rich_rs/

syntax.rs

//! Syntax: syntax-highlighted code rendering.
//!
//! This module provides syntax highlighting for source code using the `syntect` crate.
//! It supports various programming languages and color themes.
//!
//! # Example
//!
//! ```
//! use rich_rs::Syntax;
//!
//! let code = r#"fn main() {
//!     println!("Hello, World!");
//! }"#;
//!
//! let syntax = Syntax::new(code, "rust")
//!     .with_theme("monokai")
//!     .with_line_numbers(true);
//! ```

use std::collections::HashSet;
use std::io::Stdout;
use std::path::Path;

use once_cell::sync::Lazy;
use syntect::easy::HighlightLines;
use syntect::highlighting::{Style as SyntectStyle, Theme, ThemeSet};
use syntect::parsing::SyntaxSet;
use syntect::util::LinesWithEndings;

use crate::Renderable;
use crate::cells::cell_len;
use crate::color::SimpleColor as Color;
use crate::console::{Console, ConsoleOptions, OverflowMethod};
use crate::measure::Measurement;
use crate::padding::PaddingDimensions;
use crate::segment::{Segment, Segments};
use crate::style::Style;
use crate::text::Text;

// ============================================================================
// Static syntax and theme sets
// ============================================================================

/// Global syntax set loaded once at startup.
static SYNTAX_SET: Lazy<SyntaxSet> = Lazy::new(SyntaxSet::load_defaults_newlines);

/// Global theme set loaded once at startup.
static THEME_SET: Lazy<ThemeSet> = Lazy::new(ThemeSet::load_defaults);

/// Embedded Monokai theme (matches Pygments Monokai exactly).
const MONOKAI_THEME_DATA: &[u8] = include_bytes!("themes/monokai.tmTheme");

/// Embedded Monokai Plus theme (enhanced with more semantic highlighting).
const MONOKAI_PLUS_THEME_DATA: &[u8] = include_bytes!("themes/monokai-plus.tmTheme");

/// Embedded Dracula theme (imported from Pygments).
const DRACULA_THEME_DATA: &[u8] = include_bytes!("themes/dracula.tmTheme");

/// Embedded Gruvbox Dark theme (imported from Pygments).
const GRUVBOX_DARK_THEME_DATA: &[u8] = include_bytes!("themes/gruvbox-dark.tmTheme");

/// Embedded Nord theme (imported from Pygments).
const NORD_THEME_DATA: &[u8] = include_bytes!("themes/nord.tmTheme");

/// Monokai theme loaded from embedded data.
static MONOKAI_THEME: Lazy<Option<Theme>> = Lazy::new(|| {
    use std::io::Cursor;
    let mut cursor = Cursor::new(MONOKAI_THEME_DATA);
    ThemeSet::load_from_reader(&mut cursor).ok()
});

/// Monokai Plus theme loaded from embedded data.
static MONOKAI_PLUS_THEME: Lazy<Option<Theme>> = Lazy::new(|| {
    use std::io::Cursor;
    let mut cursor = Cursor::new(MONOKAI_PLUS_THEME_DATA);
    ThemeSet::load_from_reader(&mut cursor).ok()
});

/// Dracula theme loaded from embedded data.
static DRACULA_THEME: Lazy<Option<Theme>> = Lazy::new(|| {
    use std::io::Cursor;
    let mut cursor = Cursor::new(DRACULA_THEME_DATA);
    ThemeSet::load_from_reader(&mut cursor).ok()
});

/// Gruvbox Dark theme loaded from embedded data.
static GRUVBOX_DARK_THEME: Lazy<Option<Theme>> = Lazy::new(|| {
    use std::io::Cursor;
    let mut cursor = Cursor::new(GRUVBOX_DARK_THEME_DATA);
    ThemeSet::load_from_reader(&mut cursor).ok()
});

/// Nord theme loaded from embedded data.
static NORD_THEME: Lazy<Option<Theme>> = Lazy::new(|| {
    use std::io::Cursor;
    let mut cursor = Cursor::new(NORD_THEME_DATA);
    ThemeSet::load_from_reader(&mut cursor).ok()
});

/// Default theme name (matches Python Rich's default "monokai").
/// We map "monokai" to "base16-mocha.dark" which is the closest available theme.
pub const DEFAULT_THEME: &str = "monokai";

/// Fallback syntect theme name for ANSI theme highlighting.
const FALLBACK_SYNTECT_THEME: &str = "base16-mocha.dark";

/// Default padding for line numbers column.
/// Format: "  N │ " = 2 (pointer) + digits + 3 (separator " │ ")
// Match Python Rich `rich.syntax.NUMBERS_COLUMN_DEFAULT_PADDING`.
pub const NUMBERS_COLUMN_DEFAULT_PADDING: usize = 2;

// ============================================================================
// ANSI Theme Styles (for terminal-friendly themes)
// ============================================================================

/// ANSI-friendly style mappings for light terminals.
pub mod ansi_light {
    use crate::color::SimpleColor as Color;
    use crate::style::Style;

    pub fn comment() -> Style {
        Style::new().with_dim(true)
    }
    pub fn comment_preproc() -> Style {
        Style::new().with_color(Color::Standard(6)) // cyan
    }
    pub fn keyword() -> Style {
        Style::new().with_color(Color::Standard(4)) // blue
    }
    pub fn keyword_type() -> Style {
        Style::new().with_color(Color::Standard(6)) // cyan
    }
    pub fn operator_word() -> Style {
        Style::new().with_color(Color::Standard(5)) // magenta
    }
    pub fn name_builtin() -> Style {
        Style::new().with_color(Color::Standard(6)) // cyan
    }
    pub fn name_function() -> Style {
        Style::new().with_color(Color::Standard(2)) // green
    }
    pub fn name_namespace() -> Style {
        Style::new()
            .with_color(Color::Standard(6))
            .with_underline(true) // cyan underlined
    }
    pub fn name_class() -> Style {
        Style::new()
            .with_color(Color::Standard(2))
            .with_underline(true) // green underlined
    }
    pub fn name_decorator() -> Style {
        Style::new().with_color(Color::Standard(5)).with_bold(true) // magenta bold
    }
    pub fn name_variable() -> Style {
        Style::new().with_color(Color::Standard(1)) // red
    }
    pub fn name_attribute() -> Style {
        Style::new().with_color(Color::Standard(6)) // cyan
    }
    pub fn name_tag() -> Style {
        Style::new().with_color(Color::Standard(12)) // bright blue
    }
    pub fn string() -> Style {
        Style::new().with_color(Color::Standard(3)) // yellow
    }
    pub fn number() -> Style {
        Style::new().with_color(Color::Standard(4)) // blue
    }
    pub fn error() -> Style {
        Style::new()
            .with_color(Color::Standard(1))
            .with_underline(true) // red underlined
    }
}

/// ANSI-friendly style mappings for dark terminals.
pub mod ansi_dark {
    use crate::color::SimpleColor as Color;
    use crate::style::Style;

    pub fn comment() -> Style {
        Style::new().with_dim(true)
    }
    pub fn comment_preproc() -> Style {
        Style::new().with_color(Color::Standard(14)) // bright cyan
    }
    pub fn keyword() -> Style {
        Style::new().with_color(Color::Standard(12)) // bright blue
    }
    pub fn keyword_type() -> Style {
        Style::new().with_color(Color::Standard(14)) // bright cyan
    }
    pub fn operator_word() -> Style {
        Style::new().with_color(Color::Standard(13)) // bright magenta
    }
    pub fn name_builtin() -> Style {
        Style::new().with_color(Color::Standard(14)) // bright cyan
    }
    pub fn name_function() -> Style {
        Style::new().with_color(Color::Standard(10)) // bright green
    }
    pub fn name_namespace() -> Style {
        Style::new()
            .with_color(Color::Standard(14))
            .with_underline(true) // bright cyan underlined
    }
    pub fn name_class() -> Style {
        Style::new()
            .with_color(Color::Standard(10))
            .with_underline(true) // bright green underlined
    }
    pub fn name_decorator() -> Style {
        Style::new().with_color(Color::Standard(13)).with_bold(true) // bright magenta bold
    }
    pub fn name_variable() -> Style {
        Style::new().with_color(Color::Standard(9)) // bright red
    }
    pub fn name_attribute() -> Style {
        Style::new().with_color(Color::Standard(14)) // bright cyan
    }
    pub fn name_tag() -> Style {
        Style::new().with_color(Color::Standard(12)) // bright blue
    }
    pub fn string() -> Style {
        Style::new().with_color(Color::Standard(3)) // yellow
    }
    pub fn number() -> Style {
        Style::new().with_color(Color::Standard(12)) // bright blue
    }
    pub fn error() -> Style {
        Style::new()
            .with_color(Color::Standard(1))
            .with_underline(true) // red underlined
    }
}

// ============================================================================
// SyntaxTheme trait
// ============================================================================

/// Trait for syntax themes.
///
/// Abstracts the theme system to support both syntect themes and ANSI themes.
pub trait SyntaxTheme: Send + Sync {
    /// Get the style for a token (foreground, background).
    fn get_style(&self, style: &SyntectStyle) -> Style;

    /// Get the background style for the theme.
    fn get_background_style(&self) -> Style;

    /// Get the underlying syntect Theme, if available.
    fn syntect_theme(&self) -> Option<&Theme>;
}

/// A syntax theme backed by syntect's Theme.
pub struct SyntectTheme {
    theme: Theme,
    background_style: Style,
}

impl SyntectTheme {
    /// Create a new syntect-based theme.
    pub fn new(theme: Theme) -> Self {
        let bg_color = theme.settings.background.map(|c| Color::Rgb {
            r: c.r,
            g: c.g,
            b: c.b,
        });
        let background_style = match bg_color {
            Some(c) => Style::new().with_bgcolor(c),
            None => Style::new(),
        };
        Self {
            theme,
            background_style,
        }
    }

    /// Load a theme by name.
    pub fn from_name(name: &str) -> Option<Self> {
        THEME_SET.themes.get(name).map(|t| Self::new(t.clone()))
    }
}

impl SyntaxTheme for SyntectTheme {
    fn get_style(&self, style: &SyntectStyle) -> Style {
        let fg = style.foreground;
        let bg = style.background;

        let mut result = Style::new();

        // Foreground color
        result = result.with_color(Color::Rgb {
            r: fg.r,
            g: fg.g,
            b: fg.b,
        });

        // Background color (only if different from theme background)
        if let Some(theme_bg) = self.theme.settings.background {
            if bg.r != theme_bg.r || bg.g != theme_bg.g || bg.b != theme_bg.b {
                result = result.with_bgcolor(Color::Rgb {
                    r: bg.r,
                    g: bg.g,
                    b: bg.b,
                });
            }
        }

        // Font style
        let font_style = style.font_style;
        if font_style.contains(syntect::highlighting::FontStyle::BOLD) {
            result = result.with_bold(true);
        }
        if font_style.contains(syntect::highlighting::FontStyle::ITALIC) {
            result = result.with_italic(true);
        }
        if font_style.contains(syntect::highlighting::FontStyle::UNDERLINE) {
            result = result.with_underline(true);
        }

        result
    }

    fn get_background_style(&self) -> Style {
        self.background_style
    }

    fn syntect_theme(&self) -> Option<&Theme> {
        Some(&self.theme)
    }
}

/// An ANSI-compatible theme that uses standard terminal colors.
pub struct AnsiTheme {
    dark: bool,
}

impl AnsiTheme {
    /// Create a new ANSI theme for dark terminals.
    pub fn dark() -> Self {
        Self { dark: true }
    }

    /// Create a new ANSI theme for light terminals.
    pub fn light() -> Self {
        Self { dark: false }
    }
}

impl SyntaxTheme for AnsiTheme {
    fn get_style(&self, style: &SyntectStyle) -> Style {
        // For ANSI themes, we map the color to the nearest standard color
        let fg = style.foreground;

        // Simple heuristic: map based on the dominant component
        let (r, g, b) = (fg.r as u16, fg.g as u16, fg.b as u16);

        // Calculate luminance-like value
        let brightness = (r + g + b) / 3;

        // Choose a standard color based on the RGB values
        let color = if brightness < 50 {
            // Very dark - use default or black
            Color::Standard(0) // black
        } else if r > 200 && g < 100 && b < 100 {
            // Red-ish
            if self.dark {
                Color::Standard(9)
            } else {
                Color::Standard(1)
            }
        } else if g > 200 && r < 100 && b < 100 {
            // Green-ish
            if self.dark {
                Color::Standard(10)
            } else {
                Color::Standard(2)
            }
        } else if b > 200 && r < 100 && g < 100 {
            // Blue-ish
            if self.dark {
                Color::Standard(12)
            } else {
                Color::Standard(4)
            }
        } else if r > 200 && g > 200 && b < 100 {
            // Yellow-ish
            Color::Standard(3)
        } else if r > 200 && b > 200 && g < 100 {
            // Magenta-ish
            if self.dark {
                Color::Standard(13)
            } else {
                Color::Standard(5)
            }
        } else if g > 200 && b > 200 && r < 100 {
            // Cyan-ish
            if self.dark {
                Color::Standard(14)
            } else {
                Color::Standard(6)
            }
        } else if brightness > 200 {
            // Bright - use white
            Color::Standard(7)
        } else {
            // Default - use the theme's choice
            Color::Rgb {
                r: fg.r,
                g: fg.g,
                b: fg.b,
            }
        };

        let mut result = Style::new().with_color(color);

        let font_style = style.font_style;
        if font_style.contains(syntect::highlighting::FontStyle::BOLD) {
            result = result.with_bold(true);
        }
        if font_style.contains(syntect::highlighting::FontStyle::ITALIC) {
            result = result.with_italic(true);
        }
        if font_style.contains(syntect::highlighting::FontStyle::UNDERLINE) {
            result = result.with_underline(true);
        }

        result
    }

    fn get_background_style(&self) -> Style {
        Style::new()
    }

    fn syntect_theme(&self) -> Option<&Theme> {
        None
    }
}

// ============================================================================
// Syntax struct
// ============================================================================

/// A renderable for syntax-highlighted code.
///
/// `Syntax` renders source code with syntax highlighting, optional line numbers,
/// and various display options.
///
/// # Example
///
/// ```
/// use rich_rs::Syntax;
///
/// let code = "fn main() { println!(\"Hello!\"); }";
/// let syntax = Syntax::new(code, "rust")
///     .with_line_numbers(true)
///     .with_theme("monokai");
/// ```
/// A range to apply a custom style to in the syntax output.
///
/// Positions are `(line, column)` where line is 1-based and column is 0-based.
#[derive(Debug, Clone)]
struct SyntaxHighlightRange {
    style: Style,
    start: (usize, usize),
    end: (usize, usize),
}

pub struct Syntax {
    /// The source code to highlight.
    code: String,
    /// The language/lexer name.
    lexer: String,
    /// The theme to use.
    theme: Box<dyn SyntaxTheme>,
    /// Whether to dedent the code.
    dedent: bool,
    /// Whether to show line numbers.
    line_numbers: bool,
    /// Starting line number.
    start_line: usize,
    /// Optional line range to display (start, end).
    line_range: Option<(Option<usize>, Option<usize>)>,
    /// Lines to highlight.
    highlight_lines: HashSet<usize>,
    /// Fixed width for the code area.
    code_width: Option<usize>,
    /// Tab size for expansion.
    tab_size: usize,
    /// Whether to word wrap long lines.
    /// NOTE: Not yet implemented - stored for future use.
    #[allow(dead_code)]
    word_wrap: bool,
    /// Optional background color override.
    background_color: Option<Color>,
    /// Whether to show indent guides.
    /// NOTE: Not yet implemented - stored for future use.
    #[allow(dead_code)]
    indent_guides: bool,
    /// Padding around the syntax block.
    padding: (usize, usize, usize, usize),
    /// Whether an explicit theme was set (if false, use Console's theme).
    explicit_theme: bool,
    /// Custom style ranges applied on top of syntax highlighting.
    stylized_ranges: Vec<SyntaxHighlightRange>,
}

impl std::fmt::Debug for Syntax {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("Syntax")
            .field("code_len", &self.code.len())
            .field("lexer", &self.lexer)
            .field("dedent", &self.dedent)
            .field("line_numbers", &self.line_numbers)
            .field("start_line", &self.start_line)
            .field("line_range", &self.line_range)
            .field("highlight_lines", &self.highlight_lines)
            .field("code_width", &self.code_width)
            .field("tab_size", &self.tab_size)
            .field("word_wrap", &self.word_wrap)
            .field("indent_guides", &self.indent_guides)
            .field("padding", &self.padding)
            .field("explicit_theme", &self.explicit_theme)
            .finish_non_exhaustive()
    }
}

impl Syntax {
    /// Create a new Syntax object for the given code and language.
    ///
    /// # Arguments
    ///
    /// * `code` - The source code to highlight.
    /// * `lexer` - The language name (e.g., "rust", "python", "javascript").
    ///
    /// # Example
    ///
    /// ```
    /// use rich_rs::Syntax;
    ///
    /// let syntax = Syntax::new("print('hello')", "python");
    /// ```
    pub fn new(code: impl Into<String>, lexer: impl Into<String>) -> Self {
        let theme = Self::get_theme(DEFAULT_THEME);
        Self {
            code: code.into(),
            lexer: lexer.into(),
            theme,
            dedent: false,
            line_numbers: false,
            start_line: 1,
            line_range: None,
            highlight_lines: HashSet::new(),
            code_width: None,
            tab_size: 4,
            word_wrap: false,
            background_color: None,
            indent_guides: false,
            padding: (0, 0, 0, 0),
            explicit_theme: false,
            stylized_ranges: Vec::new(),
        }
    }

    /// Create a Syntax object from a file path.
    ///
    /// The language is auto-detected from the file extension.
    ///
    /// # Arguments
    ///
    /// * `path` - Path to the source file.
    ///
    /// # Returns
    ///
    /// `Ok(Syntax)` if the file was read successfully, `Err` otherwise.
    ///
    /// # Example
    ///
    /// ```ignore
    /// let syntax = Syntax::from_path("src/main.rs")?;
    /// ```
    pub fn from_path(path: impl AsRef<Path>) -> std::io::Result<Self> {
        let path = path.as_ref();
        let code = std::fs::read_to_string(path)?;
        let lexer = Self::guess_lexer(path, Some(&code));
        Ok(Self::new(code, lexer))
    }

    /// Guess the language/lexer for a file path.
    ///
    /// # Arguments
    ///
    /// * `path` - Path to examine.
    /// * `code` - Optional code content for better detection.
    ///
    /// # Returns
    ///
    /// The best-guess language name.
    pub fn guess_lexer(path: impl AsRef<Path>, code: Option<&str>) -> String {
        let path = path.as_ref();

        // Try to find syntax by extension
        if let Some(ext) = path.extension().and_then(|e| e.to_str()) {
            if let Some(syntax) = SYNTAX_SET.find_syntax_by_extension(ext) {
                return syntax.name.to_lowercase();
            }
        }

        // Try by filename
        if let Some(filename) = path.file_name().and_then(|n| n.to_str()) {
            // Check for specific filenames
            match filename.to_lowercase().as_str() {
                "makefile" | "gnumakefile" => return "makefile".to_string(),
                "dockerfile" => return "dockerfile".to_string(),
                "cmakelists.txt" => return "cmake".to_string(),
                _ => {}
            }
        }

        // Try to detect from content
        if let Some(code) = code {
            // Simple heuristics
            if code.starts_with("#!/usr/bin/env python") || code.starts_with("#!/usr/bin/python") {
                return "python".to_string();
            }
            if code.starts_with("#!/bin/bash") || code.starts_with("#!/usr/bin/env bash") {
                return "bash".to_string();
            }
            if code.starts_with("#!/usr/bin/env node") {
                return "javascript".to_string();
            }
            if code.starts_with("#!/usr/bin/env ruby") {
                return "ruby".to_string();
            }

            // Try syntect's first-line detection
            if let Some(syntax) = SYNTAX_SET.find_syntax_by_first_line(code) {
                return syntax.name.to_lowercase();
            }
        }

        // Default to plain text
        "text".to_string()
    }

    /// Get a theme by name.
    ///
    /// # Arguments
    ///
    /// * `name` - Theme name (e.g., "monokai", "dracula", "github-dark").
    ///
    /// # Returns
    ///
    /// A boxed SyntaxTheme. Falls back to Monokai if the theme is not found.
    pub fn get_theme(name: &str) -> Box<dyn SyntaxTheme> {
        // Check for ANSI themes
        match name.to_lowercase().as_str() {
            "ansi_dark" | "ansi-dark" => return Box::new(AnsiTheme::dark()),
            "ansi_light" | "ansi-light" => return Box::new(AnsiTheme::light()),
            _ => {}
        }

        // Check for our embedded themes (imported from Pygments)
        match name.to_lowercase().as_str() {
            "monokai" => {
                if let Some(ref theme) = *MONOKAI_THEME {
                    return Box::new(SyntectTheme::new(theme.clone()));
                }
            }
            "monokai-plus" | "monokai_plus" => {
                if let Some(ref theme) = *MONOKAI_PLUS_THEME {
                    return Box::new(SyntectTheme::new(theme.clone()));
                }
            }
            "dracula" => {
                if let Some(ref theme) = *DRACULA_THEME {
                    return Box::new(SyntectTheme::new(theme.clone()));
                }
            }
            "gruvbox-dark" | "gruvbox_dark" | "gruvbox" => {
                if let Some(ref theme) = *GRUVBOX_DARK_THEME {
                    return Box::new(SyntectTheme::new(theme.clone()));
                }
            }
            "nord" => {
                if let Some(ref theme) = *NORD_THEME {
                    return Box::new(SyntectTheme::new(theme.clone()));
                }
            }
            _ => {}
        }

        // Map common theme names to syntect equivalents
        let theme_name = match name.to_lowercase().as_str() {
            "one-dark" | "onedark" => "base16-ocean.dark",
            "one-light" | "onelight" => "base16-ocean.light",
            "github-dark" => "base16-ocean.dark",
            "github-light" => "base16-ocean.light",
            "solarized-dark" => "Solarized (dark)",
            "solarized-light" => "Solarized (light)",
            _ => name,
        };

        SyntectTheme::from_name(theme_name)
            .map(|t| Box::new(t) as Box<dyn SyntaxTheme>)
            .unwrap_or_else(|| {
                // Fall back to embedded Monokai or ANSI theme
                if let Some(ref theme) = *MONOKAI_THEME {
                    Box::new(SyntectTheme::new(theme.clone()))
                } else {
                    Box::new(AnsiTheme::dark())
                }
            })
    }

    /// List available theme names.
    pub fn available_themes() -> Vec<&'static str> {
        let mut themes: Vec<&str> = THEME_SET.themes.keys().map(|s| s.as_str()).collect();
        // Add ANSI themes and embedded themes
        themes.extend([
            "ansi_dark",
            "ansi_light",
            "monokai",
            "monokai-plus",
            "dracula",
            "gruvbox-dark",
            "nord",
        ]);
        themes.sort();
        themes
    }

    /// List available language/lexer names.
    pub fn available_languages() -> Vec<String> {
        SYNTAX_SET
            .syntaxes()
            .iter()
            .map(|s| s.name.to_lowercase())
            .collect()
    }

    // ========================================================================
    // Builder methods
    // ========================================================================

    /// Set the theme by name.
    ///
    /// This overrides the Console's theme for this renderable.
    pub fn with_theme(mut self, theme: impl AsRef<str>) -> Self {
        self.theme = Self::get_theme(theme.as_ref());
        self.explicit_theme = true;
        self
    }

    /// Set a custom theme.
    ///
    /// This overrides the Console's theme for this renderable.
    pub fn with_custom_theme(mut self, theme: Box<dyn SyntaxTheme>) -> Self {
        self.theme = theme;
        self.explicit_theme = true;
        self
    }

    /// Enable or disable code dedenting.
    pub fn with_dedent(mut self, dedent: bool) -> Self {
        self.dedent = dedent;
        self
    }

    /// Enable or disable line numbers.
    pub fn with_line_numbers(mut self, line_numbers: bool) -> Self {
        self.line_numbers = line_numbers;
        self
    }

    /// Set the starting line number.
    pub fn with_start_line(mut self, start_line: usize) -> Self {
        self.start_line = start_line;
        self
    }

    /// Set the line range to display.
    ///
    /// # Arguments
    ///
    /// * `start` - Optional start line (1-based, inclusive).
    /// * `end` - Optional end line (1-based, inclusive).
    pub fn with_line_range(mut self, start: Option<usize>, end: Option<usize>) -> Self {
        self.line_range = Some((start, end));
        self
    }

    /// Set lines to highlight.
    pub fn with_highlight_lines(mut self, lines: impl IntoIterator<Item = usize>) -> Self {
        self.highlight_lines = lines.into_iter().collect();
        self
    }

    /// Set a fixed code width.
    pub fn with_code_width(mut self, width: usize) -> Self {
        self.code_width = Some(width);
        self
    }

    /// Set the tab size.
    pub fn with_tab_size(mut self, tab_size: usize) -> Self {
        self.tab_size = tab_size;
        self
    }

    /// Enable or disable word wrapping.
    ///
    /// NOTE: Not yet implemented - option is stored for future use.
    pub fn with_word_wrap(mut self, word_wrap: bool) -> Self {
        self.word_wrap = word_wrap;
        self
    }

    /// Set a background color override.
    pub fn with_background_color(mut self, color: Color) -> Self {
        self.background_color = Some(color);
        self
    }

    /// Enable or disable indent guides.
    ///
    /// NOTE: Not yet implemented - option is stored for future use.
    pub fn with_indent_guides(mut self, indent_guides: bool) -> Self {
        self.indent_guides = indent_guides;
        self
    }

    /// Set padding around the syntax block.
    pub fn with_padding(mut self, padding: impl Into<PaddingDimensions>) -> Self {
        self.padding = padding.into().unpack();
        self
    }

    /// Add a custom style range to apply on top of syntax highlighting.
    ///
    /// Positions are `(line, column)` where line is 1-based and column is 0-based.
    ///
    /// # Arguments
    ///
    /// * `style` - Style to apply to the range.
    /// * `start` - Start position as (line, column).
    /// * `end` - End position as (line, column).
    pub fn stylize_range(&mut self, style: Style, start: (usize, usize), end: (usize, usize)) {
        self.stylized_ranges
            .push(SyntaxHighlightRange { style, start, end });
    }

    /// Builder method to add a highlight range.
    ///
    /// Positions are `(line, column)` where line is 1-based and column is 0-based.
    pub fn with_highlight_range(
        mut self,
        style: Style,
        start: (usize, usize),
        end: (usize, usize),
    ) -> Self {
        self.stylized_ranges
            .push(SyntaxHighlightRange { style, start, end });
        self
    }

    // ========================================================================
    // Getters
    // ========================================================================

    /// Get the source code.
    pub fn code(&self) -> &str {
        &self.code
    }

    /// Get the lexer/language name.
    pub fn lexer(&self) -> &str {
        &self.lexer
    }

    /// Check if line numbers are enabled.
    pub fn line_numbers(&self) -> bool {
        self.line_numbers
    }

    /// Get the tab size.
    pub fn tab_size(&self) -> usize {
        self.tab_size
    }

    // ========================================================================
    // Highlighting
    // ========================================================================

    /// Highlight the code and return a Text object.
    ///
    /// This converts syntect-highlighted code into a rich-rs Text object
    /// with styled spans.
    pub fn highlight(&self) -> Text {
        self.highlight_with_theme(&*self.theme)
    }

    /// Highlight the code with a specific theme.
    fn highlight_with_theme(&self, theme: &dyn SyntaxTheme) -> Text {
        let (ends_on_nl, processed_code) = self.process_code();

        // Normalize common lexer name aliases
        let lexer_lower = self.lexer.to_lowercase();
        let lexer_normalized = match lexer_lower.as_str() {
            "python3" | "py3" | "py" => "python",
            "javascript" | "js" => "javascript",
            "typescript" | "ts" => "typescript",
            "rust" | "rs" => "rust",
            "cpp" | "c++" => "c++",
            "csharp" | "cs" => "c#",
            _ => lexer_lower.as_str(),
        };

        // Find the syntax
        let syntax = SYNTAX_SET
            .find_syntax_by_token(lexer_normalized)
            .or_else(|| SYNTAX_SET.find_syntax_by_extension(lexer_normalized))
            .or_else(|| SYNTAX_SET.find_syntax_by_name(lexer_normalized))
            // Also try original if normalized didn't match
            .or_else(|| SYNTAX_SET.find_syntax_by_token(&self.lexer))
            .or_else(|| SYNTAX_SET.find_syntax_by_extension(&self.lexer))
            .or_else(|| SYNTAX_SET.find_syntax_by_name(&self.lexer))
            .unwrap_or_else(|| SYNTAX_SET.find_syntax_plain_text());

        let base_style = self.get_base_style_with_theme(theme);
        let mut text = Text::new();
        text.set_base_style(Some(base_style));

        // Highlight the code
        if let Some(syntect_theme) = theme.syntect_theme() {
            let mut highlighter = HighlightLines::new(syntax, syntect_theme);

            for line in LinesWithEndings::from(&processed_code) {
                match highlighter.highlight_line(line, &SYNTAX_SET) {
                    Ok(ranges) => {
                        for (style, token) in ranges {
                            let rich_style = theme.get_style(&style);
                            text.append(token, Some(rich_style));
                        }
                    }
                    Err(_) => {
                        // Fall back to unstyled text
                        text.append(line, None);
                    }
                }
            }
        } else {
            // For ANSI themes without syntect theme, use plain highlighting
            let mut highlighter =
                HighlightLines::new(syntax, &THEME_SET.themes[FALLBACK_SYNTECT_THEME]);

            for line in LinesWithEndings::from(&processed_code) {
                match highlighter.highlight_line(line, &SYNTAX_SET) {
                    Ok(ranges) => {
                        for (style, token) in ranges {
                            let rich_style = theme.get_style(&style);
                            text.append(token, Some(rich_style));
                        }
                    }
                    Err(_) => {
                        text.append(line, None);
                    }
                }
            }
        }

        // Apply custom stylized ranges on top of syntax highlighting.
        if !self.stylized_ranges.is_empty() {
            self.apply_stylized_ranges(&mut text);
        }

        // Remove trailing newline if the original didn't have one
        if !ends_on_nl && text.plain_text().ends_with('\n') {
            let plain = text.plain_text();
            let new_plain = plain.trim_end_matches('\n');
            if plain != new_plain {
                // Reconstruct text without trailing newline
                let mut new_text = Text::new();
                new_text.set_base_style(text.base_style());
                new_text.append(new_plain, None);
                // Copy spans but adjust for new length
                for span in text.spans() {
                    if span.start < new_plain.chars().count() {
                        new_text.stylize(
                            span.start,
                            span.end.min(new_plain.chars().count()),
                            span.style,
                        );
                    }
                }
                return new_text;
            }
        }

        text
    }

    /// Apply custom stylized ranges to the highlighted text.
    ///
    /// Converts (line, column) positions to character offsets and applies styles.
    fn apply_stylized_ranges(&self, text: &mut Text) {
        let plain = text.plain_text();

        // Build newline offset table: newlines_offsets[i] = char offset of line i+1 start
        // Line 1 starts at offset 0.
        let mut newlines_offsets: Vec<usize> = vec![0];
        for (i, c) in plain.chars().enumerate() {
            if c == '\n' {
                newlines_offsets.push(i + 1);
            }
        }
        // Sentinel at the end
        newlines_offsets.push(plain.chars().count() + 1);

        for range in &self.stylized_ranges {
            let (start_line, start_col) = range.start;
            let (end_line, end_col) = range.end;

            // Convert 1-based line to 0-based index
            let start_line_idx = start_line.saturating_sub(1);
            let end_line_idx = end_line.saturating_sub(1);

            let start_offset =
                newlines_offsets.get(start_line_idx).copied().unwrap_or(0) + start_col;

            let end_offset = newlines_offsets.get(end_line_idx).copied().unwrap_or(0) + end_col;

            if start_offset < end_offset {
                text.stylize(start_offset, end_offset, range.style);
            }
        }
    }

    /// Get the base style for the syntax block.
    fn get_base_style(&self) -> Style {
        self.get_base_style_with_theme(&*self.theme)
    }

    /// Get the base style with a specific theme.
    fn get_base_style_with_theme(&self, theme: &dyn SyntaxTheme) -> Style {
        let mut style = theme.get_background_style();
        if let Some(bg) = self.background_color {
            style = style.with_bgcolor(bg);
        }
        style
    }

    /// Process the code (dedent, normalize newlines, expand tabs).
    fn process_code(&self) -> (bool, String) {
        let ends_on_nl = self.code.ends_with('\n');
        let mut processed = if ends_on_nl {
            self.code.clone()
        } else {
            format!("{}\n", self.code)
        };

        // Dedent if requested
        if self.dedent {
            processed = Self::dedent_code(&processed);
        }

        // Expand tabs
        processed = Self::expand_tabs(&processed, self.tab_size);

        (ends_on_nl, processed)
    }

    /// Dedent code by removing common leading whitespace.
    fn dedent_code(code: &str) -> String {
        let lines: Vec<&str> = code.lines().collect();

        // Find minimum indentation (ignoring empty lines)
        let min_indent = lines
            .iter()
            .filter(|line| !line.trim().is_empty())
            .map(|line| line.len() - line.trim_start().len())
            .min()
            .unwrap_or(0);

        if min_indent == 0 {
            return code.to_string();
        }

        // Remove min_indent from each line
        lines
            .iter()
            .map(|line| {
                if line.len() >= min_indent {
                    &line[min_indent..]
                } else {
                    line.trim_start()
                }
            })
            .collect::<Vec<_>>()
            .join("\n")
            + if code.ends_with('\n') { "\n" } else { "" }
    }

    /// Expand tabs to spaces.
    fn expand_tabs(code: &str, tab_size: usize) -> String {
        if !code.contains('\t') {
            return code.to_string();
        }

        let mut result = String::new();
        let mut column = 0;

        for c in code.chars() {
            match c {
                '\t' => {
                    let spaces = tab_size - (column % tab_size);
                    for _ in 0..spaces {
                        result.push(' ');
                    }
                    column += spaces;
                }
                '\n' => {
                    result.push(c);
                    column = 0;
                }
                _ => {
                    result.push(c);
                    column += 1;
                }
            }
        }

        result
    }

    /// Compute the indent-guide foreground colour for a theme.
    ///
    /// Python Rich draws indent guides with the theme's `Comment` token colour
    /// plus the `dim` attribute; Textual's `ANSIToTruecolor` filter then
    /// pre-blends `dim` into a concrete colour (`bg + (fg - bg) * 0.66`) and
    /// strips the attribute. Derive that final colour here so the guides match
    /// the Python output exactly, instead of relying on terminal SGR dim.
    ///
    /// Returns `None` when the theme has no syntect backing or no usable
    /// background colour (callers should fall back to a plain dim style).
    fn indent_guide_color(
        theme: &dyn SyntaxTheme,
        background_override: Option<Color>,
    ) -> Option<Color> {
        const DIM_FACTOR: f64 = 0.66;

        let syntect_theme = theme.syntect_theme()?;
        let highlighter = syntect::highlighting::Highlighter::new(syntect_theme);
        let comment_scope = syntect::parsing::Scope::new("comment").ok()?;
        let fg = highlighter.style_for_stack(&[comment_scope]).foreground;

        let (bg_r, bg_g, bg_b) = match background_override {
            Some(Color::Rgb { r, g, b }) => (r, g, b),
            Some(_) => return None,
            None => {
                let bg = syntect_theme.settings.background?;
                (bg.r, bg.g, bg.b)
            }
        };

        // Match Python's truncation (rich `Color.from_rgb` goes through `int()`).
        let blend =
            |bg: u8, fg: u8| (f64::from(bg) + (f64::from(fg) - f64::from(bg)) * DIM_FACTOR) as u8;
        Some(Color::Rgb {
            r: blend(bg_r, fg.r),
            g: blend(bg_g, fg.g),
            b: blend(bg_b, fg.b),
        })
    }

    /// Get the width of the line numbers column.
    fn numbers_column_width(&self) -> usize {
        if !self.line_numbers {
            return 0;
        }
        let line_count = self.code.lines().count();
        let max_line_no = self.start_line + line_count.saturating_sub(1);
        let digits = max_line_no.to_string().len();
        digits + NUMBERS_COLUMN_DEFAULT_PADDING
    }
}

impl Renderable for Syntax {
    fn render(&self, console: &Console<Stdout>, options: &ConsoleOptions) -> Segments {
        let mut result = Segments::new();

        let (pad_top, pad_right, pad_bottom, pad_left) = self.padding;
        let horizontal_padding = pad_left + pad_right;

        // Calculate available width
        let numbers_width = self.numbers_column_width();
        let code_width = if let Some(w) = self.code_width {
            w
        } else if self.line_numbers {
            options
                .max_width
                .saturating_sub(numbers_width + 1 + horizontal_padding)
        } else {
            options.max_width.saturating_sub(horizontal_padding)
        };

        // Determine which theme to use: explicit theme or Console's theme
        let effective_theme: Option<Box<dyn SyntaxTheme>> =
            if !self.explicit_theme && options.theme_name != "default" {
                Some(Self::get_theme(&options.theme_name))
            } else {
                None
            };

        // Get highlighted text (using effective theme or self.theme)
        let text = if let Some(ref theme) = effective_theme {
            self.highlight_with_theme(&**theme)
        } else {
            self.highlight()
        };

        // Split into lines
        let lines: Vec<Text> = text.split("\n", false, true);

        // Apply line range filter
        let (start_idx, end_idx) = if let Some((start, end)) = self.line_range {
            let start = start.map(|s| s.saturating_sub(1)).unwrap_or(0);
            let end = end.unwrap_or(lines.len());
            (start, end)
        } else {
            (0, lines.len())
        };

        let filtered_lines: Vec<&Text> = lines
            .iter()
            .skip(start_idx)
            .take(end_idx.saturating_sub(start_idx))
            .collect();

        // Get base style (using effective theme or self.theme)
        let base_style = if let Some(ref theme) = effective_theme {
            self.get_base_style_with_theme(&**theme)
        } else {
            self.get_base_style()
        };
        let new_line = Segment::line();

        // Line number styling - same background as code, grayish foreground
        // Color #656660 (RGB 101, 102, 96) matches Python Rich's Monokai line numbers
        let number_style = base_style.combine(&Style::new().with_color(Color::Rgb {
            r: 101,
            g: 102,
            b: 96,
        }));

        // Highlighted line number style - bold with same background
        let highlight_number_style = base_style.combine(&Style::new().with_bold(true));

        // Indent guide style - the theme's comment colour, dim pre-blended over
        // the background (see `indent_guide_color`). Falls back to an SGR dim
        // attribute when the colour can't be derived (e.g. ANSI themes).
        let render_theme: &dyn SyntaxTheme = effective_theme.as_deref().unwrap_or(&*self.theme);
        let indent_guide_style = base_style.combine(
            &Self::indent_guide_color(render_theme, self.background_color)
                .map(|color| Style::new().with_color(color))
                .unwrap_or_else(|| Style::new().with_dim(true)),
        );

        // Add top padding
        if pad_top > 0 {
            let blank = " ".repeat(options.max_width);
            for _ in 0..pad_top {
                result.push(Segment::styled(blank.clone(), base_style));
                result.push(new_line.clone());
            }
        }

        // Render each line
        for (idx, line) in filtered_lines.iter().enumerate() {
            let line_no = self.start_line + start_idx + idx;
            let is_highlighted = self.highlight_lines.contains(&line_no);

            // Left padding
            if pad_left > 0 {
                result.push(Segment::styled(" ".repeat(pad_left), base_style));
            }

            // Line number (inside the syntax block with background)
            if self.line_numbers {
                // Match Python Rich: pointer (2 chars), then a right-aligned line number column,
                // and a single trailing space before code. No "│" separator.
                let pointer = if options.legacy_windows { "> " } else { "❱ " };
                let line_num_str = format!(
                    "{:>width$} ",
                    line_no,
                    width = numbers_width.saturating_sub(2)
                );

                if is_highlighted {
                    // Highlighted line: red pointer, bold number
                    let pointer_style = base_style
                        .combine(&Style::new().with_color(Color::Standard(1)).with_bold(true));
                    result.push(Segment::styled(pointer.to_string(), pointer_style));
                    result.push(Segment::styled(line_num_str, highlight_number_style));
                } else {
                    // Normal line: spaces for pointer area, dim number
                    result.push(Segment::styled("  ".to_string(), highlight_number_style));
                    result.push(Segment::styled(line_num_str, number_style));
                }
            }

            // Calculate indent guides if enabled
            let mut guides_width = 0;
            let line_to_render;

            if self.indent_guides {
                let plain = line.plain_text();
                let leading_spaces = plain.chars().take_while(|c| *c == ' ').count();
                let num_guides = leading_spaces / self.tab_size;

                if num_guides > 0 {
                    // Each guide is "│" + (tab_size - 1) spaces
                    for _ in 0..num_guides {
                        result.push(Segment::styled("│".to_string(), indent_guide_style));
                        result.push(Segment::styled(
                            " ".repeat(self.tab_size - 1),
                            indent_guide_style,
                        ));
                    }
                    guides_width = num_guides * self.tab_size;

                    // Use divide to extract the portion after the leading whitespace
                    let parts = line.divide([guides_width]);
                    line_to_render = if parts.len() > 1 {
                        parts.into_iter().nth(1).unwrap_or_else(|| (*line).clone())
                    } else {
                        // No content after guides, just use empty
                        Text::plain("")
                    };
                } else {
                    line_to_render = (*line).clone();
                }
            } else {
                line_to_render = (*line).clone();
            }

            // Render line content without wrapping, then clip/pad to code width.
            // Subtract indent guides width from available width
            let content_width = code_width.saturating_sub(guides_width);
            let mut line_options = options.update_width(content_width);
            line_options.no_wrap = true;
            line_options.overflow = Some(OverflowMethod::Crop);

            let line_segments: Vec<Segment> = line_to_render
                .render(console, &line_options)
                .into_iter()
                .collect();
            let adjusted =
                Segment::adjust_line_length(&line_segments, content_width, Some(base_style), true);
            for seg in adjusted {
                result.push(seg);
            }

            // Right padding
            if pad_right > 0 {
                result.push(Segment::styled(" ".repeat(pad_right), base_style));
            }

            result.push(new_line.clone());
        }

        // Add bottom padding
        if pad_bottom > 0 {
            let blank = " ".repeat(options.max_width);
            for _ in 0..pad_bottom {
                result.push(Segment::styled(blank.clone(), base_style));
                result.push(new_line.clone());
            }
        }

        result
    }

    fn measure(&self, _console: &Console<Stdout>, options: &ConsoleOptions) -> Measurement {
        let (_, pad_right, _, pad_left) = self.padding;
        let horizontal_padding = pad_left + pad_right;

        let numbers_width = self.numbers_column_width();

        if let Some(code_width) = self.code_width {
            let width = code_width + numbers_width + horizontal_padding;
            if self.line_numbers {
                return Measurement::new(numbers_width, width + 1);
            }
            return Measurement::new(numbers_width, width);
        }

        // Calculate from code
        let lines: Vec<&str> = self.code.lines().collect();
        let max_line_width = lines.iter().map(|l| cell_len(l)).max().unwrap_or(0);

        let width = max_line_width + numbers_width + horizontal_padding;
        let width = if self.line_numbers { width + 1 } else { width };

        Measurement::new(numbers_width.max(1), width.min(options.max_width))
    }
}

// ============================================================================
// Tests
// ============================================================================

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

    #[test]
    fn test_syntax_new() {
        let syntax = Syntax::new("fn main() {}", "rust");
        assert_eq!(syntax.code(), "fn main() {}");
        assert_eq!(syntax.lexer(), "rust");
    }

    #[test]
    fn test_syntax_with_line_numbers() {
        let syntax = Syntax::new("fn main() {}", "rust").with_line_numbers(true);
        assert!(syntax.line_numbers());
    }

    #[test]
    fn test_syntax_with_theme() {
        let syntax = Syntax::new("fn main() {}", "rust").with_theme("monokai");
        // Theme should be set (we can't easily inspect it, but it shouldn't panic)
        assert_eq!(syntax.code(), "fn main() {}");
    }

    #[test]
    fn test_syntax_with_tab_size() {
        let syntax = Syntax::new("fn main() {}", "rust").with_tab_size(2);
        assert_eq!(syntax.tab_size(), 2);
    }

    #[test]
    fn test_syntax_highlight() {
        let syntax = Syntax::new("fn main() {}", "rust");
        let text = syntax.highlight();
        // The highlighted text should contain the code
        assert!(text.plain_text().contains("fn"));
        assert!(text.plain_text().contains("main"));
    }

    #[test]
    fn test_syntax_highlight_python() {
        let code = r#"def hello():
    print("Hello, World!")
"#;
        let syntax = Syntax::new(code, "python");
        let text = syntax.highlight();
        assert!(text.plain_text().contains("def"));
        assert!(text.plain_text().contains("hello"));
    }

    #[test]
    fn test_syntax_dedent() {
        let code = "    fn main() {\n        println!(\"hello\");\n    }";
        let syntax = Syntax::new(code, "rust").with_dedent(true);
        let text = syntax.highlight();
        // After dedenting, the first line should start with "fn"
        assert!(text.plain_text().starts_with("fn"));
    }

    #[test]
    fn test_syntax_expand_tabs() {
        let code = "fn main() {\n\tprintln!(\"hello\");\n}";
        let syntax = Syntax::new(code, "rust").with_tab_size(4);
        let text = syntax.highlight();
        // Tabs should be expanded to spaces
        assert!(!text.plain_text().contains('\t'));
    }

    #[test]
    fn test_guess_lexer_by_extension() {
        assert_eq!(Syntax::guess_lexer("test.rs", None), "rust");
        assert_eq!(Syntax::guess_lexer("test.py", None), "python");
        assert_eq!(Syntax::guess_lexer("test.js", None), "javascript");
    }

    #[test]
    fn test_available_themes() {
        let themes = Syntax::available_themes();
        assert!(!themes.is_empty());
        assert!(themes.contains(&"ansi_dark"));
        assert!(themes.contains(&"ansi_light"));
        // Check embedded themes are listed
        assert!(themes.contains(&"dracula"), "Should contain dracula theme");
        assert!(
            themes.contains(&"gruvbox-dark"),
            "Should contain gruvbox-dark theme"
        );
        assert!(themes.contains(&"nord"), "Should contain nord theme");
        assert!(themes.contains(&"monokai"), "Should contain monokai theme");
        assert!(
            themes.contains(&"monokai-plus"),
            "Should contain monokai-plus theme"
        );
    }

    #[test]
    fn test_available_languages() {
        let languages = Syntax::available_languages();
        assert!(!languages.is_empty());
    }

    #[test]
    fn test_numbers_column_width() {
        let code = "line1\nline2\nline3\nline4\nline5\nline6\nline7\nline8\nline9\nline10";
        let syntax = Syntax::new(code, "text").with_line_numbers(true);
        // 10 lines = 2 digits + 2 padding = 4
        assert_eq!(syntax.numbers_column_width(), 4);
    }

    #[test]
    fn test_syntax_render() {
        let syntax = Syntax::new("fn main() {}", "rust");
        let console = Console::new();
        let options = ConsoleOptions::default();

        let segments = syntax.render(&console, &options);
        let output: String = segments.iter().map(|s| s.text.to_string()).collect();

        assert!(output.contains("fn"));
        assert!(output.contains("main"));
    }

    #[test]
    fn test_syntax_render_with_line_numbers() {
        let syntax = Syntax::new("line1\nline2", "text").with_line_numbers(true);
        let console = Console::new();
        let options = ConsoleOptions::default();

        let segments = syntax.render(&console, &options);
        let output: String = segments.iter().map(|s| s.text.to_string()).collect();

        // Should contain line numbers
        assert!(output.contains('1'));
        assert!(output.contains('2'));
    }

    #[test]
    fn test_syntax_measure() {
        let syntax = Syntax::new("hello", "text");
        let console = Console::new();
        let options = ConsoleOptions::default();

        let measurement = syntax.measure(&console, &options);
        assert!(measurement.maximum >= 5); // At least the length of "hello"
    }

    #[test]
    fn test_syntax_is_send_sync() {
        fn assert_send<T: Send>() {}
        fn assert_sync<T: Sync>() {}
        assert_send::<Syntax>();
        assert_sync::<Syntax>();
    }

    #[test]
    fn test_dedent_code() {
        let code = "    line1\n    line2\n    line3\n";
        let dedented = Syntax::dedent_code(code);
        assert_eq!(dedented, "line1\nline2\nline3\n");
    }

    #[test]
    fn test_dedent_code_mixed_indent() {
        let code = "    line1\n        line2\n    line3\n";
        let dedented = Syntax::dedent_code(code);
        assert_eq!(dedented, "line1\n    line2\nline3\n");
    }

    #[test]
    fn test_expand_tabs() {
        let code = "a\tb\tc";
        let expanded = Syntax::expand_tabs(code, 4);
        assert_eq!(expanded, "a   b   c");
    }

    #[test]
    fn test_expand_tabs_preserves_newlines() {
        let code = "a\tb\nc\td";
        let expanded = Syntax::expand_tabs(code, 4);
        assert_eq!(expanded, "a   b\nc   d");
    }

    #[test]
    fn test_ansi_theme() {
        let theme = AnsiTheme::dark();
        let style = SyntectStyle {
            foreground: syntect::highlighting::Color {
                r: 255,
                g: 0,
                b: 0,
                a: 255,
            },
            background: syntect::highlighting::Color {
                r: 0,
                g: 0,
                b: 0,
                a: 255,
            },
            font_style: syntect::highlighting::FontStyle::empty(),
        };
        let rich_style = theme.get_style(&style);
        // Should have a color set
        assert!(rich_style.color.is_some());
    }

    #[test]
    fn test_syntect_theme() {
        // Test that the fallback syntect theme exists
        let theme = SyntectTheme::from_name(FALLBACK_SYNTECT_THEME);
        assert!(
            theme.is_some(),
            "Fallback theme '{}' should exist",
            FALLBACK_SYNTECT_THEME
        );
        let theme = theme.unwrap();
        assert!(theme.syntect_theme().is_some());

        // Test that DEFAULT_THEME works via get_theme (which handles mapping)
        let default_theme = Syntax::get_theme(DEFAULT_THEME);
        assert!(default_theme.syntect_theme().is_some());
    }

    #[test]
    fn test_line_range() {
        let code = "line1\nline2\nline3\nline4\nline5";
        let syntax = Syntax::new(code, "text").with_line_range(Some(2), Some(4));
        let console = Console::new();
        let options = ConsoleOptions::default();

        let segments = syntax.render(&console, &options);
        let output: String = segments.iter().map(|s| s.text.to_string()).collect();

        // Should contain lines 2-4
        assert!(output.contains("line2"));
        assert!(output.contains("line3"));
        assert!(output.contains("line4"));
        // Should not contain line1 or line5
        assert!(!output.contains("line1"));
        assert!(!output.contains("line5"));
    }

    #[test]
    fn test_highlight_lines() {
        let code = "line1\nline2\nline3";
        let syntax = Syntax::new(code, "text")
            .with_line_numbers(true)
            .with_highlight_lines([2]);
        let console = Console::new();
        let options = ConsoleOptions::default();

        let segments = syntax.render(&console, &options);
        let output: String = segments.iter().map(|s| s.text.to_string()).collect();

        // Line 2 should be highlighted with pointer (❱ or > depending on legacy_windows)
        assert!(output.contains('❱') || output.contains('>'));
    }

    #[test]
    fn test_stylize_range() {
        let mut syntax = Syntax::new("line1\nline2\nline3", "text");
        let style = Style::new().with_bold(true);
        syntax.stylize_range(style, (2, 0), (2, 5)); // "line2"

        let text = syntax.highlight();
        let plain = text.plain_text();
        assert!(plain.contains("line2"));

        // Check that spans were applied
        let spans = text.spans();
        let has_bold_span = spans.iter().any(|s| s.style.bold == Some(true));
        assert!(has_bold_span, "Should have a bold span from stylize_range");
    }

    #[test]
    fn test_with_highlight_range_builder() {
        let style = Style::new().with_italic(true);
        let syntax = Syntax::new("hello world", "text").with_highlight_range(style, (1, 0), (1, 5)); // "hello"

        let text = syntax.highlight();
        let spans = text.spans();
        let has_italic_span = spans.iter().any(|s| s.style.italic == Some(true));
        assert!(
            has_italic_span,
            "Should have an italic span from with_highlight_range"
        );
    }

    /// Resolve the highlighted colour of the first occurrence of `token` in
    /// Python `code` under the default (monokai) theme.
    fn python_token_color(code: &str, token: &str) -> Option<Color> {
        let syntax = Syntax::new(code, "python");
        let text = syntax.highlight();
        let plain = text.plain_text();
        // ASCII-only test inputs: byte offset == char offset.
        let start = plain.find(token).expect("token present in highlighted text");
        let mut found = None;
        for span in text.spans() {
            if span.start <= start && start < span.end {
                if let Some(color) = span.style.color {
                    found = Some(color);
                }
            }
        }
        found
    }

    const MONOKAI_PLAIN: Color = Color::Rgb {
        r: 0xf8,
        g: 0xf8,
        b: 0xf2,
    };
    const MONOKAI_OPERATOR: Color = Color::Rgb {
        r: 0xff,
        g: 0x46,
        b: 0x89,
    };
    const MONOKAI_STRING: Color = Color::Rgb {
        r: 0xe6,
        g: 0xdb,
        b: 0x74,
    };
    const MONOKAI_COMMENT: Color = Color::Rgb {
        r: 0x95,
        g: 0x90,
        b: 0x77,
    };

    /// Pygments parity: parameter-annotation `:` is plain Punctuation (white),
    /// while the return arrow `->` is an Operator (pink).
    #[test]
    fn test_python_annotation_colon_is_plain_punctuation() {
        let code = "def f(values: Iterable[T]) -> int:\n    pass\n";
        // The first `:` in the code is the parameter annotation separator.
        assert_eq!(python_token_color(code, ":"), Some(MONOKAI_PLAIN));
        assert_eq!(python_token_color(code, "->"), Some(MONOKAI_OPERATOR));
    }

    /// Pygments parity: docstring triple-quote delimiters take the string
    /// colour (the whole docstring is one String.Doc token in Pygments).
    #[test]
    fn test_python_docstring_quotes_are_string_colored() {
        let code = "def f():\n    \"\"\"Doc.\"\"\"\n";
        assert_eq!(python_token_color(code, "\"\"\""), Some(MONOKAI_STRING));
    }

    /// Pygments parity: the `in` of `for ... in` is an Operator.Word (pink),
    /// not a plain keyword (cyan).
    #[test]
    fn test_python_for_in_is_operator_word() {
        let code = "for value in values:\n    pass\n";
        assert_eq!(python_token_color(code, "in"), Some(MONOKAI_OPERATOR));
        assert_eq!(
            python_token_color(code, "for"),
            Some(Color::Rgb {
                r: 0x66,
                g: 0xd9,
                b: 0xef
            })
        );
    }

    /// Pygments parity: the `#` delimiter is part of the comment token.
    #[test]
    fn test_python_comment_hash_is_comment_colored() {
        let code = "# hello\n";
        assert_eq!(python_token_color(code, "#"), Some(MONOKAI_COMMENT));
    }

    /// Indent guides use the theme comment colour dim-blended over the theme
    /// background (`bg + (fg - bg) * 0.66`), matching Python Rich + Textual's
    /// ANSIToTruecolor dim pre-blend: monokai #959077 over #272822 -> #6f6c5a.
    #[test]
    fn test_indent_guide_color_monokai_dim_preblend() {
        let theme = Syntax::get_theme("monokai");
        assert_eq!(
            Syntax::indent_guide_color(&*theme, None),
            Some(Color::Rgb {
                r: 0x6f,
                g: 0x6c,
                b: 0x5a
            })
        );
    }

    #[test]
    fn test_embedded_themes() {
        // Test that all embedded themes load correctly
        let themes = ["dracula", "gruvbox-dark", "nord", "monokai"];
        let code = "def hello():\n    print('Hello')";

        for theme_name in themes {
            let theme = Syntax::get_theme(theme_name);
            assert!(
                theme.syntect_theme().is_some(),
                "Theme '{}' should load a syntect theme",
                theme_name
            );

            // Test that we can render with each theme
            let syntax = Syntax::new(code, "python3").with_theme(theme_name);
            let console = Console::new();
            let options = ConsoleOptions::default();
            let segments = syntax.render(&console, &options);

            // Should produce non-empty output
            assert!(
                !segments.is_empty(),
                "Theme '{}' should produce output",
                theme_name
            );
        }
    }
}