# Audit Logging Implementation

This document describes the audit logging system implemented for the panel application. The system provides comprehensive tracking of user actions and system events for security, compliance, and monitoring purposes.

## Features

- **Comprehensive Action Tracking**: Logs all CRUD operations on projects, tasks, contracts, notes, and user management
- **Authentication Events**: Tracks login attempts, successes, and failures
- **Detailed Context**: Captures IP addresses, user agents, and request details
- **Flexible Filtering**: Query logs by user, action, resource type, date range, and more
- **Statistics Dashboard**: Provides insights into system usage patterns
- **Role-based Access**: Only admins and project managers can view audit logs
- **Performance Optimized**: Uses database indexes for efficient querying

## Architecture

### Core Components

1. **Audit Log Utility** (`src/lib/auditLog.js`)

   - Core logging functions
   - Query and statistics functions
   - Action and resource type constants

2. **API Endpoints** (`src/app/api/audit-logs/`)

   - `/api/audit-logs` - Query audit logs with filtering
   - `/api/audit-logs/stats` - Get audit log statistics

3. **UI Components** (`src/components/AuditLogViewer.js`)

   - Interactive audit log viewer
   - Advanced filtering interface
   - Statistics dashboard

4. **Admin Pages** (`src/app/admin/audit-logs/`)
   - Admin interface for viewing audit logs
   - Role-based access control

### Database Schema

The audit logs are stored in the `audit_logs` table:

```sql
CREATE TABLE audit_logs (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  user_id TEXT,                    -- User who performed the action
  action TEXT NOT NULL,            -- Action performed (see AUDIT_ACTIONS)
  resource_type TEXT,              -- Type of resource affected
  resource_id TEXT,                -- ID of the affected resource
  ip_address TEXT,                 -- IP address of the user
  user_agent TEXT,                 -- Browser/client information
  timestamp TEXT DEFAULT CURRENT_TIMESTAMP,
  details TEXT,                    -- Additional details (JSON)
  FOREIGN KEY (user_id) REFERENCES users(id)
);
```

## Usage

### Basic Logging

```javascript
import { logAuditEvent, AUDIT_ACTIONS, RESOURCE_TYPES } from "@/lib/auditLog";

// Log a simple action
logAuditEvent({
	action: AUDIT_ACTIONS.PROJECT_CREATE,
	userId: "user123",
	resourceType: RESOURCE_TYPES.PROJECT,
	resourceId: "proj-456",
	ipAddress: req.ip,
	userAgent: req.headers["user-agent"],
	details: {
		project_name: "New Project",
		project_number: "NP-001",
	},
});
```

### API Route Integration

```javascript
import { logApiAction, AUDIT_ACTIONS, RESOURCE_TYPES } from "@/lib/auditLog";

export async function POST(req) {
	const data = await req.json();

	// Perform the operation
	const result = createProject(data);

	// Log the action
	logApiAction(
		req,
		AUDIT_ACTIONS.PROJECT_CREATE,
		RESOURCE_TYPES.PROJECT,
		result.id.toString(),
		req.session,
		{ projectData: data }
	);

	return NextResponse.json({ success: true, id: result.id });
}
```

### Querying Audit Logs

```javascript
import { getAuditLogs, getAuditLogStats } from "@/lib/auditLog";

// Get recent logs
const recentLogs = getAuditLogs({
	limit: 50,
	orderBy: "timestamp",
	orderDirection: "DESC",
});

// Get logs for a specific user
const userLogs = getAuditLogs({
	userId: "user123",
	startDate: "2025-01-01T00:00:00Z",
	endDate: "2025-12-31T23:59:59Z",
});

// Get statistics
const stats = getAuditLogStats({
	startDate: "2025-01-01T00:00:00Z",
	endDate: "2025-12-31T23:59:59Z",
});
```

## Available Actions

### Authentication Actions

- `login` - Successful user login
- `logout` - User logout
- `login_failed` - Failed login attempt

### Project Actions

- `project_create` - Project creation
- `project_update` - Project modification
- `project_delete` - Project deletion
- `project_view` - Project viewing

### Task Actions

- `task_create` - Task creation
- `task_update` - Task modification
- `task_delete` - Task deletion
- `task_status_change` - Task status modification

### Project Task Actions

- `project_task_create` - Project task assignment
- `project_task_update` - Project task modification
- `project_task_delete` - Project task removal
- `project_task_status_change` - Project task status change

### Contract Actions

- `contract_create` - Contract creation
- `contract_update` - Contract modification
- `contract_delete` - Contract deletion

### Note Actions

- `note_create` - Note creation
- `note_update` - Note modification
- `note_delete` - Note deletion

### Admin Actions

- `user_create` - User account creation
- `user_update` - User account modification
- `user_delete` - User account deletion
- `user_role_change` - User role modification

### System Actions

- `data_export` - Data export operations
- `bulk_operation` - Bulk data operations

## Resource Types

- `project` - Project resources
- `task` - Task templates
- `project_task` - Project-specific tasks
- `contract` - Contracts
- `note` - Notes and comments
- `user` - User accounts
- `session` - Authentication sessions
- `system` - System-level operations

## API Endpoints

### GET /api/audit-logs

Query audit logs with optional filtering.

**Query Parameters:**

- `userId` - Filter by user ID
- `action` - Filter by action type
- `resourceType` - Filter by resource type
- `resourceId` - Filter by resource ID
- `startDate` - Filter from date (ISO string)
- `endDate` - Filter to date (ISO string)
- `limit` - Maximum results (default: 100)
- `offset` - Results offset (default: 0)
- `orderBy` - Order by field (default: timestamp)
- `orderDirection` - ASC or DESC (default: DESC)
- `includeStats` - Include statistics (true/false)

**Response:**

```json
{
  "success": true,
  "data": [
    {
      "id": 1,
      "user_id": "user123",
      "user_name": "John Doe",
      "user_email": "john@example.com",
      "action": "project_create",
      "resource_type": "project",
      "resource_id": "proj-456",
      "ip_address": "192.168.1.100",
      "user_agent": "Mozilla/5.0...",
      "timestamp": "2025-07-09T10:30:00Z",
      "details": {
        "project_name": "New Project",
        "project_number": "NP-001"
      }
    }
  ],
  "stats": {
    "total": 150,
    "actionBreakdown": [...],
    "userBreakdown": [...],
    "resourceBreakdown": [...]
  }
}
```

### GET /api/audit-logs/stats

Get audit log statistics.

**Query Parameters:**

- `startDate` - Filter from date (ISO string)
- `endDate` - Filter to date (ISO string)

**Response:**

```json
{
	"success": true,
	"data": {
		"total": 150,
		"actionBreakdown": [
			{ "action": "project_view", "count": 45 },
			{ "action": "login", "count": 23 }
		],
		"userBreakdown": [
			{ "user_id": "user123", "user_name": "John Doe", "count": 67 }
		],
		"resourceBreakdown": [{ "resource_type": "project", "count": 89 }]
	}
}
```

## Access Control

Audit logs are restricted to users with the following roles:

- `admin` - Full access to all audit logs
- `project_manager` - Full access to all audit logs

Other users cannot access audit logs.

## Testing

Run the audit logging test script:

```bash
node test-audit-logging.mjs
```

This will:

1. Create sample audit events
2. Test querying and filtering
3. Verify statistics generation
4. Test date range filtering

## Integration Status

The audit logging system has been integrated into the following API routes:

✅ **Authentication** (`src/lib/auth.js`)

- Login success/failure tracking
- Account lockout logging

✅ **Projects** (`src/app/api/projects/`)

- Project CRUD operations
- List view access

✅ **Notes** (`src/app/api/notes/`)

- Note creation, updates, and deletion

🔄 **Pending Integration:**

- Tasks API
- Project Tasks API
- Contracts API
- User management API

## Performance Considerations

- Database indexes are created on frequently queried fields
- Large result sets are paginated
- Statistics queries are optimized for common use cases
- Failed operations are logged to prevent data loss

## Security Features

- IP address tracking for forensic analysis
- User agent logging for client identification
- Failed authentication attempt tracking
- Detailed change logging for sensitive operations
- Role-based access control for audit log viewing

## Maintenance

### Log Retention

Consider implementing log retention policies:

```sql
-- Delete audit logs older than 1 year
DELETE FROM audit_logs
WHERE timestamp < datetime('now', '-1 year');
```

### Monitoring

Monitor audit log growth and performance:

```sql
-- Check audit log table size
SELECT COUNT(*) as total_logs,
       MIN(timestamp) as oldest_log,
       MAX(timestamp) as newest_log
FROM audit_logs;

-- Check most active users
SELECT user_id, COUNT(*) as activity_count
FROM audit_logs
WHERE timestamp > datetime('now', '-30 days')
GROUP BY user_id
ORDER BY activity_count DESC
LIMIT 10;
```

## Future Enhancements

- Real-time audit log streaming
- Advanced analytics and reporting
- Integration with external SIEM systems
- Automatic anomaly detection
- Compliance reporting templates
- Log export functionality