From b6069d90e582299e8b0e566b9a260d44a14f007d Mon Sep 17 00:00:00 2001
From: ruohki <hi@till.md>
Date: Sat, 28 Feb 2026 22:20:35 +0100
Subject: [PATCH] =?UTF-8?q?docs(02-02):=20complete=20markdown=20renderer?=
 =?UTF-8?q?=20plan=20=E2=80=94=20REND-01=20through=20REND-10=20satisfied?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- 02-02-SUMMARY.md: documents render_markdown() pipeline, code block borders, GFM table grid, decisions, deviations
- STATE.md: advance to plan 02 done, update decisions log (02-02 entries), resolve REND Widget trait blocker
- ROADMAP.md: mark 02-02 complete (2/3 plans done for Phase 2)
---
 .planning/ROADMAP.md                          |   8 +-
 .planning/STATE.md                            |  31 ++--
 .../02-02-SUMMARY.md                          | 134 ++++++++++++++++++
 3 files changed, 155 insertions(+), 18 deletions(-)
 create mode 100644 .planning/phases/02-vault-core-and-rendering/02-02-SUMMARY.md

diff --git a/.planning/ROADMAP.md b/.planning/ROADMAP.md
index c4e457b..8046f74 100644
--- a/.planning/ROADMAP.md
+++ b/.planning/ROADMAP.md
@@ -45,10 +45,10 @@ Plans:
   3. User lands on index.md when the app starts; when index.md is missing, a readable error page is shown instead of a crash
   4. User can scroll content longer than the terminal with j/k, arrow keys, and PgUp/PgDn
   5. User sees keyboard hints in the status bar, box-drawing borders on panels, and a CGA-era retro color theme; the layout reflows correctly when the terminal is resized
-**Plans:** 3 plans
+**Plans:** 2/3 plans complete
 Plans:
-- [ ] 02-01-PLAN.md — Dependencies, vault file loading, and syntax highlighter
-- [ ] 02-02-PLAN.md — Markdown-to-styled-lines renderer (all constructs)
+- [x] 02-01-PLAN.md — Dependencies, vault file loading, and syntax highlighter
+- [x] 02-02-PLAN.md — Markdown-to-styled-lines renderer (all constructs)
 - [ ] 02-03-PLAN.md — App integration: scrolling, status bar, error screen, startup wiring
 
 ### Phase 3: Navigation and Links
@@ -82,6 +82,6 @@ Phases execute in numeric order: 1 → 2 → 3 → 4
 | Phase | Plans Complete | Status | Completed |
 |-------|----------------|--------|-----------|
 | 1. Safety Foundation | 3/3 | Complete    | 2026-02-28 |
-| 2. Vault Core and Rendering | 0/3 | Not started | - |
+| 2. Vault Core and Rendering | 2/3 | In Progress | - |
 | 3. Navigation and Links | 0/TBD | Not started | - |
 | 4. BBS Polish and Live Content | 0/TBD | Not started | - |
diff --git a/.planning/STATE.md b/.planning/STATE.md
index fedd3e5..6bf499e 100644
--- a/.planning/STATE.md
+++ b/.planning/STATE.md
@@ -5,33 +5,33 @@
 See: .planning/PROJECT.md (updated 2026-02-28)
 
 **Core value:** Users can connect via SSH and seamlessly browse a vault of linked markdown documents with retro BBS aesthetics
-**Current focus:** Phase 2 in progress — Plan 01 complete (vault core + highlighter foundation)
+**Current focus:** Phase 2 in progress — Plans 01-02 complete (vault core + highlighter + renderer)
 
 ## Current Position
 
 Phase: 2 of 4 (Vault Core and Rendering) — IN PROGRESS
-Plan: 1 of 3 in current phase (plan 01 done)
-Status: Phase 2 Plan 01 complete — Plan 02 (markdown renderer) next
-Last activity: 2026-02-28 — Plan 01 complete (deps, vault.rs, highlighter.rs)
+Plan: 2 of 3 in current phase (plans 01-02 done)
+Status: Phase 2 Plan 02 complete — Plan 03 (app integration + scrolling) next
+Last activity: 2026-02-28 — Plan 02 complete (renderer.rs with full markdown pipeline)
 
-Progress: [████░░░░░░] 33%
+Progress: [█████░░░░░] 50%
 
 ## Performance Metrics
 
 **Velocity:**
-- Total plans completed: 4
-- Average duration: 2.2 min
-- Total execution time: 0.14 hours
+- Total plans completed: 5
+- Average duration: 2.6 min
+- Total execution time: 0.21 hours
 
 **By Phase:**
 
 | Phase | Plans | Total | Avg/Plan |
 |-------|-------|-------|----------|
 | 01-safety-foundation | 3 | 7 min | 2.3 min |
-| 02-vault-core-and-rendering | 1 | 2 min | 2.0 min |
+| 02-vault-core-and-rendering | 2 | 6 min | 3.0 min |
 
 **Recent Trend:**
-- Last 5 plans: 2 min, 3 min, 2 min, 2 min
+- Last 5 plans: 2 min, 3 min, 2 min, 2 min, 4 min
 - Trend: Stable
 
 *Updated after each plan completion*
@@ -56,8 +56,11 @@ Recent decisions affecting current work:
 - 01-03: app_config stored in App struct for Phase 2 access — vault_path accessible inside event loop
 - 01-03: Quit prompt cleared on any non-Ctrl+C key — pressing any key dismisses double-press window
 - 02-01: LinesWithNewlines iterator added to preserve trailing \n for syntect grammar correctness
-- 02-01: mod declarations omitted from main.rs — Plan 03 handles wiring for all Phase 2 modules
+- 02-01: mod declarations added to main.rs during Plan 02 (not Plan 03) — compiler needs them to check renderer.rs
 - 02-01: syntect default-fancy feature uses pure-Rust fancy-regex (avoids Oniguruma C lib)
+- 02-02: Full emit_code_block and emit_table written in Task 1 (not stubs) — avoids throwaway code
+- 02-02: Box width for code blocks capped at terminal width — prevents border overflow on long lines
+- 02-02: Table n_cols derived from max(alignments.len(), max row length) — handles malformed GFM tables
 
 ### Pending Todos
 
@@ -65,12 +68,12 @@ None.
 
 ### Blockers/Concerns
 
-- **REND**: ratatui 0.30 Widget trait confirmed: `impl Widget for &Foo` pattern required (NOT WidgetRef) — Plan 02 must use reference-based impl
+- **REND blocker resolved**: renderer.rs uses no Widget trait at all — `render_markdown()` returns `Vec<Line<'static>>` which Plan 03 passes to `Paragraph::new()`. No custom Widget needed.
 - **NAV**: Path traversal via wiki-links must be addressed in Phase 3 link resolver — canonicalize and prefix-check every resolved path
 - **LIVE**: notify 8.x API must be verified at integration time; watch only current file (not full vault) to avoid inotify exhaustion
 
 ## Session Continuity
 
 Last session: 2026-02-28
-Stopped at: Completed 02-01-PLAN.md — vault.rs and highlighter.rs created, cargo build clean
-Resume file: .planning/phases/02-vault-core-and-rendering/02-02-PLAN.md
+Stopped at: Completed 02-02-PLAN.md — renderer.rs created, cargo check clean
+Resume file: .planning/phases/02-vault-core-and-rendering/02-03-PLAN.md
diff --git a/.planning/phases/02-vault-core-and-rendering/02-02-SUMMARY.md b/.planning/phases/02-vault-core-and-rendering/02-02-SUMMARY.md
new file mode 100644
index 0000000..d93fda5
--- /dev/null
+++ b/.planning/phases/02-vault-core-and-rendering/02-02-SUMMARY.md
@@ -0,0 +1,134 @@
+---
+phase: 02-vault-core-and-rendering
+plan: 02
+subsystem: renderer
+tags: [pulldown-cmark, ratatui, syntax-highlighting, cga-colors, box-drawing, markdown-rendering]
+
+dependency_graph:
+  requires:
+    - phase: 02-01
+      provides: highlight_code(), OnceLock-based syntect initialization, CGA color mapping
+  provides:
+    - render_markdown() — markdown string to Vec<Line<'static>> conversion pipeline
+    - H1-H6 heading rendering with CGA colors and ═/─ decorators
+    - Bold/italic/inline code inline styling
+    - Ordered and unordered list rendering with ●/◦/▪ bullets
+    - Blockquote rendering with yellow │ border
+    - Horizontal rule rendering (full-width ─ in DarkGray)
+    - Image placeholder rendering [IMAGE: alt]
+    - Fenced code block rendering with ╭─╮│╰─╯ borders + syntect highlighting
+    - GFM table rendering with ┌┬┐├┼┤└┴┘ full box-drawing grid
+  affects: [02-03-app-integration]
+
+tech-stack:
+  added: []
+  patterns:
+    - RenderState struct with style_stack (Vec<Style>) for nested inline formatting
+    - Two-pass table rendering: accumulate all cells, then emit box-drawing grid
+    - TextMergeStream wrapping Parser::new_ext to coalesce adjacent Text events
+    - emit_code_block() and emit_table() as standalone free functions called by RenderState methods
+    - All Span content uses .to_string() for owned strings — Vec<Line<'static>> with no lifetime leakage
+
+key-files:
+  created:
+    - src/renderer.rs
+  modified:
+    - src/main.rs
+
+key-decisions:
+  - "Wrote full emit_code_block and emit_table implementations in Task 1 rather than stubs — stubs would have been discarded in Task 2; single pass was cleaner"
+  - "Removed unused push_fg and push_fg_mod helper methods — start_heading() constructs styles inline, keeping RenderState API minimal"
+  - "emit_code_block box_width computed as max(content_width + 4, lang.len() + 6) capped at terminal width — prevents border overflow on long lines"
+  - "Table n_cols derived from max(alignments.len(), max row length) — handles malformed tables with mismatched column counts gracefully"
+
+patterns-established:
+  - "RenderState pattern: internal struct with push/pop style_stack, flush_line() accumulates then emits, finish() returns owned Vec<Line<'static>>"
+  - "Box-drawing code blocks: ╭─ lang ─╮ / │ content padding │ / ╰─╯ with DarkGray borders and Yellow lang label"
+  - "Box-drawing tables: ┌┬┐├┼┤└┴┘ with Cyan border_style and LightCyan+BOLD header row"
+
+requirements-completed: [REND-01, REND-02, REND-03, REND-04, REND-05, REND-06, REND-07, REND-08, REND-09, REND-10]
+
+duration: 4min
+completed: 2026-02-28
+---
+
+# Phase 02 Plan 02: Markdown Renderer Summary
+
+**pulldown-cmark event pipeline producing Vec<Line<'static>> with CGA-colored headings, syntax-highlighted fenced code blocks with ╭─╮│╰─╯ borders, and GFM tables with ┌┬┐├┼┤└┴┘ box-drawing grids**
+
+## Performance
+
+- **Duration:** 4 min
+- **Started:** 2026-02-28T21:15:20Z
+- **Completed:** 2026-02-28T21:19:00Z
+- **Tasks:** 2
+- **Files modified:** 2 (src/renderer.rs created, src/main.rs updated)
+
+## Accomplishments
+
+- Complete `render_markdown(input: &str, width: u16) -> Vec<Line<'static>>` public function
+- All Phase 2 REND-01 through REND-10 requirements implemented in one module
+- Code blocks render with rounded box-drawing borders (╭─ lang ─╮ / │ │ / ╰──╯), language label in Yellow, content via `crate::highlighter::highlight_code()`
+- GFM tables render with full DOS-style box grid (┌┬┐├┼┤└┴┘), bold LightCyan header row, Left/Right/Center column alignment
+
+## Task Commits
+
+1. **Task 1: Build core markdown renderer with inline and block elements** - `9e6f79c` (feat)
+2. **Task 2: Add code block borders with syntax highlighting and GFM table grid** - `8690d2a` (feat)
+
+## Files Created/Modified
+
+- `src/renderer.rs` — Complete markdown-to-styled-lines conversion pipeline (717 lines); `render_markdown()` public API; `RenderState` internal struct with style stack, blockquote depth, list counters, two-pass table collection; `emit_code_block()` and `emit_table()` free functions
+- `src/main.rs` — Added `mod highlighter; mod renderer; mod vault;` declarations (wiring for Plan 03)
+
+## Decisions Made
+
+- Implemented full emit_code_block and emit_table in Task 1 rather than writing throwaway stubs — since both functions were already designed in the plan, writing real code once was cleaner than writing placeholder code twice
+- Removed `push_fg` and `push_fg_mod` helper methods from RenderState after they proved unused — `start_heading()` constructs styles directly with `.fg().add_modifier()` inline
+- Box width for code blocks capped at terminal `width` parameter to prevent overflow when code lines are longer than the terminal
+- Table column count derived from `max(alignments.len(), max row cell count)` to handle pathological GFM tables with mismatched header/data column counts
+
+## Deviations from Plan
+
+### Auto-fixed Issues
+
+**1. [Rule 1 - Bug] Fixed type inference error in list item bullet computation**
+- **Found during:** Task 1 (cargo check feedback)
+- **Issue:** `let (bullet_str, new_counter) = match ...` with `None` literals caused `E0282: type annotations needed for Option<_>` because Rust could not infer the Option type parameter from the unit arm
+- **Fix:** Simplified the match to return only `bullet_str: String`, eliminating the unused `new_counter` binding entirely
+- **Files modified:** src/renderer.rs
+- **Verification:** cargo check passes without error
+- **Committed in:** 9e6f79c (Task 1 commit, fixed inline during implementation)
+
+---
+
+**Total deviations:** 1 auto-fixed (1 type inference bug caught during cargo check)
+**Impact on plan:** Minor Rust type inference issue resolved immediately; no scope creep.
+
+## Issues Encountered
+
+None — plan executed cleanly after the type inference fix.
+
+## User Setup Required
+
+None — no external service configuration required.
+
+## Next Phase Readiness
+
+- `render_markdown()` is ready for Plan 03 app integration
+- `src/highlighter::init_highlighter()` must be called in `main()` before any `render_markdown()` call (Plan 03 handles this)
+- All Phase 2 rendering requirements (REND-01 through REND-10) are satisfied
+- Dead-code warnings from unwired modules will resolve when Plan 03 wires `renderer`, `vault`, and `highlighter` into the event loop
+
+## Self-Check: PASSED
+
+- [x] src/renderer.rs exists with render_markdown(), emit_code_block(), emit_table(), RenderState
+- [x] src/main.rs contains mod highlighter; mod renderer; mod vault;
+- [x] Commit 9e6f79c exists in git log (Task 1: core renderer)
+- [x] Commit 8690d2a exists in git log (Task 2: code block borders + table grid)
+- [x] cargo check passes (19 expected dead_code warnings, 0 errors)
+- [x] 02-02-SUMMARY.md created at .planning/phases/02-vault-core-and-rendering/
+
+---
+*Phase: 02-vault-core-and-rendering*
+*Completed: 2026-02-28*