#[cfg(test)]
use std::cell::Cell;
use ratatui::style::{Modifier, Style};
use ratatui::text::{Line, Span};
use unicode_width::{UnicodeWidthChar, UnicodeWidthStr};
use crate::palette;
use crate::tui::osc8;
#[cfg(test)]
thread_local! {
static PARSE_INVOCATIONS: Cell<u64> = const { Cell::new(0) };
}
#[cfg(test)]
#[must_use]
pub fn parse_invocation_count() -> u64 {
PARSE_INVOCATIONS.with(|c| c.get())
}
#[cfg(test)]
pub fn reset_parse_invocation_count() {
PARSE_INVOCATIONS.with(|c| c.set(0));
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum Block {
Heading { level: usize, text: String },
HeadingRule,
HorizontalRule,
ListItem { bullet: String, text: String },
Code { line: String },
TableRow(Vec<String>),
Paragraph { text: String },
Blank,
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct ParsedMarkdown {
blocks: Vec<Block>,
}
#[must_use]
pub fn parse(content: &str) -> ParsedMarkdown {
#[cfg(test)]
PARSE_INVOCATIONS.with(|c| c.set(c.get() + 1));
let mut blocks = Vec::new();
let mut in_code_block = false;
for raw_line in content.lines() {
let trimmed = raw_line.trim_start();
if trimmed.starts_with("```") {
in_code_block = !in_code_block;
continue;
}
if in_code_block {
blocks.push(Block::Code {
line: raw_line.to_string(),
});
continue;
}
if let Some((level, text)) = parse_heading(trimmed) {
blocks.push(Block::Heading {
level,
text: text.to_string(),
});
if level == 1 {
blocks.push(Block::HeadingRule);
}
continue;
}
if let Some((bullet, text)) = parse_list_item(trimmed) {
blocks.push(Block::ListItem {
bullet,
text: text.to_string(),
});
continue;
}
if is_horizontal_rule(trimmed) {
blocks.push(Block::HorizontalRule);
continue;
}
match parse_table_row(trimmed) {
Some(cells) => {
blocks.push(Block::TableRow(cells));
continue;
}
None if trimmed.starts_with('|') => continue, None => {}
}
if raw_line.is_empty() {
blocks.push(Block::Blank);
continue;
}
blocks.push(Block::Paragraph {
text: trimmed.to_string(),
});
}
ParsedMarkdown { blocks }
}
#[must_use]
pub fn render_parsed(parsed: &ParsedMarkdown, width: u16, base_style: Style) -> Vec<Line<'static>> {
let width = width.max(1) as usize;
let mut out: Vec<Line<'static>> = Vec::with_capacity(parsed.blocks.len());
for block in &parsed.blocks {
match block {
Block::Heading { text, .. } => {
let style = Style::default()
.fg(palette::DEEPSEEK_SKY)
.add_modifier(Modifier::BOLD);
out.extend(render_wrapped_line(text, width, style, false));
}
Block::HeadingRule => {
out.push(Line::from(Span::styled(
"─".repeat(width.min(40)),
Style::default().fg(palette::TEXT_DIM),
)));
}
Block::HorizontalRule => {
out.push(Line::from(Span::styled(
"─".repeat(width.min(60)),
Style::default().fg(palette::TEXT_DIM),
)));
}
Block::TableRow(cells) => {
out.extend(render_table_row(cells, width, base_style));
}
Block::ListItem { bullet, text } => {
let bullet_style = Style::default().fg(palette::DEEPSEEK_SKY);
out.extend(render_list_line(
bullet,
text,
width,
bullet_style,
base_style,
));
}
Block::Code { line } => {
let code_style = Style::default()
.fg(palette::DEEPSEEK_SKY)
.add_modifier(Modifier::ITALIC);
out.extend(render_wrapped_line(line, width, code_style, true));
}
Block::Paragraph { text } => {
let link_style = Style::default()
.fg(palette::DEEPSEEK_BLUE)
.add_modifier(Modifier::UNDERLINED);
out.extend(render_line_with_links(text, width, base_style, link_style));
}
Block::Blank => {
out.push(Line::from(""));
}
}
}
if out.is_empty() {
out.push(Line::from(""));
}
out
}
#[must_use]
pub fn render_markdown(content: &str, width: u16, base_style: Style) -> Vec<Line<'static>> {
let parsed = parse(content);
render_parsed(&parsed, width, base_style)
}
fn parse_heading(line: &str) -> Option<(usize, &str)> {
let trimmed = line.trim_start();
let hashes = trimmed.chars().take_while(|c| *c == '#').count();
if hashes == 0 {
return None;
}
let text = trimmed[hashes..].trim();
if text.is_empty() {
None
} else {
Some((hashes, text))
}
}
fn parse_list_item(line: &str) -> Option<(String, &str)> {
let trimmed = line.trim_start();
if trimmed.starts_with("- ") || trimmed.starts_with("* ") {
return Some(("-".to_string(), trimmed[2..].trim()));
}
let bytes = trimmed.as_bytes();
let mut idx = 0;
while idx < bytes.len() && bytes[idx].is_ascii_digit() {
idx += 1;
}
if idx == 0 || idx >= bytes.len() || bytes[idx] != b'.' {
return None;
}
let rest = &trimmed[idx + 1..];
if !rest.starts_with(' ') {
return None;
}
Some((format!("{}.", &trimmed[..idx]), rest.trim_start()))
}
fn render_wrapped_line(
line: &str,
width: usize,
style: Style,
indent_code: bool,
) -> Vec<Line<'static>> {
let prefix = if indent_code { " " } else { "" };
let prefix_width = prefix.width();
let available = width.saturating_sub(prefix_width).max(1);
let wrapped = wrap_text(line, available);
let mut out = Vec::new();
for (idx, chunk) in wrapped.into_iter().enumerate() {
if idx == 0 {
out.push(Line::from(vec![
Span::raw(prefix),
Span::styled(chunk, style),
]));
} else {
out.push(Line::from(vec![
Span::raw(" ".repeat(prefix_width)),
Span::styled(chunk, style),
]));
}
}
out
}
fn render_list_line(
bullet: &str,
text: &str,
width: usize,
bullet_style: Style,
text_style: Style,
) -> Vec<Line<'static>> {
let bullet_prefix = format!("{bullet} ");
let bullet_width = bullet_prefix.width();
let available = width.saturating_sub(bullet_width).max(1);
let wrapped = render_line_with_links(text, available, text_style, link_style());
let mut out = Vec::new();
for (idx, line) in wrapped.into_iter().enumerate() {
if idx == 0 {
let mut spans = vec![Span::styled(bullet_prefix.clone(), bullet_style)];
spans.extend(line.spans);
out.push(Line::from(spans));
} else {
let mut spans = vec![Span::raw(" ".repeat(bullet_width))];
spans.extend(line.spans);
out.push(Line::from(spans));
}
}
out
}
fn render_line_with_links(
line: &str,
width: usize,
base_style: Style,
link_style: Style,
) -> Vec<Line<'static>> {
if line.trim().is_empty() {
return vec![Line::from("")];
}
let tokens = parse_inline_spans(line, base_style, link_style);
let mut words: Vec<(String, Style)> = Vec::new();
for (text, style) in tokens {
let mut first = true;
for part in text.split(' ') {
if !first {
words.push((" ".to_string(), style));
}
if !part.is_empty() {
words.push((part.to_string(), style));
}
first = false;
}
}
let mut lines = Vec::new();
let mut current_spans: Vec<Span> = Vec::new();
let mut current_width = 0usize;
for (word, style) in words {
let ww = word.width();
if word == " " {
if !current_spans.is_empty() && current_width < width {
current_spans.push(Span::raw(" "));
current_width += 1;
}
continue;
}
if current_width > 0 && current_width + ww > width {
if let Some(last) = current_spans.last()
&& last.content.as_ref() == " "
{
current_spans.pop();
}
lines.push(Line::from(current_spans));
current_spans = Vec::new();
current_width = 0;
}
current_spans.push(Span::styled(word, style));
current_width += ww;
}
if !current_spans.is_empty() {
lines.push(Line::from(current_spans));
}
if lines.is_empty() {
lines.push(Line::from(""));
}
lines
}
fn parse_inline_spans(line: &str, base_style: Style, link_style: Style) -> Vec<(String, Style)> {
let bold_style = base_style.add_modifier(Modifier::BOLD);
let italic_style = base_style.add_modifier(Modifier::ITALIC);
let mut out = Vec::new();
let mut rest = line;
while !rest.is_empty() {
if let Some(end) = rest.strip_prefix("**").and_then(|s| s.find("**")) {
let inner = &rest[2..2 + end];
out.push((inner.to_string(), bold_style));
rest = &rest[2 + end + 2..];
continue;
}
if let Some(end) = rest.strip_prefix("__").and_then(|s| s.find("__")) {
let inner = &rest[2..2 + end];
out.push((inner.to_string(), bold_style));
rest = &rest[2 + end + 2..];
continue;
}
if rest.starts_with('*')
&& !rest.starts_with("**")
&& let Some(end) = rest[1..].find('*')
{
let inner = &rest[1..1 + end];
out.push((inner.to_string(), italic_style));
rest = &rest[1 + end + 1..];
continue;
}
if rest.starts_with('_')
&& !rest.starts_with("__")
&& let Some(end) = rest[1..].find('_')
{
let inner = &rest[1..1 + end];
out.push((inner.to_string(), italic_style));
rest = &rest[1 + end + 1..];
continue;
}
if rest.starts_with("http://") || rest.starts_with("https://") {
let end = rest.find(char::is_whitespace).unwrap_or(rest.len());
let url = &rest[..end];
let content = if osc8::enabled() {
osc8::wrap_link(url, url)
} else {
url.to_string()
};
out.push((content, link_style));
rest = &rest[end..];
continue;
}
let next = find_next_marker(rest).max(rest.chars().next().map_or(1, |c| c.len_utf8()));
out.push((rest[..next].to_string(), base_style));
rest = &rest[next..];
}
out
}
fn find_next_marker(s: &str) -> usize {
let mut i = 0;
let bytes = s.as_bytes();
while i < bytes.len() {
let ch_len = s[i..].chars().next().map_or(1, |c| c.len_utf8());
let slice = &s[i..];
if slice.starts_with("**")
|| slice.starts_with("__")
|| (slice.starts_with('*') && !slice.starts_with("**"))
|| (slice.starts_with('_') && !slice.starts_with("__"))
|| slice.starts_with("http://")
|| slice.starts_with("https://")
{
return i;
}
i += ch_len;
}
s.len()
}
fn is_horizontal_rule(line: &str) -> bool {
let stripped: String = line.chars().filter(|c| !c.is_whitespace()).collect();
(stripped.chars().all(|c| c == '-')
|| stripped.chars().all(|c| c == '*')
|| stripped.chars().all(|c| c == '_'))
&& stripped.len() >= 3
}
fn parse_table_row(line: &str) -> Option<Vec<String>> {
if !line.starts_with('|') {
return None;
}
let inner = line.trim_matches('|');
let cells: Vec<String> = inner.split('|').map(|c| c.trim().to_string()).collect();
if cells
.iter()
.all(|c| c.is_empty() || c.chars().all(|ch| ch == '-' || ch == ':' || ch == ' '))
{
return None;
}
Some(cells)
}
fn render_table_row(cells: &[String], width: usize, base_style: Style) -> Vec<Line<'static>> {
if cells.is_empty() {
return vec![Line::from("")];
}
let col_width = (width.saturating_sub(3 * cells.len() + 1)) / cells.len();
let col_width = col_width.max(4);
let sep_style = Style::default().fg(palette::TEXT_DIM);
let mut spans: Vec<Span> = vec![Span::styled("│ ".to_string(), sep_style)];
for (i, cell) in cells.iter().enumerate() {
let truncated = if cell.width() > col_width {
let mut s = String::new();
let mut w = 0;
for ch in cell.chars() {
let cw = ch.width().unwrap_or(1);
if w + cw + 1 > col_width {
s.push('…');
break;
}
s.push(ch);
w += cw;
}
s
} else {
cell.clone()
};
let cell_spans: Vec<(String, Style)> =
parse_inline_spans(&truncated, base_style, link_style());
let cell_width: usize = cell_spans.iter().map(|(t, _)| t.width()).sum();
let pad = col_width.saturating_sub(cell_width);
for (text, style) in cell_spans {
spans.push(Span::styled(text, style));
}
spans.push(Span::raw(" ".repeat(pad)));
if i + 1 < cells.len() {
spans.push(Span::styled(" │ ".to_string(), sep_style));
} else {
spans.push(Span::styled(" │".to_string(), sep_style));
}
}
vec![Line::from(spans)]
}
fn link_style() -> Style {
Style::default()
.fg(palette::DEEPSEEK_BLUE)
.add_modifier(Modifier::UNDERLINED)
}
fn wrap_text(text: &str, width: usize) -> Vec<String> {
if width == 0 {
return vec![text.to_string()];
}
let mut lines = Vec::new();
let mut current = String::new();
let mut current_width = 0;
for word in text.split_whitespace() {
let word_width = word.width();
let additional = if current.is_empty() {
word_width
} else {
word_width + 1
};
if current_width + additional > width && !current.is_empty() {
lines.push(current);
current = word.to_string();
current_width = word_width;
} else {
if !current.is_empty() {
current.push(' ');
current_width += 1;
}
current.push_str(word);
current_width += word_width;
}
}
if current.is_empty() {
lines.push(String::new());
} else {
lines.push(current);
}
lines
}
#[cfg(test)]
mod tests {
use super::*;
use ratatui::style::Style;
#[test]
fn render_markdown_matches_parse_then_render() {
let source = "# Title\n\nA paragraph with a https://example.com link.\n\n- one\n- two\n```\ncode\n```";
let direct = render_with_osc8(false, source);
let two_step = {
use std::sync::Mutex;
static OSC8_GUARD: Mutex<()> = Mutex::new(());
let _guard = OSC8_GUARD.lock().unwrap_or_else(|e| e.into_inner());
let prior = osc8::enabled();
osc8::set_enabled(false);
let parsed = parse(source);
let result: String = render_parsed(&parsed, 80, Style::default())
.iter()
.flat_map(|l| l.spans.iter().map(|s| s.content.as_ref()))
.collect();
osc8::set_enabled(prior);
result
};
assert_eq!(direct, two_step);
}
#[test]
fn parse_is_width_independent() {
let source = "Hello\n\n## Heading\n- list\n";
let a = parse(source);
let b = parse(source);
assert_eq!(a, b);
}
#[test]
fn render_parsed_word_wrap_changes_with_width() {
let parsed = parse("alpha beta gamma delta epsilon zeta");
let wide = render_parsed(&parsed, 80, Style::default());
let narrow = render_parsed(&parsed, 10, Style::default());
assert!(
narrow.len() > wide.len(),
"narrow should produce more lines"
);
}
#[test]
fn parse_invocations_increment() {
reset_parse_invocation_count();
let _ = parse("hello\n");
let _ = parse("world\n");
assert_eq!(parse_invocation_count(), 2);
}
#[test]
fn render_parsed_does_not_call_parse() {
let parsed = parse("multiline\nsource\nwith several\nlines\n");
reset_parse_invocation_count();
let _ = render_parsed(&parsed, 80, Style::default());
let _ = render_parsed(&parsed, 40, Style::default());
let _ = render_parsed(&parsed, 20, Style::default());
assert_eq!(
parse_invocation_count(),
0,
"render_parsed must not call parse"
);
}
#[test]
fn fenced_code_block_collected_in_parse() {
let parsed = parse("text\n```\ncode line one\ncode line two\n```\nmore\n");
let blocks = &parsed.blocks;
let code_lines: Vec<_> = blocks
.iter()
.filter_map(|b| match b {
Block::Code { line } => Some(line.as_str()),
_ => None,
})
.collect();
assert_eq!(code_lines, vec!["code line one", "code line two"]);
}
#[test]
fn ordered_and_unordered_list_items_parse() {
let parsed = parse("- alpha\n* beta\n1. gamma\n");
let items: Vec<_> = parsed
.blocks
.iter()
.filter_map(|b| match b {
Block::ListItem { bullet, text } => Some((bullet.as_str(), text.as_str())),
_ => None,
})
.collect();
assert_eq!(items, vec![("-", "alpha"), ("-", "beta"), ("1.", "gamma")]);
}
fn render_with_osc8(enabled: bool, source: &str) -> String {
use std::sync::Mutex;
static OSC8_GUARD: Mutex<()> = Mutex::new(());
let _guard = OSC8_GUARD.lock().unwrap_or_else(|e| e.into_inner());
let prior = osc8::enabled();
osc8::set_enabled(enabled);
let lines = render_markdown(source, 80, Style::default());
let joined = lines
.iter()
.flat_map(|l| l.spans.iter().map(|s| s.content.as_ref()))
.collect::<String>();
osc8::set_enabled(prior);
joined
}
#[test]
fn http_links_get_osc_8_wrapped_when_enabled() {
let joined = render_with_osc8(true, "see https://example.com for details");
assert!(
joined.contains("\x1b]8;;https://example.com\x1b\\https://example.com\x1b]8;;\x1b\\"),
"expected OSC 8 wrapper around URL; got {joined:?}"
);
}
#[test]
fn osc_8_disabled_emits_plain_url() {
let joined = render_with_osc8(false, "see https://example.com for details");
assert!(
!joined.contains("\x1b]8;;"),
"expected no OSC 8 wrapper when disabled; got {joined:?}"
);
assert!(joined.contains("https://example.com"));
}
#[test]
fn table_separator_row_is_dropped() {
let src = "| 项目属性 | 详情 |\n|----------|------|\n| **语言** | Rust 1.85+ |\n";
let parsed = parse(src);
let blocks: Vec<_> = parsed.blocks.iter().collect();
let table_rows: Vec<_> = blocks
.iter()
.filter(|b| matches!(b, Block::TableRow(_)))
.collect();
assert_eq!(
table_rows.len(),
2,
"expected 2 table rows, got {}: {blocks:?}",
table_rows.len()
);
}
#[test]
fn bold_markers_stripped_in_render() {
let src = "这是一个 **Rust 工作区项目**,包含多个 crate。\n";
let lines = render_markdown(src, 80, Style::default());
let text: String = lines
.iter()
.flat_map(|l| l.spans.iter().map(|s| s.content.as_ref()))
.collect();
assert!(
!text.contains("**"),
"bold markers leaked into output: {text:?}"
);
assert!(text.contains("Rust"), "bold content missing: {text:?}");
}
#[test]
fn table_renders_with_pipe_separator() {
let src = "| 文件 | 改动 |\n|---|---|\n| foo.rs | 重写 |\n";
let lines = render_markdown(src, 60, Style::default());
let text: String = lines
.iter()
.flat_map(|l| l.spans.iter().map(|s| s.content.as_ref()))
.collect();
assert!(text.contains('│'), "table pipe separator missing: {text:?}");
assert!(!text.contains("|---|"), "separator row leaked: {text:?}");
}
}