markdown2pdf 0.2.2

//! Styling module for markdown-to-pdf conversion.
//!
//! This module provides styling configuration for converting markdown elements to PDF,
//! including fonts, text styles, margins and alignments. The styling system supports
//! customization through a TOML configuration file, allowing control over properties
//! like font size, colors, spacing, alignment and text decorations for each element type.
//!
//! The styling configuration can be loaded from a TOML file or created programmatically.
//! Each element type (headings, text, emphasis, code blocks etc.) can have its own style
//! settings. The styling is applied during the PDF generation process to create properly
//! formatted output.
//!
//! Font handling is done through embedded assets, with support for different font weights
//! and styles. The styling system integrates with the PDF generation pipeline to ensure
//! consistent formatting throughout the document.

/// Text alignment options for PDF elements.
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum TextAlignment {
    /// Align text to the left margin
    Left,
    /// Center text between margins
    Center,
    /// Align text to the right margin
    Right,
    /// Spread text evenly between margins
    Justify,
}

/// Margins configuration in points.
#[derive(Clone, Copy, Debug, PartialEq)]
pub struct Margins {
    pub top: f32,
    pub right: f32,
    pub bottom: f32,
    pub left: f32,
}

/// Basic text styling properties that can be applied to any text element.
#[derive(Clone, Copy, Debug, PartialEq)]
pub struct BasicTextStyle {
    /// Font size in points
    pub size: u8,
    /// Text color in RGB format
    pub text_color: Option<(u8, u8, u8)>,
    /// Space before element in points
    pub before_spacing: f32,
    /// Space after element in points
    pub after_spacing: f32,
    /// Text alignment within container
    pub alignment: Option<TextAlignment>,
    /// Font family name
    pub font_family: Option<&'static str>,
    /// Whether text should be bold
    pub bold: bool,
    /// Whether text should be italic
    pub italic: bool,
    /// Whether text should be underlined
    pub underline: bool,
    /// Whether text should have strikethrough
    pub strikethrough: bool,
    /// Background color in RGB format
    pub background_color: Option<(u8, u8, u8)>,
}

impl BasicTextStyle {
    /// Creates a new BasicTextStyle with the specified properties.
    ///
    /// # Arguments
    /// * `size` - Font size in points
    /// * `text_color` - Optional RGB color tuple for text
    /// * `before_spacing` - Optional space before element in points
    /// * `after_spacing` - Optional space after element in points
    /// * `alignment` - Optional text alignment
    /// * `font_family` - Optional font family name
    /// * `bold` - Whether text should be bold
    /// * `italic` - Whether text should be italic
    /// * `underline` - Whether text should be underlined
    /// * `strikethrough` - Whether text should have strikethrough
    /// * `background_color` - Optional RGB color tuple for background
    pub fn new(
        size: u8,
        text_color: Option<(u8, u8, u8)>,
        before_spacing: Option<f32>,
        after_spacing: Option<f32>,
        alignment: Option<TextAlignment>,
        font_family: Option<&'static str>,
        bold: bool,
        italic: bool,
        underline: bool,
        strikethrough: bool,
        background_color: Option<(u8, u8, u8)>,
    ) -> Self {
        Self {
            size,
            text_color,
            before_spacing: before_spacing.unwrap_or(0.0),
            after_spacing: after_spacing.unwrap_or(0.0),
            alignment,
            font_family,
            bold,
            italic,
            underline,
            strikethrough,
            background_color,
        }
    }
}

// LSP in vim behaves strangely with this default implementation.
// It's not used anywhere but included just in case.
impl Default for BasicTextStyle {
    fn default() -> Self {
        Self::new(
            12, None, None, None, None, None, false, false, false, false, None,
        )
    }
}

/// Main style configuration for mapping markdown elements to PDF styles.
///
/// This struct contains style definitions for each markdown element type
/// that can appear in the document. It is used by the PDF renderer to
/// determine how to format each element.
pub struct StyleMatch {
    /// Document margins
    pub margins: Margins,
    /// Style for level 1 headings (#)
    pub heading_1: BasicTextStyle,
    /// Style for level 2 headings (##)
    pub heading_2: BasicTextStyle,
    /// Style for level 3 headings (###)
    pub heading_3: BasicTextStyle,
    /// Style for emphasized text (*text* or _text_)
    pub emphasis: BasicTextStyle,
    /// Style for strongly emphasized text (**text** or __text__)
    pub strong_emphasis: BasicTextStyle,
    /// Style for inline code (`code`)
    pub code: BasicTextStyle,
    /// Style for block quotes (> quote)
    pub block_quote: BasicTextStyle,
    /// Style for list items (- item or * item)
    pub list_item: BasicTextStyle,
    /// Style for links ([text](url))
    pub link: BasicTextStyle,
    /// Style for images (![alt](url))
    pub image: BasicTextStyle,
    /// Style for regular text
    pub text: BasicTextStyle,
    /// Style for table headers
    pub table_header: BasicTextStyle,
    /// Style for table cells
    pub table_cell: BasicTextStyle,

    // TODO: Not parsed into a actual horizontal rule currently, we need a proper styling for this
    /// Style for horizontal rules (---)
    pub horizontal_rule: BasicTextStyle,
}

/// Creates a StyleMatch with default styling settings.
///
/// The default style provides a clean, readable layout with hierarchical heading sizes,
/// appropriate base font sizes, and consistent spacing throughout the document. It sets
/// up styling for all supported markdown elements including headings, emphasis, code blocks,
/// quotes, lists and more.
impl Default for StyleMatch {
    fn default() -> Self {
        Self {
            margins: Margins {
                top: 8.0,
                right: 8.0,
                bottom: 8.0,
                left: 8.0,
            },
            heading_1: BasicTextStyle::new(
                14,
                Some((0, 0, 0)),
                Some(0.8),
                Some(0.5),
                Some(TextAlignment::Center),
                None,
                true,
                false,
                false,
                false,
                None,
            ),
            heading_2: BasicTextStyle::new(
                12,
                Some((0, 0, 0)),
                Some(0.8),
                Some(0.5),
                Some(TextAlignment::Left),
                None,
                true,
                false,
                false,
                false,
                None,
            ),
            heading_3: BasicTextStyle::new(
                10,
                Some((0, 0, 0)),
                Some(0.8),
                Some(0.5),
                Some(TextAlignment::Left),
                None,
                true,
                false,
                false,
                false,
                None,
            ),
            emphasis: BasicTextStyle::new(
                8,
                Some((0, 0, 0)),
                None,
                None,
                None,
                None,
                false,
                true,
                false,
                false,
                None,
            ),
            strong_emphasis: BasicTextStyle::new(
                8,
                Some((0, 0, 0)),
                None,
                None,
                None,
                None,
                true,
                false,
                false,
                false,
                None,
            ),
            code: BasicTextStyle::new(
                8,
                Some((128, 128, 128)),
                Some(0.4),
                Some(0.4),
                None,
                Some("Roboto"),
                false,
                false,
                false,
                false,
                Some((230, 230, 230)),
            ),
            block_quote: BasicTextStyle::new(
                8,
                Some((128, 128, 128)),
                None,
                None,
                None,
                None,
                false,
                true,
                false,
                false,
                Some((245, 245, 245)),
            ),
            list_item: BasicTextStyle::new(
                8,
                Some((0, 0, 0)),
                None,
                Some(0.5),
                None,
                None,
                false,
                false,
                false,
                false,
                None,
            ),
            table_header: BasicTextStyle::new(
                8,
                Some((0, 0, 0)),
                None,
                None,
                None,
                None,
                false,
                false,
                false,
                false,
                None,
            ),
            table_cell: BasicTextStyle::new(
                8,
                Some((0, 0, 0)),
                None,
                None,
                None,
                None,
                false,
                false,
                false,
                false,
                None,
            ),
            link: BasicTextStyle::new(
                8,
                Some((128, 128, 128)),
                None,
                None,
                None,
                None,
                false,
                false,
                true,
                false,
                None,
            ),
            image: BasicTextStyle::new(
                8,
                Some((0, 0, 0)),
                None,
                None,
                Some(TextAlignment::Center),
                None,
                false,
                false,
                false,
                false,
                None,
            ),
            text: BasicTextStyle::new(
                8,
                Some((0, 0, 0)),
                None,
                None,
                None,
                None,
                false,
                false,
                false,
                false,
                None,
            ),
            horizontal_rule: BasicTextStyle::new(
                8,
                Some((0, 0, 0)),
                None,
                Some(0.5),
                None,
                None,
                false,
                false,
                false,
                false,
                None,
            ),
        }
    }
}