# API Usage Guide

Practical examples for using the Geutebruck Cross-Switching API.

---

## Getting Started

### 1. Login

First, authenticate to get your access token:

**Request:**
```bash
curl -X POST http://localhost:8000/api/v1/auth/login \
  -H "Content-Type: application/json" \
  -d '{
    "username": "admin",
    "password": "admin123"
  }'
```

**Response:**
```json
{
  "access_token": "eyJhbGciOiJIUzI1NiIs...",
  "refresh_token": "eyJhbGciOiJIUzI1NiIs...",
  "token_type": "bearer",
  "expires_in": 3600
}
```

**Save the access token** for subsequent requests.

---

## Common Operations

### Discover Available Cameras

```bash
curl -X GET http://localhost:8000/api/v1/cameras \
  -H "Authorization: Bearer YOUR_ACCESS_TOKEN"
```

**Response:**
```json
{
  "cameras": [
    {
      "id": 1,
      "name": "Entrance Camera",
      "status": "online",
      "has_ptz": true
    },
    {
      "id": 2,
      "name": "Parking Lot Camera",
      "status": "online",
      "has_ptz": false
    }
  ],
  "total": 2
}
```

### Discover Available Monitors

```bash
curl -X GET http://localhost:8000/api/v1/monitors \
  -H "Authorization: Bearer YOUR_ACCESS_TOKEN"
```

**Response:**
```json
{
  "monitors": [
    {
      "id": 1,
      "name": "Control Room Monitor 1",
      "status": "idle",
      "current_camera_id": null
    },
    {
      "id": 2,
      "name": "Control Room Monitor 2",
      "status": "active",
      "current_camera_id": 5
    }
  ],
  "total": 2
}
```

### Find Available (Idle) Monitors

```bash
curl -X GET http://localhost:8000/api/v1/monitors/filter/available \
  -H "Authorization: Bearer YOUR_ACCESS_TOKEN"
```

Returns only monitors with no camera currently assigned.

---

## Cross-Switching Operations

### Route Camera to Monitor

**⚠️ Requires Operator role or higher**

```bash
curl -X POST http://localhost:8000/api/v1/crossswitch \
  -H "Authorization: Bearer YOUR_ACCESS_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "camera_id": 1,
    "monitor_id": 1,
    "mode": 0
  }'
```

**Response:**
```json
{
  "success": true,
  "message": "Successfully switched camera 1 to monitor 1",
  "route": {
    "id": "uuid",
    "camera_id": 1,
    "monitor_id": 1,
    "executed_at": "2025-12-09T12:00:00Z",
    "executed_by_username": "operator"
  }
}
```

### Clear Monitor

**⚠️ Requires Operator role or higher**

```bash
curl -X POST http://localhost:8000/api/v1/crossswitch/clear \
  -H "Authorization: Bearer YOUR_ACCESS_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "monitor_id": 1
  }'
```

### Get Current Routing State

```bash
curl -X GET http://localhost:8000/api/v1/crossswitch/routing \
  -H "Authorization: Bearer YOUR_ACCESS_TOKEN"
```

**Response:**
```json
{
  "routes": [
    {
      "camera_id": 1,
      "monitor_id": 1,
      "executed_at": "2025-12-09T12:00:00Z",
      "is_active": true
    }
  ],
  "total": 1
}
```

### Get Routing History

```bash
curl -X GET "http://localhost:8000/api/v1/crossswitch/history?limit=10&offset=0" \
  -H "Authorization: Bearer YOUR_ACCESS_TOKEN"
```

**Filter by camera:**
```bash
curl -X GET "http://localhost:8000/api/v1/crossswitch/history?camera_id=1" \
  -H "Authorization: Bearer YOUR_ACCESS_TOKEN"
```

**Filter by monitor:**
```bash
curl -X GET "http://localhost:8000/api/v1/crossswitch/history?monitor_id=1" \
  -H "Authorization: Bearer YOUR_ACCESS_TOKEN"
```

---

## Use Case Examples

### Use Case 1: Quick Camera Check

**Scenario**: Operator wants to quickly view entrance camera on their monitor.

**Steps:**
1. Find available monitor
2. Route entrance camera to that monitor

```bash
# Step 1: Find available monitors
curl -X GET http://localhost:8000/api/v1/monitors/filter/available \
  -H "Authorization: Bearer $TOKEN"

# Step 2: Route camera 1 to monitor 1
curl -X POST http://localhost:8000/api/v1/crossswitch \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"camera_id": 1, "monitor_id": 1}'
```

### Use Case 2: Monitor Rotation

**Scenario**: Automatically rotate through cameras on a monitor.

**Script (PowerShell):**
```powershell
$token = "YOUR_ACCESS_TOKEN"
$monitor_id = 1
$cameras = @(1, 2, 3, 4)  # Camera IDs to rotate

foreach ($camera_id in $cameras) {
    # Switch camera
    Invoke-RestMethod -Uri "http://localhost:8000/api/v1/crossswitch" `
        -Method POST `
        -Headers @{ "Authorization" = "Bearer $token" } `
        -ContentType "application/json" `
        -Body (@{ camera_id = $camera_id; monitor_id = $monitor_id } | ConvertTo-Json)

    # Wait 10 seconds
    Start-Sleep -Seconds 10
}
```

### Use Case 3: Incident Response

**Scenario**: Security incident detected, switch multiple cameras to control room monitors.

```bash
# Cameras 1-4 to monitors 1-4
for i in {1..4}; do
  curl -X POST http://localhost:8000/api/v1/crossswitch \
    -H "Authorization: Bearer $TOKEN" \
    -H "Content-Type: application/json" \
    -d "{\"camera_id\": $i, \"monitor_id\": $i}"
done
```

### Use Case 4: Audit Trail Review

**Scenario**: Review who accessed which cameras today.

```bash
# Get routing history for today
curl -X GET "http://localhost:8000/api/v1/crossswitch/history?limit=100" \
  -H "Authorization: Bearer $TOKEN" \
  | jq '.history[] | select(.executed_at | startswith("2025-12-09"))'
```

---

## Python Client Example

```python
import requests

class GeutebruckAPI:
    def __init__(self, base_url="http://localhost:8000", username="admin", password="admin123"):
        self.base_url = base_url
        self.token = None
        self.login(username, password)

    def login(self, username, password):
        """Authenticate and get token"""
        response = requests.post(
            f"{self.base_url}/api/v1/auth/login",
            json={"username": username, "password": password}
        )
        response.raise_for_status()
        self.token = response.json()["access_token"]

    def _headers(self):
        return {"Authorization": f"Bearer {self.token}"}

    def list_cameras(self):
        """Get all cameras"""
        response = requests.get(
            f"{self.base_url}/api/v1/cameras",
            headers=self._headers()
        )
        return response.json()

    def list_monitors(self):
        """Get all monitors"""
        response = requests.get(
            f"{self.base_url}/api/v1/monitors",
            headers=self._headers()
        )
        return response.json()

    def crossswitch(self, camera_id, monitor_id, mode=0):
        """Execute cross-switch"""
        response = requests.post(
            f"{self.base_url}/api/v1/crossswitch",
            headers=self._headers(),
            json={
                "camera_id": camera_id,
                "monitor_id": monitor_id,
                "mode": mode
            }
        )
        return response.json()

    def clear_monitor(self, monitor_id):
        """Clear monitor"""
        response = requests.post(
            f"{self.base_url}/api/v1/crossswitch/clear",
            headers=self._headers(),
            json={"monitor_id": monitor_id}
        )
        return response.json()

    def get_routing_state(self):
        """Get current routing state"""
        response = requests.get(
            f"{self.base_url}/api/v1/crossswitch/routing",
            headers=self._headers()
        )
        return response.json()


# Usage Example
api = GeutebruckAPI()

# List cameras
cameras = api.list_cameras()
print(f"Found {cameras['total']} cameras")

# Route camera 1 to monitor 1
result = api.crossswitch(camera_id=1, monitor_id=1)
print(f"Cross-switch: {result['message']}")

# Get routing state
routing = api.get_routing_state()
print(f"Active routes: {routing['total']}")
```

---

## C# Client Example

```csharp
using System;
using System.Net.Http;
using System.Net.Http.Json;
using System.Threading.Tasks;

public class GeutebruckApiClient
{
    private readonly HttpClient _client;
    private string _accessToken;

    public GeutebruckApiClient(string baseUrl = "http://localhost:8000")
    {
        _client = new HttpClient { BaseAddress = new Uri(baseUrl) };
    }

    public async Task LoginAsync(string username, string password)
    {
        var response = await _client.PostAsJsonAsync("/api/v1/auth/login", new
        {
            username,
            password
        });

        response.EnsureSuccessStatusCode();
        var result = await response.Content.ReadFromJsonAsync<LoginResponse>();
        _accessToken = result.AccessToken;
        _client.DefaultRequestHeaders.Authorization =
            new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", _accessToken);
    }

    public async Task<CameraListResponse> ListCamerasAsync()
    {
        var response = await _client.GetAsync("/api/v1/cameras");
        response.EnsureSuccessStatusCode();
        return await response.Content.ReadFromJsonAsync<CameraListResponse>();
    }

    public async Task<CrossSwitchResponse> ExecuteCrossSwitchAsync(int cameraId, int monitorId, int mode = 0)
    {
        var response = await _client.PostAsJsonAsync("/api/v1/crossswitch", new
        {
            camera_id = cameraId,
            monitor_id = monitorId,
            mode
        });

        response.EnsureSuccessStatusCode();
        return await response.Content.ReadFromJsonAsync<CrossSwitchResponse>();
    }
}

// Usage
var api = new GeutebruckApiClient();
await api.LoginAsync("admin", "admin123");

var cameras = await api.ListCamerasAsync();
Console.WriteLine($"Found {cameras.Total} cameras");

var result = await api.ExecuteCrossSwitchAsync(cameraId: 1, monitorId: 1);
Console.WriteLine($"Cross-switch: {result.Message}");
```

---

## Testing with Postman

1. **Import Collection**: Import the OpenAPI spec from http://localhost:8000/openapi.json
2. **Set Environment Variable**: Create `access_token` variable
3. **Login**: Run POST /api/v1/auth/login, save token to environment
4. **Test Endpoints**: All subsequent requests will use the token automatically

---

## Troubleshooting

### 401 Unauthorized

**Problem**: Token expired or invalid.

**Solution**: Re-authenticate:
```bash
# Get new token
curl -X POST http://localhost:8000/api/v1/auth/login \
  -d '{"username":"admin","password":"admin123"}'
```

### 403 Forbidden

**Problem**: User role insufficient (e.g., Viewer trying to execute cross-switch).

**Solution**: Use account with Operator or Administrator role.

### 404 Not Found

**Problem**: Camera or monitor ID doesn't exist.

**Solution**: List cameras/monitors to find valid IDs.

### 500 Internal Server Error

**Problem**: SDK Bridge communication failure or database error.

**Solution**:
1. Check health endpoint: `/health`
2. Verify SDK Bridge is running
3. Check API logs

---

## Best Practices

1. **Always check health before operations**
2. **Cache camera/monitor lists** (refreshed every 60s)
3. **Handle 401 errors** by re-authenticating
4. **Use refresh tokens** to extend sessions
5. **Log all cross-switch operations** to external system
6. **Implement retry logic** for transient failures
7. **Monitor audit logs** for security events

---

## Next Steps

- Explore interactive documentation: http://localhost:8000/docs
- Review API reference: `docs/api-reference.md`
- Check deployment guide: `docs/deployment.md`
- Review architecture: `docs/architecture.md`