barebone app with django and react, sse, jwt token, comport reader, test comport writer, requires com0com, users with groups, sample table vehicles, tokens for access and refresh

serial_bridge/backend_client.py

@@ -0,0 +1,117 @@
+"""
+Backend API Client
+Handles communication with Django backend
+"""
+import requests
+import logging
+from typing import Optional, Dict, Any
+from requests.adapters import HTTPAdapter
+from urllib3.util.retry import Retry
+
+logger = logging.getLogger(__name__)
+
+class BackendClient:
+    def __init__(self, base_url: str, timeout: int = 5, max_retries: int = 3):
+        self.base_url = base_url
+        self.timeout = timeout
+        self.max_retries = max_retries
+        self.session = self._create_session()
+    
+    def _create_session(self) -> requests.Session:
+        """Create a requests session with retry logic"""
+        session = requests.Session()
+        
+        retry_strategy = Retry(
+            total=self.max_retries,
+            backoff_factor=1,
+            status_forcelist=[429, 500, 502, 503, 504],
+            allowed_methods=["HEAD", "GET", "OPTIONS", "POST"]
+        )
+        
+        adapter = HTTPAdapter(max_retries=retry_strategy)
+        session.mount("http://", adapter)
+        session.mount("https://", adapter)
+        
+        return session
+    
+    def post_reading(self, port: str, data: str) -> bool:
+        """Post a serial port reading to the backend"""
+        try:
+            url = f"{self.base_url}/api/readings/"
+            payload = {
+                'port': port,
+                'data': data
+            }
+            
+            response = self.session.post(
+                url,
+                json=payload,
+                timeout=self.timeout
+            )
+            
+            if response.status_code in [200, 201]:
+                logger.info(f"Successfully posted reading to backend")
+                return True
+            else:
+                logger.warning(f"Backend returned status {response.status_code}")
+                return False
+                
+        except requests.exceptions.RequestException as e:
+            logger.error(f"Error posting reading to backend: {e}")
+            return False
+    
+    def get_latest_reading(self, port: Optional[str] = None) -> Optional[Dict[str, Any]]:
+        """Get the latest reading from backend"""
+        try:
+            url = f"{self.base_url}/api/readings/latest/"
+            params = {'port': port} if port else {}
+            
+            response = self.session.get(
+                url,
+                params=params,
+                timeout=self.timeout
+            )
+            
+            if response.status_code == 200:
+                return response.json()
+            else:
+                logger.warning(f"Backend returned status {response.status_code}")
+                return None
+                
+        except requests.exceptions.RequestException as e:
+            logger.error(f"Error getting latest reading: {e}")
+            return None
+
+    def get_readings(self, port: Optional[str] = None, limit: int = 10) -> Optional[list]:
+        """Get readings from backend"""
+        try:
+            url = f"{self.base_url}/api/readings/"
+            params = {'limit': limit}
+            if port:
+                params['port'] = port
+            
+            response = self.session.get(
+                url,
+                params=params,
+                timeout=self.timeout
+            )
+            
+            if response.status_code == 200:
+                return response.json()
+            else:
+                logger.warning(f"Backend returned status {response.status_code}")
+                return None
+                
+        except requests.exceptions.RequestException as e:
+            logger.error(f"Error getting readings: {e}")
+            return None
+    
+    def health_check(self) -> bool:
+        """Check if backend is available"""
+        try:
+            url = f"{self.base_url}/api/health/"
+            response = self.session.get(url, timeout=self.timeout)
+            return response.status_code == 200
+        except Exception as e:
+            logger.error(f"Backend health check failed: {e}")
+            return False