rs-rich 0.0.2

//! Exporting rendered output to SVG.
//!
//! Port of `rich/console.py`'s `export_svg` + the `CONSOLE_SVG_FORMAT` template.
//! Turns a recorded stream of [`Segment`]s (captured via
//! [`Console::export_svg`](crate::console::Console::export_svg)) into a
//! self-contained SVG image of a terminal window, using a [`TerminalTheme`].
//!
//! **Divergence:** upstream's *default* `unique_id` is `adler32` over Python's
//! `repr()` of each segment, which Rust can't reproduce. So byte-parity holds
//! only when an explicit `unique_id` is passed (see docs/DIVERGENCES.md #15) —
//! the same shape as the OSC 8 `id=` deviation (#20).

use crate::cells::cell_len;
use crate::segment::Segment;
use crate::terminal_theme::TerminalTheme;

const CHAR_HEIGHT: f64 = 20.0;
const FONT_ASPECT_RATIO: f64 = 0.61;
const MARGIN: i64 = 1;
const PADDING_TOP: i64 = 40;
const PADDING_SIDE: i64 = 8;

/// The SVG document template. Port of `console.CONSOLE_SVG_FORMAT` with single
/// literal braces (placeholders are substituted via `replace`, not `format!`).
const CONSOLE_SVG_FORMAT: &str = r#"<svg class="rich-terminal" viewBox="0 0 {width} {height}" xmlns="http://www.w3.org/2000/svg">
    <!-- Generated with Rich https://www.textualize.io -->
    <style>

    @font-face {
        font-family: "Fira Code";
        src: local("FiraCode-Regular"),
                url("https://cdnjs.cloudflare.com/ajax/libs/firacode/6.2.0/woff2/FiraCode-Regular.woff2") format("woff2"),
                url("https://cdnjs.cloudflare.com/ajax/libs/firacode/6.2.0/woff/FiraCode-Regular.woff") format("woff");
        font-style: normal;
        font-weight: 400;
    }
    @font-face {
        font-family: "Fira Code";
        src: local("FiraCode-Bold"),
                url("https://cdnjs.cloudflare.com/ajax/libs/firacode/6.2.0/woff2/FiraCode-Bold.woff2") format("woff2"),
                url("https://cdnjs.cloudflare.com/ajax/libs/firacode/6.2.0/woff/FiraCode-Bold.woff") format("woff");
        font-style: bold;
        font-weight: 700;
    }

    .{unique_id}-matrix {
        font-family: Fira Code, monospace;
        font-size: {char_height}px;
        line-height: {line_height}px;
        font-variant-east-asian: full-width;
    }

    .{unique_id}-title {
        font-size: 18px;
        font-weight: bold;
        font-family: arial;
    }

    {styles}
    </style>

    <defs>
    <clipPath id="{unique_id}-clip-terminal">
      <rect x="0" y="0" width="{terminal_width}" height="{terminal_height}" />
    </clipPath>
    {lines}
    </defs>

    {chrome}
    <g transform="translate({terminal_x}, {terminal_y})" clip-path="url(#{unique_id}-clip-terminal)">
    {backgrounds}
    <g class="{unique_id}-matrix">
    {matrix}
    </g>
    </g>
</svg>
"#;

/// Python `format(v, "g")`: 6 significant figures, trailing zeros (and a
/// trailing `.`) stripped. Used for the coordinates inside SVG tags.
fn fmt_g(v: f64) -> String {
    if v == 0.0 {
        return "0".to_string();
    }
    let exp = v.abs().log10().floor() as i32;
    let decimals = (5 - exp).max(0) as usize;
    let mut s = format!("{v:.decimals$}");
    if s.contains('.') {
        s = s.trim_end_matches('0').trim_end_matches('.').to_string();
    }
    s
}

/// Python `str(float)`: the shortest round-tripping form, keeping a `.0` for
/// integer-valued floats. Used for the template's float placeholders.
fn fmt_str(v: f64) -> String {
    let s = format!("{v}");
    if s.contains('.') || s.contains('e') {
        s
    } else {
        format!("{s}.0")
    }
}

/// HTML-escape (`quote=True`) then replace spaces with `&#160;`. Port of the
/// `escape_text` closure.
fn escape_text(text: &str) -> String {
    text.replace('&', "&amp;")
        .replace('<', "&lt;")
        .replace('>', "&gt;")
        .replace('"', "&quot;")
        .replace('\'', "&#x27;")
        .replace(' ', "&#160;")
}

/// Split `segments` into lines, padding each to `length` cells and appending a
/// trailing `\n` segment. Port of `Segment.split_and_crop_lines` (`pad=True`,
/// `include_new_lines=True`); a final line with no trailing newline gets no
/// `\n` segment.
fn split_and_crop_lines(segments: &[Segment], length: usize) -> Vec<Vec<Segment>> {
    let mut result: Vec<Vec<Segment>> = Vec::new();
    let mut line: Vec<Segment> = Vec::new();
    for seg in segments {
        if !seg.control && seg.text.contains('\n') {
            let mut text = seg.text.as_str();
            loop {
                match text.find('\n') {
                    Some(idx) => {
                        let before = &text[..idx];
                        if !before.is_empty() {
                            line.push(Segment::new(before, seg.style.clone()));
                        }
                        let mut cropped = Segment::adjust_line_length(&line, length, None);
                        cropped.push(Segment::new("\n", None));
                        result.push(cropped);
                        line = Vec::new();
                        text = &text[idx + 1..];
                    }
                    None => {
                        if !text.is_empty() {
                            line.push(Segment::new(text, seg.style.clone()));
                        }
                        break;
                    }
                }
            }
        } else {
            line.push(seg.clone());
        }
    }
    if !line.is_empty() {
        result.push(Segment::adjust_line_length(&line, length, None));
    }
    result
}

/// Look up (or insert) the class number for a CSS rule string, numbering from 1
/// in first-seen order.
fn class_number(classes: &mut Vec<(String, usize)>, rules: &str) -> usize {
    match classes.iter().find(|(existing, _)| existing == rules) {
        Some((_, n)) => *n,
        None => {
            let n = classes.len() + 1;
            classes.push((rules.to_string(), n));
            n
        }
    }
}

/// Render `segments` to a self-contained SVG document. Port of
/// `Console.export_svg`. `unique_id` prefixes every generated id/class; passing
/// a fixed value makes the output deterministic (and byte-parity — see the
/// module divergence note).
pub fn export_svg(
    segments: &[Segment],
    theme: &TerminalTheme,
    title: &str,
    unique_id: &str,
    width: usize,
) -> String {
    let char_width = CHAR_HEIGHT * FONT_ASPECT_RATIO;
    let line_height = CHAR_HEIGHT * 1.22;
    let padding_width = PADDING_SIDE + PADDING_SIDE;
    let padding_height = PADDING_TOP + PADDING_SIDE;
    let margin_width = MARGIN + MARGIN;
    let margin_height = MARGIN + MARGIN;

    let filtered: Vec<Segment> = segments.iter().filter(|s| !s.control).cloned().collect();

    let mut classes: Vec<(String, usize)> = Vec::new();
    let mut text_backgrounds: Vec<String> = Vec::new();
    let mut text_group: Vec<String> = Vec::new();

    let lines = split_and_crop_lines(&filtered, width);
    let mut last_y = 0usize;
    for (y, line) in lines.iter().enumerate() {
        last_y = y;
        let mut x = 0usize;
        for seg in line {
            let style = seg.style.clone().unwrap_or_default();
            let rules = style.get_svg_style(theme);
            let class_no = class_number(&mut classes, &rules);

            let (has_background, background) = if style.attr(6) == Some(true) {
                // reverse: the (foreground) colour becomes the background rect.
                let hex = style
                    .color()
                    .map_or(theme.foreground, |c| theme.resolve(c, true))
                    .hex();
                (true, hex)
            } else {
                let has_bg = style.bgcolor().is_some_and(|c| !c.is_default());
                let hex = style
                    .bgcolor()
                    .map_or(theme.background, |c| theme.resolve(c, false))
                    .hex();
                (has_bg, hex)
            };

            let text_length = cell_len(&seg.text);
            if has_background {
                text_backgrounds.push(format!(
                    r#"<rect fill="{background}" x="{x}" y="{y2}" width="{w}" height="{h}" shape-rendering="crispEdges"/>"#,
                    x = fmt_g(x as f64 * char_width),
                    y2 = fmt_g(y as f64 * line_height + 1.5),
                    w = fmt_g(char_width * text_length as f64),
                    h = fmt_g(line_height + 0.25),
                ));
            }

            if !seg.text.chars().all(|c| c == ' ') {
                let char_count = seg.text.chars().count();
                text_group.push(format!(
                    r#"<text class="{unique_id}-r{class_no}" x="{x}" y="{y2}" textLength="{tl}" clip-path="url(#{unique_id}-line-{y})">{content}</text>"#,
                    x = fmt_g(x as f64 * char_width),
                    y2 = fmt_g(y as f64 * line_height + CHAR_HEIGHT),
                    tl = fmt_g(char_width * char_count as f64),
                    content = escape_text(&seg.text),
                ));
            }
            x += text_length;
        }
    }

    // Per-line clip-paths for every line but the last (upstream's `range(y)`).
    let lines_svg: Vec<String> = (0..last_y)
        .map(|line_no| {
            let offset = line_no as f64 * line_height + 1.5;
            format!(
                "<clipPath id=\"{unique_id}-line-{line_no}\">\n    <rect x=\"0\" y=\"{y}\" width=\"{w}\" height=\"{h}\"/>\n            </clipPath>",
                y = fmt_g(offset),
                w = fmt_g(char_width * width as f64),
                h = fmt_g(line_height + 0.25),
            )
        })
        .collect();
    let lines_str = lines_svg.join("\n");

    let styles = classes
        .iter()
        .map(|(css, n)| format!(".{unique_id}-r{n} {{ {css} }}"))
        .collect::<Vec<_>>()
        .join("\n");

    let backgrounds = text_backgrounds.concat();
    let matrix = text_group.concat();

    let terminal_width_local = (width as f64 * char_width + padding_width as f64).ceil() as i64;
    let terminal_height_local = (last_y as f64 + 1.0) * line_height + padding_height as f64;

    let mut chrome = format!(
        r#"<rect fill="{bg}" stroke="rgba(255,255,255,0.35)" stroke-width="1" x="{ml}" y="{mt}" width="{tw}" height="{th}" rx="8"/>"#,
        bg = theme.background.hex(),
        ml = MARGIN,
        mt = MARGIN,
        tw = terminal_width_local,
        th = fmt_g(terminal_height_local),
    );
    if !title.is_empty() {
        chrome.push_str(&format!(
            r#"<text class="{unique_id}-title" fill="{fg}" text-anchor="middle" x="{x}" y="{y}">{title}</text>"#,
            fg = theme.foreground.hex(),
            x = terminal_width_local / 2,
            y = MARGIN + CHAR_HEIGHT as i64 + 6,
            title = escape_text(title),
        ));
    }
    chrome.push_str(
        "\n            <g transform=\"translate(26,22)\">\n            <circle cx=\"0\" cy=\"0\" r=\"7\" fill=\"#ff5f57\"/>\n            <circle cx=\"22\" cy=\"0\" r=\"7\" fill=\"#febc2e\"/>\n            <circle cx=\"44\" cy=\"0\" r=\"7\" fill=\"#28c840\"/>\n            </g>\n        ",
    );

    CONSOLE_SVG_FORMAT
        .replace("{unique_id}", unique_id)
        .replace("{char_height}", &(CHAR_HEIGHT as i64).to_string())
        .replace("{line_height}", &fmt_str(line_height))
        .replace(
            "{terminal_width}",
            &fmt_str(char_width * width as f64 - 1.0),
        )
        .replace(
            "{terminal_height}",
            &fmt_str((last_y as f64 + 1.0) * line_height - 1.0),
        )
        .replace(
            "{width}",
            &(terminal_width_local + margin_width).to_string(),
        )
        .replace(
            "{height}",
            &fmt_str(terminal_height_local + margin_height as f64),
        )
        .replace("{terminal_x}", &(MARGIN + PADDING_SIDE).to_string())
        .replace("{terminal_y}", &(MARGIN + PADDING_TOP).to_string())
        .replace("{styles}", &styles)
        .replace("{chrome}", &chrome)
        .replace("{backgrounds}", &backgrounds)
        .replace("{matrix}", &matrix)
        .replace("{lines}", &lines_str)
}

#[cfg(test)]
mod tests {
    use crate::color::ColorSystem;
    use crate::console::Console;

    #[test]
    fn export_svg_matches_upstream() {
        // Byte-parity with real rich 15.0.0 `export_svg(title="X", unique_id="test")`
        // at width 10 (the fixture was captured from it). A fixed unique_id makes
        // the output deterministic — see the module's divergence note (#15).
        let console = Console::builder()
            .force_terminal(true)
            .color_system(Some(ColorSystem::Truecolor))
            .width(10)
            .no_color(false)
            .build();
        let svg = console.export_svg("X", "test", |c| c.print_str("[bold red]Hi[/] ok"));
        // The fixture is stored with the same LF newlines we emit; normalise in
        // case git checked it out with CRLF on Windows.
        let expected = include_str!("../tests/golden/svg_export.svg").replace("\r\n", "\n");
        assert_eq!(svg, expected);
    }
}