# Podcast Implementation Summary

## What Was Built

A complete podcast solution for the Daily Digest blog that automatically converts blog posts to audio using Text-to-Speech (TTS) and distributes them via RSS feed.

## Features Delivered

### 1. TTS Service (`src/lib/tts.ts`)
- **Multi-provider support**: OpenAI (paid), Piper (free), macOS say (free)
- **Text preprocessing**: Automatically strips markdown, URLs, and code blocks
- **Async generation**: Non-blocking to not delay post creation
- **Error handling**: Graceful fallback if TTS fails

### 2. Audio Storage (`src/lib/storage.ts`)
- **Supabase Storage integration**: Uses existing Supabase project
- **Automatic bucket creation**: Creates `podcast-audio` bucket if needed
- **Public access**: Audio files accessible for podcast apps

### 3. RSS Feed (`src/app/api/podcast/rss/route.ts`)
- **RSS 2.0 with iTunes extensions**: Compatible with Apple Podcasts, Spotify, Google Podcasts
- **Auto-updating**: Pulls latest episodes from database
- **Proper metadata**: Titles, descriptions, duration, publication dates

### 4. Podcast Page (`src/app/podcast/page.tsx`)
- **Web audio player**: Play episodes directly on the site
- **Episode listing**: Browse all available podcast episodes
- **Subscribe links**: RSS, Apple Podcasts, Spotify
- **Responsive design**: Works on mobile and desktop

### 5. Integration with Digest Workflow
- **Updated `/api/digest`**: Now triggers TTS generation after saving post
- **Optional audio**: Can disable with `generateAudio: false`
- **Background processing**: Doesn't block the main response

### 6. Manual TTS Script (`src/scripts/generate-tts.ts`)
- **Single post**: `npm run generate-tts -- <post_id>`
- **Batch processing**: `npm run generate-tts:all`
- **Force regeneration**: `--force` flag to overwrite existing

### 7. UI Updates
- **Blog post audio player**: Shows audio player for posts with audio
- **Podcast link in header**: Easy navigation to podcast page
- **Visual indicators**: Shows which posts have audio

## Files Created/Modified

### New Files
```
src/
├── app/
│   ├── api/podcast/rss/route.ts     # RSS feed endpoint
│   └── podcast/page.tsx             # Podcast web player
├── lib/
│   ├── tts.ts                       # TTS service abstraction
│   ├── storage.ts                   # Supabase storage helpers
│   └── podcast.ts                   # RSS generation utilities
├── scripts/
│   └── generate-tts.ts              # Manual TTS generation script
└── ../PODCAST_SETUP.md              # Setup documentation
```

### Modified Files
```
src/
├── app/
│   ├── api/digest/route.ts          # Added TTS trigger
│   └── page.tsx                     # Added audio player, podcast link
├── ../package.json                  # Added generate-tts scripts
├── ../tsconfig.json                 # Added scripts to includes
└── ../.env.local                    # Added TTS environment variables
```

## Configuration

### Environment Variables
```bash
# Enable TTS generation
ENABLE_TTS=true

# TTS Provider: openai, piper, or macsay
TTS_PROVIDER=openai

# OpenAI settings (if using OpenAI)
OPENAI_API_KEY=sk-your-key-here
TTS_VOICE=alloy  # alloy, echo, fable, onyx, nova, shimmer

# Piper settings (if using Piper)
PIPER_MODEL_PATH=./models/en_US-lessac-medium.onnx
```

### Database Schema
```sql
ALTER TABLE blog_messages 
ADD COLUMN audio_url TEXT,
ADD COLUMN audio_duration INTEGER;
```

## URLs

- **RSS Feed**: `https://blog-backup-two.vercel.app/api/podcast/rss`
- **Podcast Page**: `https://blog-backup-two.vercel.app/podcast`
- **Blog**: `https://blog-backup-two.vercel.app`

## Cost Analysis

| Component | Provider | Monthly Cost |
|-----------|----------|--------------|
| TTS | OpenAI | ~$2-4 |
| TTS | Piper/macOS | $0 |
| Storage | Supabase | $0 (free tier) |
| RSS Hosting | Vercel | $0 |
| **Total** | | **$0-4/month** |

## Next Steps to Deploy

1. **Database**: Run the SQL to add `audio_url` and `audio_duration` columns
2. **Supabase Storage**: Create `podcast-audio` bucket (or let app auto-create)
3. **Environment**: Add `ENABLE_TTS=true` and `OPENAI_API_KEY` to production
4. **Deploy**: `npm run build && vercel --prod`
5. **Test**: Generate a test episode and verify RSS feed
6. **Submit**: Add RSS URL to Apple Podcasts, Spotify, etc.

## Documentation

See `PODCAST_SETUP.md` for complete setup instructions, troubleshooting, and usage guide.