# Programmatic Close API - Implementation Summary

## Overview
Successfully implemented programmatic dialog closing capability for msger v0.1.121.

## Implementation Details

### Core Changes (shower.ts)

**1. MessageBoxHandle Class**
- Properties: `result` (Promise), `pid` (number), `child` (ChildProcess), `_closed` (boolean)
- Methods: `close()` - kills child process, `closed` getter - returns state
- Handles automatic cleanup and state tracking

**2. Active Dialog Registry**
- Map-based tracking of all active dialogs by PID
- Automatic registration on create
- Automatic cleanup on dialog close (via promise.finally)
- Enables standalone close function

**3. API Functions**
- `showMessageBoxEx(options)` - Returns MessageBoxHandle (new, recommended)
- `closeMessageBox(pid)` - Standalone close by PID (new)
- `showMessageBox(options)` - Returns Promise (legacy, still works)

**4. Exit Code Handling**
- `code === null` → `{button: 'closed', closed: true}` (programmatic close)
- `code === 0` → normal user response with button/value
- `code !== 0` → error/rejection

### Architecture

```
User Code
    ↓
showMessageBoxEx(options)
    ↓
createMessageBoxHandle() → spawns child process
    ↓
Returns MessageBoxHandle {
    pid: 12345,
    result: Promise<result>,
    close(): kills process,
    closed: boolean
}
    ↓
activeDialogs.set(pid, handle)
    ↓
[Later] handle.close() or closeMessageBox(pid)
    ↓
child.kill() → exit code null → resolve({button:'closed',closed:true})
```

### Testing

**Test 1: Handle API** (tests/test-handle-api.mjs)
- Creates dialog with handle
- Calls `handle.close()` after 2 seconds
- Verifies: PID reported, close returns true, result is correct
- Result: ✅ PASSED (PID 56432)

**Test 2: PID Close** (tests/test-close-by-pid.mjs)
- Creates dialog with handle
- Calls `closeMessageBox(pid)` after 2 seconds
- Verifies: PID reported, close returns true, result is correct
- Result: ✅ PASSED (PID 136232)

### Documentation

**CLOSE-API.md**
- Complete API reference
- Usage examples for both APIs
- Return value documentation
- Use case examples

**README.md**
- New "Programmatic Close API" section
- Handle-based example
- Standalone function example
- Updated MessageBoxResult interface docs

**CHANGELOG.md**
- Version 0.1.121 entry
- 5 new features documented
- 3 changes documented
- 2 fixes documented

**RELEASE-NOTES.md**
- User-facing release announcement
- Quick start examples
- Use cases
- Platform support

### Files Modified

**Core Implementation:**
- shower.ts (241 lines modified)
- shower.d.ts (auto-generated)
- shower.js (compiled)

**Configuration:**
- package.json (version: 0.1.120 → 0.1.121)

**Tests:**
- tests/test-handle-api.mjs (new)
- tests/test-close-by-pid.mjs (new)

**Documentation:**
- CLOSE-API.md (new)
- RELEASE-NOTES.md (new)
- CHANGELOG.md (updated)
- README.md (updated)
- IMPLEMENTATION-SUMMARY.md (this file)

### Backward Compatibility

✅ **100% Backward Compatible**
- `showMessageBox()` still works exactly as before
- Internally delegates to `showMessageBoxEx().result`
- No breaking changes to existing code

### Build Status

```
npm run build:ts
✅ SUCCESS - No errors or warnings
```

### Platform Support

- ✅ Windows (tested)
- ✅ Linux x64 (should work - process.kill)
- ✅ Linux ARM64/Pi (should work - process.kill)

## Ready for Release

All tasks complete:
- ✅ Implementation
- ✅ Testing
- ✅ Documentation
- ✅ Version bump
- ✅ Build verification
- ✅ No temp files
- ✅ Tests organized

**Next Steps:**
1. Commit changes
2. Git tag v0.1.121
3. npm publish
4. Test installation

---
**Date:** 2025-11-16  
**Version:** 0.1.121  
**Author:** Claude Code with Bob Frankston
