# API Troubleshooting Guide

This guide helps you diagnose and resolve common issues with the Telegram Marketing Agent API.

## Table of Contents

- [Authentication Issues](#authentication-issues)
- [Rate Limiting](#rate-limiting)
- [Campaign Execution Problems](#campaign-execution-problems)
- [Data Import/Export Issues](#data-importexport-issues)
- [Webhook Problems](#webhook-problems)
- [Performance Issues](#performance-issues)
- [Error Codes Reference](#error-codes-reference)

## Authentication Issues

### Problem: 401 Unauthorized Error

**Symptoms:**
```json
{
  "success": false,
  "error": "Unauthorized",
  "code": "UNAUTHORIZED"
}
```

**Solutions:**

1. **Check Token Format**
   ```bash
   # Correct format
   curl -H "Authorization: Bearer YOUR_TOKEN" https://api.example.com/v1/users
   
   # Common mistakes
   curl -H "Authorization: YOUR_TOKEN" # Missing "Bearer" prefix
   curl -H "Authorization: bearer YOUR_TOKEN" # Lowercase "bearer"
   ```

2. **Verify Token Expiration**
   - Access tokens expire after 24 hours
   - Use the refresh token endpoint to get a new access token
   ```bash
   curl -X POST https://api.example.com/v1/auth/refresh \
     -H "Content-Type: application/json" \
     -d '{"refreshToken": "YOUR_REFRESH_TOKEN"}'
   ```

3. **Check API Key (if using)**
   ```bash
   curl -H "X-API-Key: YOUR_API_KEY" https://api.example.com/v1/users
   ```

### Problem: 403 Forbidden Error

**Symptoms:**
- User authenticated but lacks permissions
- Specific endpoints return forbidden

**Solutions:**

1. Check user role and permissions
2. Verify endpoint access requirements
3. Contact admin for permission updates

## Rate Limiting

### Problem: 429 Too Many Requests

**Symptoms:**
```json
{
  "success": false,
  "error": "Too many requests",
  "code": "RATE_LIMIT_EXCEEDED",
  "details": {
    "retryAfter": 60
  }
}
```

**Solutions:**

1. **Check Rate Limit Headers**
   ```
   X-RateLimit-Limit: 100
   X-RateLimit-Remaining: 0
   X-RateLimit-Reset: 1642012800
   ```

2. **Implement Exponential Backoff**
   ```javascript
   async function retryWithBackoff(fn, maxRetries = 3) {
     for (let i = 0; i < maxRetries; i++) {
       try {
         return await fn();
       } catch (error) {
         if (error.status === 429 && i < maxRetries - 1) {
           const delay = Math.pow(2, i) * 1000;
           await new Promise(resolve => setTimeout(resolve, delay));
         } else {
           throw error;
         }
       }
     }
   }
   ```

3. **Batch Operations**
   - Use bulk endpoints when available
   - Group multiple operations into single requests

## Campaign Execution Problems

### Problem: Campaign Fails to Execute

**Symptoms:**
- Campaign status remains "draft"
- Execution endpoint returns errors

**Solutions:**

1. **Validate Campaign Configuration**
   ```bash
   # Check campaign details
   curl -X GET https://api.example.com/v1/orchestrator/campaigns/CAMPAIGN_ID \
     -H "Authorization: Bearer YOUR_TOKEN"
   ```

2. **Common Issues:**
   - Empty target audience
   - Missing message content
   - Invalid scheduling parameters
   - Telegram account not connected

3. **Test Mode First**
   ```bash
   curl -X POST https://api.example.com/v1/orchestrator/campaigns/CAMPAIGN_ID/execute \
     -H "Authorization: Bearer YOUR_TOKEN" \
     -H "Content-Type: application/json" \
     -d '{
       "test": true,
       "testUsers": ["user_123", "user_456"]
     }'
   ```

### Problem: Low Delivery Rate

**Solutions:**

1. **Check Rate Limits**
   - Telegram has strict rate limits
   - Reduce messages per second in campaign settings

2. **Verify User Status**
   - Check if users have blocked the bot
   - Ensure phone numbers are valid

3. **Monitor Telegram Account Health**
   - Check for account restrictions
   - Verify account connection status

## Data Import/Export Issues

### Problem: Import Fails with Validation Errors

**Solutions:**

1. **Validate CSV Format**
   ```csv
   telegramId,username,firstName,lastName,phoneNumber,tags
   123456789,johndoe,John,Doe,+1234567890,"customer,active"
   ```

2. **Common Issues:**
   - Missing required fields
   - Invalid phone number format
   - Special characters in CSV
   - File encoding (use UTF-8)

3. **Use Template**
   ```bash
   # Download template
   curl -X GET https://api.example.com/v1/users/import/template \
     -H "Authorization: Bearer YOUR_TOKEN" \
     -o user_template.csv
   ```

### Problem: Export Timeout for Large Datasets

**Solutions:**

1. **Use Filters**
   ```json
   {
     "format": "csv",
     "filters": {
       "status": "active",
       "createdAt": {
         "from": "2024-01-01",
         "to": "2024-01-31"
       }
     },
     "limit": 10000
   }
   ```

2. **Paginated Export**
   - Export in batches
   - Use background job for large exports

## Webhook Problems

### Problem: Webhooks Not Triggering

**Solutions:**

1. **Verify Webhook Configuration**
   ```bash
   curl -X GET https://api.example.com/v1/webhooks/WEBHOOK_ID \
     -H "Authorization: Bearer YOUR_TOKEN"
   ```

2. **Test Webhook**
   ```bash
   curl -X POST https://api.example.com/v1/webhooks/WEBHOOK_ID/test \
     -H "Authorization: Bearer YOUR_TOKEN" \
     -H "Content-Type: application/json" \
     -d '{
       "event": "campaign.completed",
       "payload": {"test": true}
     }'
   ```

3. **Common Issues:**
   - URL not publicly accessible
   - SSL certificate problems
   - Timeout (webhook must respond within 10s)
   - Response status not 2xx

### Problem: Duplicate Webhook Events

**Solutions:**

1. Implement idempotency using event IDs
2. Check webhook logs for retry attempts
3. Ensure webhook responds quickly

## Performance Issues

### Problem: Slow API Response Times

**Solutions:**

1. **Use Caching Headers**
   ```bash
   # Check if response is cached
   curl -I https://api.example.com/v1/analytics/dashboard \
     -H "Authorization: Bearer YOUR_TOKEN"
   ```

2. **Optimize Queries**
   - Use specific field selection
   - Implement pagination
   - Add appropriate filters

3. **Batch Operations**
   ```json
   {
     "operations": [
       {"method": "GET", "path": "/users/user_123"},
       {"method": "GET", "path": "/users/user_456"}
     ]
   }
   ```

### Problem: Timeout Errors

**Solutions:**

1. **Increase Client Timeout**
   ```javascript
   const response = await fetch(url, {
     timeout: 30000 // 30 seconds
   });
   ```

2. **Use Async Operations**
   - For long-running tasks, use job queues
   - Poll for results

## Error Codes Reference

### HTTP Status Codes

| Code | Meaning | Common Causes |
|------|---------|---------------|
| 400 | Bad Request | Invalid parameters, malformed JSON |
| 401 | Unauthorized | Missing/invalid token, expired token |
| 403 | Forbidden | Insufficient permissions |
| 404 | Not Found | Resource doesn't exist |
| 409 | Conflict | Duplicate resource, conflicting state |
| 422 | Unprocessable Entity | Validation errors |
| 429 | Too Many Requests | Rate limit exceeded |
| 500 | Internal Server Error | Server-side issue |
| 502 | Bad Gateway | Service unavailable |
| 503 | Service Unavailable | Maintenance, overload |

### Application Error Codes

| Code | Description | Solution |
|------|-------------|----------|
| `AUTH_FAILED` | Authentication failed | Check credentials |
| `TOKEN_EXPIRED` | Access token expired | Refresh token |
| `INVALID_INPUT` | Input validation failed | Check request body |
| `RESOURCE_NOT_FOUND` | Requested resource not found | Verify ID/path |
| `DUPLICATE_RESOURCE` | Resource already exists | Use update instead |
| `CAMPAIGN_NOT_READY` | Campaign missing required data | Complete campaign setup |
| `TELEGRAM_ERROR` | Telegram API error | Check account status |
| `QUOTA_EXCEEDED` | Account quota exceeded | Upgrade plan |

## Debug Mode

Enable debug mode for detailed error information:

```bash
curl -X GET https://api.example.com/v1/users \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -H "X-Debug-Mode: true"
```

## Getting Help

If you're still experiencing issues:

1. **Check Logs**
   - Request ID in response headers
   - Include in support tickets

2. **API Status**
   - Check https://status.example.com
   - Follow @api_status for updates

3. **Support Channels**
   - Email: api-support@example.com
   - Discord: https://discord.gg/example
   - GitHub Issues: https://github.com/example/api/issues

## Best Practices

1. **Always Handle Errors**
   ```javascript
   try {
     const response = await api.createCampaign(data);
   } catch (error) {
     if (error.code === 'RATE_LIMIT_EXCEEDED') {
       // Handle rate limit
     } else if (error.code === 'VALIDATION_ERROR') {
       // Handle validation errors
     } else {
       // Handle other errors
     }
   }
   ```

2. **Log Everything**
   - Request/response bodies
   - Headers
   - Timestamps
   - Error messages

3. **Monitor Your Integration**
   - Set up alerts for failures
   - Track success rates
   - Monitor response times

4. **Use SDK When Available**
   - Automatic retry logic
   - Built-in error handling
   - Type safety