# Library Availability Monitor

A Node.js service that monitors San Diego libraries for parking pass availability and sends notifications via ntfy when passes become available at the desired branch.

## Features

- 📚 Monitors specific library book availability via BiblioCommons API
- 📱 Sends push notifications via ntfy when new books become available
- ⏰ Polls hourly and tracks availability changes
- 🔄 Graceful error handling and recovery
- 🧪 Comprehensive testing suite
- 🎭 Mock testing capabilities
- 🚀 Easy deployment to Linux servers

## Setup

### Prerequisites

- Node.js 18+ 
- npm
- SSH access to deployment server (optional)

### Installation

1. Clone or download this repository
2. Install dependencies:
   ```bash
   npm install
   ```

3. Configure your ntfy settings in `index.js`:
   ```javascript
   const CONFIG = {
       NTFY_TOPIC: 'your-topic-name',
       NTFY_SERVER: 'https://ntfy.sh', // or your own server
       // ... other settings
   };
   ```

## Usage

### Running the Monitor

```bash
# Start the monitor
npm start

# Development mode with auto-restart
npm run dev
```

### Testing

```bash
# Run all tests
npm test

# Validate against real API response example
npm run validate

# Interactive mock testing
npm run mock

# Simulate availability changes
node mock.js test 3  # Simulate 3 available books
node mock.js notify  # Send test notification
node mock.js status  # Show current state
node mock.js reset   # Reset state file
```

### Deployment

The included deployment script uploads and manages the service on a remote Linux server:

```bash
# Deploy to configured server
npm run deploy

# Or run directly
./deploy.sh
```

#### Deployment Setup

1. Configure SSH access to your server as 'linode' in `~/.ssh/config`:
   ```
   Host linode
       HostName your-server-ip
       User your-username
       IdentityFile ~/.ssh/your-key
   ```

2. The deployment script will:
   - Upload files to `/opt/sd-park-pass-ntfy`
   - Install dependencies
   - Create and start a systemd service
   - Enable auto-start on boot

## Configuration

### Main Configuration (index.js)

```javascript
const CONFIG = {
    API_URL: 'https://gateway.bibliocommons.com/v2/libraries/sandiego/bibs/S161C1805116/availability',
    BRANCH_NAME: 'Rancho Penasquitos',
    NTFY_TOPIC: 'sdparkpass',
    NTFY_SERVER: 'https://ntfy.sh',
    POLL_INTERVAL: '0 * * * *', // Every hour
    // ...
};
```

### Systemd Service

The service runs as user `nobody` for security and includes:
- Automatic restart on failure
- Proper logging via journald
- Security hardening
- Environment isolation

View logs:
```bash
sudo journalctl -u sd-park-pass-ntfy -f
```

## API Response Format

The monitor expects BiblioCommons API responses in this format:

```json
{
  "entities": {
    "bibItems": {
      "1805116|31336107103179||76": {
        "collection": "Adult - Circulation Desk",
        "callNumber": "CA STATE LIBRARY PARKS PASS HIKING BACKPACK",
        "itemId": "1805116|31336107103179||76",
        "branch": {
          "name": "Rancho Penasquitos",
          "code": "29"
        },
        "availability": {
          "status": "AVAILABLE",
          "statusType": "AVAILABLE",
          "libraryStatus": "Available"
        },
        "branchName": "Rancho Penasquitos",
        "dueDate": null
      }
    }
  }
}
```

The monitor looks for:
- Items with `branchName` containing "Rancho Penasquitos"
- Items with `availability.statusType` NOT equal to "UNAVAILABLE"
- Available status types include: "AVAILABLE", "RECENTLY_RETURNED"

## State Management

The monitor tracks availability in `last_availability.json`:

```json
{
  "availabilityCount": 2,
  "lastUpdated": "2025-07-13T10:00:00.000Z",
  "previousCount": 1,
  "branch": "Rancho Penasquitos",
  "apiUrl": "https://..."
}
```

## Notification Types

- 📚 **High Priority**: New books became available
- ⚠️ **Low Priority**: Errors or status changes
- 🔴 **Service Events**: Start/stop notifications

## Troubleshooting

### Common Issues

1. **No notifications received**:
   - Check ntfy topic subscription on your phone
   - Verify NTFY_SERVER and NTFY_TOPIC settings
   - Test with `node mock.js notify`

2. **API errors**:
   - Check network connectivity
   - Verify API URL is still valid
   - Monitor rate limiting

3. **Service not starting**:
   - Check file permissions
   - Review systemd logs: `journalctl -u sd-park-pass-ntfy`
   - Ensure Node.js is installed on server

### Mock Testing

Use the mock script to verify functionality:

```bash
# Interactive mode
node mock.js

# Commands in interactive mode:
> test 5     # Simulate 5 available books
> notify     # Send test notification  
> status     # Show current state
> reset      # Clear state file
> quit       # Exit
```

## Files

- `index.js` - Main application
- `test.js` - Test suite
- `mock.js` - Mock testing script
- `validate-real-response.js` - Validates parsing against real API response
- `deploy.sh` - Deployment script
- `sd-park-pass-ntfy.service` - Systemd service file
- `test-config.js` - Test configuration and mock data
- `example-response.json` - Real API response example for reference

## License

ISC