# Shell Input Editor Improvement Plan

## Problem Statement ✅ RESOLVED

The current `src/interfaces/terminal/components/shell-input.tsx` had several
usability issues:

- ~~Cursor gets stuck on the top line during text overflow~~ ✅ **FIXED**
- ~~Pasting doesn't work~~ ✅ **FIXED**
- Generally less robust than the original implementation (partially improved)

## Analysis

After comparing the current implementation with the original at
`/Users/jesse/git/lace/src/ui/components/ShellInput.tsx`, several key
differences explain the problems:

### Original Implementation Strengths

1. **Better key handling**: Proper debug logging (`bufferOps.addDebug`) and
   cleaner key event processing
2. **More comprehensive completion system**: Uses a full `CompletionManager`
   with proper context and item types
3. **Viewport scrolling**: Has proper completion scrolling with viewport
   management
4. **Better state management**: More sophisticated completion state with proper
   prefix tracking

### Current Implementation Problems

1. **Backwards key mappings** (lines 257-263): `delete` mapped to backward and
   `backspace` mapped to forward - backwards from normal expectations
2. **Missing paste support**: No clipboard handling code
3. **Simpler autocomplete**: Uses basic file scanning vs comprehensive
   completion system
4. **No debug capabilities**: Missing the `addDebug` functionality that helps
   with development
5. **Less robust text rendering**: The `TextRenderer` is being passed fewer
   props

## Root Causes

- **Cursor getting stuck**: Likely related to text buffer implementation
  differences and cursor positioning during text wrapping
- **Paste not working**: Original has better input handling and may have
  clipboard integration that current version lacks

## Implementation Plan

### ~~Phase 1: Fix Critical Key Mappings~~ 🚫 **SKIPPED**

- [ ] Swap delete/backspace key mappings (lines 257-263) - _Skipped per user
      request_
- [ ] Verify arrow key behavior matches expectations

### ~~Phase 2: Restore Debug Capabilities~~ 🚫 **SKIPPED**

- [x] ~~Add back `addDebug` functionality to buffer operations~~ - _Not needed
      per user feedback_
- [x] ~~Ensure debug logging works for key event troubleshooting~~

### Phase 3: Import Robust Completion System 🔄 **PENDING**

- [ ] Import the sophisticated `CompletionManager` system from original
- [ ] Implement viewport scrolling for completions
- [ ] Add proper completion context and item type handling

### Phase 4: Text Buffer Improvements ✅ **COMPLETED**

- [x] Compare `useTextBuffer` implementations
- [x] Fix cursor positioning during text wrapping (added `preferredColumn`
      memory)
- [x] Ensure proper multi-line text handling
- [x] Added comprehensive test suite for wrapping behavior

### Phase 5: Add Paste Support ✅ **COMPLETED**

- [x] Investigate original's clipboard integration
- [x] Implement paste functionality with full clipboard API
- [x] Test with various clipboard content types (multi-line, special chars,
      errors)
- [x] Added Ctrl+V/Cmd+V keyboard shortcuts
- [x] Comprehensive test suite with 17 test cases

### Phase 6: TextRenderer Enhancement ✅ **COMPLETED**

- [x] Ensure all necessary props are passed to TextRenderer
- [x] Verify text rendering matches original behavior
- [x] Test edge cases like long lines and multi-line content
- [x] Added robust bounds checking for cursor position
- [x] Improved safety with empty lines array handling
- [x] Comprehensive test suite with 19 edge case tests

## Success Criteria

- [x] Cursor moves correctly during text overflow ✅ **ACHIEVED**
- [x] Paste functionality works reliably ✅ **ACHIEVED**
- [ ] Autocomplete behaves like the original 🔄 _Pending Phase 3_
- [x] No regression in existing functionality ✅ **VERIFIED** (all tests
      passing)
- [x] ~~Debug capabilities available for future troubleshooting~~ _Not needed_

## Testing Strategy

1. **Manual testing**: Type long lines, test cursor movement, paste content
2. **Comparison testing**: Side-by-side behavior comparison with original
3. **Edge case testing**: Very long inputs, multi-line content, special
   characters
4. **Autocomplete testing**: File completion, command completion, navigation

## Implementation Summary

### Completed Work

- **Phase 4**: Fixed cursor positioning issues by implementing `preferredColumn`
  memory system
- **Phase 5**: Full paste functionality with clipboard API, keyboard shortcuts,
  and comprehensive error handling
- **Phase 6**: TextRenderer robustness improvements with bounds checking and
  edge case handling
- Created GitHub issues for advanced paste features:
  - [Issue #10](https://github.com/obra/lace/issues/10): Atomic paste blocks for
    large content (5+ lines)
  - [Issue #11](https://github.com/obra/lace/issues/11): Document and image
    paste with AI model integration

### Remaining Work

- **Phase 3**: Import sophisticated CompletionManager system from original
  implementation

### Key Improvements Made

1. **Cursor Memory**: Added `preferredColumn` to `TextBufferState` to remember
   desired cursor position when moving between lines of different lengths
2. **Paste Infrastructure**: Complete clipboard integration with async API,
   multi-line support, and platform-specific keyboard shortcuts
3. **Renderer Robustness**: Enhanced TextRenderer with bounds checking, safe
   cursor positioning, and empty lines array handling
4. **Test Coverage**: Added comprehensive test suites for cursor positioning,
   paste functionality, and edge case rendering
5. **Error Handling**: Graceful fallbacks for clipboard access errors and
   rendering edge cases

### Technical Debt Addressed

- Fixed the "cursor gets stuck on top line" issue that was the primary user
  complaint
- Eliminated paste functionality gap compared to original implementation
- Improved TextRenderer safety and bounds checking for edge cases
- Maintained backward compatibility with existing text buffer operations

The current implementation now provides a solid foundation for text editing with
reliable cursor behavior, modern clipboard integration, and robust rendering.
The core usability issues have been resolved, with only the advanced completion
system (Phase 3) remaining for future enhancement.
