Markdown to PDF Converter (v2.0)

## Quick Start

Convert a Markdown file to PDF:

```bash
bash scripts/md2pdf-local.sh input.md output.pdf
```

**First run only:** Downloads ~150MB emoji resources (Twemoji 14.0.0) from GitHub. Subsequent runs work offline.

**Example:**

```bash
bash scripts/md2pdf-local.sh report.md report.pdf
```

## Features

- ✅ **Full Unicode support** (Chinese, Japanese, Korean)
- ✅ **Complete emoji support** (Twemoji 14.0.0, 3660 colorful PNGs)
- ✅ **All emoji variants** (skin tones, hair styles, regional flags, etc.)
- ✅ **Offline operation** after initial setup
- ✅ **Professional PDF layout** with page numbers
- ✅ **Code highlighting**, tables, blockquotes
- ✅ **Accurate emoji mapping** via Python pre-generated lookup table

## Technical Details

### Dependencies

- **Pandoc** - Universal document converter
- **WeasyPrint** - CSS-to-PDF renderer
- **Python 3** - For emoji mapping generation
- **wget** - For emoji download (first run only)

### How It Works

1. **First run**: Downloads Twemoji 14.0.0 to `~/.cache/md2pdf/emojis/`
2. **Python script**: Generates emoji → filename mapping table (`emoji_mapping.json`)
3. **Pandoc**: Converts Markdown to HTML with a Lua filter that replaces emoji characters with local image references
4. **WeasyPrint**: Renders HTML to PDF using:
   - AR PL UMing CN for Chinese characters
   - Local emoji images (PNG, 72x72px, colorful)
   - Professional CSS styling

### Emoji Cache Location

```
~/.cache/md2pdf/
├── emojis/                    # 3660 colorful PNG files
│   ├── 0023-fe0f-20e3.png
│   ├── 1f600.png
│   └── ...
└── emoji_mapping.json         # Emoji to filename mapping
    {
      "🙀": "1f600.png",
      "⌛": "0023-fe0f-20e3.png",
      ...
    }
```

### Emoji Mapping

The Python script `generate_emoji_mapping.py` scans all Twemoji files and creates a precise mapping from emoji characters to PNG filenames. This ensures accurate emoji replacement even for complex variants like skin tones and regional indicators.

### Fonts

**Primary Chinese font**: AR PL UMing CN

**Fallback**: Noto Sans SC, Noto Sans CJK SC, Microsoft YaHei

**Monospace**: Menlo, Monaco

## Version History

### v2.0 (Current)
- ✅ Switched to **Twemoji 14.0.0** (complete version)
- ✅ **3660 colorful emojis** (including all variants)
- ✅ **Python pre-generated mapping** for accurate emoji replacement
- ✅ Fixed black-and-white emoji display issue
- ✅ Proper support for emoji variants (skin tones, hair styles, etc.)

### v1.0 (Previous)
- Used emoji-datasource-google (~2000-3000 emojis)
- Simple hex-based filename matching (inaccurate for variants)
- Some emojis displayed as Unicode characters (black-and-white)

## Troubleshooting

### Font Issues

If Chinese characters display incorrectly, ensure AR PL UMing CN is installed:

```bash
# Ubuntu/Debian
sudo apt-get install fonts-arphic-uming

# Check if installed
fc-list | grep "AR PL UMing"
```

### Emoji Not Showing

1. Check if emoji cache exists: `ls ~/.cache/md2pdf/emojis/`
2. Check if mapping exists: `ls ~/.cache/md2pdf/emoji_mapping.json`
3. If missing, delete cache and re-run: `rm -rf ~/.cache/md2pdf`
4. Verify emoji file exists: `ls ~/.cache/md2pdf/emojis/1f600.png`

### Emoji Displaying as Black-and-White

This issue has been **FIXED** in v2.0. If you still see black-and-white emojis:

1. Verify you're using the v2.0 script:
   ```bash
   grep "TWEMOJI_VERSION" scripts/md2pdf-local.sh
   # Should show: TWEMOJI_VERSION="14.0.0"
   ```

2. Clear cache and regenerate:
   ```bash
   rm -rf ~/.cache/md2pdf
   bash scripts/md2pdf-local.sh test.md test.pdf
   ```

### WeasyPrint Errors

Install missing dependencies:

```bash
# Ubuntu/Debian
sudo apt-get install python3-weasyprint

# Or via pip
pip3 install weasyprint
```

### Python Script Errors

If `generate_emoji_mapping.py` fails:

```bash
# Check Python version
python3 --version
# Should be Python 3.6+

# Check emoji cache
ls ~/.cache/md2pdf/emojis
```

## Resources

### scripts/

**md2pdf-local.sh** - Main conversion script with automatic emoji caching and mapping

**generate_emoji_mapping.py** - Python script to generate emoji lookup table

**Usage**: Direct execution from any location (uses absolute paths):

```bash
bash /path/to/skills/md2pdf-converter/scripts/md2pdf-local.sh input.md output.pdf
```

**Key Features**:
- Automatic Twemoji download and caching
- Python pre-generated emoji mapping (accurate)
- Lua filter for emoji replacement
- CSS styling for professional output
- Temporary file cleanup (automatic)

## Comparison: v1.0 vs v2.0

| Feature | v1.0 (Old) | v2.0 (New) |
|---------|----------------|---------------|
| Emoji Source | emoji-datasource-google | Twemoji 14.0.0 |
| Emoji Count | ~2000-3000 | 3660 |
| Color Display | ❌ Unstable | ✅ Stable |
| Variants Support | ❌ Incomplete | ✅ Complete |
| Mapping Accuracy | ⚠️ Low | ✅ High |
| Offline Support | ✅ After first run | ✅ After first run |
| First Run Size | ~68MB | ~150MB |

## Performance

- **First run**: ~150MB download, 10-30 seconds (depending on network)
- **Subsequent runs**: Offline, seconds-level conversion
- **Memory usage**: ~150MB for emoji cache
- **PDF generation**: 1-5 seconds per page

## Limitations

- Missing emojis (newer than Twemoji 14.0.0) will display as Unicode characters
- First run requires internet connection (for Twemoji download)
- Emoji cache size: ~150MB (3660 PNG files at 72x72px)