rust_docx/parse/

util.rs

use std::collections::HashMap;

use crate::model::{
    ImageHorizontalAlign, ImageVerticalAlign, ParagraphAlignment, ParagraphBorderSet,
    ParagraphBorderStyle, ParagraphIndent, ParagraphLineRule, ParagraphSpacing, ParagraphTabStop,
    ParagraphTabStopAlignment, ParagraphTabStopLeader, TableBorderSet, TableBorderStyle,
    TextRunBorderStyle, TextStyle,
};
use crate::package::OoxmlPart;
use crate::parse::context::{ContentTypeLookup, ThemeColorMap, ThemeFontMap};
use crate::parse::re;
use crate::xml::{
    decode_xml_entities, extract_balanced_tag_blocks, get_attribute, normalize_alignment,
    parse_integer_attribute,
};
#[cfg(target_arch = "wasm32")]
use base64::{engine::general_purpose::STANDARD, Engine as _};

pub fn regex_capture(xml: &str, pattern: &str) -> Option<String> {
    if xml.is_empty() {
        return None;
    }
    re::get(pattern)?
        .captures(xml)
        .and_then(|caps| caps.get(1).map(|m| m.as_str().to_string()))
}

pub fn regex_capture_tag(xml: &str, pattern: &str) -> Option<String> {
    if xml.is_empty() {
        return None;
    }
    re::get(pattern)?.find(xml).map(|m| m.as_str().to_string())
}

pub fn normalize_hex_color(value: Option<&str>) -> Option<String> {
    let value = value?.trim();
    if value.is_empty() || value.eq_ignore_ascii_case("auto") {
        return None;
    }

    if re::get(r"^[0-9a-fA-F]{6}$")?.is_match(value) {
        return Some(format!("#{value}"));
    }

    if re::get(r"^[0-9a-fA-F]{3}$")?.is_match(value) {
        let expanded: String = value.chars().flat_map(|c| [c, c]).collect();
        return Some(format!("#{expanded}"));
    }

    if re::get(r"^#[0-9a-fA-F]{6}$")?.is_match(value) {
        return Some(value.to_string());
    }

    None
}

pub fn emu_to_pixels(value: Option<&str>) -> Option<f64> {
    let value = value?;
    if value.is_empty() {
        return None;
    }
    let parsed: f64 = value.parse().ok()?;
    if !parsed.is_finite() {
        return None;
    }
    Some(((parsed / 9525.0) * 1000.0).round() / 1000.0)
}

pub fn to_model_alignment(raw: Option<&str>) -> Option<ParagraphAlignment> {
    match normalize_alignment(raw)? {
        "left" => Some(ParagraphAlignment::Left),
        "center" => Some(ParagraphAlignment::Center),
        "right" => Some(ParagraphAlignment::Right),
        "justify" => Some(ParagraphAlignment::Justify),
        _ => None,
    }
}

pub fn normalize_heading_level(value: Option<&str>) -> Option<crate::model::HeadingLevel> {
    let value = value?;
    let caps = re::get(r"(?i)heading\s*([1-9])")?.captures(value)?;
    let level: i64 = caps.get(1)?.as_str().parse().ok()?;
    match level {
        1 => Some(crate::model::HeadingLevel::One),
        2 => Some(crate::model::HeadingLevel::Two),
        3 => Some(crate::model::HeadingLevel::Three),
        4 => Some(crate::model::HeadingLevel::Four),
        5 => Some(crate::model::HeadingLevel::Five),
        6 => Some(crate::model::HeadingLevel::Six),
        7 => Some(crate::model::HeadingLevel::Seven),
        8 => Some(crate::model::HeadingLevel::Eight),
        9 => Some(crate::model::HeadingLevel::Nine),
        _ => None,
    }
}

pub fn prefer_alternate_content_choice(xml: &str) -> String {
    active_xml(xml).into_owned()
}

pub(crate) fn active_xml(xml: &str) -> std::borrow::Cow<'_, str> {
    static ALTERNATE_CONTENT: std::sync::LazyLock<memchr::memmem::Finder<'static>> =
        std::sync::LazyLock::new(|| memchr::memmem::Finder::new(b"<mc:AlternateContent"));
    if ALTERNATE_CONTENT.find(xml.as_bytes()).is_none() {
        return std::borrow::Cow::Borrowed(xml);
    }

    if let Some(choices) = crate::xml_index::alternate_choices(xml) {
        if choices.is_empty() {
            return std::borrow::Cow::Borrowed(xml);
        }
        let mut output = String::with_capacity(xml.len());
        let mut cursor = 0;
        for (alternate, content) in choices {
            output.push_str(&xml[cursor..alternate.start]);
            output.push_str(&xml[content.start..content.end]);
            cursor = alternate.end;
        }
        output.push_str(&xml[cursor..]);
        return std::borrow::Cow::Owned(output);
    }

    if let Some(output) = balanced_active_xml(xml) {
        return std::borrow::Cow::Owned(output);
    }

    if let Some(output) = scan_active_xml(xml) {
        return output;
    }

    let re = re::get_unchecked(r"(?is)<mc:AlternateContent\b[\s\S]*?</mc:AlternateContent>");
    re.replace_all(xml, |caps: &regex::Captures| {
        let alternate_xml = &caps[0];
        let choice_re = re::get_unchecked(r"(?is)<mc:Choice\b[\s\S]*?</mc:Choice>");
        let Some(choice_xml) = choice_re.find(alternate_xml) else {
            return alternate_xml.to_string();
        };
        let choice = choice_xml.as_str();
        let without_open = re::get_unchecked(r"(?i)<mc:Choice\b[^>]*>")
            .replace(choice, "")
            .to_string();
        re::get_unchecked(r"(?i)</mc:Choice>")
            .replace(&without_open, "")
            .to_string()
    })
}

fn balanced_active_xml(xml: &str) -> Option<String> {
    let mut active = xml.to_string();
    loop {
        let ranges = crate::xml::extract_balanced_tag_ranges(&active, "mc:AlternateContent");
        if ranges.is_empty() {
            return Some(active);
        }
        let mut output = String::with_capacity(active.len());
        let mut cursor = 0;
        for range in ranges {
            let alternate = &active[range.start..range.end];
            let branch = crate::xml::direct_child_tag(alternate, "mc:Choice")
                .or_else(|| crate::xml::direct_child_tag(alternate, "mc:Fallback"))?;
            let begin = crate::xml::tag_token_end(branch, 0)?;
            let end = branch.rfind("</")?;
            if begin > end {
                return None;
            }
            output.push_str(&active[cursor..range.start]);
            output.push_str(&branch[begin..end]);
            cursor = range.end;
        }
        output.push_str(&active[cursor..]);
        if output.len() >= active.len() {
            return None;
        }
        active = output;
    }
}

fn scan_active_xml(xml: &str) -> Option<std::borrow::Cow<'_, str>> {
    fn opening(xml: &str, mut start: usize, prefix: &str) -> Result<Option<usize>, ()> {
        while let Some(position) = crate::xml::find_ignore_ascii_case(xml, start, prefix) {
            let after = position + prefix.len();
            match xml.as_bytes().get(after) {
                Some(byte) if !byte.is_ascii() => return Err(()),
                Some(byte) if byte.is_ascii_alphanumeric() || *byte == b'_' => start = after,
                _ => return Ok(Some(position)),
            }
        }
        Ok(None)
    }
    const ALTERNATE_OPEN: &str = "<mc:AlternateContent";
    const ALTERNATE_CLOSE: &str = "</mc:AlternateContent>";
    const CHOICE_OPEN: &str = "<mc:Choice";
    const CHOICE_CLOSE: &str = "</mc:Choice>";
    let mut output: Option<String> = None;
    let mut cursor = 0;
    while let Some(start) = opening(xml, cursor, ALTERNATE_OPEN).ok()? {
        let Some(close) = crate::xml::find_ignore_ascii_case(xml, start + ALTERNATE_OPEN.len(), ALTERNATE_CLOSE) else {
            break;
        };
        let end = close + ALTERNATE_CLOSE.len();
        let alternate = &xml[start..end];
        let target = output.get_or_insert_with(|| String::with_capacity(xml.len()));
        target.push_str(&xml[cursor..start]);
        let choice = opening(alternate, 0, CHOICE_OPEN).ok()?.and_then(|start| {
            let close = crate::xml::find_ignore_ascii_case(alternate, start + CHOICE_OPEN.len(), CHOICE_CLOSE)?;
            let content = start + alternate[start..close + CHOICE_CLOSE.len()].find('>')? + 1;
            Some((content, close))
        });
        if let Some((content, close)) = choice {
            if content < close {
                target.push_str(&alternate[content..close]);
            }
        } else {
            target.push_str(alternate);
        }
        cursor = end;
    }
    Some(match output {
        Some(mut output) => {
            output.push_str(&xml[cursor..]);
            std::borrow::Cow::Owned(output)
        }
        None => std::borrow::Cow::Borrowed(xml),
    })
}

pub fn merge_text_styles(styles: &[Option<TextStyle>]) -> Option<TextStyle> {
    merge_text_style_refs(&styles.iter().map(Option::as_ref).collect::<Vec<_>>())
}

pub(crate) fn merge_text_style_refs(styles: &[Option<&TextStyle>]) -> Option<TextStyle> {
    let mut present = styles.iter().flatten();
    let first = *present.next()?;
    if present.next().is_none() {
        return Some(first.clone());
    }
    let mut merged = TextStyle {
        bold: None,
        italic: None,
        underline: None,
        strike: None,
        all_caps: None,
        small_caps: None,
        color: None,
        highlight: None,
        background_color: None,
        font_size_pt: None,
        font_size_cs_pt: None,
        font_family: None,
        source_font_family: None,
        font_family_ascii: None,
        font_family_h_ansi: None,
        font_family_east_asia: None,
        font_family_cs: None,
        font_theme_ascii: None,
        font_theme_h_ansi: None,
        font_theme_east_asia: None,
        font_theme_cs: None,
        resolved_font_family_ascii: None,
        resolved_font_family_h_ansi: None,
        resolved_font_family_east_asia: None,
        resolved_font_family_cs: None,
        font_hint: None,
        language: None,
        language_east_asia: None,
        language_bidi: None,
        right_to_left: None,
        complex_script: None,
        character_spacing_twips: None,
        character_scale_percent: None,
        source_character_scale: None,
        kerning_min_font_size_pt: None,
        ligatures: None,
        contextual_alternates: None,
        vertical_align: None,
        run_border: None,
    };
    let mut has_any = false;

    for style in styles.iter().rev().flatten() {
        has_any = true;
        if merged.bold.is_none() {
            merged.bold = style.bold;
        }
        if merged.italic.is_none() {
            merged.italic = style.italic;
        }
        if merged.underline.is_none() {
            merged.underline = style.underline;
        }
        if merged.strike.is_none() {
            merged.strike = style.strike;
        }
        if merged.all_caps.is_none() {
            merged.all_caps = style.all_caps;
        }
        if merged.small_caps.is_none() {
            merged.small_caps = style.small_caps;
        }
        if merged.color.is_none() {
            merged.color = style.color.clone();
        }
        if merged.highlight.is_none() {
            merged.highlight = style.highlight.clone();
        }
        if merged.background_color.is_none() {
            merged.background_color = style.background_color.clone();
        }
        if merged.font_size_pt.is_none() {
            merged.font_size_pt = style.font_size_pt;
        }
        if merged.font_size_cs_pt.is_none() {
            merged.font_size_cs_pt = style.font_size_cs_pt;
        }
        if merged.font_family.is_none() {
            merged.font_family = style.font_family.clone();
        }
        if merged.source_font_family.is_none() {
            merged.source_font_family = style.source_font_family.clone();
        }
        if merged.font_family_ascii.is_none() {
            merged.font_family_ascii = style.font_family_ascii.clone();
        }
        if merged.font_family_h_ansi.is_none() {
            merged.font_family_h_ansi = style.font_family_h_ansi.clone();
        }
        if merged.font_family_east_asia.is_none() {
            merged.font_family_east_asia = style.font_family_east_asia.clone();
        }
        if merged.font_family_cs.is_none() {
            merged.font_family_cs = style.font_family_cs.clone();
        }
        if merged.font_theme_ascii.is_none() {
            merged.font_theme_ascii = style.font_theme_ascii.clone();
        }
        if merged.font_theme_h_ansi.is_none() {
            merged.font_theme_h_ansi = style.font_theme_h_ansi.clone();
        }
        if merged.font_theme_east_asia.is_none() {
            merged.font_theme_east_asia = style.font_theme_east_asia.clone();
        }
        if merged.font_theme_cs.is_none() {
            merged.font_theme_cs = style.font_theme_cs.clone();
        }
        if merged.resolved_font_family_ascii.is_none() {
            merged.resolved_font_family_ascii = style.resolved_font_family_ascii.clone();
        }
        if merged.resolved_font_family_h_ansi.is_none() {
            merged.resolved_font_family_h_ansi = style.resolved_font_family_h_ansi.clone();
        }
        if merged.resolved_font_family_east_asia.is_none() {
            merged.resolved_font_family_east_asia = style.resolved_font_family_east_asia.clone();
        }
        if merged.resolved_font_family_cs.is_none() {
            merged.resolved_font_family_cs = style.resolved_font_family_cs.clone();
        }
        if merged.font_hint.is_none() {
            merged.font_hint = style.font_hint.clone();
        }
        if merged.language.is_none() {
            merged.language = style.language.clone();
        }
        if merged.language_east_asia.is_none() {
            merged.language_east_asia = style.language_east_asia.clone();
        }
        if merged.language_bidi.is_none() {
            merged.language_bidi = style.language_bidi.clone();
        }
        if merged.right_to_left.is_none() {
            merged.right_to_left = style.right_to_left;
        }
        if merged.complex_script.is_none() {
            merged.complex_script = style.complex_script;
        }
        if merged.character_scale_percent.is_none() && merged.source_character_scale.is_none() {
            merged.character_scale_percent = style.character_scale_percent;
            merged.source_character_scale = style.source_character_scale.clone();
        }
        if merged.character_spacing_twips.is_none() {
            merged.character_spacing_twips = style.character_spacing_twips;
        }
        if merged.kerning_min_font_size_pt.is_none() {
            merged.kerning_min_font_size_pt = style.kerning_min_font_size_pt;
        }
        if merged.ligatures.is_none() {
            merged.ligatures = style.ligatures;
        }
        if merged.contextual_alternates.is_none() {
            merged.contextual_alternates = style.contextual_alternates;
        }
        if merged.vertical_align.is_none() {
            merged.vertical_align = style.vertical_align;
        }
        if merged.run_border.is_none() {
            merged.run_border = style.run_border.clone();
        }
    }

    if has_any {
        Some(merged)
    } else {
        None
    }
}

pub fn merge_paragraph_spacing(
    inherited: Option<&ParagraphSpacing>,
    direct: Option<&ParagraphSpacing>,
) -> Option<ParagraphSpacing> {
    if inherited.is_none() && direct.is_none() {
        return None;
    }
    let merged = ParagraphSpacing {
        before_twips: direct
            .and_then(|d| d.before_twips)
            .or(inherited.and_then(|i| i.before_twips)),
        after_twips: direct
            .and_then(|d| d.after_twips)
            .or(inherited.and_then(|i| i.after_twips)),
        before_auto_spacing: direct
            .and_then(|d| d.before_auto_spacing)
            .or(inherited.and_then(|i| i.before_auto_spacing)),
        after_auto_spacing: direct
            .and_then(|d| d.after_auto_spacing)
            .or(inherited.and_then(|i| i.after_auto_spacing)),
        line_twips: direct
            .and_then(|d| d.line_twips)
            .or(inherited.and_then(|i| i.line_twips)),
        line_rule: direct
            .and_then(|d| d.line_rule)
            .or(inherited.and_then(|i| i.line_rule)),
    };
    if merged.before_twips.is_none()
        && merged.after_twips.is_none()
        && merged.before_auto_spacing.is_none()
        && merged.after_auto_spacing.is_none()
        && merged.line_twips.is_none()
        && merged.line_rule.is_none()
    {
        return None;
    }
    Some(merged)
}

pub fn merge_paragraph_indent(
    inherited: Option<&ParagraphIndent>,
    direct: Option<&ParagraphIndent>,
) -> Option<ParagraphIndent> {
    if inherited.is_none() && direct.is_none() {
        return None;
    }
    let merged = ParagraphIndent {
        left_twips: direct
            .and_then(|d| d.left_twips)
            .or(inherited.and_then(|i| i.left_twips)),
        right_twips: direct
            .and_then(|d| d.right_twips)
            .or(inherited.and_then(|i| i.right_twips)),
        first_line_twips: direct
            .and_then(|d| d.first_line_twips)
            .or(inherited.and_then(|i| i.first_line_twips)),
        hanging_twips: direct
            .and_then(|d| d.hanging_twips)
            .or(inherited.and_then(|i| i.hanging_twips)),
    };
    if merged.left_twips.is_none()
        && merged.right_twips.is_none()
        && merged.first_line_twips.is_none()
        && merged.hanging_twips.is_none()
    {
        return None;
    }
    Some(merged)
}

pub fn merge_paragraph_boolean(inherited: Option<bool>, direct: Option<bool>) -> Option<bool> {
    direct.or(inherited)
}

pub fn merge_paragraph_border_style(
    inherited: Option<&ParagraphBorderStyle>,
    direct: Option<&ParagraphBorderStyle>,
) -> Option<ParagraphBorderStyle> {
    if inherited.is_none() && direct.is_none() {
        return None;
    }
    let border_type = direct
        .map(|d| d.border_type.clone())
        .or_else(|| inherited.map(|i| i.border_type.clone()))?;
    Some(ParagraphBorderStyle {
        border_type,
        color: direct
            .and_then(|d| d.color.clone())
            .or_else(|| inherited.and_then(|i| i.color.clone())),
        size_eighth_pt: direct
            .and_then(|d| d.size_eighth_pt)
            .or(inherited.and_then(|i| i.size_eighth_pt)),
        space_pt: direct
            .and_then(|d| d.space_pt)
            .or(inherited.and_then(|i| i.space_pt)),
        frame: direct
            .and_then(|d| d.frame)
            .or(inherited.and_then(|i| i.frame)),
        shadow: direct
            .and_then(|d| d.shadow)
            .or(inherited.and_then(|i| i.shadow)),
    })
}

pub fn merge_paragraph_border_sets(
    inherited: Option<&ParagraphBorderSet>,
    direct: Option<&ParagraphBorderSet>,
) -> Option<ParagraphBorderSet> {
    if inherited.is_none() && direct.is_none() {
        return None;
    }
    let merged = ParagraphBorderSet {
        top: merge_paragraph_border_style(
            inherited.and_then(|i| i.top.as_ref()),
            direct.and_then(|d| d.top.as_ref()),
        ),
        right: merge_paragraph_border_style(
            inherited.and_then(|i| i.right.as_ref()),
            direct.and_then(|d| d.right.as_ref()),
        ),
        bottom: merge_paragraph_border_style(
            inherited.and_then(|i| i.bottom.as_ref()),
            direct.and_then(|d| d.bottom.as_ref()),
        ),
        left: merge_paragraph_border_style(
            inherited.and_then(|i| i.left.as_ref()),
            direct.and_then(|d| d.left.as_ref()),
        ),
        between: merge_paragraph_border_style(
            inherited.and_then(|i| i.between.as_ref()),
            direct.and_then(|d| d.between.as_ref()),
        ),
        bar: merge_paragraph_border_style(
            inherited.and_then(|i| i.bar.as_ref()),
            direct.and_then(|d| d.bar.as_ref()),
        ),
    };
    if merged.top.is_none()
        && merged.right.is_none()
        && merged.bottom.is_none()
        && merged.left.is_none()
        && merged.between.is_none()
        && merged.bar.is_none()
    {
        return None;
    }
    Some(merged)
}

pub fn merge_paragraph_tab_stops(
    inherited: Option<&[ParagraphTabStop]>,
    direct: Option<&[ParagraphTabStop]>,
) -> Option<Vec<ParagraphTabStop>> {
    if inherited.is_none() && direct.is_none() {
        return None;
    }
    let mut by_position: HashMap<i64, ParagraphTabStop> = HashMap::new();
    for stop in inherited.unwrap_or(&[]) {
        if let Some(pos) = stop.position_twips {
            by_position.insert(pos, stop.clone());
        }
    }
    for stop in direct.unwrap_or(&[]) {
        if let Some(pos) = stop.position_twips {
            by_position.insert(pos, stop.clone());
        }
    }
    if by_position.is_empty() {
        return None;
    }
    let mut combined: Vec<_> = by_position.into_values().collect();
    combined.sort_by_key(|s| s.position_twips.unwrap_or(0));
    Some(combined)
}

pub fn merge_table_border_sets(
    inherited: Option<&TableBorderSet>,
    direct: Option<&TableBorderSet>,
) -> Option<TableBorderSet> {
    if inherited.is_none() && direct.is_none() {
        return None;
    }
    let merged = TableBorderSet {
        top: direct
            .and_then(|d| d.top.clone())
            .or_else(|| inherited.and_then(|i| i.top.clone())),
        right: direct
            .and_then(|d| d.right.clone())
            .or_else(|| inherited.and_then(|i| i.right.clone())),
        bottom: direct
            .and_then(|d| d.bottom.clone())
            .or_else(|| inherited.and_then(|i| i.bottom.clone())),
        left: direct
            .and_then(|d| d.left.clone())
            .or_else(|| inherited.and_then(|i| i.left.clone())),
        inside_h: direct
            .and_then(|d| d.inside_h.clone())
            .or_else(|| inherited.and_then(|i| i.inside_h.clone())),
        inside_v: direct
            .and_then(|d| d.inside_v.clone())
            .or_else(|| inherited.and_then(|i| i.inside_v.clone())),
        tl2br: direct
            .and_then(|d| d.tl2br.clone())
            .or_else(|| inherited.and_then(|i| i.tl2br.clone())),
        tr2bl: direct
            .and_then(|d| d.tr2bl.clone())
            .or_else(|| inherited.and_then(|i| i.tr2bl.clone())),
    };
    if merged.top.is_none()
        && merged.right.is_none()
        && merged.bottom.is_none()
        && merged.left.is_none()
        && merged.inside_h.is_none()
        && merged.inside_v.is_none()
        && merged.tl2br.is_none()
        && merged.tr2bl.is_none()
    {
        return None;
    }
    Some(merged)
}

pub fn on_off_value_to_boolean(value: Option<&str>) -> Option<bool> {
    let value = value?.trim();
    if value.is_empty() {
        return None;
    }
    match value.to_ascii_lowercase().as_str() {
        "1" | "true" | "on" => Some(true),
        "0" | "false" | "off" => Some(false),
        _ => None,
    }
}

pub fn decode_xml_attribute(value: Option<&str>) -> Option<String> {
    value.map(decode_xml_entities)
}

pub fn decode_hex_code_point(value: Option<&str>) -> Option<String> {
    let value = value?
        .trim()
        .trim_start_matches("0x")
        .trim_start_matches("0X");
    if value.is_empty() || !value.chars().all(|c| c.is_ascii_hexdigit()) {
        return None;
    }
    let code_point = i32::from_str_radix(value, 16).ok()?;
    if code_point <= 0 {
        return None;
    }
    char::from_u32(code_point as u32).map(|c| c.to_string())
}

pub fn parse_on_off_tag_value(tag_xml: Option<&str>, attributes: &[&str]) -> Option<bool> {
    let tag_xml = tag_xml?;
    for attribute in attributes {
        if let Some(raw) = get_attribute(tag_xml, attribute) {
            return on_off_value_to_boolean(Some(&raw));
        }
    }
    Some(true)
}

pub fn clamp(value: f64, minimum: f64, maximum: f64) -> f64 {
    value.max(minimum).min(maximum)
}

pub fn clamp_i64(value: i64, minimum: i64, maximum: i64) -> i64 {
    value.max(minimum).min(maximum)
}

pub fn escape_xml_text(value: &str) -> String {
    let bytes = value.as_bytes();
    if memchr::memchr3(b'&', b'<', b'>', bytes).is_none()
        && memchr::memchr2(b'"', b'\'', bytes).is_none()
    {
        return value.to_owned();
    }
    value
        .replace('&', "&amp;")
        .replace('<', "&lt;")
        .replace('>', "&gt;")
        .replace('"', "&quot;")
        .replace('\'', "&apos;")
}

pub fn svg_data_uri(svg: &str) -> String {
    const PREFIX: &[u8] = b"data:image/svg+xml;charset=utf-8,";
    const HEX: &[u8; 16] = b"0123456789ABCDEF";
    const UNRESERVED: [bool; 256] = {
        let mut values = [false; 256];
        let mut byte = 0;
        while byte < values.len() {
            values[byte] = matches!(byte as u8,
                b'A'..=b'Z' | b'a'..=b'z' | b'0'..=b'9' | b'-' | b'_' | b'.' | b'~');
            byte += 1;
        }
        values
    };
    let capacity = svg.len().checked_add(svg.len() / 8)
        .and_then(|length| length.checked_add(PREFIX.len()))
        .expect("encoded data exceeds addressable size");
    let mut output = Vec::with_capacity(capacity);
    output.extend_from_slice(PREFIX);
    let bytes = svg.as_bytes();
    let mut start = 0;
    for (at, &byte) in bytes.iter().enumerate() {
        if UNRESERVED[byte as usize] {
            continue;
        }
        output.extend_from_slice(&bytes[start..at]);
        output.extend_from_slice(&[b'%', HEX[(byte >> 4) as usize], HEX[(byte & 15) as usize]]);
        start = at + 1;
    }
    output.extend_from_slice(&bytes[start..]);
    String::from_utf8(output).expect("percent-encoded output is ASCII")
}

pub fn bytes_to_base64(bytes: &[u8]) -> String {
    #[cfg(not(target_arch = "wasm32"))]
    { base64_simd::STANDARD.encode_to_string(bytes) }
    #[cfg(target_arch = "wasm32")]
    { STANDARD.encode(bytes) }
}

pub(crate) fn append_base64(bytes: &[u8], output: &mut String) {
    #[cfg(not(target_arch = "wasm32"))]
    base64_simd::STANDARD.encode_append(bytes, output);
    #[cfg(target_arch = "wasm32")]
    STANDARD.encode_string(bytes, output);
}

pub(crate) fn base64_data_uri(content_type: &str, bytes: &[u8]) -> String {
    let encoded = base64::encoded_len(bytes.len(), true).expect("encoded data exceeds addressable size");
    let mut output = String::with_capacity(13 + content_type.len() + encoded);
    output.push_str("data:");
    output.push_str(content_type);
    output.push_str(";base64,");
    append_base64(bytes, &mut output);
    output
}

pub fn extension_from_part_name(part_name: &str) -> Option<String> {
    let last_dot = part_name.rfind('.')?;
    if last_dot == part_name.len() - 1 {
        return None;
    }
    Some(part_name[last_dot + 1..].to_ascii_lowercase())
}

pub fn content_type_for_part(part_name: &str, content_types: &ContentTypeLookup) -> Option<String> {
    if let Some(override_type) = content_types
        .override_by_part_name
        .get(part_name)
        .or_else(|| {
            content_types
                .override_by_part_name
                .get(&format!("/{part_name}"))
        })
    {
        return Some(override_type.clone());
    }
    let extension = extension_from_part_name(part_name)?;
    let mime_by_extension: HashMap<&str, &str> = [
        ("png", "image/png"),
        ("jpg", "image/jpeg"),
        ("jpeg", "image/jpeg"),
        ("gif", "image/gif"),
        ("bmp", "image/bmp"),
        ("wmf", "image/wmf"),
        ("emf", "image/emf"),
        ("webp", "image/webp"),
        ("svg", "image/svg+xml"),
    ]
    .into_iter()
    .collect();
    content_types
        .default_by_extension
        .get(&extension)
        .cloned()
        .or_else(|| {
            mime_by_extension
                .get(extension.as_str())
                .map(|s| (*s).to_string())
        })
}

pub fn resolve_part_path(base_part_name: &str, target: &str) -> String {
    if target.is_empty() {
        return String::new();
    }
    if re::get_unchecked(r"(?i)^[a-z][a-z0-9+.-]*:").is_match(target) || target.starts_with('#') {
        return target.to_string();
    }
    if target.starts_with('/') {
        return target[1..].to_string();
    }
    let mut output: Vec<&str> = base_part_name.split('/').collect();
    output.pop();
    for segment in target.split('/') {
        if segment.is_empty() || segment == "." {
            continue;
        }
        if segment == ".." {
            output.pop();
            continue;
        }
        output.push(segment);
    }
    output.join("/")
}

pub fn relationship_part_name_for_part(part_name: &str) -> String {
    let mut segments: Vec<&str> = part_name.split('/').collect();
    let file_name = segments.pop().unwrap_or("");
    let folder = segments.join("/");
    if folder.is_empty() {
        format!("_rels/{file_name}.rels")
    } else {
        format!("{folder}/_rels/{file_name}.rels")
    }
}

pub fn parse_relationships_from_parts(
    parts: &HashMap<String, OoxmlPart>,
    part_name: &str,
) -> HashMap<String, String> {
    let mut map = HashMap::new();
    let relationships_part_name = relationship_part_name_for_part(part_name);
    let Some(relationships_part) = parts.get(&relationships_part_name) else {
        return map;
    };
    let re = re::get_unchecked(r"(?i)<Relationship\b[^>]*>");
    for mat in re.find_iter(&relationships_part.content) {
        let tag = mat.as_str();
        let Some(id) = get_attribute(tag, "Id") else {
            continue;
        };
        let Some(target) = get_attribute(tag, "Target") else {
            continue;
        };
        map.insert(id, resolve_part_path(part_name, &target));
    }
    map
}

pub fn is_windows_metafile_content_type(
    content_type: Option<&str>,
    part_name: Option<&str>,
) -> bool {
    if let Some(normalized) = content_type.map(|value| value.trim().to_ascii_lowercase()) {
        if matches!(
            normalized.as_str(),
            "image/wmf"
                | "image/x-wmf"
                | "application/x-wmf"
                | "image/emf"
                | "image/x-emf"
                | "application/x-emf"
        ) {
            return true;
        }
    }
    matches!(
        part_name.and_then(extension_from_part_name).as_deref(),
        Some("wmf" | "emf")
    )
}

pub fn rasterize_windows_metafile_to_png_data_uri(
    _bytes: &[u8],
    _part_name: Option<&str>,
) -> Option<String> {
    None
}

/// Converts vector EMF assets to an SVG data URI. WMF and EMFs containing
/// unsupported drawing records return `None` so the caller
/// keeps the unsupported-image placeholder.
pub fn windows_metafile_to_svg_data_uri(bytes: &[u8]) -> Option<String> {
    crate::emf::emf_to_svg(bytes).map(|svg| svg_data_uri(&svg))
}

pub fn resolve_theme_font(theme_token: Option<&str>, theme_fonts: &ThemeFontMap) -> Option<String> {
    let theme_token = theme_token?;
    let normalized = theme_token.to_ascii_lowercase();
    if normalized.starts_with("major") {
        if normalized.contains("eastasia") {
            return theme_fonts
                .major_east_asia
                .clone()
                .or_else(|| theme_fonts.major_latin.clone());
        }
        if normalized.contains("bidi") || normalized.contains("cs") {
            return theme_fonts
                .major_complex_script
                .clone()
                .or_else(|| theme_fonts.major_latin.clone());
        }
        return theme_fonts.major_latin.clone();
    }
    if normalized.starts_with("minor") {
        if normalized.contains("eastasia") {
            return theme_fonts
                .minor_east_asia
                .clone()
                .or_else(|| theme_fonts.minor_latin.clone());
        }
        if normalized.contains("bidi") || normalized.contains("cs") {
            return theme_fonts
                .minor_complex_script
                .clone()
                .or_else(|| theme_fonts.minor_latin.clone());
        }
        return theme_fonts.minor_latin.clone();
    }
    None
}

pub fn resolve_drawing_color_from_xml(
    color_xml: Option<&str>,
    theme_colors: &ThemeColorMap,
) -> Option<(String, Option<f64>)> {
    super::colors::resolve_drawing_color_from_xml(color_xml, theme_colors)
        .map(|resolved| (resolved.color, resolved.opacity))
}

pub fn parse_paragraph_spacing_from_xml(xml: &str) -> Option<ParagraphSpacing> {
    if xml.is_empty() {
        return None;
    }
    let spacing_tag = super::scan::find_tag_token_ref(xml, "w:spacing")?;
    let line_rule_raw = get_attribute(&spacing_tag, "w:lineRule").map(|v| v.to_ascii_lowercase());
    let line_rule = match line_rule_raw.as_deref() {
        Some("auto") => Some(ParagraphLineRule::Auto),
        Some("exact") => Some(ParagraphLineRule::Exact),
        Some("atleast") => Some(ParagraphLineRule::AtLeast),
        _ => None,
    };
    let spacing = ParagraphSpacing {
        before_twips: parse_integer_attribute(&spacing_tag, "w:before"),
        after_twips: parse_integer_attribute(&spacing_tag, "w:after"),
        before_auto_spacing: super::styles::parse_on_off_value(
            get_attribute(&spacing_tag, "w:beforeAutospacing").as_deref(),
        ),
        after_auto_spacing: super::styles::parse_on_off_value(
            get_attribute(&spacing_tag, "w:afterAutospacing").as_deref(),
        ),
        line_twips: parse_integer_attribute(&spacing_tag, "w:line"),
        line_rule,
    };
    if spacing.before_twips.is_none()
        && spacing.after_twips.is_none()
        && spacing.before_auto_spacing.is_none()
        && spacing.after_auto_spacing.is_none()
        && spacing.line_twips.is_none()
        && spacing.line_rule.is_none()
    {
        return None;
    }
    Some(spacing)
}

pub fn parse_paragraph_indent_from_xml(xml: &str) -> Option<ParagraphIndent> {
    if xml.is_empty() {
        return None;
    }
    let indent_tag = super::scan::find_tag_token_ref(xml, "w:ind")?;
    let indent = ParagraphIndent {
        left_twips: parse_integer_attribute(&indent_tag, "w:left"),
        right_twips: parse_integer_attribute(&indent_tag, "w:right"),
        first_line_twips: parse_integer_attribute(&indent_tag, "w:firstLine"),
        hanging_twips: parse_integer_attribute(&indent_tag, "w:hanging"),
    };
    if indent.left_twips.is_none()
        && indent.right_twips.is_none()
        && indent.first_line_twips.is_none()
        && indent.hanging_twips.is_none()
    {
        return None;
    }
    Some(indent)
}

pub fn parse_paragraph_shading_from_xml(xml: &str) -> Option<String> {
    if xml.is_empty() {
        return None;
    }
    let shading_tag = super::scan::find_tag_token_ref(xml, "w:shd")?;
    normalize_hex_color(get_attribute(&shading_tag, "w:fill").as_deref())
}

pub fn parse_text_run_border_style(tag_xml: Option<&str>) -> Option<TextRunBorderStyle> {
    let tag_xml = tag_xml?;
    let border_type = get_attribute(tag_xml, "w:val")?.trim().to_ascii_lowercase();
    if border_type.is_empty() {
        return None;
    }
    let size_eighth_pt = parse_integer_attribute(tag_xml, "w:sz").map(|v| v as f64);
    let space_pt = parse_integer_attribute(tag_xml, "w:space").map(|v| v as f64);
    let raw_color = get_attribute(tag_xml, "w:color");
    let color = if raw_color
        .as_deref()
        .map(|c| c.eq_ignore_ascii_case("auto"))
        .unwrap_or(false)
    {
        None
    } else {
        normalize_hex_color(raw_color.as_deref())
    };
    let frame = get_attribute(tag_xml, "w:frame")
        .as_deref()
        .and_then(|value| on_off_value_to_boolean(Some(value)));
    let shadow = get_attribute(tag_xml, "w:shadow")
        .as_deref()
        .and_then(|value| on_off_value_to_boolean(Some(value)));
    Some(TextRunBorderStyle {
        border_type,
        color,
        size_eighth_pt: size_eighth_pt.filter(|v| *v >= 0.0),
        space_pt: space_pt.filter(|v| *v >= 0.0),
        frame,
        shadow,
    })
}

pub fn parse_paragraph_border_style(tag_xml: Option<&str>) -> Option<ParagraphBorderStyle> {
    let tag_xml = tag_xml?;
    let border_type = get_attribute(tag_xml, "w:val")?.trim().to_ascii_lowercase();
    if border_type.is_empty() {
        return None;
    }
    let size_eighth_pt = parse_integer_attribute(tag_xml, "w:sz").map(|v| v as f64);
    let space_pt = parse_integer_attribute(tag_xml, "w:space").map(|v| v as f64);
    let raw_color = get_attribute(tag_xml, "w:color");
    let color = if raw_color
        .as_deref()
        .map(|c| c.eq_ignore_ascii_case("auto"))
        .unwrap_or(false)
    {
        Some("#000000".to_string())
    } else {
        normalize_hex_color(raw_color.as_deref())
    };
    let frame = get_attribute(tag_xml, "w:frame")
        .as_deref()
        .and_then(|value| on_off_value_to_boolean(Some(value)));
    let shadow = get_attribute(tag_xml, "w:shadow")
        .as_deref()
        .and_then(|value| on_off_value_to_boolean(Some(value)));
    Some(ParagraphBorderStyle {
        border_type,
        color,
        size_eighth_pt: size_eighth_pt.filter(|v| *v >= 0.0),
        space_pt: space_pt.filter(|v| *v >= 0.0),
        frame,
        shadow,
    })
}

pub fn parse_paragraph_border_set_from_xml(xml: &str) -> Option<ParagraphBorderSet> {
    if xml.is_empty() {
        return None;
    }
    let paragraph_border_xml = extract_balanced_tag_blocks(xml, "w:pBdr")
        .into_iter()
        .next()
        .or_else(|| super::scan::find_tag_token_ref(xml, "w:pBdr").map(str::to_owned))?;
    if paragraph_border_xml.is_empty() {
        return None;
    }
    let top = parse_paragraph_border_style(
        super::scan::find_tag_token_ref(&paragraph_border_xml, "w:top").as_deref(),
    );
    let right = parse_paragraph_border_style(
        super::scan::find_tag_token_ref(&paragraph_border_xml, "w:right").as_deref(),
    );
    let bottom = parse_paragraph_border_style(
        super::scan::find_tag_token_ref(&paragraph_border_xml, "w:bottom").as_deref(),
    );
    let left = parse_paragraph_border_style(
        super::scan::find_tag_token_ref(&paragraph_border_xml, "w:left").as_deref(),
    );
    let between = parse_paragraph_border_style(
        super::scan::find_tag_token_ref(&paragraph_border_xml, "w:between").as_deref(),
    );
    let bar = parse_paragraph_border_style(
        super::scan::find_tag_token_ref(&paragraph_border_xml, "w:bar").as_deref(),
    );
    if top.is_none()
        && right.is_none()
        && bottom.is_none()
        && left.is_none()
        && between.is_none()
        && bar.is_none()
    {
        return None;
    }
    Some(ParagraphBorderSet {
        top,
        right,
        bottom,
        left,
        between,
        bar,
    })
}

pub fn parse_table_border_style(tag_xml: Option<&str>) -> Option<TableBorderStyle> {
    let tag_xml = tag_xml?;
    let border_type = get_attribute(tag_xml, "w:val")?.trim().to_ascii_lowercase();
    if border_type.is_empty() {
        return None;
    }
    let size_eighth_pt = parse_integer_attribute(tag_xml, "w:sz").map(|v| v as f64);
    let raw_color = get_attribute(tag_xml, "w:color");
    let color = if raw_color
        .as_deref()
        .map(|c| c.eq_ignore_ascii_case("auto"))
        .unwrap_or(false)
    {
        Some("#000000".to_string())
    } else {
        normalize_hex_color(raw_color.as_deref())
    };
    Some(TableBorderStyle {
        border_type,
        color,
        size_eighth_pt: size_eighth_pt.filter(|v| *v >= 0.0),
    })
}

pub fn parse_table_border_set(xml: &str) -> Option<TableBorderSet> {
    let top = parse_table_border_style(super::scan::find_tag_token_ref(xml, "w:top").as_deref());
    let right =
        parse_table_border_style(super::scan::find_tag_token_ref(xml, "w:right").as_deref());
    let bottom =
        parse_table_border_style(super::scan::find_tag_token_ref(xml, "w:bottom").as_deref());
    let left = parse_table_border_style(super::scan::find_tag_token_ref(xml, "w:left").as_deref());
    let inside_h =
        parse_table_border_style(super::scan::find_tag_token_ref(xml, "w:insideH").as_deref());
    let inside_v =
        parse_table_border_style(super::scan::find_tag_token_ref(xml, "w:insideV").as_deref());
    let tl2br =
        parse_table_border_style(super::scan::find_tag_token_ref(xml, "w:tl2br").as_deref());
    let tr2bl =
        parse_table_border_style(super::scan::find_tag_token_ref(xml, "w:tr2bl").as_deref());
    if top.is_none()
        && right.is_none()
        && bottom.is_none()
        && left.is_none()
        && inside_h.is_none()
        && inside_v.is_none()
        && tl2br.is_none()
        && tr2bl.is_none()
    {
        return None;
    }
    Some(TableBorderSet {
        top,
        right,
        bottom,
        left,
        inside_h,
        inside_v,
        tl2br,
        tr2bl,
    })
}

pub fn normalize_tab_stop_alignment(value: Option<&str>) -> Option<ParagraphTabStopAlignment> {
    match value?.to_ascii_lowercase().as_str() {
        "clear" => Some(ParagraphTabStopAlignment::Clear),
        "left" => Some(ParagraphTabStopAlignment::Left),
        "center" => Some(ParagraphTabStopAlignment::Center),
        "right" => Some(ParagraphTabStopAlignment::Right),
        "decimal" => Some(ParagraphTabStopAlignment::Decimal),
        "bar" => Some(ParagraphTabStopAlignment::Bar),
        _ => None,
    }
}

pub fn normalize_tab_stop_leader(value: Option<&str>) -> Option<ParagraphTabStopLeader> {
    match value? {
        "none" => Some(ParagraphTabStopLeader::LeaderNone),
        "dot" => Some(ParagraphTabStopLeader::Dot),
        "hyphen" => Some(ParagraphTabStopLeader::Hyphen),
        "underscore" => Some(ParagraphTabStopLeader::Underscore),
        "middleDot" => Some(ParagraphTabStopLeader::MiddleDot),
        _ => None,
    }
}

pub fn parse_paragraph_tab_stops_from_xml(xml: &str) -> Vec<ParagraphTabStop> {
    if xml.is_empty() {
        return Vec::new();
    }
    let tabs_tag = regex_capture_tag(
        xml,
        r"(?is)<w:tabs\b[^>]*>[\s\S]*?</w:tabs>|<w:tabs\b[^>]*/>",
    )
    .unwrap_or_default();
    if tabs_tag.is_empty() {
        return Vec::new();
    }
    let re = re::get_unchecked(r"(?i)<w:tab\b[^>]*/>");
    let mut tab_stops = Vec::new();
    for mat in re.find_iter(&tabs_tag) {
        let tab_tag = mat.as_str();
        let Some(position_twips) = parse_integer_attribute(tab_tag, "w:pos") else {
            continue;
        };
        tab_stops.push(ParagraphTabStop {
            alignment: normalize_tab_stop_alignment(get_attribute(tab_tag, "w:val").as_deref())
                .or(Some(ParagraphTabStopAlignment::Left)),
            leader: normalize_tab_stop_leader(get_attribute(tab_tag, "w:leader").as_deref())
                .or(Some(ParagraphTabStopLeader::LeaderNone)),
            position_twips: Some(position_twips),
        });
    }
    tab_stops.sort_by_key(|s| s.position_twips.unwrap_or(0));
    tab_stops
}

/// Raw `w:numPr` sub-values before inheritance: `(numId, ilvl)`, each `None`
/// when its element is absent. Returns `None` when the properties block has no
/// `w:numPr` at all. Callers use this to distinguish an ilvl-only override
/// (level change on a style-provided list) from numbering removal (numId=0).
pub fn parse_paragraph_numbering_parts_from_xml(xml: &str) -> Option<(Option<i64>, Option<i64>)> {
    if xml.is_empty() {
        return None;
    }
    let numbering_xml = extract_balanced_tag_blocks(xml, "w:numPr")
        .into_iter()
        .next()
        .or_else(|| super::scan::find_tag_token_ref(xml, "w:numPr").map(str::to_owned))?;
    if numbering_xml.is_empty() {
        return None;
    }
    let num_id = regex_capture(&numbering_xml, r#"(?i)<w:numId\b[^>]*w:val="(-?\d+)""#)
        .and_then(|raw| raw.parse::<i64>().ok());
    let ilvl = regex_capture(&numbering_xml, r#"(?i)<w:ilvl\b[^>]*w:val="(-?\d+)""#)
        .and_then(|raw| raw.parse::<i64>().ok());
    Some((num_id, ilvl))
}

pub fn parse_paragraph_numbering_from_xml(xml: &str) -> Option<crate::model::ParagraphNumbering> {
    if xml.is_empty() {
        return None;
    }
    let numbering_xml = extract_balanced_tag_blocks(xml, "w:numPr")
        .into_iter()
        .next()
        .or_else(|| super::scan::find_tag_token_ref(xml, "w:numPr").map(str::to_owned))?;
    if numbering_xml.is_empty() {
        return None;
    }
    let num_id_raw = regex_capture(&numbering_xml, r#"(?i)<w:numId\b[^>]*w:val="(-?\d+)""#)?;
    let num_id: i64 = num_id_raw.parse().ok()?;
    if num_id <= 0 {
        return None;
    }
    let ilvl_raw = regex_capture(&numbering_xml, r#"(?i)<w:ilvl\b[^>]*w:val="(-?\d+)""#);
    let ilvl_value: i64 = ilvl_raw.and_then(|v| v.parse().ok()).unwrap_or(0);
    Some(crate::model::ParagraphNumbering {
        num_id,
        ilvl: ilvl_value.max(0),
    })
}

pub fn to_image_horizontal_align(raw: Option<&str>) -> Option<ImageHorizontalAlign> {
    match raw? {
        "left" => Some(ImageHorizontalAlign::Left),
        "center" => Some(ImageHorizontalAlign::Center),
        "right" => Some(ImageHorizontalAlign::Right),
        "inside" => Some(ImageHorizontalAlign::Inside),
        "outside" => Some(ImageHorizontalAlign::Outside),
        _ => None,
    }
}

pub fn to_image_vertical_align(raw: Option<&str>) -> Option<ImageVerticalAlign> {
    match raw? {
        "top" => Some(ImageVerticalAlign::Top),
        "center" => Some(ImageVerticalAlign::Center),
        "bottom" => Some(ImageVerticalAlign::Bottom),
        "inside" => Some(ImageVerticalAlign::Inside),
        "outside" => Some(ImageVerticalAlign::Outside),
        _ => None,
    }
}

pub fn strip_text_box_content(xml: &str) -> String {
    let re = re::get_unchecked(r"(?is)<w:txbxContent\b[\s\S]*?</w:txbxContent>");
    re.replace_all(xml, "").to_string()
}

pub fn normalize_legacy_form_display_value(value: Option<&str>) -> Option<String> {
    let value = value?;
    let normalized = value
        .replace('\u{2002}', " ")
        .replace('\u{2003}', " ")
        .replace('\u{00a0}', " ");
    if normalized.trim().is_empty() {
        None
    } else {
        Some(normalized)
    }
}

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

    #[test]
    fn parses_only_valid_st_on_off_lexical_values() {
        for value in ["1", "true", "TRUE", "on", "ON"] {
            assert_eq!(on_off_value_to_boolean(Some(value)), Some(true));
        }
        for value in ["0", "false", "FALSE", "off", "OFF"] {
            assert_eq!(on_off_value_to_boolean(Some(value)), Some(false));
        }
        for value in ["", "yes", "no", "maybe"] {
            assert_eq!(on_off_value_to_boolean(Some(value)), None);
        }
    }
}

#[cfg(test)]
mod base64_output_tests {
    use super::*;
    use base64::Engine as _;

    #[test]
    fn encoding_preserves_all_tails_and_prefixed_output() {
        let mut state = 0x61c4_28d9_u64;
        let mut bytes = Vec::new();
        for _ in 0..=1048576 {
            state = state.wrapping_mul(6364136223846793005).wrapping_add(1);
            bytes.push((state >> 32) as u8);
        }
        for length in (0..=512).chain([1023, 1024, 4097, 65539, 1048577]) {
            let data = &bytes[..length];
            let expected = base64::engine::general_purpose::STANDARD.encode(data);
            assert_eq!(bytes_to_base64(data), expected);
            for prefix in ["", "prefix:", "π:payload,"] {
                let mut output = prefix.to_owned();
                append_base64(data, &mut output);
                assert_eq!(output, format!("{prefix}{expected}"));
            }
            assert_eq!(base64_data_uri("application/octet-stream", data), format!("data:application/octet-stream;base64,{expected}"));
        }
    }
}

#[cfg(test)]
mod svg_uri_encoding_tests {
    #[test]
    fn reserved_characters_and_unicode_use_uppercase_utf8_escapes() {
        assert_eq!(super::svg_data_uri("<svg a=\"a b&é😀\"/>"), "data:image/svg+xml;charset=utf-8,%3Csvg%20a%3D%22a%20b%26%C3%A9%F0%9F%98%80%22%2F%3E");
        assert_eq!(super::svg_data_uri("AZaz09-_.~"), "data:image/svg+xml;charset=utf-8,AZaz09-_.~");
        assert_eq!(super::svg_data_uri(""), "data:image/svg+xml;charset=utf-8,");
        assert_eq!(super::svg_data_uri("\0\t\r\n%+/"), "data:image/svg+xml;charset=utf-8,%00%09%0D%0A%25%2B%2F");
    }
}

#[cfg(test)]
mod alternate_scanner_tests {
    fn reference(xml: &str) -> String {
        use super::re;
        let re = re::get_unchecked(r"(?is)<mc:AlternateContent\b[\s\S]*?</mc:AlternateContent>");
        re.replace_all(xml, |caps: &regex::Captures| {
            let alternate = &caps[0];
            let Some(choice) = re::get_unchecked(r"(?is)<mc:Choice\b[\s\S]*?</mc:Choice>").find(alternate) else {
                return alternate.to_owned();
            };
            let content = re::get_unchecked(r"(?i)<mc:Choice\b[^>]*>").replace(choice.as_str(), "");
            re::get_unchecked(r"(?i)</mc:Choice>").replace(&content, "").into_owned()
        }).into_owned()
    }

    #[test]
    fn scanner_preserves_lazy_matching_and_boundary_behavior() {
        let opens = ["<mc:AlternateContent>", "<MC:ALTERNATECONTENT>", "<mc:AlternateContent:extra>", "<mc:AlternateContent_>", "<mc:AlternateContenté>", "<mc:AlternateContent\u{301}>", "<mc:AlternateContent"];
        let contents = ["<mc:Choice>one</mc:Choice><mc:Fallback>two</mc:Fallback>", "<MC:CHOICE a=\"x>y\">one</MC:CHOICE>", "<mc:Choice:extra>one</mc:Choice>", "<mc:Choice_>one</mc:Choice>", "<mc:Choiceé>one</mc:Choice>", "<mc:Choice\u{301}>one</mc:Choice>", "<mc:Choice</mc:Choice>", "<mc:Choice>outer<mc:Choice>inner</mc:Choice>tail</mc:Choice>", "<mc:Fallback>retained</mc:Fallback>", "<mc:AlternateContent><mc:Choice>nested</mc:Choice></mc:AlternateContent>"];
        for open in opens {
            for content in contents {
                for close in ["</mc:AlternateContent>", "</MC:ALTERNATECONTENT>", ""] {
                    let xml = format!("before{open}{content}{close}after<mc:AlternateContent><mc:Choice>last</mc:Choice></mc:AlternateContent>");
                    if let Some(scanned) = super::scan_active_xml(&xml) {
                        assert_eq!(scanned, reference(&xml));
                    }
                }
            }
        }
        assert!(super::scan_active_xml("<mc:AlternateContent><mc:Choice>one</mc:Choice></mc:AlternateContent>").is_some());
    }
}

#[cfg(test)]
mod sparse_encoding_tests {
    #[test]
    fn all_scalar_values_survive_encoded_and_unchanged_boundaries() {
        use std::fmt::Write;
        for scalar in (0..=0x10ffff).filter_map(char::from_u32) {
            let text = format!("a{scalar}%{scalar}z");
            let mut expected = String::from("data:image/svg+xml;charset=utf-8,");
            for byte in text.bytes() {
                if byte.is_ascii_alphanumeric() || b"-_.~".contains(&byte) {
                    expected.push(byte as char);
                } else {
                    write!(expected, "%{byte:02X}").unwrap();
                }
            }
            assert_eq!(super::svg_data_uri(&text), expected);
        }
    }

    #[test]
    fn long_runs_and_xml_escaping_preserve_exact_bytes() {
        let run = "AZaz09-_.~".repeat(10000);
        assert_eq!(super::svg_data_uri(&run), format!("data:image/svg+xml;charset=utf-8,{run}"));
        let text = format!("{run}é{run}%");
        assert_eq!(super::svg_data_uri(&text), format!("data:image/svg+xml;charset=utf-8,{run}%C3%A9{run}%25"));
        assert_eq!(super::escape_xml_text(&run), run);
        assert_eq!(super::escape_xml_text("a&<>\"'é\r\n"), "a&amp;&lt;&gt;&quot;&apos;é\r\n");
        assert_eq!(super::escape_xml_text("é\r\n"), "é\r\n");
    }
}