Fix: Make client_id parameter optional in /api/reports/last-sync endpoint

- Make client_id query parameter optional in /api/reports/last-sync
- When client_id is not provided, return sync information for all clients associated with the authenticated user's API token
- Add requires_full_sync flag to each client's response when no records exist across ALL report tables
- Update REPORTS_SYNC_PROTOCOL_DOCUMENTATION.md with checking last sync status section
- Add GET LAST SYNC INFORMATION section to REPORTS_SYNC_API_SPECIFICATION.txt

This fix allows clients to query their sync status without needing to know their client_id, making the API more user-friendly and enabling automatic recovery detection.

REPORTS_SYNC_API_SPECIFICATION.txt

@@ -384,6 +384,166 @@ retry_after (integer, optional)
   - Seconds to wait before retrying
   - Only present for rate limit errors
 
+================================================================================
+GET LAST SYNC INFORMATION
+================================================================================
+
+URL: /api/reports/last-sync
+Method: GET
+Authentication: Bearer Token (required)
+Content-Type: application/json
+
+Query Parameters:
+----------------
+client_id (string, optional)
+  - Unique identifier for the client
+  - If provided, retrieves sync information for a specific client
+  - If not provided, returns information for all clients associated with the authenticated user's API token
+
+Request Example (Single Client):
+--------------------------------
+GET /api/reports/last-sync?client_id=abc123def456
+
+Authorization: Bearer your-api-token-here
+
+Request Example (All Clients):
+------------------------------
+GET /api/reports/last-sync
+
+Authorization: Bearer your-api-token-here
+
+Success Response for Single Client (200 OK):
+--------------------------------------------
+{
+  "success": true,
+  "client_id": "abc123def456",
+  "last_sync_id": "sync_20260201_082615_a1b2c3d4",
+  "last_sync_timestamp": "2026-02-01T08:26:15.123456",
+  "last_sync_type": "incremental",
+  "last_date_range": "all",
+  "last_start_date": "2026-01-01T00:00:00",
+  "last_end_date": "2026-02-01T08:26:15",
+  "total_syncs": 5,
+  "requires_full_sync": false,
+  "last_sync_summary": {
+    "total_payin": 15000.00,
+    "total_payout": 10500.00,
+    "net_profit": 4500.00,
+    "total_bets": 45,
+    "total_matches": 1,
+    "cap_compensation_balance": 5000.00
+  },
+  "server_timestamp": "2026-02-01T08:30:00.123456"
+}
+
+Success Response for All Clients (200 OK):
+------------------------------------------
+{
+  "success": true,
+  "message": "Found 2 client(s) for this user",
+  "clients": [
+    {
+      "client_id": "abc123def456",
+      "last_sync_id": "sync_20260201_082615_a1b2c3d4",
+      "last_sync_timestamp": "2026-02-01T08:26:15.123456",
+      "last_sync_type": "incremental",
+      "total_syncs": 5,
+      "requires_full_sync": false,
+      "last_sync_summary": {
+        "total_payin": 15000.00,
+        "total_payout": 10500.00,
+        "net_profit": 4500.00,
+        "total_bets": 45,
+        "total_matches": 1,
+        "cap_compensation_balance": 5000.00
+      }
+    },
+    {
+      "client_id": "xyz789ghi012",
+      "last_sync_id": null,
+      "last_sync_timestamp": null,
+      "last_sync_type": null,
+      "total_syncs": 0,
+      "requires_full_sync": true,
+      "last_sync_summary": null
+    }
+  ],
+  "server_timestamp": "2026-02-01T08:30:00.123456"
+}
+
+Response Fields (Single Client):
+--------------------------------
+success (boolean, required)
+  - Always true for successful request
+
+client_id (string, required)
+  - Client identifier for which sync information was retrieved
+
+last_sync_id (string, optional)
+  - Sync ID of the most recent sync
+  - null if no sync records exist
+
+last_sync_timestamp (string, optional)
+  - ISO 8601 format timestamp of the most recent sync
+  - null if no sync records exist
+
+last_sync_type (string, optional)
+  - Type of the most recent sync ("full" or "incremental")
+  - null if no sync records exist
+
+last_date_range (string, optional)
+  - Date range of the most recent sync
+  - null if no sync records exist
+
+last_start_date (string, optional)
+  - Start date of the most recent sync
+  - null if no sync records exist
+
+last_end_date (string, optional)
+  - End date of the most recent sync
+  - null if no sync records exist
+
+total_syncs (integer, required)
+  - Total number of sync operations for this client
+
+requires_full_sync (boolean, required)
+  - IMPORTANT: Indicates whether the server requires a full sync for this client
+  - Set to true when the server has NO records for this client across ALL report tables (bets, extraction_stats, match_reports)
+  - Client should perform a full sync (send all historical data) when this is true
+  - If ANY record exists for the client in ANY table, this flag will be false
+
+last_sync_summary (object, optional)
+  - Summary statistics from the most recent sync
+  - null if no sync records exist
+
+server_timestamp (string, required)
+  - ISO 8601 format timestamp on server
+  - When the server processed the request
+
+Response Fields (All Clients):
+-------------------------------
+success (boolean, required)
+  - Always true for successful request
+
+message (string, required)
+  - Human-readable message describing the result
+
+clients (array, required)
+  - Array of client objects, each containing the same fields as the single client response
+  - Each client object includes: client_id, last_sync_id, last_sync_timestamp, last_sync_type, total_syncs, requires_full_sync, last_sync_summary
+
+server_timestamp (string, required)
+  - ISO 8601 format timestamp on server
+  - When the server processed the request
+
+Error Response (403 Forbidden):
+--------------------------------
+{
+  "success": false,
+  "error": "Access denied",
+  "details": "You do not have access to this client"
+}
+
 ================================================================================
 CLIENT RETRY BEHAVIOR
 ================================================================================

REPORTS_SYNC_PROTOCOL_DOCUMENTATION.md

@@ -265,6 +265,80 @@ The client should:
 
 **Important**: The server checks across ALL report tables (bets, extraction_stats, match_reports) to determine if a full sync is required. If ANY record exists for the client in ANY table, `requires_full_sync` will be false.
 
+### Checking Last Sync Status
+
+The `/api/reports/last-sync` endpoint allows clients to check their sync status:
+
+**Endpoint**: `GET /api/reports/last-sync?client_id=<client_id>` (optional)
+
+**Authentication**: Bearer token required
+
+**Parameters**:
+- `client_id` (optional): Specific client ID to query. If not provided, returns information for all clients associated with the authenticated user's API token.
+
+**Response when client_id is provided**:
+```json
+{
+  "success": true,
+  "client_id": "client_123",
+  "last_sync_id": "sync_20260201_214327_abc12345",
+  "last_sync_timestamp": "2026-02-01T21:43:27.249Z",
+  "last_sync_type": "incremental",
+  "total_syncs": 5,
+  "requires_full_sync": false,
+  "last_sync_summary": {
+    "total_payin": 100000.0,
+    "total_payout": 95000.0,
+    "net_profit": 5000.0,
+    "total_bets": 50,
+    "total_matches": 1,
+    "cap_compensation_balance": 5000.0
+  },
+  "server_timestamp": "2026-02-02T10:00:00.000Z"
+}
+```
+
+**Response when client_id is NOT provided** (returns all clients for the authenticated user):
+```json
+{
+  "success": true,
+  "message": "Found 2 client(s) for this user",
+  "clients": [
+    {
+      "client_id": "client_123",
+      "last_sync_id": "sync_20260201_214327_abc12345",
+      "last_sync_timestamp": "2026-02-01T21:43:27.249Z",
+      "last_sync_type": "incremental",
+      "total_syncs": 5,
+      "requires_full_sync": false,
+      "last_sync_summary": {
+        "total_payin": 100000.0,
+        "total_payout": 95000.0,
+        "net_profit": 5000.0,
+        "total_bets": 50,
+        "total_matches": 1,
+        "cap_compensation_balance": 5000.0
+      }
+    },
+    {
+      "client_id": "client_456",
+      "last_sync_id": null,
+      "last_sync_timestamp": null,
+      "last_sync_type": null,
+      "total_syncs": 0,
+      "requires_full_sync": true,
+      "last_sync_summary": null
+    }
+  ],
+  "server_timestamp": "2026-02-02T10:00:00.000Z"
+}
+```
+
+**Usage**:
+- Client can call this endpoint without parameters to get status for all its clients
+- Client can check the `requires_full_sync` flag for each client to determine if a full sync is needed
+- This is useful for monitoring sync status across multiple clients
+
 ### Error Response
 
 ```json

app/api/routes.py

@@ -1457,16 +1457,82 @@ def api_get_last_sync():
                 'details': 'Invalid or expired API token'
             }), 401
         
-        # Get client_id from query parameter
+        # Get client_id from query parameter (optional)
         client_id = request.args.get('client_id')
+        
+        # If client_id is not provided, get all clients for this user
         if not client_id:
+            # Get all clients associated with this user's API tokens
+            user_token_ids = [t.id for t in APIToken.query.filter_by(user_id=user.id).all()]
+            if user_token_ids:
+                client_ids = [c.rustdesk_id for c in ClientActivity.query.filter(
+                    ClientActivity.api_token_id.in_(user_token_ids)
+                ).all()]
+                
+                if not client_ids:
                     return jsonify({
-                'success': False,
-                'error': 'Invalid request',
-                'details': 'client_id parameter is required'
-            }), 400
+                        'success': True,
+                        'message': 'No clients found for this user',
+                        'clients': [],
+                        'server_timestamp': datetime.utcnow().isoformat()
+                    }), 200
+                
+                # Return last sync info for all clients
+                clients_data = []
+                for cid in client_ids:
+                    last_sync = ReportSync.query.filter_by(client_id=cid)\
+                        .order_by(desc(ReportSync.sync_timestamp))\
+                        .first()
+                    
+                    if last_sync:
+                        total_syncs = ReportSync.query.filter_by(client_id=cid).count()
+                        clients_data.append({
+                            'client_id': cid,
+                            'last_sync_id': last_sync.sync_id,
+                            'last_sync_timestamp': last_sync.sync_timestamp.isoformat() if last_sync.sync_timestamp else None,
+                            'last_sync_type': last_sync.sync_type if hasattr(last_sync, 'sync_type') else 'unknown',
+                            'total_syncs': total_syncs,
+                            'last_sync_summary': {
+                                'total_payin': float(last_sync.total_payin) if last_sync.total_payin else 0.0,
+                                'total_payout': float(last_sync.total_payout) if last_sync.total_payout else 0.0,
+                                'net_profit': float(last_sync.net_profit) if last_sync.net_profit else 0.0,
+                                'total_bets': last_sync.total_bets,
+                                'total_matches': last_sync.total_matches,
+                                'cap_compensation_balance': float(last_sync.cap_compensation_balance) if last_sync.cap_compensation_balance else 0.0
+                            }
+                        })
+                    else:
+                        # Check if any records exist for this client
+                        total_bets_for_client = Bet.query.filter_by(client_id=cid).count()
+                        total_stats_for_client = ExtractionStats.query.filter_by(client_id=cid).count()
+                        total_match_reports_for_client = MatchReport.query.filter_by(client_id=cid).count()
+                        requires_full_sync = (total_bets_for_client == 0 and total_stats_for_client == 0 and total_match_reports_for_client == 0)
+                        
+                        clients_data.append({
+                            'client_id': cid,
+                            'last_sync_id': None,
+                            'last_sync_timestamp': None,
+                            'last_sync_type': None,
+                            'total_syncs': 0,
+                            'requires_full_sync': requires_full_sync,
+                            'last_sync_summary': None
+                        })
+                
+                return jsonify({
+                    'success': True,
+                    'message': f'Found {len(clients_data)} client(s) for this user',
+                    'clients': clients_data,
+                    'server_timestamp': datetime.utcnow().isoformat()
+                }), 200
+            else:
+                return jsonify({
+                    'success': True,
+                    'message': 'No API tokens found for this user',
+                    'clients': [],
+                    'server_timestamp': datetime.utcnow().isoformat()
+                }), 200
         
-        # Verify user has access to this client
+        # Verify user has access to this specific client
         if not user.is_admin:
             # Check if this client belongs to user's API tokens
             user_token_ids = [t.id for t in APIToken.query.filter_by(user_id=user.id).all()]