rdocx_layout/

engine.rs

//! Layout engine orchestrator: ties all phases together.

use rdocx_oxml::document::{BodyContent, CT_SectPr};
use rdocx_oxml::header_footer::HdrFtrType;
use rdocx_oxml::properties::CT_PPr;
use rdocx_oxml::shared::ST_HighlightColor;
use rdocx_oxml::styles::CT_Styles;
use rdocx_oxml::text::{BreakType, CT_P, FieldType, RunContent};

use crate::block::{self, LayoutBlock, ParagraphBlock};
use crate::error::Result;
use crate::font::FontManager;
use crate::input::LayoutInput;
use crate::line::{self, InlineItem, LineBreakParams, LineItem, TextSegment};
use crate::output::{
    Color, DocumentMetadata, FieldKind, GlyphRun, LayoutResult, PageFrame, Point,
    PositionedElement, Rect,
};
use crate::paginator::{self, HeaderFooterContent, PageGeometry};
use crate::style_resolver::{self, NumberingState};
use crate::table;

/// The layout engine.
pub struct Engine {
    font_manager: FontManager,
}

impl Default for Engine {
    fn default() -> Self {
        Self::new()
    }
}

impl Engine {
    pub fn new() -> Self {
        Engine {
            font_manager: FontManager::new(),
        }
    }

    /// Lay out the entire document.
    pub fn layout(&mut self, input: &LayoutInput) -> Result<LayoutResult> {
        // Load user-provided / DOCX-embedded fonts (highest priority)
        if !input.fonts.is_empty() {
            self.font_manager.load_additional_fonts(&input.fonts);
        }

        let styles = &input.styles;
        let mut num_state = NumberingState::new();

        // Get final section properties (body-level sectPr)
        let final_sect_pr = input
            .document
            .body
            .sect_pr
            .as_ref()
            .cloned()
            .unwrap_or_else(CT_SectPr::default_letter);

        // Build sections: each section has blocks + geometry + header/footer
        let mut sections: Vec<paginator::Section> = Vec::new();
        let mut current_blocks: Vec<LayoutBlock> = Vec::new();
        let mut current_sect_pr: Option<CT_SectPr> = None; // Will be set from paragraph sect_pr

        for content in &input.document.body.content {
            match content {
                BodyContent::Paragraph(para) => {
                    // Check if this paragraph ends a section (has sect_pr)
                    let para_sect_pr = para.properties.as_ref().and_then(|p| p.sect_pr.clone());

                    let sect_pr_for_layout = para_sect_pr
                        .as_ref()
                        .or(current_sect_pr.as_ref())
                        .unwrap_or(&final_sect_pr);
                    let geometry = sect_pr_to_geometry(sect_pr_for_layout);

                    let mut para_block = layout_paragraph(
                        para,
                        geometry.content_width(),
                        styles,
                        input,
                        &mut self.font_manager,
                        &mut num_state,
                    )?;

                    // Detect heading style for outline generation
                    if let Some(level) = detect_heading_level(para, styles) {
                        para_block.heading_level = Some(level);
                        para_block.heading_text = Some(para.text());
                    }

                    current_blocks.push(LayoutBlock::Paragraph(para_block));

                    // If this paragraph has sect_pr, it ends a section
                    if let Some(sect_pr) = para_sect_pr {
                        let geometry = sect_pr_to_geometry(&sect_pr);
                        let header_footer = layout_header_footer(
                            &sect_pr,
                            input,
                            styles,
                            &mut self.font_manager,
                            &mut num_state,
                        )?;
                        let title_pg = sect_pr.title_pg.unwrap_or(false);
                        sections.push(paginator::Section {
                            blocks: std::mem::take(&mut current_blocks),
                            geometry,
                            header_footer,
                            title_pg,
                        });
                        current_sect_pr = Some(sect_pr);
                    }
                }
                BodyContent::Table(tbl) => {
                    let sect_pr_for_layout = current_sect_pr.as_ref().unwrap_or(&final_sect_pr);
                    let geometry = sect_pr_to_geometry(sect_pr_for_layout);

                    let table_block = table::layout_table(
                        tbl,
                        geometry.content_width(),
                        styles,
                        input,
                        &mut self.font_manager,
                        &mut num_state,
                    )?;
                    current_blocks.push(LayoutBlock::Table(table_block));
                }
                _ => {} // Skip RawXml elements during layout
            }
        }

        // Remaining blocks belong to the final section
        let final_geometry = sect_pr_to_geometry(&final_sect_pr);
        let final_hf = layout_header_footer(
            &final_sect_pr,
            input,
            styles,
            &mut self.font_manager,
            &mut num_state,
        )?;
        let final_title_pg = final_sect_pr.title_pg.unwrap_or(false);
        sections.push(paginator::Section {
            blocks: current_blocks,
            geometry: final_geometry,
            header_footer: final_hf,
            title_pg: final_title_pg,
        });

        // Paginate across all sections
        let (mut pages, outlines) = paginator::paginate_sections(&sections, &self.font_manager);

        // Post-pagination pass: substitute field placeholders
        let total_pages = pages.len();
        for page in &mut pages {
            let page_num = page.page_number;
            substitute_fields(
                &mut page.elements,
                page_num,
                total_pages,
                &mut self.font_manager,
            );
        }

        // Post-pagination pass: apply page background color
        apply_page_background(&mut pages, input);

        // Post-pagination pass: resolve anchor (background) images
        resolve_anchor_images(&mut pages, input);

        // Post-pagination pass: resolve inline image data
        resolve_inline_images(&mut pages, input);

        // Post-pagination pass: render footnotes at page bottoms
        if input.footnotes.is_some() || input.endnotes.is_some() {
            render_page_footnotes(
                &mut pages,
                input,
                styles,
                &final_geometry,
                &mut self.font_manager,
                &mut num_state,
            )?;
        }

        // Collect font data
        let fonts = self.font_manager.all_font_data();

        // Convert core properties to document metadata
        let metadata = input.core_properties.as_ref().map(|cp| DocumentMetadata {
            title: cp.title.clone(),
            author: cp.creator.clone(),
            subject: cp.subject.clone(),
            keywords: cp.keywords.clone(),
            creator: Some("rdocx".to_string()),
        });

        Ok(LayoutResult {
            pages,
            fonts,
            metadata,
            outlines,
        })
    }
}

/// Apply page background color from `w:background` element to all pages.
fn apply_page_background(pages: &mut [PageFrame], input: &LayoutInput) {
    let bg_xml = match &input.document.background_xml {
        Some(xml) => xml,
        None => return,
    };

    // Parse w:color attribute from background XML
    let xml_str = std::str::from_utf8(bg_xml).unwrap_or("");
    let color = extract_background_color(xml_str);
    let color = match color {
        Some(c) => c,
        None => return,
    };

    // Insert a full-page FilledRect at position 0 on every page (renders underneath everything)
    for page in pages.iter_mut() {
        page.elements.insert(
            0,
            PositionedElement::FilledRect {
                rect: Rect {
                    x: 0.0,
                    y: 0.0,
                    width: page.width,
                    height: page.height,
                },
                color,
            },
        );
    }
}

/// Extract the background color hex from w:background XML.
fn extract_background_color(xml: &str) -> Option<Color> {
    // Look for w:color="RRGGBB" or color="RRGGBB"
    for attr in ["w:color=\"", "color=\""] {
        if let Some(start) = xml.find(attr) {
            let val_start = start + attr.len();
            if let Some(end) = xml[val_start..].find('"') {
                let hex = &xml[val_start..val_start + end];
                if hex.len() == 6 && hex != "auto" {
                    return Some(Color::from_hex(hex));
                }
            }
        }
    }
    None
}

/// Resolve anchor (floating) images from the document and inject them into page frames.
///
/// For `behind_doc=true` images: inserts at the START of page elements (renders underneath).
/// For `behind_doc=false` images: inserts at the END (renders on top).
fn resolve_anchor_images(pages: &mut [PageFrame], input: &LayoutInput) {
    use crate::output::Rect;
    use rdocx_oxml::text::RunContent;

    // Collect all anchor drawings from body content
    let mut anchor_images: Vec<(bool, f64, f64, f64, f64, String)> = Vec::new();

    for content in &input.document.body.content {
        if let BodyContent::Paragraph(p) = content {
            for run in &p.runs {
                for rc in &run.content {
                    if let RunContent::Drawing(drawing) = rc
                        && let Some(ref anchor) = drawing.anchor
                    {
                        let behind = anchor.behind_doc;
                        // Convert EMU positions and extents to points
                        let x = anchor.pos_h_offset.to_pt();
                        let y = anchor.pos_v_offset.to_pt();
                        let w = anchor.extent_cx.to_pt();
                        let h = anchor.extent_cy.to_pt();
                        anchor_images.push((behind, x, y, w, h, anchor.embed_id.clone()));
                    }
                }
            }
        }
    }

    if anchor_images.is_empty() {
        return;
    }

    // For each anchor image, resolve image data and add to pages
    for (behind, x, y, w, h, embed_id) in &anchor_images {
        let (data, content_type) = if let Some(img) = input.images.get(embed_id) {
            (img.data.clone(), img.content_type.clone())
        } else {
            continue;
        };

        let element = PositionedElement::Image {
            rect: Rect {
                x: *x,
                y: *y,
                width: *w,
                height: *h,
            },
            data,
            content_type,
            embed_id: None, // Already resolved
        };

        if *behind {
            // Behind-doc images go on the first page only
            // (proper page association would require paragraph-to-page mapping)
            if let Some(page) = pages.first_mut() {
                page.elements.insert(0, element);
            }
        } else if let Some(page) = pages.first_mut() {
            // Foreground anchor images go on the first page only
            page.elements.push(element);
        }
    }
}

/// Resolve inline image data from input.images by embed_id.
///
/// During pagination, inline images are created with empty data and an embed_id.
/// This pass fills in the actual image bytes and content type.
fn resolve_inline_images(pages: &mut [PageFrame], input: &LayoutInput) {
    for page in pages.iter_mut() {
        for element in &mut page.elements {
            if let PositionedElement::Image {
                data,
                content_type,
                embed_id: Some(eid),
                ..
            } = element
                && data.is_empty()
                && let Some(img) = input.images.get(eid.as_str())
            {
                *data = img.data.clone();
                *content_type = img.content_type.clone();
            }
        }
    }
}

/// Replace field placeholder GlyphRuns with actual values.
fn substitute_fields(
    elements: &mut [PositionedElement],
    page_number: usize,
    total_pages: usize,
    fm: &mut crate::font::FontManager,
) {
    for element in elements.iter_mut() {
        if let PositionedElement::Text(run) = element
            && let Some(fk) = run.field_kind
        {
            let value = match fk {
                FieldKind::Page => page_number.to_string(),
                FieldKind::NumPages => total_pages.to_string(),
            };
            // Re-shape the text with the actual value
            if let Ok(shaped) = fm.shape_text(run.font_id, &value, run.font_size) {
                run.text = value;
                run.glyph_ids = shaped.glyph_ids;
                run.advances = shaped.advances;
            }
        }
    }
}

/// Render footnote/endnote content at the bottom of each page.
///
/// For each page, collects footnote IDs from glyph runs, then
/// renders a separator line and the footnote text in a smaller font.
fn render_page_footnotes(
    pages: &mut [PageFrame],
    input: &LayoutInput,
    styles: &CT_Styles,
    geometry: &paginator::PageGeometry,
    fm: &mut FontManager,
    num_state: &mut NumberingState,
) -> Result<()> {
    let footnote_font_size = 8.0; // Standard footnote font size
    let separator_offset = 6.0; // Space above separator
    let separator_width_frac = 0.33; // Separator is 1/3 of content width

    for page in pages.iter_mut() {
        // Collect footnote IDs referenced on this page (in order, deduplicated)
        let mut footnote_ids: Vec<i32> = Vec::new();
        for element in &page.elements {
            if let PositionedElement::Text(run) = element
                && let Some(fn_id) = run.footnote_id
                && !footnote_ids.contains(&fn_id)
            {
                footnote_ids.push(fn_id);
            }
        }

        if footnote_ids.is_empty() {
            continue;
        }

        // Find the footnote paragraphs to render
        let mut footnote_blocks: Vec<(i32, Vec<block::ParagraphBlock>)> = Vec::new();
        for &fn_id in &footnote_ids {
            // Check footnotes first, then endnotes
            let paragraphs = input
                .footnotes
                .as_ref()
                .and_then(|fns| fns.get_by_id(fn_id))
                .or_else(|| input.endnotes.as_ref().and_then(|ens| ens.get_by_id(fn_id)));

            if let Some(footnote) = paragraphs {
                let mut fn_blocks = Vec::new();
                for para in &footnote.paragraphs {
                    if let Ok(pb) = layout_paragraph(
                        para,
                        geometry.content_width(),
                        styles,
                        input,
                        fm,
                        num_state,
                    ) {
                        fn_blocks.push(pb);
                    }
                }
                footnote_blocks.push((fn_id, fn_blocks));
            }
        }

        if footnote_blocks.is_empty() {
            continue;
        }

        // Calculate total footnote height
        let total_fn_height: f64 = footnote_blocks
            .iter()
            .flat_map(|(_, blocks)| blocks.iter())
            .map(|b| b.content_height())
            .sum();

        // Position footnotes at page bottom, above bottom margin
        let footnote_area_top =
            page.height - geometry.margin_bottom - total_fn_height - separator_offset;

        // Draw separator line
        let sep_y = footnote_area_top;
        let sep_width = geometry.content_width() * separator_width_frac;
        page.elements.push(PositionedElement::Line {
            start: Point {
                x: geometry.margin_left,
                y: sep_y,
            },
            end: Point {
                x: geometry.margin_left + sep_width,
                y: sep_y,
            },
            width: 0.5,
            color: Color::BLACK,
            dash_pattern: None,
        });

        // Render each footnote
        let mut cursor_y = sep_y + separator_offset;
        for (fn_id, blocks) in &footnote_blocks {
            for pb in blocks {
                let baseline_y = cursor_y + pb.lines.first().map(|l| l.ascent).unwrap_or(0.0);

                // Render the footnote number marker as superscript
                let marker_text = fn_id.to_string();
                let marker_size = footnote_font_size * 0.58;
                if let Ok(font_id) = fm.resolve_font(Some("serif"), false, false)
                    && let Ok(shaped) = fm.shape_text(font_id, &marker_text, marker_size)
                {
                    page.elements.push(PositionedElement::Text(GlyphRun {
                        origin: Point {
                            x: geometry.margin_left,
                            y: baseline_y - footnote_font_size * 0.33,
                        },
                        font_id,
                        font_size: marker_size,
                        glyph_ids: shaped.glyph_ids,
                        advances: shaped.advances,
                        text: marker_text,
                        color: Color::BLACK,
                        bold: false,
                        italic: false,
                        field_kind: None,
                        footnote_id: None,
                    }));
                }

                // Render footnote paragraph lines
                let indent = 12.0; // Indent after marker
                for line in &pb.lines {
                    let line_baseline = cursor_y + line.ascent;
                    for item in &line.items {
                        if let LineItem::Text(seg) | LineItem::Marker(seg) = item {
                            page.elements.push(PositionedElement::Text(GlyphRun {
                                origin: Point {
                                    x: geometry.margin_left + indent,
                                    y: line_baseline - seg.baseline_offset,
                                },
                                font_id: seg.font_id,
                                font_size: seg.font_size,
                                glyph_ids: seg.glyph_ids.clone(),
                                advances: seg.advances.clone(),
                                text: seg.text.clone(),
                                color: seg.color,
                                bold: seg.bold,
                                italic: seg.italic,
                                field_kind: None,
                                footnote_id: None,
                            }));
                        }
                    }
                    cursor_y += line.height;
                }
            }
        }
    }

    Ok(())
}

/// Detect if a paragraph has a heading style, returning the level (1-9).
fn detect_heading_level(para: &CT_P, styles: &CT_Styles) -> Option<u32> {
    let style_id = para.properties.as_ref()?.style_id.as_deref()?;
    // Check if style ID matches "Heading1" .. "Heading9"
    if let Some(rest) = style_id.strip_prefix("Heading") {
        return rest.parse::<u32>().ok().filter(|n| (1..=9).contains(n));
    }
    // Also check style name in the styles definitions
    if let Some(style_def) = styles.get_by_id(style_id)
        && let Some(ref name) = style_def.name
        && let Some(rest) = name.strip_prefix("heading ")
    {
        return rest.parse::<u32>().ok().filter(|n| (1..=9).contains(n));
    }
    None
}

/// Lay out a single paragraph into a ParagraphBlock.
pub fn layout_paragraph(
    para: &CT_P,
    available_width: f64,
    styles: &CT_Styles,
    input: &LayoutInput,
    fm: &mut FontManager,
    num_state: &mut NumberingState,
) -> Result<ParagraphBlock> {
    // Resolve paragraph properties
    let para_style_id = para.properties.as_ref().and_then(|p| p.style_id.as_deref());

    let resolved_ppr = style_resolver::resolve_paragraph_properties(para_style_id, styles);

    // Merge direct paragraph properties
    let mut effective_ppr = resolved_ppr;
    if let Some(ref direct_ppr) = para.properties {
        merge_direct_ppr(&mut effective_ppr, direct_ppr);
    }

    // Convert paragraph properties to layout values
    let space_before = effective_ppr.space_before.map(|t| t.to_pt()).unwrap_or(0.0);
    let space_after = effective_ppr.space_after.map(|t| t.to_pt()).unwrap_or(0.0);
    let ind_left = effective_ppr.ind_left.map(|t| t.to_pt()).unwrap_or(0.0);
    let ind_right = effective_ppr.ind_right.map(|t| t.to_pt()).unwrap_or(0.0);
    let ind_first_line = effective_ppr
        .ind_first_line
        .map(|t| t.to_pt())
        .unwrap_or(0.0);
    let ind_hanging = effective_ppr.ind_hanging.map(|t| t.to_pt()).unwrap_or(0.0);

    let keep_next = effective_ppr.keep_next.unwrap_or(false);
    let keep_lines = effective_ppr.keep_lines.unwrap_or(false);
    let page_break_before = effective_ppr.page_break_before.unwrap_or(false);
    let widow_control = effective_ppr.widow_control.unwrap_or(true);
    let jc = effective_ppr.jc;

    // Collect tab stops
    let tab_stops = effective_ppr
        .tabs
        .as_ref()
        .map(|t| t.tabs.clone())
        .unwrap_or_default();

    // Parse shading color
    let shading = effective_ppr
        .shading
        .as_ref()
        .and_then(|shd| shd.fill.as_ref())
        .filter(|f| f != &"auto")
        .map(|f| Color::from_hex(f));

    // Convert runs to inline items
    let mut inline_items = Vec::new();

    // Handle numbering marker
    if let (Some(num_id), Some(numbering)) = (effective_ppr.num_id, input.numbering.as_ref()) {
        let ilvl = effective_ppr.num_ilvl.unwrap_or(0);
        if let Some(marker) = style_resolver::generate_marker(num_id, ilvl, numbering, num_state) {
            // Shape the marker text
            let marker_rpr = marker.marker_rpr;
            let marker_font_size = marker_rpr.sz.map(|hp| hp.to_pt()).unwrap_or_else(|| {
                style_resolver::resolve_run_properties(para_style_id, None, styles)
                    .sz
                    .map(|hp| hp.to_pt())
                    .unwrap_or(11.0)
            });
            let marker_bold = marker_rpr.bold.unwrap_or(false);
            let marker_italic = marker_rpr.italic.unwrap_or(false);
            let marker_font_family = marker_rpr.font_ascii.as_deref();

            if let Ok(font_id) = fm.resolve_font(marker_font_family, marker_bold, marker_italic)
                && let Ok(shaped) = fm.shape_text(font_id, &marker.marker_text, marker_font_size)
            {
                let metrics = fm.metrics(font_id, marker_font_size)?;
                let color = marker_rpr
                    .color
                    .as_ref()
                    .map(|c| Color::from_hex(c))
                    .unwrap_or(Color::BLACK);

                inline_items.push(InlineItem::Marker(TextSegment {
                    text: marker.marker_text,
                    font_id,
                    font_size: marker_font_size,
                    glyph_ids: shaped.glyph_ids,
                    advances: shaped.advances,
                    width: shaped.width,
                    ascent: metrics.ascent,
                    descent: metrics.descent,
                    color,
                    bold: marker_bold,
                    italic: marker_italic,
                    underline: None,
                    strike: false,
                    dstrike: false,
                    highlight: None,
                    baseline_offset: 0.0,
                    hyperlink_url: None,
                    field_kind: None,
                    footnote_id: None,
                }));

                // Add a space/tab after the marker
                inline_items.push(InlineItem::Tab);
            }
        }
    }

    // Build hyperlink URL map: run index → URL
    let mut run_hyperlink_url: std::collections::HashMap<usize, String> =
        std::collections::HashMap::new();
    for hl in &para.hyperlinks {
        if let Some(ref rel_id) = hl.rel_id
            && let Some(url) = input.hyperlink_urls.get(rel_id)
        {
            for run_idx in hl.run_start..hl.run_end {
                run_hyperlink_url.insert(run_idx, url.clone());
            }
        }
    }

    // Process runs
    for (run_idx, run) in para.runs.iter().enumerate() {
        let current_hyperlink_url = run_hyperlink_url.get(&run_idx).cloned();

        let run_style_id = run.properties.as_ref().and_then(|p| p.style_id.as_deref());

        let resolved_rpr =
            style_resolver::resolve_run_properties(para_style_id, run_style_id, styles);

        // Merge direct run properties
        let mut effective_rpr = resolved_rpr;
        if let Some(ref direct_rpr) = run.properties {
            effective_rpr.merge_from(direct_rpr);
        }

        // Skip hidden text
        if effective_rpr.vanish == Some(true) {
            continue;
        }

        let mut font_size = effective_rpr.sz.map(|hp| hp.to_pt()).unwrap_or(11.0);
        let bold = effective_rpr.bold.unwrap_or(false);
        let italic = effective_rpr.italic.unwrap_or(false);

        // Resolve font family: theme font takes priority when no explicit font is set
        let font_family = resolve_font_family(&effective_rpr, input.theme.as_ref());

        // Resolve color: theme color takes priority over literal color value
        let color = resolve_run_color(&effective_rpr, input.theme.as_ref());

        // Decoration properties
        let underline = effective_rpr.underline;
        let strike = effective_rpr.strike.unwrap_or(false);
        let dstrike = effective_rpr.dstrike.unwrap_or(false);
        let highlight = effective_rpr.highlight.and_then(highlight_to_color);

        // Superscript/subscript handling
        let mut baseline_offset = 0.0;
        if let Some(ref va) = effective_rpr.vert_align {
            match va.as_str() {
                "superscript" => {
                    // Reduce font size to ~58% and raise baseline
                    let original_size = font_size;
                    font_size *= 0.58;
                    baseline_offset = original_size * 0.33; // raise by 1/3 of original size
                }
                "subscript" => {
                    // Reduce font size to ~58% and lower baseline
                    let original_size = font_size;
                    font_size *= 0.58;
                    baseline_offset = -(original_size * 0.14); // lower
                }
                _ => {}
            }
        }

        // Position offset (in half-points, positive=raise)
        if let Some(pos) = effective_rpr.position {
            baseline_offset += pos as f64 / 2.0; // half-points to points
        }

        let font_id = fm.resolve_font(font_family.as_deref(), bold, italic)?;
        let metrics = fm.metrics(font_id, font_size)?;

        for content in &run.content {
            match content {
                RunContent::Text(ct_text) => {
                    let text = if effective_rpr.caps == Some(true) {
                        ct_text.text.to_uppercase()
                    } else {
                        ct_text.text.clone()
                    };

                    if text.is_empty() {
                        continue;
                    }

                    let mut shaped = fm.shape_text(font_id, &text, font_size)?;

                    // Apply character spacing from run properties (in twips)
                    if let Some(spacing) = effective_rpr.spacing {
                        let extra = spacing.to_pt();
                        for advance in &mut shaped.advances {
                            *advance += extra;
                        }
                        shaped.width += extra * shaped.advances.len() as f64;
                    }

                    inline_items.push(InlineItem::Text(TextSegment {
                        text,
                        font_id,
                        font_size,
                        glyph_ids: shaped.glyph_ids,
                        advances: shaped.advances,
                        width: shaped.width,
                        ascent: metrics.ascent,
                        descent: metrics.descent,
                        color,
                        bold,
                        italic,
                        underline,
                        strike,
                        dstrike,
                        highlight,
                        baseline_offset,
                        hyperlink_url: current_hyperlink_url.clone(),
                        field_kind: None,
                        footnote_id: None,
                    }));
                }
                RunContent::Tab => {
                    inline_items.push(InlineItem::Tab);
                }
                RunContent::Break(bt) => match bt {
                    BreakType::Line => inline_items.push(InlineItem::LineBreak),
                    BreakType::Page => inline_items.push(InlineItem::PageBreak),
                    BreakType::Column => inline_items.push(InlineItem::ColumnBreak),
                },
                RunContent::Drawing(drawing) => {
                    if let Some(ref inline) = drawing.inline {
                        let width = inline.extent_cx.to_pt();
                        let height = inline.extent_cy.to_pt();
                        inline_items.push(InlineItem::Image {
                            width,
                            height,
                            embed_id: inline.embed_id.clone(),
                        });
                    }
                }
                RunContent::Field { field_type } => {
                    // Shape a placeholder ("99") for estimated width
                    let placeholder = "99";
                    let fk = match field_type {
                        FieldType::Page => FieldKind::Page,
                        FieldType::NumPages => FieldKind::NumPages,
                        FieldType::Other(_) => continue, // skip unsupported fields
                    };
                    let shaped = fm.shape_text(font_id, placeholder, font_size)?;
                    inline_items.push(InlineItem::Text(TextSegment {
                        text: placeholder.to_string(),
                        font_id,
                        font_size,
                        glyph_ids: shaped.glyph_ids,
                        advances: shaped.advances,
                        width: shaped.width,
                        ascent: metrics.ascent,
                        descent: metrics.descent,
                        color,
                        bold,
                        italic,
                        underline: None,
                        strike: false,
                        dstrike: false,
                        highlight: None,
                        baseline_offset,
                        hyperlink_url: None,
                        field_kind: Some(fk),
                        footnote_id: None,
                    }));
                }
                RunContent::FootnoteRef { id } | RunContent::EndnoteRef { id } => {
                    // Render as superscript number
                    let marker = id.to_string();
                    let sup_size = font_size * 0.58;
                    let sup_offset = font_size * 0.33; // raise baseline
                    let shaped = fm.shape_text(font_id, &marker, sup_size)?;
                    let sup_metrics = fm.metrics(font_id, sup_size)?;
                    inline_items.push(InlineItem::Text(TextSegment {
                        text: marker,
                        font_id,
                        font_size: sup_size,
                        glyph_ids: shaped.glyph_ids,
                        advances: shaped.advances,
                        width: shaped.width,
                        ascent: sup_metrics.ascent,
                        descent: sup_metrics.descent,
                        color,
                        bold,
                        italic,
                        underline: None,
                        strike: false,
                        dstrike: false,
                        highlight: None,
                        baseline_offset: sup_offset,
                        hyperlink_url: None,
                        field_kind: None,
                        footnote_id: Some(*id),
                    }));
                }
            }
        }
    }

    // Line breaking
    let line_params = LineBreakParams {
        available_width,
        ind_left,
        ind_right,
        ind_first_line,
        ind_hanging,
        tab_stops,
        line_spacing: effective_ppr.line_spacing,
        line_rule: effective_ppr.line_rule,
        jc,
    };

    let lines = line::break_into_lines(&inline_items, &line_params, fm)?;

    Ok(block::build_paragraph_block(
        lines,
        space_before,
        space_after,
        effective_ppr.borders,
        shading,
        ind_left,
        ind_right,
        jc,
        keep_next,
        keep_lines,
        page_break_before,
        widow_control,
    ))
}

/// Merge direct paragraph properties (only fields explicitly set in the XML).
fn merge_direct_ppr(effective: &mut CT_PPr, direct: &CT_PPr) {
    // Don't merge style_id — that was already used for resolution
    if direct.jc.is_some() {
        effective.jc = direct.jc;
    }
    if direct.space_before.is_some() {
        effective.space_before = direct.space_before;
    }
    if direct.space_after.is_some() {
        effective.space_after = direct.space_after;
    }
    if direct.line_spacing.is_some() {
        effective.line_spacing = direct.line_spacing;
    }
    if direct.line_rule.is_some() {
        effective.line_rule = direct.line_rule.clone();
    }
    if direct.ind_left.is_some() {
        effective.ind_left = direct.ind_left;
    }
    if direct.ind_right.is_some() {
        effective.ind_right = direct.ind_right;
    }
    if direct.ind_first_line.is_some() {
        effective.ind_first_line = direct.ind_first_line;
    }
    if direct.ind_hanging.is_some() {
        effective.ind_hanging = direct.ind_hanging;
    }
    if direct.keep_next.is_some() {
        effective.keep_next = direct.keep_next;
    }
    if direct.keep_lines.is_some() {
        effective.keep_lines = direct.keep_lines;
    }
    if direct.page_break_before.is_some() {
        effective.page_break_before = direct.page_break_before;
    }
    if direct.widow_control.is_some() {
        effective.widow_control = direct.widow_control;
    }
    if direct.borders.is_some() {
        effective.borders = direct.borders.clone();
    }
    if direct.tabs.is_some() {
        effective.tabs = direct.tabs.clone();
    }
    if direct.shading.is_some() {
        effective.shading = direct.shading.clone();
    }
    if direct.num_id.is_some() {
        effective.num_id = direct.num_id;
    }
    if direct.num_ilvl.is_some() {
        effective.num_ilvl = direct.num_ilvl;
    }
}

/// Convert section properties to page geometry.
fn sect_pr_to_geometry(sect_pr: &CT_SectPr) -> PageGeometry {
    PageGeometry {
        page_width: sect_pr.page_width.map(|t| t.to_pt()).unwrap_or(612.0),
        page_height: sect_pr.page_height.map(|t| t.to_pt()).unwrap_or(792.0),
        margin_top: sect_pr.margin_top.map(|t| t.to_pt()).unwrap_or(72.0),
        margin_right: sect_pr.margin_right.map(|t| t.to_pt()).unwrap_or(72.0),
        margin_bottom: sect_pr.margin_bottom.map(|t| t.to_pt()).unwrap_or(72.0),
        margin_left: sect_pr.margin_left.map(|t| t.to_pt()).unwrap_or(72.0),
        header_distance: sect_pr.header_distance.map(|t| t.to_pt()).unwrap_or(36.0),
        footer_distance: sect_pr.footer_distance.map(|t| t.to_pt()).unwrap_or(36.0),
    }
}

/// Lay out header and footer content (both Default and First-page).
fn layout_header_footer(
    sect_pr: &CT_SectPr,
    input: &LayoutInput,
    styles: &CT_Styles,
    fm: &mut FontManager,
    num_state: &mut NumberingState,
) -> Result<Option<HeaderFooterContent>> {
    let mut has_content = false;
    let mut header_blocks = Vec::new();
    let mut footer_blocks = Vec::new();
    let mut first_header_blocks = Vec::new();
    let mut first_footer_blocks = Vec::new();

    let geometry = sect_pr_to_geometry(sect_pr);
    let width = geometry.content_width();

    for href in &sect_pr.header_refs {
        let target_blocks = match href.hdr_ftr_type {
            HdrFtrType::Default => &mut header_blocks,
            HdrFtrType::First => &mut first_header_blocks,
            _ => continue, // skip Even for now
        };
        if let Some(hdr) = input.headers.get(&href.rel_id) {
            for para in &hdr.paragraphs {
                let block = layout_paragraph(para, width, styles, input, fm, num_state)?;
                target_blocks.push(block);
            }
            has_content = true;
        }
    }

    for fref in &sect_pr.footer_refs {
        let target_blocks = match fref.hdr_ftr_type {
            HdrFtrType::Default => &mut footer_blocks,
            HdrFtrType::First => &mut first_footer_blocks,
            _ => continue, // skip Even for now
        };
        if let Some(ftr) = input.footers.get(&fref.rel_id) {
            for para in &ftr.paragraphs {
                let block = layout_paragraph(para, width, styles, input, fm, num_state)?;
                target_blocks.push(block);
            }
            has_content = true;
        }
    }

    if has_content {
        Ok(Some(HeaderFooterContent {
            header_blocks,
            footer_blocks,
            first_header_blocks,
            first_footer_blocks,
        }))
    } else {
        Ok(None)
    }
}

/// Resolve the effective font family for a run, considering theme fonts.
///
/// Priority: explicit font_ascii > theme font > None (use default).
fn resolve_font_family(
    rpr: &rdocx_oxml::properties::CT_RPr,
    theme: Option<&rdocx_oxml::theme::Theme>,
) -> Option<String> {
    // Explicit font name takes priority
    if rpr.font_ascii.is_some() {
        return rpr.font_ascii.clone();
    }

    // Resolve theme font reference
    if let (Some(theme_ref), Some(theme)) = (&rpr.font_ascii_theme, theme) {
        let font = match theme_ref.as_str() {
            "majorAscii" | "majorHAnsi" | "majorBidi" | "majorEastAsia" => {
                theme.major_font.as_deref()
            }
            "minorAscii" | "minorHAnsi" | "minorBidi" | "minorEastAsia" => {
                theme.minor_font.as_deref()
            }
            _ => None,
        };
        if let Some(f) = font {
            return Some(f.to_string());
        }
    }

    None
}

/// Resolve the effective color for a run, considering theme colors.
///
/// Priority: literal color (non-auto) > theme color > black.
fn resolve_run_color(
    rpr: &rdocx_oxml::properties::CT_RPr,
    theme: Option<&rdocx_oxml::theme::Theme>,
) -> Color {
    // If theme color is specified, resolve it from the theme
    if let Some(ref theme_name) = rpr.color_theme
        && let Some(theme) = theme
        && let Some(hex) = theme.colors.get(theme_name)
    {
        return Color::from_hex(hex);
    }

    // Fall back to literal color value
    rpr.color
        .as_ref()
        .filter(|c| c.as_str() != "auto")
        .map(|c| Color::from_hex(c))
        .unwrap_or(Color::BLACK)
}

/// Convert a highlight color enum to an RGBA Color.
fn highlight_to_color(h: ST_HighlightColor) -> Option<Color> {
    match h {
        ST_HighlightColor::None => None,
        ST_HighlightColor::Black => Some(Color {
            r: 0.0,
            g: 0.0,
            b: 0.0,
            a: 1.0,
        }),
        ST_HighlightColor::Blue => Some(Color {
            r: 0.0,
            g: 0.0,
            b: 1.0,
            a: 1.0,
        }),
        ST_HighlightColor::Cyan => Some(Color {
            r: 0.0,
            g: 1.0,
            b: 1.0,
            a: 1.0,
        }),
        ST_HighlightColor::DarkBlue => Some(Color {
            r: 0.0,
            g: 0.0,
            b: 0.545,
            a: 1.0,
        }),
        ST_HighlightColor::DarkCyan => Some(Color {
            r: 0.0,
            g: 0.545,
            b: 0.545,
            a: 1.0,
        }),
        ST_HighlightColor::DarkGray => Some(Color {
            r: 0.663,
            g: 0.663,
            b: 0.663,
            a: 1.0,
        }),
        ST_HighlightColor::DarkGreen => Some(Color {
            r: 0.0,
            g: 0.392,
            b: 0.0,
            a: 1.0,
        }),
        ST_HighlightColor::DarkMagenta => Some(Color {
            r: 0.545,
            g: 0.0,
            b: 0.545,
            a: 1.0,
        }),
        ST_HighlightColor::DarkRed => Some(Color {
            r: 0.545,
            g: 0.0,
            b: 0.0,
            a: 1.0,
        }),
        ST_HighlightColor::DarkYellow => Some(Color {
            r: 0.545,
            g: 0.545,
            b: 0.0,
            a: 1.0,
        }),
        ST_HighlightColor::Green => Some(Color {
            r: 0.0,
            g: 1.0,
            b: 0.0,
            a: 1.0,
        }),
        ST_HighlightColor::LightGray => Some(Color {
            r: 0.827,
            g: 0.827,
            b: 0.827,
            a: 1.0,
        }),
        ST_HighlightColor::Magenta => Some(Color {
            r: 1.0,
            g: 0.0,
            b: 1.0,
            a: 1.0,
        }),
        ST_HighlightColor::Red => Some(Color {
            r: 1.0,
            g: 0.0,
            b: 0.0,
            a: 1.0,
        }),
        ST_HighlightColor::White => Some(Color {
            r: 1.0,
            g: 1.0,
            b: 1.0,
            a: 1.0,
        }),
        ST_HighlightColor::Yellow => Some(Color {
            r: 1.0,
            g: 1.0,
            b: 0.0,
            a: 1.0,
        }),
    }
}

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

    fn make_input_with_text(text: &str) -> LayoutInput {
        let mut doc = rdocx_oxml::document::CT_Document::new();
        let mut p = CT_P::new();
        p.add_run(text);
        doc.body.add_paragraph(p);

        LayoutInput {
            document: doc,
            styles: CT_Styles::new_default(),
            numbering: None,
            headers: HashMap::new(),
            footers: HashMap::new(),
            images: HashMap::new(),
            core_properties: None,
            hyperlink_urls: HashMap::new(),
            footnotes: None,
            endnotes: None,
            theme: None,
            fonts: Vec::new(),
        }
    }

    #[test]
    fn layout_simple_document() {
        let input = make_input_with_text("Hello World");
        let result = Engine::new().layout(&input);
        // On systems without fonts, this may fail — that's OK
        if let Ok(result) = result {
            assert!(!result.pages.is_empty());
            assert_eq!(result.pages[0].page_number, 1);
            assert!((result.pages[0].width - 612.0).abs() < 0.01);
        }
    }

    #[test]
    fn layout_empty_document() {
        let mut doc = rdocx_oxml::document::CT_Document::new();
        doc.body.add_paragraph(CT_P::new());

        let input = LayoutInput {
            document: doc,
            styles: CT_Styles::new_default(),
            numbering: None,
            headers: HashMap::new(),
            footers: HashMap::new(),
            images: HashMap::new(),
            core_properties: None,
            hyperlink_urls: HashMap::new(),
            footnotes: None,
            endnotes: None,
            theme: None,
            fonts: Vec::new(),
        };

        let result = Engine::new().layout(&input);
        if let Ok(result) = result {
            assert_eq!(result.pages.len(), 1);
        }
    }

    #[test]
    fn layout_with_heading_style() {
        let mut doc = rdocx_oxml::document::CT_Document::new();
        let mut p = CT_P::new();
        p.properties = Some(CT_PPr {
            style_id: Some("Heading1".to_string()),
            ..Default::default()
        });
        p.add_run("Chapter 1");
        doc.body.add_paragraph(p);

        let input = LayoutInput {
            document: doc,
            styles: CT_Styles::new_default(),
            numbering: None,
            headers: HashMap::new(),
            footers: HashMap::new(),
            images: HashMap::new(),
            core_properties: None,
            hyperlink_urls: HashMap::new(),
            footnotes: None,
            endnotes: None,
            theme: None,
            fonts: Vec::new(),
        };

        let result = Engine::new().layout(&input);
        if let Ok(result) = result {
            assert!(!result.pages.is_empty());
            // Should produce one outline entry for Heading1
            assert_eq!(result.outlines.len(), 1);
            assert_eq!(result.outlines[0].title, "Chapter 1");
            assert_eq!(result.outlines[0].level, 1);
            assert_eq!(result.outlines[0].page_index, 0);
        }
    }

    #[test]
    fn layout_nested_headings_produce_outlines() {
        let mut doc = rdocx_oxml::document::CT_Document::new();

        // H1
        let mut h1 = CT_P::new();
        h1.properties = Some(CT_PPr {
            style_id: Some("Heading1".to_string()),
            ..Default::default()
        });
        h1.add_run("Chapter 1");
        doc.body.add_paragraph(h1);

        // H2 under H1
        let mut h2 = CT_P::new();
        h2.properties = Some(CT_PPr {
            style_id: Some("Heading2".to_string()),
            ..Default::default()
        });
        h2.add_run("Section 1.1");
        doc.body.add_paragraph(h2);

        // Another H1
        let mut h1b = CT_P::new();
        h1b.properties = Some(CT_PPr {
            style_id: Some("Heading1".to_string()),
            ..Default::default()
        });
        h1b.add_run("Chapter 2");
        doc.body.add_paragraph(h1b);

        let input = LayoutInput {
            document: doc,
            styles: CT_Styles::new_default(),
            numbering: None,
            headers: HashMap::new(),
            footers: HashMap::new(),
            images: HashMap::new(),
            core_properties: None,
            hyperlink_urls: HashMap::new(),
            footnotes: None,
            endnotes: None,
            theme: None,
            fonts: Vec::new(),
        };

        let result = Engine::new().layout(&input);
        if let Ok(result) = result {
            assert_eq!(result.outlines.len(), 3);
            assert_eq!(result.outlines[0].level, 1);
            assert_eq!(result.outlines[0].title, "Chapter 1");
            assert_eq!(result.outlines[1].level, 2);
            assert_eq!(result.outlines[1].title, "Section 1.1");
            assert_eq!(result.outlines[2].level, 1);
            assert_eq!(result.outlines[2].title, "Chapter 2");
        }
    }

    #[test]
    fn sect_pr_geometry_conversion() {
        let sect = CT_SectPr::default_letter();
        let geom = sect_pr_to_geometry(&sect);
        assert!((geom.page_width - 612.0).abs() < 0.01);
        assert!((geom.page_height - 792.0).abs() < 0.01);
        assert!((geom.margin_top - 72.0).abs() < 0.01);
        assert!((geom.content_width() - 468.0).abs() < 0.01);
    }

    #[test]
    fn sect_pr_a4_geometry() {
        let sect = CT_SectPr::default_a4();
        let geom = sect_pr_to_geometry(&sect);
        // A4: 210mm = 595.3pt, 297mm = 841.9pt
        assert!((geom.page_width - 595.3).abs() < 0.5);
        assert!((geom.page_height - 841.9).abs() < 0.5);
    }
}