
    pub blank_lines: BlankLines,
    /// Math delimiter style preference
    pub math_delimiter_style: MathDelimiterStyle,
    /// Math indentation (spaces)
    pub math_indent: usize,
    /// Tab stop handling (normalize or preserve)
    pub tab_stops: TabStopMode,
    /// Tab width for expanding tabs when normalizing
    pub tab_width: usize,
    /// Use panache-native greedy wrapping instead of textwrap.
    pub built_in_greedy_wrap: bool,
}

impl Default for StyleConfig {
    fn default() -> Self {
        Self {
            wrap: Some(WrapMode::Reflow),
            blank_lines: BlankLines::Collapse,
            math_delimiter_style: MathDelimiterStyle::default(),
            math_indent: 0,
            tab_stops: TabStopMode::Normalize,
            tab_width: 4,
            built_in_greedy_wrap: true,
        }
    }
}

impl StyleConfig {
    // No flavor-specific defaults needed - just use field defaults
}

#[derive(Debug, Clone, Copy, Serialize, Deserialize, PartialEq, Eq, Default)]
pub enum PandocCompat {
    /// Alias for Panache's pinned newest supported Pandoc-compat behavior.
    ///
    /// This is intentionally NOT "floating upstream latest". It resolves to
    /// a concrete version that Panache has verified, and is bumped manually.
    #[serde(rename = "latest")]
    Latest,
    /// Match Pandoc 3.7 behavior for ambiguous syntax edge cases.
    #[serde(rename = "3.7", alias = "3-7", alias = "v3.7", alias = "v3-7")]
    V3_7,
    /// Match Pandoc 3.9 behavior for ambiguous syntax edge cases.
    #[default]
    #[serde(rename = "3.9", alias = "3-9", alias = "v3.9", alias = "v3-9")]
    V3_9,
}

impl PandocCompat {
    /// Pinned target for `latest`.
    pub const PINNED_LATEST: Self = Self::V3_9;

    pub fn effective(self) -> Self {
        match self {
            Self::Latest => Self::PINNED_LATEST,
            other => other,
        }
    }
}

/// Parser configuration.
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Default)]
#[serde(default, rename_all = "kebab-case")]
pub struct ParserConfig {
    /// Compatibility target for ambiguous Pandoc behavior.
    pub pandoc_compat: PandocCompat,
}

impl ParserConfig {
    pub fn effective_pandoc_compat(&self) -> PandocCompat {
        self.pandoc_compat.effective()
    }
}

/// Linter configuration.
/// Preferred shape is `[lint.rules] rule-name = true/false`.
/// Legacy `[lint] rule-name = true/false` is still supported (deprecated).
#[derive(Debug, Clone, Serialize, PartialEq, Default)]
pub struct LintConfig {
    pub rules: HashMap<String, bool>,
}

impl LintConfig {
    fn normalize_rule_name(name: &str) -> String {
        name.trim().to_lowercase().replace('_', "-")
    }

    fn normalize(mut self) -> Self {
        self.rules = self
            .rules
            .into_iter()
            .map(|(name, enabled)| (Self::normalize_rule_name(&name), enabled))
            .collect();
        self
    }

    pub fn is_rule_enabled(&self, rule_name: &str) -> bool {
        let normalized = Self::normalize_rule_name(rule_name);
        self.rules.get(&normalized).copied().unwrap_or(true)
    }
}

impl<'de> Deserialize<'de> for LintConfig {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        let value = toml::Value::deserialize(deserializer)?;
        let mut rules = HashMap::new();
        let mut used_legacy_shape = false;

        let mut table = value
            .as_table()
            .cloned()
            .ok_or_else(|| serde::de::Error::custom("expected [lint] table"))?;

        // New shape: [lint.rules]
        if let Some(rules_value) = table.remove("rules") {
            let rules_table = rules_value
                .as_table()
                .ok_or_else(|| serde::de::Error::custom("[lint.rules] must be a table"))?;
            for (name, enabled) in rules_table {
                let enabled = enabled.as_bool().ok_or_else(|| {
                    serde::de::Error::custom(format!(
                        "[lint.rules] entry '{}' must be true or false",
                        name
                    ))
                })?;
                rules.insert(name.clone(), enabled);
            }
        }

        // Legacy shape: [lint] rule-name = true/false
        for (name, enabled) in table {
            let enabled = enabled.as_bool().ok_or_else(|| {
                serde::de::Error::custom(format!(
                    "Unsupported [lint] key '{}'; use [lint.rules] for rule toggles",
                    name
                ))
            })?;
            used_legacy_shape = true;
            rules.insert(name, enabled);
        }

        if used_legacy_shape {
            eprintln!(
                "Warning: [lint] rule = true/false is deprecated; use [lint.rules] rule = true/false."
            );
        }

        Ok(Self { rules }.normalize())
    }
}

/// Internal deserialization struct that allows for optional fields
#[derive(Debug, Clone, Deserialize)]
#[serde(rename_all = "kebab-case")]
struct RawConfig {
    #[serde(default)]
    flavor: Flavor,
    #[serde(default)]
    extensions: Option<toml::Value>,
    #[serde(default)]
    line_ending: Option<LineEnding>,
    #[serde(default = "default_line_width")]
    line_width: usize,
    #[serde(default)]
    pandoc_compat: Option<PandocCompat>,

    // New preferred formatting section
    #[serde(default)]
    #[serde(rename = "format")]
    format_section: Option<StyleConfig>,

    // DEPRECATED: [style] section (kept for backwards compatibility)
    #[serde(default)]
    style: Option<StyleConfig>,

    // DEPRECATED: Old top-level style fields (kept for backwards compatibility)
    #[serde(default)]
    math_indent: usize,
    #[serde(default)]
    math_delimiter_style: MathDelimiterStyle,
    #[serde(default)]
    wrap: Option<WrapMode>,
    #[serde(default = "default_blank_lines")]
    blank_lines: BlankLines,
    #[serde(default)]
    tab_stops: TabStopMode,
    #[serde(default = "default_tab_width")]
    tab_width: usize,
    // Parser configuration (deprecated home for pandoc-compat)
    #[serde(default)]
    parser: Option<ParserConfig>,

    // NEW: Language → Formatter(s) mapping
    // This will be a raw Value that we'll parse manually to handle both formats
    #[serde(default)]
    formatters: Option<toml::Value>,

    /// Max parallel external tool invocations (formatters/linters) per document.
    #[serde(default)]
    external_max_parallel: Option<usize>,

    #[serde(default)]
    linters: HashMap<String, String>,
    #[serde(default)]
    lint: Option<LintConfig>,
    #[serde(default)]
    cache_dir: Option<String>,
    #[serde(default)]
    exclude: Option<Vec<String>>,
    #[serde(default)]
    extend_exclude: Vec<String>,
    #[serde(default)]
    include: Option<Vec<String>>,
    #[serde(default)]
    extend_include: Vec<String>,
    #[serde(default)]
    flavor_overrides: HashMap<String, Flavor>,
}

fn default_line_width() -> usize {
    80
}

fn default_external_max_parallel() -> usize {
    // Conservative cap: documents may have hundreds of code blocks.
    std::thread::available_parallelism()
        .map(|n| n.get())
        .unwrap_or(1)
        .clamp(1, 8)
}

fn default_blank_lines() -> BlankLines {
    BlankLines::Collapse
}

fn default_tab_width() -> usize {
    4
}

pub const DEFAULT_EXCLUDE_PATTERNS: &[&str] = &[
    ".Rproj.user/",
    ".bzr/",
    ".cache/",
    ".devevn/",
    ".direnv/",
    ".git/",
    ".hg/",
    ".julia/",
    ".mypy_cache/",
    ".nox/",
    ".pytest_cache/",
    ".ruff_cache/",
    ".svn/",
    ".tmp/",
    ".tox/",
    ".venv/",
    ".vscode/",
    "_book/",
    "_build/",
    "_freeze/",
    "_site/",
    "build/",
    "dist/",
    "node_modules/",
    "renv/",
    "target/",
    "tests/testthat/_snaps",
    "**/LICENSE.md",
];

pub const DEFAULT_INCLUDE_PATTERNS: &[&str] =
    &["*.md", "*.qmd", "*.Rmd", "*.markdown", "*.mdown", "*.mkd"];
const MARKDOWN_FAMILY_EXTENSIONS: &[&str] = &["md", "markdown", "mdown", "mkd"];

/// Resolve a single formatter name to a FormatterConfig.
///
/// Resolve a formatter name to a FormatterConfig.
///
/// Resolution order:
/// 1. Check if it's a named definition in formatter_definitions
///    - If name matches a built-in preset, inherit unspecified fields from preset
///    - If name doesn't match preset, require full cmd specification
/// 2. Fall back to built-in preset (no custom definition)
/// 3. Error if neither found
///
/// # Examples
///
/// ```toml
/// # Partial override - inherits cmd/stdin from built-in "air"
/// [formatters.air]
/// args = ["format", "--custom"]
///
/// # Append args to preset - final: ["format", "{}", "-i", "2"]
/// [formatters.air]
/// append_args = ["-i", "2"]
///
/// # Full custom - no preset match, requires cmd
/// [formatters.custom-fmt]
/// cmd = "my-formatter"
/// args = ["--flag"]
/// ```
fn resolve_formatter_name(
    name: &str,
    formatter_definitions: &HashMap<String, FormatterDefinition>,
) -> Result<FormatterConfig, String> {
    // Check for named definition first
    if let Some(definition) = formatter_definitions.get(name) {
        // Named definition exists - resolve it

        // NEW FORMAT: preset field not allowed in named definitions
        // (Use direct preset reference in [formatters] mapping instead)
        if definition.preset.is_some() {
            return Err(format!(
                "Formatter '{}': 'preset' field not allowed in named definitions. Use [formatters] mapping instead (e.g., `lang = \"{}\"`).",
                name, name
            ));
        }

        // Try to load built-in preset as base (if name matches)
        let preset = get_formatter_preset(name);

        // Build config by applying overrides to preset (or requiring cmd if no preset)
        match (preset, &definition.cmd) {
            // Case 1: Preset exists - use as base and apply overrides
            (Some(mut base_config), _) => {
                // Override cmd if specified
                if let Some(cmd) = &definition.cmd {
                    base_config.cmd = cmd.clone();
                }
                // Override args if specified
                if let Some(args) = &definition.args {
                    base_config.args = args.clone();
                }
                // Override stdin if specified
                if let Some(stdin) = definition.stdin {
                    base_config.stdin = stdin;
                }

                // Apply prepend_args and append_args modifiers
                apply_arg_modifiers(&mut base_config.args, definition);

                Ok(base_config)
            }
            // Case 2: No preset, but cmd specified - full custom formatter
            (None, Some(cmd)) => {
                let mut args = definition.args.clone().unwrap_or_default();

                // Apply prepend_args and append_args modifiers
                apply_arg_modifiers(&mut args, definition);

                Ok(FormatterConfig {
                    cmd: cmd.clone(),
                    args,
                    enabled: true,
                    stdin: definition.stdin.unwrap_or(true),
                })
            }
            // Case 3: No preset, no cmd - error
            (None, None) => Err(format!(
                "Formatter '{}': must specify 'cmd' field (not a known preset)",
                name
            )),
        }
    } else {
        // Not a named definition - check built-in presets
        get_formatter_preset(name).ok_or_else(|| {
            format!(
                "Unknown formatter '{}': not a named definition or built-in preset. \
                 Define it in [formatters.{}] section or use a known preset.",
                name, name
            )
        })
    }
}

/// Apply prepend_args and append_args modifiers to an argument list.
///
/// Modifiers are applied in order: prepend_args + base_args + append_args
/// If no base args exist, they're treated as empty (user responsibility).
fn apply_arg_modifiers(args: &mut Vec<String>, definition: &FormatterDefinition) {
    // Prepend args if specified
    if let Some(prepend) = &definition.prepend_args {
        let mut new_args = prepend.clone();
        new_args.append(args);
        *args = new_args;
    }

    // Append args if specified
    if let Some(append) = &definition.append_args {
        args.extend_from_slice(append);
    }
}

/// Resolve a language's formatter value (single or multiple) to a list of FormatterConfigs.
fn resolve_language_formatters(
    lang: &str,
    value: &FormatterValue,
    formatter_definitions: &HashMap<String, FormatterDefinition>,
) -> Result<Vec<FormatterConfig>, String> {
    let formatter_names = match value {
        FormatterValue::Single(name) => vec![name.as_str()],
        FormatterValue::Multiple(names) => names.iter().map(|s| s.as_str()).collect(),
    };

    // Resolve each formatter name
    formatter_names
        .into_iter()
        .map(|name| {
            // Language guards apply only to built-in presets. Named formatter
            // definitions are user-owned and may be intentionally reused across
            // languages (e.g. a custom "prettier" definition).
            if !formatter_definitions.contains_key(name) {
                validate_formatter_language_for_preset(lang, name)?;
            }
            resolve_formatter_name(name, formatter_definitions)
                .map_err(|e| format!("Language '{}': {}", lang, e))
        })
        .collect()
}

impl RawConfig {
    /// Finalize into Config, applying flavor-based defaults where needed
    fn finalize(self) -> Config {
        let parser_from_section = self.parser.unwrap_or_default();
        let parser_pandoc_compat = parser_from_section.pandoc_compat;

        let resolved_pandoc_compat = if let Some(pandoc_compat) = self.pandoc_compat {
            if parser_pandoc_compat != PandocCompat::default()
                && parser_pandoc_compat != pandoc_compat
            {
                eprintln!(
                    "Warning: Both top-level 'pandoc-compat' and [parser].pandoc-compat are set. Using top-level 'pandoc-compat'."
                );
            }
            pandoc_compat
        } else {
            if parser_pandoc_compat != PandocCompat::default() {
                eprintln!(
                    "Warning: [parser].pandoc-compat is deprecated. Please use top-level 'pandoc-compat'."
                );
            }
            parser_pandoc_compat
        };

        // Check for deprecated top-level style fields
        let has_deprecated_fields = self.wrap.is_some()
            || self.math_indent != 0
            || self.math_delimiter_style != MathDelimiterStyle::default()
            || self.blank_lines != default_blank_lines()
            || self.tab_stops != TabStopMode::Normalize
            || self.tab_width != default_tab_width();

        if has_deprecated_fields && self.format_section.is_none() && self.style.is_none() {
            eprintln!(
                "Warning: top-level style fields (wrap, math-indent, etc.) \
                 are deprecated. Please move them under [format] section. \
                 See documentation for the new format."
            );
        }

        // Merge formatting config: prefer [format], then deprecated [style], then old top-level fields.
        let style = if let Some(format_config) = self.format_section {
            if self.style.is_some() {
                eprintln!(
                    "Warning: Both [format] and deprecated [style] sections found. \
                     Using [format] section."
                );
            }
            if has_deprecated_fields {
                eprintln!(
                    "Warning: Both [format] section and top-level style fields found. \
                     Using [format] section and ignoring top-level fields."
                );
            }

            format_config
        } else if let Some(style_config) = self.style {
            eprintln!("Warning: [style] section is deprecated. Please use [format] instead.");
            if has_deprecated_fields {
                eprintln!(
                    "Warning: Both deprecated [style] section and top-level style fields found. \
                     Using [style] section and ignoring top-level fields."
                );
            }
            style_config
        } else {
            // Old format - construct StyleConfig from top-level fields
            StyleConfig {
                wrap: self.wrap.or(Some(WrapMode::Reflow)),
                blank_lines: self.blank_lines,
                math_delimiter_style: self.math_delimiter_style,
                math_indent: self.math_indent,
                tab_stops: self.tab_stops,
                tab_width: self.tab_width,
                built_in_greedy_wrap: true,
            }
        };

        Config {
            extensions: resolve_extensions_for_flavor(self.extensions.as_ref(), self.flavor),
            line_ending: self.line_ending.or(Some(LineEnding::Auto)),
            flavor: self.flavor,
            line_width: self.line_width,
            wrap: style.wrap,
            blank_lines: style.blank_lines,
            math_delimiter_style: style.math_delimiter_style,
            math_indent: style.math_indent,
            tab_stops: style.tab_stops,
            tab_width: style.tab_width,
            formatters: resolve_formatters(self.formatters),
            linters: self.linters,
            lint: self.lint.unwrap_or_default().normalize(),
            cache_dir: self.cache_dir,
            external_max_parallel: self
                .external_max_parallel
                .unwrap_or_else(default_external_max_parallel),
            parser: ParserConfig {
                pandoc_compat: resolved_pandoc_compat,
            },
            built_in_greedy_wrap: style.built_in_greedy_wrap,
            exclude: self.exclude,
            extend_exclude: self.extend_exclude,
            include: self.include,
            extend_include: self.extend_include,
            flavor_overrides: self.flavor_overrides,
        }
    }
}

fn parse_flavor_key(s: &str) -> Option<Flavor> {
    match s.replace('_', "-").to_lowercase().as_str() {
        "pandoc" => Some(Flavor::Pandoc),
        "quarto" => Some(Flavor::Quarto),
        "rmarkdown" | "r-markdown" => Some(Flavor::RMarkdown),
        "gfm" => Some(Flavor::Gfm),
        "common-mark" | "commonmark" => Some(Flavor::CommonMark),
        "multimarkdown" | "multi-markdown" => Some(Flavor::MultiMarkdown),
        _ => None,
    }
}

fn resolve_extensions_for_flavor(
    extensions_value: Option<&toml::Value>,
    flavor: Flavor,
) -> Extensions {
    let Some(value) = extensions_value else {
        return Extensions::for_flavor(flavor);
    };

    let Some(table) = value.as_table() else {
        eprintln!("Warning: [extensions] must be a table; using flavor defaults.");
        return Extensions::for_flavor(flavor);
    };

    let mut global_overrides = HashMap::new();
    let mut flavor_overrides = HashMap::new();

    for (key, val) in table {
        if let Some(enabled) = val.as_bool() {
            global_overrides.insert(key.clone(), enabled);
            continue;
        }

        let Some(flavor_table) = val.as_table() else {
            eprintln!(
                "Warning: [extensions] entry '{}' must be a boolean or table; ignoring.",
                key
            );
            continue;
        };

        let Some(target_flavor) = parse_flavor_key(key) else {
            eprintln!(
                "Warning: [extensions.{}] is not a known flavor table; ignoring.",
                key
            );
            continue;
        };

        if target_flavor != flavor {
            continue;
        }

        for (sub_key, sub_val) in flavor_table {
            let Some(enabled) = sub_val.as_bool() else {
                eprintln!(
                    "Warning: [extensions.{}] entry '{}' must be true or false; ignoring.",
                    key, sub_key
                );
                continue;
            };
            flavor_overrides.insert(sub_key.clone(), enabled);
        }
    }

    let base = Extensions::merge_with_flavor(global_overrides, flavor);
    Extensions::merge_overrides(base, flavor_overrides)
}

/// Resolve formatter configuration from both old and new formats.
/// Returns HashMap<String, Vec<FormatterConfig>> for language → formatter(s) mapping.
fn resolve_formatters(
    raw_formatters: Option<toml::Value>,
) -> HashMap<String, Vec<FormatterConfig>> {
    let Some(value) = raw_formatters else {
        return HashMap::new();
    };

    // Try to determine which format this is
    let toml::Value::Table(table) = value else {
        eprintln!("Warning: Invalid formatters configuration - expected table");
        return HashMap::new();
    };

    // Strategy: Detect old format vs new format
    // Old format: ALL entries are tables with preset/cmd/args (language-specific configs)
    // New format: Mix of strings/arrays (language mappings) and optionally tables (named definitions)

    let has_string_or_array = table
        .values()
        .any(|v| matches!(v, toml::Value::String(_) | toml::Value::Array(_)));

    if has_string_or_array {
        // New format detected (has language mappings as strings/arrays)
        resolve_new_format_formatters(table)
    } else {
        // Old format (all entries are tables)
        resolve_old_format_formatters(table)
    }
}

/// Resolve new format: [formatters] = { r = "air", python = ["isort", "black"] }
/// Plus optional [formatters.air] and [formatters.isort] definitions.
fn resolve_new_format_formatters(
    table: toml::map::Map<String, toml::Value>,
) -> HashMap<String, Vec<FormatterConfig>> {
    let mut mappings = HashMap::new();
    let mut definitions = HashMap::new();

    // First pass: separate mappings from definitions
    for (key, value) in table {
        match &value {
            toml::Value::String(_) | toml::Value::Array(_) => {
                // This is a language mapping
                let formatter_value: Result<FormatterValue, _> = value.try_into();
                match formatter_value {
                    Ok(fv) => {
                        mappings.insert(key, fv);
                    }
                    Err(e) => {
                        eprintln!("Error parsing formatter value for '{}': {}", key, e);
                    }
                }
            }
            toml::Value::Table(_) => {
                // This is a named formatter definition
                let definition: Result<FormatterDefinition, _> = value.try_into();
                match definition {
                    Ok(def) => {
                        definitions.insert(key, def);
                    }
                    Err(e) => {
                        eprintln!("Error parsing formatter definition '{}': {}", key, e);
                    }
                }
            }
            _ => {
                eprintln!(
                    "Warning: Invalid formatter entry '{}' - must be string, array, or table",
                    key
                );
            }
        }
    }

    // Second pass: resolve mappings using definitions
    let mut resolved = HashMap::new();
    for (lang, value) in mappings {
        match resolve_language_formatters(&lang, &value, &definitions) {
            Ok(configs) if !configs.is_empty() => {
                resolved.insert(lang, configs);
            }
            Ok(_) => {} // Empty list
            Err(e) => {
                eprintln!("Error resolving formatters for language '{}': {}", lang, e);
                eprintln!("Skipping formatter for '{}'", lang);
            }
        }
    }

    resolved
}

/// Resolve old format: [formatters.r] with preset/cmd fields directly.
fn resolve_old_format_formatters(
    table: toml::map::Map<String, toml::Value>,
) -> HashMap<String, Vec<FormatterConfig>> {
    eprintln!(
        "Warning: Old formatter configuration format detected. \
         Please migrate to the new format with [formatters] section. \
         See documentation for the new format."
    );

    let mut resolved = HashMap::new();
    for (lang, value) in table {
        let definition: Result<FormatterDefinition, _> = value.try_into();
        match definition {
            Ok(def) => {
                // Skip if disabled (old format only)
                // enabled is Option<bool> now, so check for Some(false)
                if def.enabled == Some(false) {
                    continue;
                }

                match resolve_old_format_definition(&lang, &def) {
                    Ok(config) => {
                        resolved.insert(lang, vec![config]);
                    }
                    Err(e) => {
                        eprintln!("Error in old formatter config for '{}': {}", lang, e);
                        eprintln!("Skipping formatter for '{}'", lang);
                    }
                }
            }
            Err(e) => {
                eprintln!("Error parsing old formatter config for '{}': {}", lang, e);
            }
        }
    }

    resolved
}

/// Resolve old-format formatter definition (inline preset/cmd in formatters.LANG).
fn resolve_old_format_definition(
    _lang: &str,
    definition: &FormatterDefinition,
) -> Result<FormatterConfig, String> {
    // Check for conflicts
    if definition.preset.is_some() && definition.cmd.is_some() {
        return Err("'preset' and 'cmd' are mutually exclusive".to_string());
    }

    if let Some(preset_name) = &definition.preset {
        // Resolve preset
        let preset = get_formatter_preset(preset_name).ok_or_else(|| {
            let available = formatter_preset_names().join(", ");
            format!(
                "Unknown formatter preset '{}'. Available presets: {}",
                preset_name, available
            )
        })?;

        let mut args = definition.args.clone().unwrap_or(preset.args);

        // Apply prepend/append modifiers
        apply_arg_modifiers(&mut args, definition);

        Ok(FormatterConfig {
            cmd: preset.cmd,
            args,
            enabled: true, // enabled field checked by caller
            stdin: preset.stdin,
        })
    } else if let Some(cmd) = &definition.cmd {
        // Custom command
        let mut args = definition.args.clone().unwrap_or_default();

        // Apply prepend/append modifiers
        apply_arg_modifiers(&mut args, definition);

        Ok(FormatterConfig {
            cmd: cmd.clone(),
            args,
            enabled: true,
            stdin: definition.stdin.unwrap_or(true),
        })
    } else {
        Err("must specify either 'preset' or 'cmd'".to_string())
    }
}

#[derive(Debug, Clone)]
pub struct Config {
    pub flavor: Flavor,
    pub extensions: Extensions,
    pub line_ending: Option<LineEnding>,
    pub line_width: usize,
    pub math_indent: usize,
    pub math_delimiter_style: MathDelimiterStyle,
    pub tab_stops: TabStopMode,
    pub tab_width: usize,
    pub wrap: Option<WrapMode>,
    pub blank_lines: BlankLines,
    /// Language → Formatter(s) mapping (supports multiple formatters per language)
    pub formatters: HashMap<String, Vec<FormatterConfig>>,
    pub linters: HashMap<String, String>,
    /// Max parallel external tool invocations (formatters/linters) per document.
    pub external_max_parallel: usize,
    /// Parser configuration (experimental)
    pub parser: ParserConfig,
    /// Linter rule toggles.
    pub lint: LintConfig,
    /// Optional CLI cache directory override.
    pub cache_dir: Option<String>,
    pub built_in_greedy_wrap: bool,
    pub exclude: Option<Vec<String>>,
    pub extend_exclude: Vec<String>,
    pub include: Option<Vec<String>>,
    pub extend_include: Vec<String>,
    pub flavor_overrides: HashMap<String, Flavor>,
}

impl<'de> Deserialize<'de> for Config {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        RawConfig::deserialize(deserializer).map(|raw| raw.finalize())
    }
}

impl Default for Config {
    fn default() -> Self {
        let flavor = Flavor::default();
        Self {
            flavor,
            extensions: Extensions::for_flavor(flavor),
            line_ending: Some(LineEnding::Auto),
            line_width: 80,
            math_indent: 0,
            math_delimiter_style: MathDelimiterStyle::default(),
            tab_stops: TabStopMode::Normalize,
            tab_width: 4,
            wrap: Some(WrapMode::Reflow),
            blank_lines: BlankLines::Collapse,
            formatters: HashMap::new(), // Opt-in: empty by default
            linters: HashMap::new(),    // Opt-in: empty by default
            external_max_parallel: default_external_max_parallel(),
            parser: ParserConfig::default(),
            lint: LintConfig::default(),
            cache_dir: None,
            built_in_greedy_wrap: true,
            exclude: None,
            extend_exclude: Vec::new(),
            include: None,
            extend_include: Vec::new(),
            flavor_overrides: HashMap::new(),
        }
    }
}

#[derive(Default, Clone)]
pub struct ConfigBuilder {
    config: Config,
}

impl ConfigBuilder {
    pub fn math_indent(mut self, indent: usize) -> Self {
        self.config.math_indent = indent;
        self
    }

    pub fn tab_stops(mut self, mode: TabStopMode) -> Self {
        self.config.tab_stops = mode;
        self
    }

    pub fn tab_width(mut self, width: usize) -> Self {
        self.config.tab_width = width;
        self
    }

    pub fn line_width(mut self, width: usize) -> Self {
        self.config.line_width = width;
        self
    }

    pub fn line_ending(mut self, ending: LineEnding) -> Self {
        self.config.line_ending = Some(ending);
        self
    }

    pub fn blank_lines(mut self, mode: BlankLines) -> Self {
        self.config.blank_lines = mode;
        self
    }

    pub fn build(self) -> Config {
        self.config
    }
}

#[derive(Debug, Clone, Deserialize, PartialEq)]
#[serde(rename_all = "kebab-case")]
pub enum WrapMode {
    Preserve,
    Reflow,
    Sentence,
}

#[derive(Debug, Clone, Deserialize, PartialEq)]
#[serde(rename_all = "kebab-case")]
pub enum LineEnding {
    Auto,
    Lf,
    Crlf,
}

#[derive(Debug, Clone, Deserialize, PartialEq)]
#[serde(rename_all = "kebab-case")]
pub enum BlankLines {
    /// Preserve original blank lines (any number)
    Preserve,
    /// Collapse multiple consecutive blank lines to a single blank line
    Collapse,
}

const CANDIDATE_NAMES: &[&str] = &[".panache.toml", "panache.toml"];

/// Check for deprecated snake_case extension names and warn users.
fn check_deprecated_extension_names(s: &str, path: &Path) {
    // Parse as generic TOML to inspect raw keys
    let Ok(toml_value) = toml::from_str::<toml::Value>(s) else {
        return; // If TOML is invalid, let the main parser handle the error
    };

    let Some(extensions_table) = toml_value
        .as_table()
        .and_then(|t| t.get("extensions"))
        .and_then(|v| v.as_table())
    else {
        return; // No [extensions] section
    };

    // List of all extension field names that should be kebab-case
    let deprecated_names: Vec<&str> = extensions_table
        .keys()
        .filter(|k| k.contains('_'))
        .map(|k| k.as_str())
        .collect();

    if !deprecated_names.is_empty() {
        eprintln!(
            "Warning: Deprecated snake_case extension names found in {}:",
            path.display()
        );
        eprintln!("  The following extensions use deprecated snake_case naming:");
        for name in &deprecated_names {
            let kebab = name.replace('_', "-");
            eprintln!("    {} -> {} (use kebab-case)", name, kebab);
        }
        eprintln!("  Snake_case extension names are deprecated and will be removed in v1.0.0.");
        eprintln!(
            "  Please update your config to use kebab-case (e.g., quarto-crossrefs instead of quarto_crossrefs)."
        );
    }
}

/// Check for deprecated snake_case formatter field names and warn users.
fn check_deprecated_formatter_names(s: &str, path: &Path) {
    // Parse as generic TOML to inspect raw keys
    let Ok(toml_value) = toml::from_str::<toml::Value>(s) else {
        return;
    };

    let Some(formatters_table) = toml_value
        .as_table()
        .and_then(|t| t.get("formatters"))
        .and_then(|v| v.as_table())
    else {
        return; // No [formatters] section
    };

    // Check each formatter definition for deprecated field names
    let mut found_deprecated = false;
    for (formatter_name, formatter_value) in formatters_table {
        if let Some(formatter_def) = formatter_value.as_table() {
            let deprecated_fields: Vec<&str> = formatter_def
                .keys()
                .filter(|k| matches!(k.as_str(), "prepend_args" | "append_args"))
                .map(|k| k.as_str())
                .collect();

            if !deprecated_fields.is_empty() {
                if !found_deprecated {
                    eprintln!(
                        "Warning: Deprecated snake_case formatter field names found in {}:",
                        path.display()
                    );
                    found_deprecated = true;
                }
                eprintln!("  In [formatters.{}]:", formatter_name);
                for field in deprecated_fields {
                    let kebab = field.replace('_', "-");
                    eprintln!("    {} -> {}", field, kebab);
                }
            }
        }
    }

    if found_deprecated {
        eprintln!(
            "  Snake_case formatter field names are deprecated and will be removed in v1.0.0."
        );
        eprintln!(
            "  Please update your config to use kebab-case (e.g., prepend-args instead of prepend_args)."
        );
    }
}

/// Check for deprecated code-block style configuration and warn users.
fn check_deprecated_code_block_style_options(s: &str, path: &Path) {
    let Ok(toml_value) = toml::from_str::<toml::Value>(s) else {
        return;
    };
    let Some(root) = toml_value.as_table() else {
        return;
    };

    let top_level = root.contains_key("code-blocks");
    let format_nested = root
        .get("format")
        .and_then(|v| v.as_table())
        .is_some_and(|format| format.contains_key("code-blocks"));
    let style_nested = root
        .get("style")
        .and_then(|v| v.as_table())
        .is_some_and(|style| style.contains_key("code-blocks"));

    if top_level || format_nested || style_nested {
        eprintln!(
            "Warning: Deprecated code block style options found in {}:",
            path.display()
        );
        if format_nested {
            eprintln!("  - [format.code-blocks]");
        }
        if top_level {
            eprintln!("  - [code-blocks]");
        }
        if style_nested {
            eprintln!("  - [style.code-blocks]");
        }
        eprintln!("  These options are now no-ops and will be removed in a future release.");
    }
}

fn parse_config_str(s: &str, path: &Path) -> io::Result<Config> {
    // Check for deprecated names before parsing
    check_deprecated_extension_names(s, path);
    check_deprecated_formatter_names(s, path);
    check_deprecated_code_block_style_options(s, path);

    let config: Config = toml::from_str(s).map_err(|e| {
        io::Error::new(
            io::ErrorKind::InvalidData,
            format!("invalid config {}: {e}", path.display()),
        )
    })?;

    Ok(config)
}

fn read_config(path: &Path) -> io::Result<Config> {
    log::debug!("Reading config from: {}", path.display());
    let s = fs::read_to_string(path)?;
    let config = parse_config_str(&s, path)?;
    log::debug!("Loaded config from: {}", path.display());
    Ok(config)
}

fn find_in_tree(start_dir: &Path) -> Option<PathBuf> {
    for dir in start_dir.ancestors() {
        for name in CANDIDATE_NAMES {
            let p = dir.join(name);
            if p.is_file() {
                return Some(p);
            }
        }
    }
    None
}

fn xdg_config_path() -> Option<PathBuf> {
    if let Ok(xdg) = env::var("XDG_CONFIG_HOME") {
        let p = Path::new(&xdg).join("panache").join("config.toml");
        if p.is_file() {
            return Some(p);
        }
    }
    if let Ok(home) = env::var("HOME") {
        let p = Path::new(&home)
            .join(".config")
            .join("panache")
            .join("config.toml");
        if p.is_file() {
            return Some(p);
        }
    }
    None
}

/// Load configuration with precedence:
/// 1) explicit path (error if unreadable/invalid)
/// 2) walk up from start_dir: .panache.toml, panache.toml
/// 3) XDG: $XDG_CONFIG_HOME/panache/config.toml or ~/.config/panache/config.toml
/// 4) default config
///
/// Flavor detection logic (when input_file is provided):
/// - .qmd files: Always use Quarto flavor
/// - .Rmd files: Always use RMarkdown flavor
/// - Markdown-family files (.md/.markdown/.mdown/.mkd): Use most-specific
///   `flavor-overrides` match when provided, else use `flavor` from config
/// - Other extensions: Use `flavor` from config
///
/// The `flavor` config field determines the default flavor for stdin and files
/// without a matching extension override.
pub fn load(
    explicit: Option<&Path>,
    start_dir: &Path,
    input_file: Option<&Path>,
) -> io::Result<(Config, Option<PathBuf>)> {
    let (mut cfg, cfg_path) = if let Some(path) = explicit {
        let cfg = read_config(path)?;
        (cfg, Some(path.to_path_buf()))
    } else if let Some(p) = find_in_tree(start_dir)
        && let Ok(cfg) = read_config(&p)
    {
        (cfg, Some(p))
    } else if let Some(p) = xdg_config_path()
        && let Ok(cfg) = read_config(&p)
    {
        (cfg, Some(p))
    } else {
        log::debug!("No config file found, using defaults");
        (Config::default(), None)
    };

    if let Some(flavor) = detect_flavor(input_file, cfg_path.as_deref(), &cfg) {
        cfg.flavor = flavor;
        cfg.extensions = if let Some(path) = cfg_path.as_deref() {
            fs::read_to_string(path)
                .ok()
                .and_then(|s| toml::from_str::<toml::Value>(&s).ok())
                .map(|root| resolve_extensions_for_flavor(root.get("extensions"), flavor))
                .unwrap_or_else(|| Extensions::for_flavor(flavor))
        } else {
            Extensions::for_flavor(flavor)
        };
    }

    Ok((cfg, cfg_path))
}

fn detect_flavor(
    input_file: Option<&Path>,
    cfg_path: Option<&Path>,
    cfg: &Config,
) -> Option<Flavor> {
    let input_path = input_file?;
    let ext = input_path.extension().and_then(|e| e.to_str())?;
    let ext_lower = ext.to_lowercase();

    match ext_lower.as_str() {
        "qmd" => {
            log::debug!("Using Quarto flavor for .qmd file");
            Some(Flavor::Quarto)
        }
        "rmd" => {
            log::debug!("Using RMarkdown flavor for .Rmd file");
            Some(Flavor::RMarkdown)
        }
        _ if MARKDOWN_FAMILY_EXTENSIONS.contains(&ext_lower.as_str()) => {
            let base_dir = cfg_path.and_then(Path::parent);
            let override_flavor =
                detect_flavor_override(input_path, base_dir, &cfg.flavor_overrides);
            let final_flavor = override_flavor.unwrap_or(cfg.flavor);
            if let Some(flavor) = override_flavor {
                log::debug!(
                    "Using {:?} flavor for {} (matched flavor-overrides)",
                    flavor,
                    input_path.display()
                );
            } else {
                log::debug!(
                    "Using {:?} flavor for {} (from config)",
                    final_flavor,
                    input_path.display()
                );
            }
            Some(final_flavor)
        }
        _ => None,
    }
}

fn detect_flavor_override(
    input_path: &Path,
    base_dir: Option<&Path>,
    overrides: &HashMap<String, Flavor>,
) -> Option<Flavor> {
    if overrides.is_empty() {
        return None;
    }

    let full_path = normalize_path_for_matching(input_path);
    let rel_path = base_dir
        .and_then(|base| input_path.strip_prefix(base).ok())
        .map(normalize_path_for_matching);
    let file_name = input_path
        .file_name()
        .and_then(|name| name.to_str())
        .map(|name| name.to_string());

    let mut best: Option<((usize, usize, usize), Flavor)> = None;
    for (pattern, flavor) in overrides {
        let matched = glob_matches_path(pattern, &full_path)
            || rel_path
                .as_deref()
                .is_some_and(|relative| glob_matches_path(pattern, relative))
            || file_name
                .as_deref()
                .is_some_and(|name| glob_matches_path(pattern, name));
        if !matched {
            continue;
        }

        let score = pattern_specificity(pattern);
        if best.is_none_or(|(best_score, _)| score > best_score) {
            best = Some((score, *flavor));
        }
    }

    best.map(|(_, flavor)| flavor)
}

fn normalize_path_for_matching(path: &Path) -> String {
    path.to_string_lossy().replace('\\', "/")
}

fn pattern_specificity(pattern: &str) -> (usize, usize, usize) {
    let literal_chars = pattern.chars().filter(|c| *c != '*' && *c != '?').count();
    let segment_count = pattern
        .split('/')
        .filter(|segment| !segment.is_empty())
        .count();
    let wildcard_count = pattern.chars().filter(|c| *c == '*' || *c == '?').count();
    (literal_chars, segment_count, usize::MAX - wildcard_count)
}

fn glob_matches_path(pattern: &str, path: &str) -> bool {
    let normalized_pattern = pattern.replace('\\', "/");
    GlobBuilder::new(&normalized_pattern)
        .literal_separator(true)
        .build()
        .map(|glob| glob.compile_matcher().is_match(path))
        .unwrap_or(false)
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn missing_fields_uses_defaults() {
        let toml_str = r#"
            wrap = "reflow"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        assert_eq!(cfg.line_width, 80);
        // Formatters are opt-in, so empty by default
        assert!(cfg.formatters.is_empty());
        assert!(cfg.cache_dir.is_none());
    }

    #[test]
    fn formatter_config_basic() {
        let toml_str = r#"
            [formatters.python]
            cmd = "black"
            args = ["-"]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let python_fmt = &cfg.formatters.get("python").unwrap()[0];
        assert_eq!(python_fmt.cmd, "black");
        assert_eq!(python_fmt.args, vec!["-"]);
        assert!(python_fmt.enabled);
    }

    #[test]
    fn formatter_config_multiple_languages() {
        let toml_str = r#"
            [formatters.r]
            cmd = "air"
            args = ["--preset=tidyverse"]
            
            [formatters.python]
            cmd = "black"
            args = ["-", "--line-length=88"]
            
            [formatters.rust]
            cmd = "rustfmt"
            enabled = false
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        // Old format detected - should have 2 formatters (rust disabled)
        assert_eq!(cfg.formatters.len(), 2);

        let r_fmt = &cfg.formatters.get("r").unwrap()[0];
        assert_eq!(r_fmt.cmd, "air");
        assert_eq!(r_fmt.args, vec!["--preset=tidyverse"]);
        assert!(r_fmt.enabled);

        let py_fmt = &cfg.formatters.get("python").unwrap()[0];
        assert_eq!(py_fmt.cmd, "black");
        assert_eq!(py_fmt.args.len(), 2);

        // rust is disabled in old format, so it shouldn't be in the map
        assert!(!cfg.formatters.contains_key("rust"));
    }

    #[test]
    fn cache_dir_parsing() {
        let toml_str = r#"
            cache-dir = ".panache/local-cache"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        assert_eq!(cfg.cache_dir.as_deref(), Some(".panache/local-cache"));
    }

    #[test]
    fn formatter_config_no_args() {
        let toml_str = r#"
            [formatters.rustfmt]
            cmd = "rustfmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let fmt = &cfg.formatters.get("rustfmt").unwrap()[0];
        assert_eq!(fmt.cmd, "rustfmt");
        assert!(fmt.args.is_empty());
        assert!(fmt.enabled);
    }

    #[test]
    fn formatter_empty_cmd_is_valid() {
        // Empty cmd is technically valid in deserialization
        // Validation happens at runtime
        let toml_str = r#"
            [formatters.test]
            cmd = ""
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("test").unwrap()[0];
        assert_eq!(fmt.cmd, "");
    }

    #[test]
    fn preset_resolution_air() {
        let toml_str = r#"
            [formatters.r]
            preset = "air"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let r_fmt = &cfg.formatters.get("r").unwrap()[0];
        assert_eq!(r_fmt.cmd, "air");
        assert_eq!(r_fmt.args, vec!["format", "{}"]);
        assert!(!r_fmt.stdin);
        assert!(r_fmt.enabled);
    }

    #[test]
    fn preset_resolution_ruff() {
        let toml_str = r#"
            [formatters.python]
            preset = "ruff"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let py_fmt = &cfg.formatters.get("python").unwrap()[0];
        assert_eq!(py_fmt.cmd, "ruff");
        assert_eq!(
            py_fmt.args,
            vec!["format", "--stdin-filename", "stdin.py", "-"]
        );
        assert!(py_fmt.stdin);
        assert!(py_fmt.enabled);
    }

    #[test]
    fn preset_resolution_black() {
        let toml_str = r#"
            [formatters.python]
            preset = "black"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let py_fmt = &cfg.formatters.get("python").unwrap()[0];
        assert_eq!(py_fmt.cmd, "black");
        assert_eq!(py_fmt.args, vec!["-"]);
        assert!(py_fmt.stdin);
    }

    #[test]
    fn preset_resolution_sqlfmt() {
        let toml_str = r#"
            [formatters.sql]
            preset = "sqlfmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("sql").unwrap()[0];
        assert_eq!(fmt.cmd, "sqlfmt");
        assert_eq!(fmt.args, vec!["-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_alejandra() {
        let toml_str = r#"
            [formatters.nix]
            preset = "alejandra"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("nix").unwrap()[0];
        assert_eq!(fmt.cmd, "alejandra");
        assert!(fmt.args.is_empty());
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_terraform_fmt() {
        let toml_str = r#"
            [formatters.hcl]
            preset = "terraform-fmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("hcl").unwrap()[0];
        assert_eq!(fmt.cmd, "terraform");
        assert_eq!(fmt.args, vec!["fmt", "-no-color", "-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_yamlfix() {
        let toml_str = r#"
            [formatters.yaml]
            preset = "yamlfix"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("yaml").unwrap()[0];
        assert_eq!(fmt.cmd, "yamlfix");
        assert_eq!(fmt.args, vec!["-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_gofmt() {
        let toml_str = r#"
            [formatters.go]
            preset = "gofmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("go").unwrap()[0];
        assert_eq!(fmt.cmd, "gofmt");
        assert!(fmt.args.is_empty());
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_gofumpt() {
        let toml_str = r#"
            [formatters.go]
            preset = "gofumpt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("go").unwrap()[0];
        assert_eq!(fmt.cmd, "gofumpt");
        assert!(fmt.args.is_empty());
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_nixfmt() {
        let toml_str = r#"
            [formatters.nix]
            preset = "nixfmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("nix").unwrap()[0];
        assert_eq!(fmt.cmd, "nixfmt");
        assert!(fmt.args.is_empty());
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_gleam() {
        let toml_str = r#"
            [formatters.gleam]
            preset = "gleam"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("gleam").unwrap()[0];
        assert_eq!(fmt.cmd, "gleam");
        assert_eq!(fmt.args, vec!["format", "--stdin"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_yq() {
        let toml_str = r#"
            [formatters.yaml]
            preset = "yq"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("yaml").unwrap()[0];
        assert_eq!(fmt.cmd, "yq");
        assert_eq!(fmt.args, vec!["-P", "-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_asmfmt() {
        let toml_str = r#"
            [formatters.asm]
            preset = "asmfmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("asm").unwrap()[0];
        assert_eq!(fmt.cmd, "asmfmt");
        assert!(fmt.args.is_empty());
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_astyle() {
        let toml_str = r#"
            [formatters.cpp]
            preset = "astyle"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("cpp").unwrap()[0];
        assert_eq!(fmt.cmd, "astyle");
        assert_eq!(fmt.args, vec!["--quiet"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_autocorrect() {
        let toml_str = r#"
            [formatters.text]
            preset = "autocorrect"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("text").unwrap()[0];
        assert_eq!(fmt.cmd, "autocorrect");
        assert_eq!(fmt.args, vec!["--stdin"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_cmake_format() {
        let toml_str = r#"
            [formatters.cmake]
            preset = "cmake-format"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("cmake").unwrap()[0];
        assert_eq!(fmt.cmd, "cmake-format");
        assert_eq!(fmt.args, vec!["-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_cue_fmt() {
        let toml_str = r#"
            [formatters.cue]
            preset = "cue-fmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("cue").unwrap()[0];
        assert_eq!(fmt.cmd, "cue");
        assert_eq!(fmt.args, vec!["fmt", "-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_jsonnetfmt() {
        let toml_str = r#"
            [formatters.jsonnet]
            preset = "jsonnetfmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("jsonnet").unwrap()[0];
        assert_eq!(fmt.cmd, "jsonnetfmt");
        assert_eq!(fmt.args, vec!["-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_dfmt() {
        let toml_str = r#"
            [formatters.d]
            preset = "dfmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("d").unwrap()[0];
        assert_eq!(fmt.cmd, "dfmt");
        assert!(fmt.args.is_empty());
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_efmt() {
        let toml_str = r#"
            [formatters.erl]
            preset = "efmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("erl").unwrap()[0];
        assert_eq!(fmt.cmd, "efmt");
        assert_eq!(fmt.args, vec!["-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_nginxfmt() {
        let toml_str = r#"
            [formatters.nginx]
            preset = "nginxfmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("nginx").unwrap()[0];
        assert_eq!(fmt.cmd, "nginxfmt");
        assert_eq!(fmt.args, vec!["-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_tclfmt() {
        let toml_str = r#"
            [formatters.tcl]
            preset = "tclfmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("tcl").unwrap()[0];
        assert_eq!(fmt.cmd, "tclfmt");
        assert_eq!(fmt.args, vec!["-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_tex_fmt() {
        let toml_str = r#"
            [formatters.tex]
            preset = "tex-fmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("tex").unwrap()[0];
        assert_eq!(fmt.cmd, "tex-fmt");
        assert_eq!(fmt.args, vec!["-s"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_typstyle() {
        let toml_str = r#"
            [formatters.typst]
            preset = "typstyle"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("typst").unwrap()[0];
        assert_eq!(fmt.cmd, "typstyle");
        assert!(fmt.args.is_empty());
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_gdformat() {
        let toml_str = r#"
            [formatters.gdscript]
            preset = "gdformat"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("gdscript").unwrap()[0];
        assert_eq!(fmt.cmd, "gdformat");
        assert_eq!(fmt.args, vec!["-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_hurlfmt() {
        let toml_str = r#"
            [formatters.hurl]
            preset = "hurlfmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("hurl").unwrap()[0];
        assert_eq!(fmt.cmd, "hurlfmt");
        assert!(fmt.args.is_empty());
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_ktfmt() {
        let toml_str = r#"
            [formatters.kotlin]
            preset = "ktfmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("kotlin").unwrap()[0];
        assert_eq!(fmt.cmd, "ktfmt");
        assert_eq!(fmt.args, vec!["-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_leptosfmt() {
        let toml_str = r#"
            [formatters.rust]
            preset = "leptosfmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("rust").unwrap()[0];
        assert_eq!(fmt.cmd, "leptosfmt");
        assert_eq!(fmt.args, vec!["--stdin"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_pycln() {
        let toml_str = r#"
            [formatters.python]
            preset = "pycln"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("python").unwrap()[0];
        assert_eq!(fmt.cmd, "pycln");
        assert_eq!(fmt.args, vec!["--silence", "-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_pyproject_fmt() {
        let toml_str = r#"
            [formatters.toml]
            preset = "pyproject-fmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("toml").unwrap()[0];
        assert_eq!(fmt.cmd, "pyproject-fmt");
        assert_eq!(fmt.args, vec!["-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_google_java_format() {
        let toml_str = r#"
            [formatters.java]
            preset = "google-java-format"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("java").unwrap()[0];
        assert_eq!(fmt.cmd, "google-java-format");
        assert_eq!(fmt.args, vec!["-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_racketfmt() {
        let toml_str = r#"
            [formatters.racket]
            preset = "racketfmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("racket").unwrap()[0];
        assert_eq!(fmt.cmd, "raco");
        assert_eq!(fmt.args, vec!["fmt"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_rubyfmt() {
        let toml_str = r#"
            [formatters.ruby]
            preset = "rubyfmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("ruby").unwrap()[0];
        assert_eq!(fmt.cmd, "rubyfmt");
        assert!(fmt.args.is_empty());
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_rufo() {
        let toml_str = r#"
            [formatters.ruby]
            preset = "rufo"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("ruby").unwrap()[0];
        assert_eq!(fmt.cmd, "rufo");
        assert!(fmt.args.is_empty());
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_bean_format() {
        let toml_str = r#"
            [formatters.beancount]
            preset = "bean-format"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("beancount").unwrap()[0];
        assert_eq!(fmt.cmd, "bean-format");
        assert_eq!(fmt.args, vec!["-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_beautysh() {
        let toml_str = r#"
            [formatters.bash]
            preset = "beautysh"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("bash").unwrap()[0];
        assert_eq!(fmt.cmd, "beautysh");
        assert_eq!(fmt.args, vec!["-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_cljfmt() {
        let toml_str = r#"
            [formatters.clojure]
            preset = "cljfmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("clojure").unwrap()[0];
        assert_eq!(fmt.cmd, "cljfmt");
        assert_eq!(fmt.args, vec!["fix", "-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_fish_indent() {
        let toml_str = r#"
            [formatters.fish]
            preset = "fish_indent"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("fish").unwrap()[0];
        assert_eq!(fmt.cmd, "fish_indent");
        assert!(fmt.args.is_empty());
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_fixjson() {
        let toml_str = r#"
            [formatters.json]
            preset = "fixjson"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("json").unwrap()[0];
        assert_eq!(fmt.cmd, "fixjson");
        assert!(fmt.args.is_empty());
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_bibtex_tidy() {
        let toml_str = r#"
            [formatters.bibtex]
            preset = "bibtex-tidy"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("bibtex").unwrap()[0];
        assert_eq!(fmt.cmd, "bibtex-tidy");
        assert_eq!(fmt.args, vec!["--quiet"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_bpfmt() {
        let toml_str = r#"
            [formatters.bp]
            preset = "bpfmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("bp").unwrap()[0];
        assert_eq!(fmt.cmd, "bpfmt");
        assert_eq!(fmt.args, vec!["-w", "{}"]);
        assert!(!fmt.stdin);
    }

    #[test]
    fn preset_resolution_bsfmt() {
        let toml_str = r#"
            [formatters.brs]
            preset = "bsfmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("brs").unwrap()[0];
        assert_eq!(fmt.cmd, "bsfmt");
        assert_eq!(fmt.args, vec!["{}", "--write"]);
        assert!(!fmt.stdin);
    }

    #[test]
    fn preset_resolution_buf() {
        let toml_str = r#"
            [formatters.proto]
            preset = "buf"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("proto").unwrap()[0];
        assert_eq!(fmt.cmd, "buf");
        assert_eq!(fmt.args, vec!["format", "-w", "{}"]);
        assert!(!fmt.stdin);
    }

    #[test]
    fn preset_resolution_buildifier() {
        let toml_str = r#"
            [formatters.bazel]
            preset = "buildifier"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("bazel").unwrap()[0];
        assert_eq!(fmt.cmd, "buildifier");
        assert_eq!(fmt.args, vec!["-path", "{}", "-"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_resolution_cabal_fmt() {
        let toml_str = r#"
            [formatters.cabal]
            preset = "cabal-fmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("cabal").unwrap()[0];
        assert_eq!(fmt.cmd, "cabal-fmt");
        assert_eq!(fmt.args, vec!["--inplace", "{}"]);
        assert!(!fmt.stdin);
    }

    #[test]
    fn preset_resolution_prettier_typescript() {
        let toml_str = r#"
            [formatters.typescript]
            preset = "prettier"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmt = &cfg.formatters.get("typescript").unwrap()[0];
        assert_eq!(fmt.cmd, "prettier");
        assert_eq!(fmt.args, vec!["--stdin-filepath", "{}"]);
        assert!(fmt.stdin);
    }

    #[test]
    fn preset_and_cmd_mutually_exclusive() {
        let toml_str = r#"
            [formatters.r]
            preset = "air"
            cmd = "styler"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        // The formatter should be skipped (error logged), so r shouldn't be in the map
        assert!(!cfg.formatters.contains_key("r"));
    }

    #[test]
    fn unknown_preset_fails() {
        let toml_str = r#"
            [formatters.r]
            preset = "nonexistent"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        // The formatter should be skipped (error logged), so r shouldn't be in the map
        assert!(!cfg.formatters.contains_key("r"));
    }

    #[test]
    fn preset_language_mismatch_is_rejected() {
        let toml_str = r#"
            [formatters]
            python = "gofmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        assert!(!cfg.formatters.contains_key("python"));
    }

    #[test]
    fn preset_language_alias_is_accepted() {
        let toml_str = r#"
            [formatters]
            yml = "yamlfmt"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmts = cfg.formatters.get("yml").unwrap();
        assert_eq!(fmts.len(), 1);
        assert_eq!(fmts[0].cmd, "yamlfmt");
    }

    #[test]
    fn named_definition_skips_builtin_language_guard() {
        let toml_str = r#"
            [formatters]
            javascript = "prettier"

            [formatters.prettier]
            cmd = "prettier"
            args = ["--print-width=100"]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        let fmts = cfg.formatters.get("javascript").unwrap();
        assert_eq!(fmts.len(), 1);
        assert_eq!(fmts[0].cmd, "prettier");
        assert_eq!(fmts[0].args, vec!["--print-width=100"]);
    }

    #[test]
    fn preset_metadata_lookup_contains_url() {
        let meta = formatter_preset_metadata("gofmt").unwrap();
        assert_eq!(meta.name, "gofmt");
        assert_eq!(meta.cmd, "gofmt");
        assert!(meta.url.contains("pkg.go.dev"));
    }

    #[test]
    fn preset_metadata_language_lookup_works() {
        let names: Vec<&str> = formatter_presets_for_language("yaml")
            .iter()
            .map(|meta| meta.name)
            .collect();
        assert!(names.contains(&"yamlfmt"));
        assert!(names.contains(&"yamlfix"));
        assert!(names.contains(&"yq"));
    }

    #[test]
    fn preset_metadata_language_lookup_includes_prettier_for_typescript() {
        let names: Vec<&str> = formatter_presets_for_language("typescript")
            .iter()
            .map(|meta| meta.name)
            .collect();
        assert!(names.contains(&"prettier"));
    }

    #[test]
    fn builtin_defaults_when_no_config() {
        let cfg = Config::default();
        // Formatters are opt-in, so empty by default
        assert!(cfg.formatters.is_empty());
        assert!(cfg.lint.is_rule_enabled("heading-hierarchy"));
        assert!(cfg.lint.is_rule_enabled("undefined-references"));
    }

    #[test]
    fn lint_config_allows_rule_toggles() {
        let toml_str = r#"
            [lint.rules]
            heading-hierarchy = false
            undefined-references = false
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        assert!(!cfg.lint.is_rule_enabled("heading-hierarchy"));
        assert!(!cfg.lint.is_rule_enabled("undefined-references"));
        assert!(cfg.lint.is_rule_enabled("duplicate-reference-labels"));
    }

    #[test]
    fn lint_config_normalizes_snake_case_rule_names() {
        let toml_str = r#"
            [lint.rules]
            undefined_references = false
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        assert!(!cfg.lint.is_rule_enabled("undefined-references"));
    }

    #[test]
    fn lint_config_legacy_top_level_rules_still_supported() {
        let toml_str = r#"
            [lint]
            undefined-references = false
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        assert!(!cfg.lint.is_rule_enabled("undefined-references"));
    }

    #[test]
    fn path_selector_fields_parse() {
        let toml_str = r#"
            exclude = ["tests/", "build/"]
            extend-exclude = ["snapshots/"]
            include = ["*.qmd"]
            extend-include = ["*.md"]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        assert_eq!(
            cfg.exclude,
            Some(vec!["tests/".to_string(), "build/".to_string()])
        );
        assert_eq!(cfg.extend_exclude, vec!["snapshots/".to_string()]);
        assert_eq!(cfg.include, Some(vec!["*.qmd".to_string()]));
        assert_eq!(cfg.extend_include, vec!["*.md".to_string()]);
    }

    #[test]
    fn path_selector_fields_default_to_unset_or_empty() {
        let cfg = toml::from_str::<Config>("line-width = 100").unwrap();
        assert!(cfg.exclude.is_none());
        assert!(cfg.extend_exclude.is_empty());
        assert!(cfg.include.is_none());
        assert!(cfg.extend_include.is_empty());
    }

    #[test]
    fn default_exclude_patterns_include_license_md() {
        assert!(DEFAULT_EXCLUDE_PATTERNS.contains(&"**/LICENSE.md"));
    }

    #[test]
    fn flavor_overrides_parse() {
        let toml_str = r#"
            [flavor-overrides]
            "README.md" = "gfm"
            "docs/**/*.md" = "quarto"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        assert_eq!(cfg.flavor_overrides.get("README.md"), Some(&Flavor::Gfm));
        assert_eq!(
            cfg.flavor_overrides.get("docs/**/*.md"),
            Some(&Flavor::Quarto)
        );
    }

    #[test]
    fn flavor_override_uses_most_specific_match() {
        let mut overrides = HashMap::new();
        overrides.insert("docs/**/*.md".to_string(), Flavor::Pandoc);
        overrides.insert("docs/README.md".to_string(), Flavor::Gfm);
        let input = Path::new("/project/docs/README.md");

        let flavor = detect_flavor_override(input, Some(Path::new("/project")), &overrides);
        assert_eq!(flavor, Some(Flavor::Gfm));
    }

    #[test]
    fn detect_flavor_uses_override_for_markdown_family() {
        let mut cfg = Config {
            flavor: Flavor::Pandoc,
            ..Config::default()
        };
        cfg.flavor_overrides
            .insert("README.md".to_string(), Flavor::Gfm);

        let flavor = detect_flavor(
            Some(Path::new("/project/README.md")),
            Some(Path::new("/project/panache.toml")),
            &cfg,
        );
        assert_eq!(flavor, Some(Flavor::Gfm));
    }

    #[test]
    fn detect_flavor_keeps_qmd_rmd_extension_defaults() {
        let mut cfg = Config {
            flavor: Flavor::Gfm,
            ..Config::default()
        };
        cfg.flavor_overrides
            .insert("docs/**/*.qmd".to_string(), Flavor::Pandoc);
        cfg.flavor_overrides
            .insert("docs/**/*.Rmd".to_string(), Flavor::Quarto);

        let qmd_flavor = detect_flavor(
            Some(Path::new("/project/docs/chapter.qmd")),
            Some(Path::new("/project/panache.toml")),
            &cfg,
        );
        let rmd_flavor = detect_flavor(
            Some(Path::new("/project/docs/chapter.Rmd")),
            Some(Path::new("/project/panache.toml")),
            &cfg,
        );

        assert_eq!(qmd_flavor, Some(Flavor::Quarto));
        assert_eq!(rmd_flavor, Some(Flavor::RMarkdown));
    }

    #[test]
    fn user_config_adds_formatters() {
        let toml_str = r#"
            [formatters.r]
            cmd = "custom"
            args = ["--flag"]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        // Only R should be configured
        assert_eq!(cfg.formatters.len(), 1);
        let r_fmt = &cfg.formatters.get("r").unwrap()[0];
        assert_eq!(r_fmt.cmd, "custom");
        assert_eq!(r_fmt.args, vec!["--flag"]);
    }

    #[test]
    fn empty_formatters_section_stays_empty() {
        let toml_str = r#"
            line_width = 100
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        // Formatters are opt-in, should be empty
        assert!(cfg.formatters.is_empty());
    }

    #[test]
    fn preset_with_enabled_false() {
        let toml_str = r#"
            [formatters.r]
            preset = "air"
            enabled = false
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        // Old format with enabled=false should not include the formatter
        assert!(!cfg.formatters.contains_key("r"));
    }

    #[test]
    fn default_flavor_is_pandoc() {
        let default_cfg = Config::default();
        assert_eq!(default_cfg.flavor, Flavor::Pandoc);
    }

    #[test]
    fn extensions_merge_with_flavor_quarto() {
        // Test that extension overrides properly merge with Quarto flavor defaults
        let toml_str = r#"
            flavor = "quarto"
            
            [extensions]
            quarto-crossrefs = false
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        // The overridden extension should be false
        assert!(!cfg.extensions.quarto_crossrefs);

        // Other Quarto-specific extensions should still use Quarto defaults (true)
        assert!(cfg.extensions.quarto_callouts);
        assert!(cfg.extensions.quarto_shortcodes);

        // General Pandoc extensions should also use Quarto defaults
        assert!(cfg.extensions.citations);
        assert!(cfg.extensions.yaml_metadata_block);
        assert!(cfg.extensions.fenced_divs);
    }

    #[test]
    fn extensions_merge_with_flavor_pandoc() {
        // Test that extension overrides work with Pandoc flavor
        let toml_str = r#"
            flavor = "pandoc"
            
            [extensions]
            citations = false
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        // The overridden extension should be false
        assert!(!cfg.extensions.citations);

        // Other Pandoc extensions should still use Pandoc defaults (true)
        assert!(cfg.extensions.yaml_metadata_block);
        assert!(cfg.extensions.fenced_divs);

        // Quarto extensions should be false in Pandoc flavor
        assert!(!cfg.extensions.quarto_crossrefs);
        assert!(!cfg.extensions.quarto_callouts);
    }

    #[test]
    fn extensions_no_override_uses_flavor_defaults() {
        // Test that omitting [extensions] uses flavor defaults
        let toml_str = r#"
            flavor = "quarto"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        // Should use Quarto defaults
        assert!(cfg.extensions.quarto_crossrefs);
        assert!(cfg.extensions.quarto_callouts);
        assert!(cfg.extensions.quarto_shortcodes);
    }

    #[test]
    fn extensions_empty_section_uses_flavor_defaults() {
        // Test that empty [extensions] section still uses flavor defaults
        let toml_str = r#"
            flavor = "quarto"
            
            [extensions]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        // Should use Quarto defaults
        assert!(cfg.extensions.quarto_crossrefs);
        assert!(cfg.extensions.quarto_callouts);
        assert!(cfg.extensions.quarto_shortcodes);
    }

    #[test]
    fn extensions_multiple_overrides() {
        // Test multiple extension overrides
        let toml_str = r#"
            flavor = "quarto"
            
            [extensions]
            quarto-crossrefs = false
            citations = false
            emoji = true
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        // Overridden extensions
        assert!(!cfg.extensions.quarto_crossrefs);
        assert!(!cfg.extensions.citations);
        assert!(cfg.extensions.emoji);

        // Other Quarto defaults should remain
        assert!(cfg.extensions.quarto_callouts);
        assert!(cfg.extensions.quarto_shortcodes);
    }

    #[test]
    fn extensions_per_flavor_override_wins_over_global() {
        let toml_str = r#"
            flavor = "gfm"

            [extensions]
            task-lists = false
            citations = true

            [extensions.gfm]
            task-lists = true
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        assert!(cfg.extensions.task_lists);
        assert!(cfg.extensions.citations);
    }

    #[test]
    fn extensions_per_flavor_table_is_ignored_for_other_flavors() {
        let toml_str = r#"
            flavor = "pandoc"

            [extensions]
            citations = false

            [extensions.gfm]
            citations = true
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        assert!(!cfg.extensions.citations);
    }

    #[test]
    fn extensions_per_flavor_commonmark_alias_works() {
        let toml_str = r#"
            flavor = "common-mark"

            [extensions]
            citations = true

            [extensions.commonmark]
            citations = false
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        assert!(!cfg.extensions.citations);
    }

    #[test]
    fn multimarkdown_flavor_enables_mmd_header_identifiers_by_default() {
        let cfg = toml::from_str::<Config>("flavor = \"multimarkdown\"").unwrap();

        assert_eq!(cfg.flavor, Flavor::MultiMarkdown);
        assert!(cfg.extensions.mmd_header_identifiers);
        assert!(cfg.extensions.mmd_title_block);
        assert!(cfg.extensions.mmd_link_attributes);
        assert!(!cfg.extensions.pandoc_title_block);
        assert!(cfg.extensions.tex_math_double_backslash);
        assert!(cfg.extensions.definition_lists);
        assert!(cfg.extensions.raw_attribute);
    }

    #[test]
    fn extensions_per_flavor_multimarkdown_table_works() {
        let toml_str = r#"
            flavor = "multimarkdown"

            [extensions]
            mmd-header-identifiers = false

            [extensions.multimarkdown]
            mmd-header-identifiers = true
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        assert!(cfg.extensions.mmd_header_identifiers);
    }

    #[test]
    fn extensions_per_flavor_multimarkdown_title_block_override_works() {
        let toml_str = r#"
            flavor = "multimarkdown"

            [extensions]
            mmd-title-block = false

            [extensions.multimarkdown]
            mmd-title-block = true
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        assert!(cfg.extensions.mmd_title_block);
    }

    #[test]
    fn extensions_per_flavor_multimarkdown_link_attributes_override_works() {
        let toml_str = r#"
            flavor = "multimarkdown"

            [extensions]
            mmd-link-attributes = false

            [extensions.multimarkdown]
            mmd-link-attributes = true
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        assert!(cfg.extensions.mmd_link_attributes);
    }

    #[test]
    fn alerts_enabled_by_default_for_gfm() {
        let cfg = toml::from_str::<Config>("flavor = \"gfm\"").unwrap();
        assert!(cfg.extensions.alerts);
    }

    #[test]
    fn auto_identifiers_enabled_by_default_for_pandoc_and_gfm() {
        let pandoc = toml::from_str::<Config>("flavor = \"pandoc\"").unwrap();
        let gfm = toml::from_str::<Config>("flavor = \"gfm\"").unwrap();
        assert!(pandoc.extensions.auto_identifiers);
        assert!(gfm.extensions.auto_identifiers);
    }

    #[test]
    fn gfm_auto_identifiers_enabled_by_default_only_for_gfm() {
        let pandoc = toml::from_str::<Config>("flavor = \"pandoc\"").unwrap();
        let gfm = toml::from_str::<Config>("flavor = \"gfm\"").unwrap();
        let commonmark = toml::from_str::<Config>("flavor = \"common-mark\"").unwrap();

        assert!(!pandoc.extensions.gfm_auto_identifiers);
        assert!(gfm.extensions.gfm_auto_identifiers);
        assert!(!commonmark.extensions.gfm_auto_identifiers);
    }

    #[test]
    fn footnotes_enabled_by_default_for_gfm() {
        let cfg = toml::from_str::<Config>("flavor = \"gfm\"").unwrap();
        assert!(cfg.extensions.footnotes);
    }

    #[test]
    fn fenced_code_blocks_enabled_by_default_for_gfm() {
        let cfg = toml::from_str::<Config>("flavor = \"gfm\"").unwrap();
        assert!(cfg.extensions.backtick_code_blocks);
        assert!(cfg.extensions.fenced_code_blocks);
    }

    #[test]
    fn tex_math_gfm_enabled_by_default_for_gfm() {
        let cfg = toml::from_str::<Config>("flavor = \"gfm\"").unwrap();
        assert!(cfg.extensions.tex_math_gfm);
    }

    #[test]
    fn executable_code_enabled_by_default_for_quarto_and_rmarkdown() {
        let quarto = toml::from_str::<Config>("flavor = \"quarto\"").unwrap();
        let rmarkdown = toml::from_str::<Config>("flavor = \"rmarkdown\"").unwrap();

        assert!(quarto.extensions.executable_code);
        assert!(rmarkdown.extensions.executable_code);
        assert!(quarto.extensions.quarto_inline_code);
        assert!(quarto.extensions.rmarkdown_inline_code);
        assert!(rmarkdown.extensions.rmarkdown_inline_code);
        assert!(!rmarkdown.extensions.quarto_inline_code);
    }

    #[test]
    fn bookdown_equation_references_enabled_by_default_only_for_rmarkdown() {
        let pandoc = toml::from_str::<Config>("flavor = \"pandoc\"").unwrap();
        let quarto = toml::from_str::<Config>("flavor = \"quarto\"").unwrap();
        let rmarkdown = toml::from_str::<Config>("flavor = \"rmarkdown\"").unwrap();

        assert!(!pandoc.extensions.bookdown_equation_references);
        assert!(!quarto.extensions.bookdown_equation_references);
        assert!(rmarkdown.extensions.bookdown_equation_references);
    }

    #[test]
    fn executable_code_disabled_by_default_for_pandoc_gfm_and_commonmark() {
        let pandoc = toml::from_str::<Config>("flavor = \"pandoc\"").unwrap();
        let gfm = toml::from_str::<Config>("flavor = \"gfm\"").unwrap();
        let commonmark = toml::from_str::<Config>("flavor = \"common-mark\"").unwrap();

        assert!(!pandoc.extensions.executable_code);
        assert!(!gfm.extensions.executable_code);
        assert!(!commonmark.extensions.executable_code);
        assert!(!pandoc.extensions.quarto_inline_code);
        assert!(!pandoc.extensions.rmarkdown_inline_code);
        assert!(!gfm.extensions.quarto_inline_code);
        assert!(!gfm.extensions.rmarkdown_inline_code);
        assert!(!commonmark.extensions.quarto_inline_code);
        assert!(!commonmark.extensions.rmarkdown_inline_code);
    }

    #[test]
    fn gfm_disables_non_gfm_pandoc_extensions() {
        let cfg = toml::from_str::<Config>("flavor = \"gfm\"").unwrap();
        assert!(!cfg.extensions.citations);
        assert!(!cfg.extensions.definition_lists);
        assert!(!cfg.extensions.fenced_divs);
        assert!(!cfg.extensions.raw_tex);
    }

    #[test]
    fn commonmark_defaults_match_minimal_set() {
        let cfg = toml::from_str::<Config>("flavor = \"common-mark\"").unwrap();
        assert!(cfg.extensions.raw_html);
        assert!(!cfg.extensions.auto_identifiers);
        assert!(!cfg.extensions.autolinks);
        assert!(!cfg.extensions.inline_links);
        assert!(!cfg.extensions.reference_links);
    }

    #[test]
    fn alerts_disabled_by_default_for_pandoc() {
        let cfg = toml::from_str::<Config>("flavor = \"pandoc\"").unwrap();
        assert!(!cfg.extensions.alerts);
    }

    #[test]
    fn format_section_new_format() {
        let toml_str = r#"
            flavor = "quarto"
            
            [format]
            wrap = "sentence"
            built-in-greedy-wrap = true
            blank-lines = "collapse"
            math-delimiter-style = "dollars"
            math-indent = 2
            tab-stops = "preserve"
            tab-width = 4
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        assert_eq!(cfg.wrap, Some(WrapMode::Sentence));
        assert_eq!(cfg.blank_lines, BlankLines::Collapse);
        assert_eq!(cfg.math_delimiter_style, MathDelimiterStyle::Dollars);
        assert_eq!(cfg.math_indent, 2);
        assert_eq!(cfg.tab_stops, TabStopMode::Preserve);
        assert_eq!(cfg.tab_width, 4);
        assert!(cfg.built_in_greedy_wrap);
    }

    #[test]
    fn format_section_with_deprecated_code_blocks_is_accepted() {
        let toml_str = r#"
            flavor = "pandoc"
            
            [format]
            wrap = "preserve"
            
            [format.code-blocks]
            fence-style = "tilde"
            attribute-style = "explicit"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        assert_eq!(cfg.wrap, Some(WrapMode::Preserve));
        assert!(cfg.built_in_greedy_wrap);
    }

    #[test]
    fn backwards_compat_old_format_still_works() {
        let toml_str = r#"
            flavor = "quarto"
            wrap = "reflow"
            math-indent = 4
            
            [code-blocks]
            fence-style = "backtick"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        // Old format should still work
        assert_eq!(cfg.wrap, Some(WrapMode::Reflow));
        assert_eq!(cfg.math_indent, 4);
    }

    #[test]
    fn format_section_takes_precedence() {
        let toml_str = r#"
            flavor = "quarto"
            
            # Old format (should be ignored)
            wrap = "preserve"
            math-indent = 10
            
            # New format (should take precedence)
            [format]
            wrap = "sentence"
            math-indent = 2
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        // New [format] section should win
        assert_eq!(cfg.wrap, Some(WrapMode::Sentence));
        assert_eq!(cfg.math_indent, 2);
    }

    #[test]
    fn deprecated_style_section_still_supported() {
        let toml_str = r#"
            [style]
            wrap = "preserve"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();
        assert_eq!(cfg.wrap, Some(WrapMode::Preserve));
    }
}

#[cfg(test)]
mod line_ending_test {
    use super::*;

    #[test]
    fn test_deserialize_line_ending_in_config() {
        #[derive(Deserialize)]
        struct TestConfig {
            line_ending: LineEnding,
        }

        let cfg: TestConfig = toml::from_str(r#"line_ending = "lf""#).unwrap();
        assert_eq!(cfg.line_ending, LineEnding::Lf);

        let cfg2: TestConfig = toml::from_str(r#"line_ending = "auto""#).unwrap();
        assert_eq!(cfg2.line_ending, LineEnding::Auto);

        let cfg3: TestConfig = toml::from_str(r#"line_ending = "crlf""#).unwrap();
        assert_eq!(cfg3.line_ending, LineEnding::Crlf);
    }
}

#[cfg(test)]
mod raw_config_test {
    use super::*;

    #[test]
    fn test_raw_config_line_ending() {
        // Must use hyphen (line-ending) not underscore due to #[serde(rename_all = "kebab-case")]
        let cfg: Config = toml::from_str(r#"line-ending = "lf""#).unwrap();
        assert_eq!(cfg.line_ending, Some(LineEnding::Lf));

        // Test that it goes through RawConfig properly
        let content = r#"
        line-ending = "crlf"
        line-width = 100
        "#;
        let cfg2: Config = toml::from_str(content).unwrap();
        assert_eq!(cfg2.line_ending, Some(LineEnding::Crlf));
        assert_eq!(cfg2.line_width, 100);
    }
}

#[cfg(test)]
mod field_name_test {
    use super::*;

    #[test]
    fn test_line_ending_field_name() {
        // The RawConfig uses #[serde(rename_all = "kebab-case")] so field names use hyphens
        let cfg: Config = toml::from_str(r#"line-ending = "lf""#).unwrap();
        assert_eq!(cfg.line_ending, Some(LineEnding::Lf));

        // Test all three values
        let cfg_auto: Config = toml::from_str(r#"line-ending = "auto""#).unwrap();
        assert_eq!(cfg_auto.line_ending, Some(LineEnding::Auto));

        let cfg_crlf: Config = toml::from_str(r#"line-ending = "crlf""#).unwrap();
        assert_eq!(cfg_crlf.line_ending, Some(LineEnding::Crlf));
    }
}

#[cfg(test)]
mod code_blocks_config_test {
    use super::*;

    #[test]
    fn deprecated_top_level_code_blocks_is_accepted_as_noop() {
        let toml_str = r#"
            flavor = "pandoc"
            
            [code-blocks]
            attribute-style = "explicit"
        "#;
        let cfg: Config = toml::from_str(toml_str).unwrap();
        assert_eq!(cfg.flavor, Flavor::Pandoc);
    }

    #[test]
    fn deprecated_format_code_blocks_is_accepted_as_noop() {
        let toml_str = r#"
            flavor = "quarto"
            [format]
            wrap = "reflow"
            
            [format.code-blocks]
            attribute-style = "explicit"
        "#;
        let cfg: Config = toml::from_str(toml_str).unwrap();
        assert_eq!(cfg.wrap, Some(WrapMode::Reflow));
    }

    #[test]
    fn no_code_blocks_config_still_parses() {
        let toml_str = r#"
            flavor = "quarto"
        "#;
        let cfg: Config = toml::from_str(toml_str).unwrap();
        assert_eq!(cfg.flavor, Flavor::Quarto);
    }

    // ===== New Formatter Format Tests =====

    #[test]
    fn new_format_single_formatter() {
        let toml_str = r#"
            [formatters]
            r = "air"
            python = "black"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        assert_eq!(cfg.formatters.len(), 2);

        // Check R formatter (resolved from built-in preset)
        let r_fmts = cfg.formatters.get("r").unwrap();
        assert_eq!(r_fmts.len(), 1);
        assert_eq!(r_fmts[0].cmd, "air");
        assert_eq!(r_fmts[0].args, vec!["format", "{}"]);

        // Check Python formatter (resolved from built-in preset)
        let py_fmts = cfg.formatters.get("python").unwrap();
        assert_eq!(py_fmts.len(), 1);
        assert_eq!(py_fmts[0].cmd, "black");
    }

    #[test]
    fn new_format_multiple_formatters() {
        let toml_str = r#"
            [formatters]
            python = ["ruff", "black"]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let py_fmts = cfg.formatters.get("python").unwrap();
        assert_eq!(py_fmts.len(), 2);
        assert_eq!(py_fmts[0].cmd, "ruff");
        assert_eq!(py_fmts[1].cmd, "black");
    }

    #[test]
    fn new_format_with_custom_definition() {
        let toml_str = r#"
            [formatters]
            r = "custom-air"
            
            [formatters.custom-air]
            cmd = "air"
            args = ["format", "--custom-flag"]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let r_fmts = cfg.formatters.get("r").unwrap();
        assert_eq!(r_fmts.len(), 1);
        assert_eq!(r_fmts[0].cmd, "air");
        assert_eq!(r_fmts[0].args, vec!["format", "--custom-flag"]);
    }

    #[test]
    fn new_format_empty_array() {
        let toml_str = r#"
            [formatters]
            r = []
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        // Empty array means no formatting for this language
        assert!(!cfg.formatters.contains_key("r"));
    }

    #[test]
    fn new_format_reusable_definition() {
        let toml_str = r#"
            [formatters]
            javascript = "prettier"
            typescript = "prettier"
            json = "prettier"
            
            [formatters.prettier]
            cmd = "prettier"
            args = ["--print-width=100"]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        assert_eq!(cfg.formatters.len(), 3);

        // All should use the same prettier config
        for lang in ["javascript", "typescript", "json"] {
            let fmts = cfg.formatters.get(lang).unwrap();
            assert_eq!(fmts.len(), 1);
            assert_eq!(fmts[0].cmd, "prettier");
            assert_eq!(fmts[0].args, vec!["--print-width=100"]);
        }
    }

    // ===== Preset inheritance tests =====

    #[test]
    fn preset_inheritance_override_only_args() {
        let toml_str = r#"
            [formatters]
            r = "air"
            
            [formatters.air]
            args = ["format", "--custom-flag", "{}"]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let r_fmts = cfg.formatters.get("r").unwrap();
        assert_eq!(r_fmts.len(), 1);
        // cmd and stdin inherited from built-in "air" preset
        assert_eq!(r_fmts[0].cmd, "air");
        assert!(!r_fmts[0].stdin);
        // args overridden
        assert_eq!(r_fmts[0].args, vec!["format", "--custom-flag", "{}"]);
    }

    #[test]
    fn preset_inheritance_override_only_cmd() {
        let toml_str = r#"
            [formatters]
            r = "air"
            
            [formatters.air]
            cmd = "custom-air"
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let r_fmts = cfg.formatters.get("r").unwrap();
        assert_eq!(r_fmts.len(), 1);
        // cmd overridden
        assert_eq!(r_fmts[0].cmd, "custom-air");
        // args and stdin inherited from built-in "air" preset
        assert_eq!(r_fmts[0].args, vec!["format", "{}"]);
        assert!(!r_fmts[0].stdin);
    }

    #[test]
    fn preset_inheritance_override_only_stdin() {
        let toml_str = r#"
            [formatters]
            r = "air"
            
            [formatters.air]
            stdin = true
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let r_fmts = cfg.formatters.get("r").unwrap();
        assert_eq!(r_fmts.len(), 1);
        // cmd and args inherited from built-in "air" preset
        assert_eq!(r_fmts[0].cmd, "air");
        assert_eq!(r_fmts[0].args, vec!["format", "{}"]);
        // stdin overridden
        assert!(r_fmts[0].stdin);
    }

    #[test]
    fn preset_inheritance_override_multiple_fields() {
        let toml_str = r#"
            [formatters]
            python = "black"
            
            [formatters.black]
            args = ["--line-length=100"]
            stdin = false
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let py_fmts = cfg.formatters.get("python").unwrap();
        assert_eq!(py_fmts.len(), 1);
        // cmd inherited
        assert_eq!(py_fmts[0].cmd, "black");
        // args and stdin overridden
        assert_eq!(py_fmts[0].args, vec!["--line-length=100"]);
        assert!(!py_fmts[0].stdin);
    }

    #[test]
    fn preset_inheritance_override_all_fields() {
        let toml_str = r#"
            [formatters]
            r = "air"
            
            [formatters.air]
            cmd = "totally-different"
            args = ["custom"]
            stdin = true
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let r_fmts = cfg.formatters.get("r").unwrap();
        assert_eq!(r_fmts.len(), 1);
        // All fields overridden (complete replacement)
        assert_eq!(r_fmts[0].cmd, "totally-different");
        assert_eq!(r_fmts[0].args, vec!["custom"]);
        assert!(r_fmts[0].stdin);
    }

    #[test]
    fn preset_inheritance_empty_definition_uses_preset() {
        let toml_str = r#"
            [formatters]
            r = "air"
            
            [formatters.air]
            # Empty definition - should use preset as-is
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let r_fmts = cfg.formatters.get("r").unwrap();
        assert_eq!(r_fmts.len(), 1);
        // All fields from built-in preset
        assert_eq!(r_fmts[0].cmd, "air");
        assert_eq!(r_fmts[0].args, vec!["format", "{}"]);
        assert!(!r_fmts[0].stdin);
    }

    #[test]
    fn preset_inheritance_unknown_name_without_cmd_errors() {
        let toml_str = r#"
            [formatters]
            r = "unknown-formatter"
            
            [formatters.unknown-formatter]
            args = ["--flag"]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        // Should fail to resolve - unknown preset and no cmd
        // Error logged, formatter not included in map
        assert!(!cfg.formatters.contains_key("r"));
    }

    #[test]
    fn preset_inheritance_unknown_name_with_cmd_works() {
        let toml_str = r#"
            [formatters]
            r = "unknown-formatter"
            
            [formatters.unknown-formatter]
            cmd = "my-custom-formatter"
            args = ["--flag"]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let r_fmts = cfg.formatters.get("r").unwrap();
        assert_eq!(r_fmts.len(), 1);
        // Should work - has cmd even though name doesn't match preset
        assert_eq!(r_fmts[0].cmd, "my-custom-formatter");
        assert_eq!(r_fmts[0].args, vec!["--flag"]);
        assert!(r_fmts[0].stdin); // default
    }

    // ===== Tests for append_args and prepend_args =====

    #[test]
    fn append_args_with_preset_inheritance() {
        let toml_str = r#"
            [formatters]
            r = "air"
            
            [formatters.air]
            append-args = ["-i", "2"]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let r_fmts = cfg.formatters.get("r").unwrap();
        assert_eq!(r_fmts.len(), 1);
        // Preset args: ["format", "{}"]
        // After append: ["format", "{}", "-i", "2"]
        assert_eq!(r_fmts[0].cmd, "air");
        assert_eq!(r_fmts[0].args, vec!["format", "{}", "-i", "2"]);
        assert!(!r_fmts[0].stdin);
    }

    #[test]
    fn prepend_args_with_preset_inheritance() {
        let toml_str = r#"
            [formatters]
            r = "air"
            
            [formatters.air]
            prepend-args = ["--verbose"]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let r_fmts = cfg.formatters.get("r").unwrap();
        assert_eq!(r_fmts.len(), 1);
        // Preset args: ["format", "{}"]
        // After prepend: ["--verbose", "format", "{}"]
        assert_eq!(r_fmts[0].cmd, "air");
        assert_eq!(r_fmts[0].args, vec!["--verbose", "format", "{}"]);
        assert!(!r_fmts[0].stdin);
    }

    #[test]
    fn both_prepend_and_append_args() {
        let toml_str = r#"
            [formatters]
            r = "air"
            
            [formatters.air]
            prepend_args = ["--verbose"]
            append_args = ["-i", "2"]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let r_fmts = cfg.formatters.get("r").unwrap();
        assert_eq!(r_fmts.len(), 1);
        // Preset args: ["format", "{}"]
        // After prepend + append: ["--verbose", "format", "{}", "-i", "2"]
        assert_eq!(r_fmts[0].args, vec!["--verbose", "format", "{}", "-i", "2"]);
    }

    #[test]
    fn append_args_with_explicit_args() {
        let toml_str = r#"
            [formatters]
            r = "custom"
            
            [formatters.custom]
            cmd = "shfmt"
            args = ["-filename", "$FILENAME"]
            append_args = ["-i", "2"]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let r_fmts = cfg.formatters.get("r").unwrap();
        assert_eq!(r_fmts.len(), 1);
        // Explicit args with append: ["-filename", "$FILENAME", "-i", "2"]
        assert_eq!(r_fmts[0].cmd, "shfmt");
        assert_eq!(r_fmts[0].args, vec!["-filename", "$FILENAME", "-i", "2"]);
    }

    #[test]
    fn prepend_args_with_explicit_args() {
        let toml_str = r#"
            [formatters]
            r = "custom"
            
            [formatters.custom]
            cmd = "formatter"
            args = ["input.txt"]
            prepend_args = ["--config", "cfg.toml"]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let r_fmts = cfg.formatters.get("r").unwrap();
        assert_eq!(r_fmts.len(), 1);
        // Explicit args with prepend: ["--config", "cfg.toml", "input.txt"]
        assert_eq!(r_fmts[0].args, vec!["--config", "cfg.toml", "input.txt"]);
    }

    #[test]
    fn args_override_with_append_still_applies() {
        let toml_str = r#"
            [formatters]
            r = "air"
            
            [formatters.air]
            args = ["custom", "override"]
            append_args = ["--extra"]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let r_fmts = cfg.formatters.get("r").unwrap();
        assert_eq!(r_fmts.len(), 1);
        // Overridden args + append: ["custom", "override", "--extra"]
        assert_eq!(r_fmts[0].args, vec!["custom", "override", "--extra"]);
    }

    #[test]
    fn empty_append_prepend_arrays() {
        let toml_str = r#"
            [formatters]
            r = "air"
            
            [formatters.air]
            prepend_args = []
            append_args = []
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let r_fmts = cfg.formatters.get("r").unwrap();
        assert_eq!(r_fmts.len(), 1);
        // Empty modifiers = no-op, preset args unchanged
        assert_eq!(r_fmts[0].args, vec!["format", "{}"]);
    }

    #[test]
    fn modifiers_without_base_args() {
        let toml_str = r#"
            [formatters]
            r = "custom"
            
            [formatters.custom]
            cmd = "formatter"
            prepend_args = ["--flag"]
            append_args = ["--other"]
        "#;
        let cfg = toml::from_str::<Config>(toml_str).unwrap();

        let r_fmts = cfg.formatters.get("r").unwrap();
        assert_eq!(r_fmts.len(), 1);
        // No base args (no preset, no explicit args), modifiers create args from scratch
        // Result: ["--flag", "--other"]
        assert_eq!(r_fmts[0].args, vec!["--flag", "--other"]);
    }
}

#[cfg(test)]
mod parser_config_test {
    use super::*;

    #[test]
    fn test_parser_config_default() {
        let cfg = Config::default();
        assert_eq!(cfg.parser.pandoc_compat, PandocCompat::V3_9);
    }

    #[test]
    fn test_parser_config_empty() {
        // Verify empty parser config deserializes correctly
        let toml_str = r#"
            [parser]
        "#;
        let cfg: Config = toml::from_str(toml_str).unwrap();
        assert_eq!(cfg.parser.pandoc_compat, PandocCompat::V3_9);
    }

    #[test]
    fn test_parser_config_pandoc_compat_latest() {
        let toml_str = r#"
            pandoc-compat = "latest"
        "#;
        let cfg: Config = toml::from_str(toml_str).unwrap();
        assert_eq!(cfg.parser.pandoc_compat, PandocCompat::Latest);
        assert_eq!(cfg.parser.effective_pandoc_compat(), PandocCompat::V3_9);
    }

    #[test]
    fn test_parser_config_pandoc_compat_accepts_version_aliases() {
        for value in ["3.7", "3-7", "v3.7", "v3-7"] {
            let toml_str = format!("pandoc-compat = \"{}\"\n", value);
            let cfg: Config = toml::from_str(&toml_str).unwrap();
            assert_eq!(cfg.parser.pandoc_compat, PandocCompat::V3_7);
        }

        for value in ["3.9", "3-9", "v3.9", "v3-9"] {
            let toml_str = format!("pandoc-compat = \"{}\"\n", value);
            let cfg: Config = toml::from_str(&toml_str).unwrap();
            assert_eq!(cfg.parser.pandoc_compat, PandocCompat::V3_9);
        }
    }

    #[test]
    fn test_parser_config_pandoc_compat_parser_section_backwards_compat() {
        let toml_str = r#"
            [parser]
            pandoc-compat = "latest"
        "#;
        let cfg: Config = toml::from_str(toml_str).unwrap();
        assert_eq!(cfg.parser.pandoc_compat, PandocCompat::Latest);
    }

    #[test]
    fn test_parser_config_pandoc_compat_top_level_takes_precedence() {
        let toml_str = r#"
            pandoc-compat = "3.7"

            [parser]
            pandoc-compat = "latest"
        "#;
        let cfg: Config = toml::from_str(toml_str).unwrap();
        assert_eq!(cfg.parser.pandoc_compat, PandocCompat::V3_7);
    }
}

#[test]
fn test_snake_case_alias_backwards_compat() {
    // Verify that snake_case (old format) still works via aliases
    let toml_str = r#"
            flavor = "quarto"
            
            [extensions]
            quarto_crossrefs = false
            tex_math_dollars = true
            tex_math_gfm = true
        "#;
    let cfg = toml::from_str::<Config>(toml_str).unwrap();

    assert!(!cfg.extensions.quarto_crossrefs);
    assert!(cfg.extensions.tex_math_dollars);
    assert!(cfg.extensions.tex_math_gfm);
}

#[test]
fn test_kebab_case_new_format() {
    // Verify that kebab-case (new format) works
    let toml_str = r#"
            flavor = "quarto"
            
            [extensions]
            quarto-crossrefs = false
            tex-math-dollars = true
            tex-math-gfm = true
        "#;
    let cfg = toml::from_str::<Config>(toml_str).unwrap();

    assert!(!cfg.extensions.quarto_crossrefs);
    assert!(cfg.extensions.tex_math_dollars);
    assert!(cfg.extensions.tex_math_gfm);
}

#[test]
fn test_formatter_prepend_append_args_snake_case() {
    // Old format with snake_case
    let toml_str = r#"
            [formatters.test]
            cmd = "test"
            args = ["--middle"]
            prepend_args = ["--before"]
            append_args = ["--after"]
        "#;
    let cfg = toml::from_str::<Config>(toml_str).unwrap();
    let fmt = &cfg.formatters.get("test").unwrap()[0];

    assert_eq!(fmt.cmd, "test");
    assert_eq!(fmt.args, vec!["--before", "--middle", "--after"]);
}

#[test]
fn test_formatter_prepend_append_args_kebab_case() {
    // New format with kebab-case
    let toml_str = r#"
            [formatters.test]
            cmd = "test"
            args = ["--middle"]
            prepend-args = ["--before"]
            append-args = ["--after"]
        "#;
    let cfg = toml::from_str::<Config>(toml_str).unwrap();
    let fmt = &cfg.formatters.get("test").unwrap()[0];

    assert_eq!(fmt.cmd, "test");
    assert_eq!(fmt.args, vec!["--before", "--middle", "--after"]);
}