# Progress Bars Implementation Summary

## Overview
Added visual progress bars to the mcp-vector-search indexing pipeline to provide real-time feedback during long-running operations.

## Changes Made

### 1. Enhanced `src/mcp_vector_search/core/progress.py`

Added two new methods to the `ProgressTracker` class:

#### `progress_bar(current, total, prefix, width=40)`
- Simple inline progress bar that updates in place
- Shows percentage and counts (e.g., "Parsing files... ━━━━━━━━━╸ 45% 328/730")
- Thread-safe (no background threads, works with Kuzu)
- Uses `\r` to update the same line

#### `progress_bar_with_eta(current, total, prefix, width=40, start_time)`
- Enhanced progress bar with ETA (estimated time remaining)
- Calculates time based on current rate
- Shows format: "Embedding chunks... ━━━━━━━━━━━━━╸ 67% 54,234/81,238 [01:23 remaining]"
- Automatically prints newline when complete (100%)

### 2. Updated `src/mcp_vector_search/core/indexer.py`

#### Constructor Changes
- Added `progress_tracker` parameter to `SemanticIndexer.__init__()`
- Stores reference to optional ProgressTracker instance

#### Pipeline Mode (`_index_with_pipeline`)
**Phase 1: Chunking Producer**
- Tracks start time for ETA calculation
- Updates progress bar after each file batch is processed
- Shows: "Parsing files... ━━━━━╸ 45% 328/730 [00:12 remaining]"

**Phase 2: Embedding Consumer**
- Tracks start time and estimates total chunks
- Updates progress bar after each batch is embedded
- Shows: "Embedding chunks... ━━━━━━━╸ 67% 54,234/81,238 [01:23 remaining]"

#### Sequential Mode
**`_phase1_chunk_files`**
- Tracks parsing progress per file
- Updates progress bar after each file is parsed and chunked

**`_phase2_embed_chunks`**
- Tracks embedding progress per batch
- Estimates total chunks from first batch
- Updates progress bar with ETA

### 3. Updated `src/mcp_vector_search/cli/commands/index.py`

- Moved ProgressTracker creation before indexer instantiation
- Progress tracker now **always enabled** (not just in verbose mode)
- Passed to `SemanticIndexer` constructor via `progress_tracker` parameter

## Key Features

### Thread-Safe Design
- No Rich background threads (compatible with Kuzu's non-thread-safe nature)
- Uses direct `sys.stderr.write()` for line updates
- Safe to use in async/multiprocessing contexts

### Adaptive Display
- Falls back to logger.info() if no progress tracker available
- Progress bars automatically complete (print newline at 100%)
- Works alongside existing logging infrastructure

### Performance
- Minimal overhead (simple string formatting)
- Updates in place without scrolling the terminal
- ETA calculations use simple rate-based estimation

## Example Output

```
📄 Phase 1: Chunking 730 files (parsing and extracting code structure)...
  Parsing files... ━━━━━━━━━━━━━━━━━━━━ 45% 328/730 [00:12 remaining]

🧠 Phase 2: Embedding pending chunks (GPU processing for semantic search)...
  Embedding chunks... ━━━━━━━━━━━━━━━━━━━━ 67% 54,234/81,238 [01:23 remaining]

✓ Two-phase indexing complete: 730 files, 54,234 chunks created, 54,234 chunks embedded
```

## Testing

Created test scripts:
- `test_progress_bar.py` - Full integration test with Rich console
- `test_progress_simple.py` - Minimal test of raw progress bar logic

Both tests verify:
- Simple progress bars work correctly
- ETA calculation is accurate
- Progress bars update smoothly
- Completion triggers newline properly

## Usage

Progress bars are now automatically enabled for all indexing operations:

```bash
# Progress bars shown by default
uv run mcp-vector-search index

# Works with force reindex
uv run mcp-vector-search index --force

# Works with specific phases
uv run mcp-vector-search index --phase chunk
uv run mcp-vector-search index --phase embed
```

## Backward Compatibility

- Existing logging still works
- If progress tracker is None, falls back to logger.info()
- No breaking changes to API or CLI
- Works with all existing flags and options

## Future Enhancements

Potential improvements (not implemented yet):
- Add file discovery progress bar ("Scanning files... 730/730")
- Show current file being processed in progress bar
- Add throughput metrics (files/sec, chunks/sec)
- Color-code progress based on speed (green=fast, yellow=normal, red=slow)
- Add option to disable progress bars (--no-progress flag)

## Architecture Principles

The implementation follows the project's existing patterns:
- Simple, print-based output (no complex TUI frameworks)
- Thread-safe by design (no background threads)
- Works with Kuzu's non-thread-safe constraints
- Minimal dependencies (just sys and time from stdlib + Rich console)
- Async-compatible (no blocking operations)
