bbs-md/.planning/phases/01-safety-foundation/01-02-SUMMARY.md

phase, plan, subsystem, tags, requires, provides, affects, tech-stack, key-files, key-decisions, patterns-established, requirements-completed, duration, completed

phase	plan	subsystem	tags	requires	provides	affects	tech-stack	key-files	key-decisions	patterns-established	requirements-completed	duration	completed
01-safety-foundation	02	terminal	rust ratatui crossterm signal-hook atomic-bool panic-hook raw-mode		src/terminal.rs: init_terminal(), restore_terminal(), install_panic_hook(), Term type alias src/signals.rs: SignalFlags, register_signals(), init_logging() stub	01-03 all future phases (terminal safety envelope)	added patterns ratatui::crossterm (via re-export — crossterm is a transitive dependency) signal-hook 0.4.3 (direct dependency, already in Cargo.toml) main screen buffer with Viewport::Fullscreen instead of alternate screen let _ = for all cleanup operations in restore and panic hook AtomicBool polling for signal handling without async runtime take_hook + set_hook for panic hook chaining	created modified src/terminal.rs src/signals.rs src/main.rs	Use ratatui::crossterm re-export instead of direct crossterm dependency (avoids version conflicts) SIGINT not registered via signal-hook — handled via crossterm key events for double-press Ctrl+C (Plan 03) restore_terminal() never calls ratatui::restore() — that would call LeaveAlternateScreen which was never entered	Cleanup-safe pattern: every operation in restore_terminal() and panic hook uses let _ = No unwrap() or ? in panic hook — double-panic prevention Viewport::Fullscreen for main screen BBS immersive mode	LIFE-01 LIFE-02 LIFE-03 LIFE-04	3min	2026-02-28

Phase 1 Plan 02: Terminal Safety Primitives Summary

Main-screen BBS terminal with panic recovery hook, SIGHUP/SIGTERM AtomicBool flag registration, and broken-pipe-safe cleanup using ratatui::crossterm re-export

Performance

• Duration: ~3 min
• Started: 2026-02-28T20:10:36Z
• Completed: 2026-02-28T20:12:58Z
• Tasks: 2
• Files modified: 3

Accomplishments

• Terminal initializes on the main screen buffer (not alternate screen) with raw mode — immersive BBS feel where TUI output persists in scroll history after exit
• Panic hook restores terminal state before printing a BBS-themed user message, then delegates to original hook for sysop details (journald/SSH log)
• SIGHUP and SIGTERM register a shared AtomicBool flag for event loop polling; SIGINT deliberately excluded to enable double-press Ctrl+C via crossterm key events in Plan 03
• All cleanup paths (restore_terminal, panic hook) use let _ = on every operation — no double-panic risk

Task Commits

Each task was committed atomically:

1. Task 1: Terminal init/restore and panic hook - b258b6d (feat)
2. Task 2: Signal handling and logging stub - 966b47e (feat)

Files Created/Modified

• src/terminal.rs - init_terminal() (main screen, raw mode, Viewport::Fullscreen), restore_terminal() (let _ = pattern), install_panic_hook() (BBS message + original hook delegation), Term type alias
• src/signals.rs - SignalFlags struct, register_signals() (SIGHUP + SIGTERM only), should_terminate() poll method, init_logging() Phase 1 stub
• src/main.rs - Added mod signals; and mod terminal; declarations

Decisions Made

• Used ratatui::crossterm re-export path instead of adding crossterm as a direct dependency. Crossterm is a transitive dependency only; using the re-export avoids version conflicts and keeps Cargo.toml minimal.
• SIGINT is NOT registered via signal-hook. The double-press Ctrl+C state machine (SHEL-01) will use crossterm key events (KeyCode::Char('c') + KeyModifiers::CONTROL) in the event loop — registering SIGINT twice causes double-handling.
• restore_terminal() never calls ratatui::restore(). That function calls LeaveAlternateScreen unconditionally, which corrupts the terminal since we never entered the alternate screen.

Deviations from Plan

Auto-fixed Issues

1. [Rule 3 - Blocking] Used ratatui::crossterm re-export instead of bare crossterm import

• Found during: Task 1 (terminal.rs build verification)
• Issue: use crossterm::... failed to compile — crossterm is a transitive dependency not listed in Cargo.toml directly. Compiler error: "use of unresolved module or unlinked crate crossterm" with hint pointing to ratatui::crossterm
• Fix: Changed all crossterm:: imports to ratatui::crossterm:: re-export path. Also updated the inlined execute! calls inside the panic hook closure to use the fully-qualified ratatui::crossterm:: path.
• Files modified: src/terminal.rs
• Verification: cargo build succeeds
• Committed in: b258b6d (Task 1 commit)

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Total deviations: 1 auto-fixed (1 blocking import error) Impact on plan: Necessary fix — imports must resolve for compilation. Using re-export path is semantically identical and more robust against version mismatches.

Issues Encountered

None beyond the crossterm import deviation documented above.

User Setup Required

None - no external service configuration required.

Next Phase Readiness

• Terminal safety envelope is complete: all exit paths (panic, signal, normal quit) restore the terminal correctly
• install_panic_hook() should be called first in main() before any terminal init
• register_signals() returns a SignalFlags whose should_terminate() method the Plan 03 event loop will poll at the top of each iteration
• init_terminal() and restore_terminal() are ready for Plan 03 integration into the application entry point

Self-Check: PASSED

• src/terminal.rs: FOUND
• src/signals.rs: FOUND
• 01-02-SUMMARY.md: FOUND
• Commit b258b6d (Task 1): FOUND
• Commit 966b47e (Task 2): FOUND

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Phase: 01-safety-foundation Completed: 2026-02-28