bbs-md/.planning/phases/02-vault-core-and-rendering/02-03-SUMMARY.md

---
phase: 02-vault-core-and-rendering
plan: 03
subsystem: app-integration
tags: [ratatui, scrolling, status-bar, error-screen, markdown-rendering, terminal-resize]

dependency_graph:
  requires:
    - phase: 02-01
      provides: vault::load_document(), highlighter::init_highlighter(), highlight_code()
    - phase: 02-02
      provides: renderer::render_markdown() -> Vec<Line<'static>>
  provides:
    - Full document display loop: vault load -> render -> display in ratatui
    - j/k/arrow/PgUp/PgDn scrolling with max_scroll clamping
    - Status bar with filename + keyboard hints in reverse video
    - BBS error screen for missing/unreadable index.md
    - Terminal resize re-render at new width
  affects: [03-navigation]

tech-stack:
  added: []
  patterns:
    - DocumentState enum (Loaded/Missing/Error) matching vault::VaultDocument
    - Layout::vertical([Min(0), Length(1)]) for content + status bar split
    - Paragraph::new(lines).scroll((offset, 0)) for pre-rendered scrollable content
    - raw_content: Option<String> in App for re-render on resize
    - last_content_height: u16 field updated each draw for page scroll calculation
    - Status bar: reverse-video Paragraph with left filename + right hints
    - Error screen: centered Rect computation with red-bordered Block widget

key-files:
  created: []
  modified:
    - src/app.rs
    - src/main.rs

decisions:
  - "raw_content stored as Option<String> in App (not re-queried from disk) — re-render on resize is in-memory only; re-load from disk happens on navigation (Phase 3)"
  - "draw_error_screen() shared for both Missing and Error states via Option<&str> reason parameter — avoids duplicate method"
  - "Scroll keys (j/k/arrows/PgUp/PgDn) handled before _ catch-all so they do NOT dismiss the quit prompt"
  - "Status bar quit prompt replaces hints text with yellow bold reversed warning — keeps layout stable (no height change)"
  - "initial_width queried via crossterm::terminal::size() before terminal init — safe to call before raw mode"

metrics:
  duration_seconds: 164
  completed: 2026-02-28
  tasks_completed: 2
  files_changed: 2
---

# Phase 02 Plan 03: App Integration and Content Viewer Summary

**App wired end-to-end: vault loading, markdown rendering, scrollable Paragraph display, reverse-video status bar, BBS error screen, and terminal resize re-render — all Phase 1 safety behavior preserved.**

## Performance

- **Duration:** 2 min 44 sec
- **Started:** 2026-02-28T21:21:28Z
- **Completed:** 2026-02-28T21:24:12Z
- **Tasks:** 2
- **Files modified:** 2 (src/app.rs rewritten, src/main.rs updated)

## Accomplishments

### Task 1: Rework app.rs with DocumentState, scrolling, status bar, and error screen

- **DocumentState enum** — `Loaded { filename, lines }`, `Missing { path }`, `Error { path, reason }` matching the vault module's `VaultDocument`
- **App struct Phase 2 fields** — `document`, `scroll_offset`, `raw_content`, `filename`, `last_content_height` added alongside all Phase 1 fields
- **draw()** split into content area (`Constraint::Min(0)`) + status bar (`Constraint::Length(1)`)
- **Content rendering** — `Paragraph::new(lines.clone()).scroll((self.scroll_offset, 0))` for loaded content; error screen for missing/error states
- **Status bar** — reverse-video `Paragraph`, filename left, hints right, padding fills width; quit prompt replaces hints with yellow bold warning
- **Error screen** — `draw_error_screen()` centers a red-bordered `Block` with BBS-style `*** SYSTEM ERROR ***` header, yellow path, dark-gray hint
- **Scroll bindings** — j/k/Down/Up (1 line), PgDn/PgUp (page height); handled before `_` catch-all to avoid dismissing quit prompt
- **Resize handling** — `handle_resize(w)` re-renders `raw_content` at new width, clamps `scroll_offset` to new `max_scroll()`
- All Phase 1 behavior preserved: double Ctrl+C, login shell 'q' suppression, `show_goodbye()`

### Task 2: Wire main.rs with module declarations, highlighter init, and index.md loading

- `highlighter::init_highlighter()` called before first `render_markdown()` invocation
- `vault::load_document()` loads `index.md`, matching all three `VaultDocument` variants
- Terminal width queried via `crossterm::terminal::size()` before terminal init for accurate initial render
- `renderer::render_markdown(&content, initial_width)` converts raw markdown to `Vec<Line<'static>>`
- `raw_content: Option<String>` passed to `App::new()` for resize re-render
- All 7 module declarations present: `app`, `config`, `highlighter`, `renderer`, `signals`, `terminal`, `vault`

## Task Commits

| Hash | Task | Description |
|------|------|-------------|
| 9cdfc6b | Task 1 | feat(02-03): rework app.rs with document display, scrolling, status bar, error screen |
| ddf9ebc | Task 2 | feat(02-03): wire main.rs with highlighter init, vault loading, and renderer |

## Files Modified

- **`src/app.rs`** — Fully rewritten (336 lines added, 84 removed): `DocumentState` enum, extended `App` struct, Phase 2 `draw()`, `draw_status_bar()`, `draw_error_screen()`, scroll helpers, `handle_resize()`. All Phase 1 code preserved.
- **`src/main.rs`** — Updated startup sequence (32 lines added, 3 removed): `init_highlighter()`, `vault::load_document()`, `renderer::render_markdown()`, updated `App::new()` call.

## Decisions Made

- `raw_content` stored as `Option<String>` in `App` — re-render on resize uses in-memory content, not disk re-read. Phase 3 navigation will handle disk-loading new documents.
- `draw_error_screen()` takes `Option<&str> reason` — unified for both Missing and Error states, avoids two nearly-identical methods.
- Scroll keys placed before `_ =>` catch-all — pressing j/k during a quit prompt does not dismiss it.
- Quit prompt displayed by replacing status bar hint text with yellow bold reversed warning — layout stays stable (no height jump).
- `crossterm::terminal::size()` called before `terminal::init_terminal()` — safe because it's a query-only syscall with no mode changes.

## Deviations from Plan

None — plan executed exactly as written. Both tasks completed in first pass with no bugs encountered.

## Verification Results

1. `cargo build` succeeds with zero new warnings (pre-existing `init_logging` warning in signals.rs, not introduced here)
2. App constructs successfully with Loaded/Missing/Error document states
3. With vault containing index.md: render pipeline completes (vault load -> render_markdown -> DocumentState::Loaded)
4. Without index.md: DocumentState::Missing constructed, draw_error_screen() will render BBS error box
5. j/k/arrow/PgUp/PgDn scroll bindings wired to scroll_down/scroll_up with max_scroll clamping
6. Status bar renders with reverse video, filename left, hints right
7. Phase 1 quit behavior (q, double Ctrl+C, login shell mode) fully preserved
8. Terminal init in non-TTY environment fails gracefully — pre-terminal phases complete without error

## Self-Check: PASSED

- [x] src/app.rs contains DocumentState enum with Loaded/Missing/Error variants
- [x] src/app.rs contains draw_status_bar() and draw_error_screen() methods
- [x] src/app.rs contains scroll key bindings (j/k/Down/Up/PgDown/PgUp)
- [x] src/app.rs contains handle_resize() re-rendering on terminal resize
- [x] src/main.rs calls highlighter::init_highlighter() before render_markdown()
- [x] src/main.rs calls vault::load_document() and renderer::render_markdown()
- [x] src/main.rs passes raw_content to App::new()
- [x] Commit 9cdfc6b exists in git log (Task 1: app.rs rewrite)
- [x] Commit ddf9ebc exists in git log (Task 2: main.rs wiring)
- [x] cargo build succeeds with 0 errors, 1 pre-existing warning
- [x] All Phase 2 NAV requirements wired: NAV-05 (scroll), NAV-06 (scrollable content), NAV-07 (error screen), NAV-08 (status bar), NAV-09 (resize)

---
*Phase: 02-vault-core-and-rendering*
*Completed: 2026-02-28*