| 1 | //! todo-md parsing and kanban rendering. |
| 2 | //! |
| 3 | //! Implements the todo-md spec (the `todo-md` repo): a `TODO.md` is split |
| 4 | //! into sections by ATX headings; `- [ ]` / `- [x]` list items in a section |
| 5 | //! are tasks; lines indented under a task are its details (opaque markdown). |
| 6 | //! A heading containing `[x]` marks a done section — every task in it counts |
| 7 | //! as done. Sections that contain tasks render as kanban columns; prose-only |
| 8 | //! sections render as ordinary markdown below the board. |
| 9 | //! |
| 10 | //! This module is the first "custom renderer" for a well-known filename; |
| 11 | //! `ui::custom_renderer` is the registry that routes filenames here. |
| 12 | |
| 13 | use maud::{ |
| 14 | Markup, |
| 15 | html, |
| 16 | }; |
| 17 | |
| 18 | use crate::ui::render_markdown; |
| 19 | |
| 20 | pub struct Section { |
| 21 | /// Heading level (1–6); 0 for the implicit preamble section. |
| 22 | pub level: u8, |
| 23 | /// Heading text with any `[x]` / `✓` done-marker stripped. |
| 24 | pub title: String, |
| 25 | /// Done section: tasks in it count as done regardless of their checkbox. |
| 26 | pub done: bool, |
| 27 | pub tasks: Vec<Task>, |
| 28 | /// Non-task content of the section, verbatim (used for the notes area). |
| 29 | pub prose: String, |
| 30 | } |
| 31 | |
| 32 | pub struct Task { |
| 33 | pub done: bool, |
| 34 | pub title: String, |
| 35 | /// Raw markdown block of nested/indented lines, dedented one level. |
| 36 | pub details: String, |
| 37 | } |
| 38 | |
| 39 | /// Whether a path names a `TODO.md` (any directory, any case). |
| 40 | pub fn is_todo_md(path: &str) -> bool { |
| 41 | std::path::Path::new(path) |
| 42 | .file_name() |
| 43 | .is_some_and(|n| n.eq_ignore_ascii_case("TODO.md")) |
| 44 | } |
| 45 | |
| 46 | /// Parse a todo-md document into sections. The preamble (content before the |
| 47 | /// first heading) becomes a level-0 section with an empty title. |
| 48 | pub fn parse(text: &str) -> Vec<Section> { |
| 49 | let mut sections = vec![Section { |
| 50 | level: 0, |
| 51 | title: String::new(), |
| 52 | done: false, |
| 53 | tasks: Vec::new(), |
| 54 | prose: String::new(), |
| 55 | }]; |
| 56 | let mut in_fence = false; |
| 57 | // Index into the current section's tasks while detail lines may still |
| 58 | // attach; None once a non-indented line ends the task block. |
| 59 | let mut open_task = false; |
| 60 | |
| 61 | for line in text.lines() { |
| 62 | let cur = sections.last_mut().expect("never empty"); |
| 63 | if line.trim_start().starts_with("```") { |
| 64 | in_fence = !in_fence; |
| 65 | } |
| 66 | if in_fence || line.trim_start().starts_with("```") { |
| 67 | // Fenced content is never structural. |
| 68 | append_line(cur, open_task, line); |
| 69 | continue; |
| 70 | } |
| 71 | |
| 72 | if let Some((level, rest)) = heading(line) { |
| 73 | let done = rest.contains("[x]") || rest.contains("[X]") || rest.contains('✓'); |
| 74 | let title = rest |
| 75 | .replace("[x]", "") |
| 76 | .replace("[X]", "") |
| 77 | .replace('✓', "") |
| 78 | .trim() |
| 79 | .to_string(); |
| 80 | sections.push(Section { |
| 81 | level, |
| 82 | title, |
| 83 | done, |
| 84 | tasks: Vec::new(), |
| 85 | prose: String::new(), |
| 86 | }); |
| 87 | open_task = false; |
| 88 | continue; |
| 89 | } |
| 90 | |
| 91 | if let Some((done, title)) = task_line(line) { |
| 92 | cur.tasks.push(Task { |
| 93 | done, |
| 94 | title: title.to_string(), |
| 95 | details: String::new(), |
| 96 | }); |
| 97 | open_task = true; |
| 98 | continue; |
| 99 | } |
| 100 | |
| 101 | // Indented (or blank) lines under a task are its details; anything |
| 102 | // else is section prose and closes the task block. |
| 103 | if open_task && !line.is_empty() && !line.starts_with(" ") { |
| 104 | open_task = false; |
| 105 | } |
| 106 | append_line(cur, open_task, line); |
| 107 | } |
| 108 | |
| 109 | for s in &mut sections { |
| 110 | if s.done { |
| 111 | for t in &mut s.tasks { |
| 112 | t.done = true; |
| 113 | } |
| 114 | } |
| 115 | for t in &mut s.tasks { |
| 116 | // Drop trailing blank lines swallowed while the task was open. |
| 117 | while t.details.ends_with('\n') { |
| 118 | t.details.pop(); |
| 119 | } |
| 120 | } |
| 121 | } |
| 122 | sections |
| 123 | } |
| 124 | |
| 125 | fn append_line(section: &mut Section, to_task: bool, line: &str) { |
| 126 | let target = if to_task { |
| 127 | let t = section.tasks.last_mut().expect("open task exists"); |
| 128 | &mut t.details |
| 129 | } else { |
| 130 | &mut section.prose |
| 131 | }; |
| 132 | // Dedent detail lines one level (2–4 spaces) so they render as their own |
| 133 | // markdown rather than a code block. |
| 134 | let line = if to_task { |
| 135 | let spaces = line.len() - line.trim_start_matches(' ').len(); |
| 136 | &line[spaces.min(4).min(line.len())..] |
| 137 | } else { |
| 138 | line |
| 139 | }; |
| 140 | target.push_str(line); |
| 141 | target.push('\n'); |
| 142 | } |
| 143 | |
| 144 | fn heading(line: &str) -> Option<(u8, &str)> { |
| 145 | let hashes = line.bytes().take_while(|&b| b == b'#').count(); |
| 146 | if (1..=6).contains(&hashes) && line[hashes..].starts_with(' ') { |
| 147 | Some((hashes as u8, line[hashes..].trim())) |
| 148 | } else { |
| 149 | None |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | fn task_line(line: &str) -> Option<(bool, &str)> { |
| 154 | let open = line.strip_prefix("- [ ] "); |
| 155 | let done = line.strip_prefix("- [x] ").or(line.strip_prefix("- [X] ")); |
| 156 | match (open, done) { |
| 157 | (Some(rest), _) => Some((false, rest.trim())), |
| 158 | (_, Some(rest)) => Some((true, rest.trim())), |
| 159 | _ => None, |
| 160 | } |
| 161 | } |
| 162 | |
| 163 | /// Render a todo-md document as a kanban board (columns = task-bearing |
| 164 | /// sections) with prose sections as a notes area below. `None` if the file |
| 165 | /// contains no tasks at all — callers fall back to plain markdown. |
| 166 | pub fn render_board(text: &str) -> Option<Markup> { |
| 167 | let sections = parse(text); |
| 168 | if sections.iter().all(|s| s.tasks.is_empty()) { |
| 169 | return None; |
| 170 | } |
| 171 | |
| 172 | // Prose-only sections (and stray preamble/column prose) become one |
| 173 | // markdown notes blob, headings preserved. |
| 174 | let mut notes = String::new(); |
| 175 | for s in §ions { |
| 176 | let prose_empty = s.prose.trim().is_empty(); |
| 177 | if s.tasks.is_empty() && s.level > 0 && prose_empty { |
| 178 | continue; // empty section: nothing to show either way |
| 179 | } |
| 180 | if s.tasks.is_empty() { |
| 181 | if s.level > 0 { |
| 182 | notes.push_str(&format!("{} {}\n", "#".repeat(s.level as usize), s.title)); |
| 183 | } |
| 184 | if !prose_empty { |
| 185 | notes.push_str(&s.prose); |
| 186 | notes.push('\n'); |
| 187 | } |
| 188 | } |
| 189 | } |
| 190 | |
| 191 | Some(html! { |
| 192 | div.kanban { |
| 193 | @for s in sections.iter().filter(|s| !s.tasks.is_empty()) { |
| 194 | div.col { |
| 195 | h3 { |
| 196 | @if s.title.is_empty() { "Tasks" } @else { (s.title) } |
| 197 | span.count { |
| 198 | @if s.done { |
| 199 | ({ s.tasks.len().to_string() }) " done" |
| 200 | } @else { |
| 201 | ({ s.tasks.iter().filter(|t| !t.done).count().to_string() }) |
| 202 | " open" |
| 203 | } |
| 204 | } |
| 205 | } |
| 206 | @for t in &s.tasks { |
| 207 | div.card.done[t.done] { |
| 208 | div.title { |
| 209 | input type="checkbox" disabled checked[t.done]; |
| 210 | span { (render_markdown(&t.title)) } |
| 211 | } |
| 212 | @if !t.details.trim().is_empty() { |
| 213 | details { |
| 214 | summary { "details" } |
| 215 | div.card-details { (render_markdown(&t.details)) } |
| 216 | } |
| 217 | } |
| 218 | } |
| 219 | } |
| 220 | } |
| 221 | } |
| 222 | } |
| 223 | @if !notes.trim().is_empty() { |
| 224 | details.todo-notes { |
| 225 | summary { "notes" } |
| 226 | div.md-body { (render_markdown(¬es)) } |
| 227 | } |
| 228 | } |
| 229 | }) |
| 230 | } |
| 231 | |
| 232 | #[cfg(test)] |
| 233 | mod tests { |
| 234 | use super::*; |
| 235 | |
| 236 | const DOC: &str = "\ |
| 237 | intro prose |
| 238 | |
| 239 | # Now |
| 240 | |
| 241 | - [ ] first task |
| 242 | - a detail line |
| 243 | - another `detail` |
| 244 | - [x] finished task |
| 245 | |
| 246 | # Done [x] |
| 247 | |
| 248 | - [ ] moved here, checkbox stale |
| 249 | |
| 250 | # Notes |
| 251 | |
| 252 | just prose, no tasks |
| 253 | |
| 254 | ``` |
| 255 | # not a heading |
| 256 | - [ ] not a task |
| 257 | ``` |
| 258 | "; |
| 259 | |
| 260 | #[test] |
| 261 | fn parses_sections_tasks_details() { |
| 262 | let s = parse(DOC); |
| 263 | assert_eq!(s.len(), 4); // preamble + 3 headings |
| 264 | assert_eq!(s[0].level, 0); |
| 265 | assert_eq!(s[0].prose.trim(), "intro prose"); |
| 266 | |
| 267 | assert_eq!(s[1].title, "Now"); |
| 268 | assert!(!s[1].done); |
| 269 | assert_eq!(s[1].tasks.len(), 2); |
| 270 | assert_eq!(s[1].tasks[0].title, "first task"); |
| 271 | assert!(!s[1].tasks[0].done); |
| 272 | assert_eq!(s[1].tasks[0].details, "- a detail line\n- another `detail`"); |
| 273 | assert!(s[1].tasks[1].done); |
| 274 | |
| 275 | // Done section: heading marker wins over the task's own checkbox. |
| 276 | assert_eq!(s[2].title, "Done"); |
| 277 | assert!(s[2].done); |
| 278 | assert!(s[2].tasks[0].done); |
| 279 | |
| 280 | // Fenced content is not structural. |
| 281 | assert_eq!(s[3].title, "Notes"); |
| 282 | assert!(s[3].tasks.is_empty()); |
| 283 | assert!(s[3].prose.contains("# not a heading")); |
| 284 | } |
| 285 | |
| 286 | #[test] |
| 287 | fn todo_md_by_filename() { |
| 288 | assert!(is_todo_md("TODO.md")); |
| 289 | assert!(is_todo_md("docs/todo.MD")); |
| 290 | assert!(!is_todo_md("TODO.txt")); |
| 291 | assert!(!is_todo_md("NOT-TODO.md")); |
| 292 | } |
| 293 | |
| 294 | #[test] |
| 295 | fn board_renders_columns_and_falls_back() { |
| 296 | let board = render_board(DOC).expect("has tasks").into_string(); |
| 297 | assert!(board.contains("kanban")); |
| 298 | assert!(board.contains("Now")); |
| 299 | assert!(board.contains("first task")); |
| 300 | assert!(board.contains("just prose"), "notes area kept: {board}"); |
| 301 | assert!(render_board("# readme\n\nonly prose\n").is_none()); |
| 302 | } |
| 303 | } |