use std::{
collections::{HashMap, HashSet},
fmt::Write,
fs,
io::{self, Write as _},
path::{self, Path, PathBuf},
str,
sync::{atomic::AtomicUsize, Arc},
time::Instant,
};
use ansi_colours::{ansi256_from_rgb, rgb_from_ansi256};
use anstyle::{Ansi256Color, AnsiColor, Color, Effects, RgbColor};
use anyhow::Result;
use serde::{ser::SerializeMap, Deserialize, Deserializer, Serialize, Serializer};
use serde_json::{json, Value};
use tree_sitter_highlight::{HighlightConfiguration, HighlightEvent, Highlighter, HtmlRenderer};
use tree_sitter_loader::Loader;
pub const HTML_HEAD_HEADER: &str = "
<!doctype HTML>
<head>
<title>Tree-sitter Highlighting</title>
<style>
body {
font-family: monospace
}
.line-number {
user-select: none;
text-align: right;
color: rgba(27,31,35,.3);
padding: 0 10px;
}
.line {
white-space: pre;
}
</style>";
pub const HTML_BODY_HEADER: &str = "
</head>
<body>
";
pub const HTML_FOOTER: &str = "
</body>
";
#[derive(Debug, Default)]
pub struct Style {
pub ansi: anstyle::Style,
pub css: Option<String>,
}
#[derive(Debug)]
pub struct Theme {
pub styles: Vec<Style>,
pub highlight_names: Vec<String>,
}
#[derive(Default, Deserialize, Serialize)]
pub struct ThemeConfig {
#[serde(default)]
pub theme: Theme,
}
impl Theme {
pub fn load(path: &path::Path) -> io::Result<Self> {
let json = fs::read_to_string(path)?;
Ok(serde_json::from_str(&json).unwrap_or_default())
}
#[must_use]
pub fn default_style(&self) -> Style {
Style::default()
}
}
impl<'de> Deserialize<'de> for Theme {
fn deserialize<D>(deserializer: D) -> std::result::Result<Self, D::Error>
where
D: Deserializer<'de>,
{
let mut styles = Vec::new();
let mut highlight_names = Vec::new();
if let Ok(colors) = HashMap::<String, Value>::deserialize(deserializer) {
highlight_names.reserve(colors.len());
styles.reserve(colors.len());
for (name, style_value) in colors {
let mut style = Style::default();
parse_style(&mut style, style_value);
highlight_names.push(name);
styles.push(style);
}
}
Ok(Self {
styles,
highlight_names,
})
}
}
impl Serialize for Theme {
fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
where
S: Serializer,
{
let mut map = serializer.serialize_map(Some(self.styles.len()))?;
for (name, style) in self.highlight_names.iter().zip(&self.styles) {
let style = &style.ansi;
let color = style.get_fg_color().map(|color| match color {
Color::Ansi(color) => match color {
AnsiColor::Black => json!("black"),
AnsiColor::Blue => json!("blue"),
AnsiColor::Cyan => json!("cyan"),
AnsiColor::Green => json!("green"),
AnsiColor::Magenta => json!("purple"),
AnsiColor::Red => json!("red"),
AnsiColor::White => json!("white"),
AnsiColor::Yellow => json!("yellow"),
_ => unreachable!(),
},
Color::Ansi256(Ansi256Color(n)) => json!(n),
Color::Rgb(RgbColor(r, g, b)) => json!(format!("#{r:x?}{g:x?}{b:x?}")),
});
let effects = style.get_effects();
if effects.contains(Effects::BOLD)
|| effects.contains(Effects::ITALIC)
|| effects.contains(Effects::UNDERLINE)
{
let mut style_json = HashMap::new();
if let Some(color) = color {
style_json.insert("color", color);
}
if effects.contains(Effects::BOLD) {
style_json.insert("bold", Value::Bool(true));
}
if effects.contains(Effects::ITALIC) {
style_json.insert("italic", Value::Bool(true));
}
if effects.contains(Effects::UNDERLINE) {
style_json.insert("underline", Value::Bool(true));
}
map.serialize_entry(&name, &style_json)?;
} else if let Some(color) = color {
map.serialize_entry(&name, &color)?;
} else {
map.serialize_entry(&name, &Value::Null)?;
}
}
map.end()
}
}
impl Default for Theme {
fn default() -> Self {
serde_json::from_value(json!({
"attribute": {"color": 124, "italic": true},
"comment": {"color": 245, "italic": true},
"constant": 94,
"constant.builtin": {"color": 94, "bold": true},
"constructor": 136,
"embedded": null,
"function": 26,
"function.builtin": {"color": 26, "bold": true},
"keyword": 56,
"module": 136,
"number": {"color": 94, "bold": true},
"operator": {"color": 239, "bold": true},
"property": 124,
"property.builtin": {"color": 124, "bold": true},
"punctuation": 239,
"punctuation.bracket": 239,
"punctuation.delimiter": 239,
"punctuation.special": 239,
"string": 28,
"string.special": 30,
"tag": 18,
"type": 23,
"type.builtin": {"color": 23, "bold": true},
"variable": 252,
"variable.builtin": {"color": 252, "bold": true},
"variable.parameter": {"color": 252, "underline": true}
}))
.unwrap()
}
}
fn parse_style(style: &mut Style, json: Value) {
if let Value::Object(entries) = json {
for (property_name, value) in entries {
match property_name.as_str() {
"bold" => {
if value == Value::Bool(true) {
style.ansi = style.ansi.bold();
}
}
"italic" => {
if value == Value::Bool(true) {
style.ansi = style.ansi.italic();
}
}
"underline" => {
if value == Value::Bool(true) {
style.ansi = style.ansi.underline();
}
}
"color" => {
if let Some(color) = parse_color(value) {
style.ansi = style.ansi.fg_color(Some(color));
}
}
_ => {}
}
}
style.css = Some(style_to_css(style.ansi));
} else if let Some(color) = parse_color(json) {
style.ansi = style.ansi.fg_color(Some(color));
style.css = Some(style_to_css(style.ansi));
} else {
style.css = None;
}
if let Some(Color::Rgb(RgbColor(red, green, blue))) = style.ansi.get_fg_color() {
if !terminal_supports_truecolor() {
let ansi256 = Color::Ansi256(Ansi256Color(ansi256_from_rgb((red, green, blue))));
style.ansi = style.ansi.fg_color(Some(ansi256));
}
}
}
fn parse_color(json: Value) -> Option<Color> {
match json {
Value::Number(n) => n.as_u64().map(|n| Color::Ansi256(Ansi256Color(n as u8))),
Value::String(s) => match s.to_lowercase().as_str() {
"black" => Some(Color::Ansi(AnsiColor::Black)),
"blue" => Some(Color::Ansi(AnsiColor::Blue)),
"cyan" => Some(Color::Ansi(AnsiColor::Cyan)),
"green" => Some(Color::Ansi(AnsiColor::Green)),
"purple" => Some(Color::Ansi(AnsiColor::Magenta)),
"red" => Some(Color::Ansi(AnsiColor::Red)),
"white" => Some(Color::Ansi(AnsiColor::White)),
"yellow" => Some(Color::Ansi(AnsiColor::Yellow)),
s => {
if let Some((red, green, blue)) = hex_string_to_rgb(s) {
Some(Color::Rgb(RgbColor(red, green, blue)))
} else {
None
}
}
},
_ => None,
}
}
fn hex_string_to_rgb(s: &str) -> Option<(u8, u8, u8)> {
if s.starts_with('#') && s.len() >= 7 {
if let (Ok(red), Ok(green), Ok(blue)) = (
u8::from_str_radix(&s[1..3], 16),
u8::from_str_radix(&s[3..5], 16),
u8::from_str_radix(&s[5..7], 16),
) {
Some((red, green, blue))
} else {
None
}
} else {
None
}
}
fn style_to_css(style: anstyle::Style) -> String {
let mut result = String::new();
let effects = style.get_effects();
if effects.contains(Effects::UNDERLINE) {
write!(&mut result, "text-decoration: underline;").unwrap();
}
if effects.contains(Effects::BOLD) {
write!(&mut result, "font-weight: bold;").unwrap();
}
if effects.contains(Effects::ITALIC) {
write!(&mut result, "font-style: italic;").unwrap();
}
if let Some(color) = style.get_fg_color() {
write_color(&mut result, color);
}
result
}
fn write_color(buffer: &mut String, color: Color) {
match color {
Color::Ansi(color) => match color {
AnsiColor::Black => write!(buffer, "color: black").unwrap(),
AnsiColor::Red => write!(buffer, "color: red").unwrap(),
AnsiColor::Green => write!(buffer, "color: green").unwrap(),
AnsiColor::Yellow => write!(buffer, "color: yellow").unwrap(),
AnsiColor::Blue => write!(buffer, "color: blue").unwrap(),
AnsiColor::Magenta => write!(buffer, "color: purple").unwrap(),
AnsiColor::Cyan => write!(buffer, "color: cyan").unwrap(),
AnsiColor::White => write!(buffer, "color: white").unwrap(),
_ => unreachable!(),
},
Color::Ansi256(Ansi256Color(n)) => {
let (r, g, b) = rgb_from_ansi256(n);
write!(buffer, "color: #{r:02x}{g:02x}{b:02x}").unwrap();
}
Color::Rgb(RgbColor(r, g, b)) => write!(buffer, "color: #{r:02x}{g:02x}{b:02x}").unwrap(),
}
}
fn terminal_supports_truecolor() -> bool {
std::env::var("COLORTERM")
.is_ok_and(|truecolor| truecolor == "truecolor" || truecolor == "24bit")
}
pub struct HighlightOptions {
pub theme: Theme,
pub check: bool,
pub captures_path: Option<PathBuf>,
pub inline_styles: bool,
pub html: bool,
pub quiet: bool,
pub print_time: bool,
pub cancellation_flag: Arc<AtomicUsize>,
}
pub fn highlight(
loader: &Loader,
path: &Path,
name: &str,
config: &HighlightConfiguration,
print_name: bool,
opts: &HighlightOptions,
) -> Result<()> {
if opts.check {
let names = if let Some(path) = opts.captures_path.as_deref() {
let file = fs::read_to_string(path)?;
let capture_names = file
.lines()
.filter_map(|line| {
if line.trim().is_empty() || line.trim().starts_with(';') {
return None;
}
line.split(';').next().map(|s| s.trim().trim_matches('"'))
})
.collect::<HashSet<_>>();
config.nonconformant_capture_names(&capture_names)
} else {
config.nonconformant_capture_names(&HashSet::new())
};
if names.is_empty() {
eprintln!("All highlight captures conform to standards.");
} else {
eprintln!(
"Non-standard highlight {} detected:",
if names.len() > 1 {
"captures"
} else {
"capture"
}
);
for name in names {
eprintln!("* {name}");
}
}
}
let source = fs::read(path)?;
let stdout = io::stdout();
let mut stdout = stdout.lock();
let time = Instant::now();
let mut highlighter = Highlighter::new();
let events =
highlighter.highlight(config, &source, Some(&opts.cancellation_flag), |string| {
loader.highlight_config_for_injection_string(string)
})?;
let theme = &opts.theme;
if !opts.quiet && print_name {
writeln!(&mut stdout, "{name}")?;
}
if opts.html {
if !opts.quiet {
writeln!(&mut stdout, "{HTML_HEAD_HEADER}")?;
writeln!(&mut stdout, " <style>")?;
let names = theme.highlight_names.iter();
let styles = theme.styles.iter();
for (name, style) in names.zip(styles) {
if let Some(css) = &style.css {
writeln!(&mut stdout, " .{name} {{ {css}; }}")?;
}
}
writeln!(&mut stdout, " </style>")?;
writeln!(&mut stdout, "{HTML_BODY_HEADER}")?;
}
let mut renderer = HtmlRenderer::new();
renderer.render(events, &source, &move |highlight, output| {
if opts.inline_styles {
output.extend(b"style='");
output.extend(
theme.styles[highlight.0]
.css
.as_ref()
.map_or_else(|| "".as_bytes(), |css_style| css_style.as_bytes()),
);
output.extend(b"'");
} else {
output.extend(b"class='");
let mut parts = theme.highlight_names[highlight.0].split('.').peekable();
while let Some(part) = parts.next() {
output.extend(part.as_bytes());
if parts.peek().is_some() {
output.extend(b" ");
}
}
output.extend(b"'");
}
})?;
if !opts.quiet {
writeln!(&mut stdout, "<table>")?;
for (i, line) in renderer.lines().enumerate() {
writeln!(
&mut stdout,
"<tr><td class=line-number>{}</td><td class=line>{line}</td></tr>",
i + 1,
)?;
}
writeln!(&mut stdout, "</table>")?;
writeln!(&mut stdout, "{HTML_FOOTER}")?;
}
} else {
let mut style_stack = vec![theme.default_style().ansi];
for event in events {
match event? {
HighlightEvent::HighlightStart(highlight) => {
style_stack.push(theme.styles[highlight.0].ansi);
}
HighlightEvent::HighlightEnd => {
style_stack.pop();
}
HighlightEvent::Source { start, end } => {
let style = style_stack.last().unwrap();
write!(&mut stdout, "{style}").unwrap();
stdout.write_all(&source[start..end])?;
write!(&mut stdout, "{style:#}").unwrap();
}
}
}
}
if opts.print_time {
eprintln!("Time: {}ms", time.elapsed().as_millis());
}
Ok(())
}
#[cfg(test)]
mod tests {
use std::env;
use super::*;
const JUNGLE_GREEN: &str = "#26A69A";
const DARK_CYAN: &str = "#00AF87";
#[test]
fn test_parse_style() {
let original_environment_variable = env::var("COLORTERM");
let mut style = Style::default();
assert_eq!(style.ansi.get_fg_color(), None);
assert_eq!(style.css, None);
env::set_var("COLORTERM", "");
parse_style(&mut style, Value::String(DARK_CYAN.to_string()));
assert_eq!(
style.ansi.get_fg_color(),
Some(Color::Ansi256(Ansi256Color(36)))
);
assert_eq!(style.css, Some("color: #00af87".to_string()));
env::set_var("COLORTERM", "truecolor");
parse_style(&mut style, Value::String(JUNGLE_GREEN.to_string()));
assert_eq!(
style.ansi.get_fg_color(),
Some(Color::Rgb(RgbColor(38, 166, 154)))
);
assert_eq!(style.css, Some("color: #26a69a".to_string()));
env::set_var("COLORTERM", "");
parse_style(&mut style, Value::String(JUNGLE_GREEN.to_string()));
assert_eq!(
style.ansi.get_fg_color(),
Some(Color::Ansi256(Ansi256Color(72)))
);
assert_eq!(style.css, Some("color: #26a69a".to_string()));
if let Ok(environment_variable) = original_environment_variable {
env::set_var("COLORTERM", environment_variable);
} else {
env::remove_var("COLORTERM");
}
}
}