feat: implement backend API clients for multi-marketplace integration and frontend service layer

backend/ae_api/__init__.py

@@ -0,0 +1,15 @@
+from .client import AEClient
+from .services.transactions import TransactionsService
+from .services.products import ProductsService
+
+class AliExpressAPI:
+    """
+    Main entry point for AE Platform (AliExpress Russia) SDK.
+    Instantiates all services with a shared client.
+    """
+    def __init__(self, api_token: str = None, user_id: str = None):
+        self.client = AEClient(api_token, user_id)
+        
+        # Initialize services
+        self.transactions = TransactionsService(self.client)
+        self.products = ProductsService(self.client)

backend/ae_api/client.py

@@ -0,0 +1,76 @@
+import os
+import requests
+import time
+from typing import Dict, Any, Optional
+from .exceptions import AEAPIError, AEAuthError, AERateLimitError, AEBadRequestError, AENotFoundError
+
+class AEClient:
+    """Base client for interacting with AE Platform API."""
+    
+    BASE_URL = "https://api2.aeplatform.ru/api/v1"
+    
+    def __init__(self, api_token: Optional[str] = None, user_id: Optional[str] = None):
+        # Fetch from env if not provided
+        self.api_token = api_token or os.getenv('AE_API_TOKEN')
+        self.user_id = user_id or os.getenv('AE_USER_ID')
+        
+        if not self.api_token:
+            raise ValueError("AE_API_TOKEN must be provided")
+            
+        self.session = requests.Session()
+        # AE Platform API requires JWT token and locale
+        self.session.headers.update({
+            "Authorization": self.api_token, # Token from documentation is passed directly in Authorization header
+            "x-request-locale": "ru_RU",
+            "Content-Type": "application/json"
+        })
+
+    def request(self, method: str, path: str, data: Optional[Dict[str, Any]] = None, params: Optional[Dict[str, Any]] = None, retries: int = 3) -> Dict[str, Any]:
+        """Perform HTTP request to AE Platform API with automatic retries."""
+        url = f"{self.BASE_URL}{path}"
+        
+        for attempt in range(retries):
+            try:
+                response = self.session.request(method, url, json=data, params=params)
+                
+                # Check rate limiting
+                if response.status_code == 429:
+                    if attempt < retries - 1:
+                        time.sleep(2 ** attempt)  # Exponential backoff
+                        continue
+                    raise AERateLimitError("Rate limit exceeded")
+
+                if response.status_code in (401, 403):
+                    raise AEAuthError(f"Authentication failed: {response.text}")
+                    
+                if response.status_code in (400, 422):
+                    raise AEBadRequestError(f"Bad Request / Unprocessable Entity: {response.text}")
+
+                if response.status_code == 404:
+                    raise AENotFoundError(f"Not Found: {response.text}")
+                    
+                response.raise_for_status()
+                
+                if response.content:
+                    try:
+                        return response.json()
+                    except ValueError:
+                        return {"status": "success", "text": response.text}
+                return {}
+
+            except requests.exceptions.RequestException as e:
+                if attempt < retries - 1:
+                    time.sleep(2 ** attempt)
+                    continue
+                raise AEAPIError(f"Request failed: {str(e)}")
+                
+        raise AEAPIError("Request failed after max retries")
+
+    def post(self, path: str, data: Optional[Dict[str, Any]] = None) -> Dict[str, Any]:
+        return self.request("POST", path, data=data)
+
+    def get(self, path: str, params: Optional[Dict[str, Any]] = None) -> Dict[str, Any]:
+        return self.request("GET", path, params=params)
+
+    def put(self, path: str, data: Optional[Dict[str, Any]] = None) -> Dict[str, Any]:
+        return self.request("PUT", path, data=data)

backend/ae_api/exceptions.py

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+class AEAPIError(Exception):
+    """Base exception for all AE Platform API errors."""
+    pass
+
+class AEAuthError(AEAPIError):
+    """Raised when authentication fails (HTTP 401 or 403)."""
+    pass
+
+class AERateLimitError(AEAPIError):
+    """Raised when API rate limits are exceeded (HTTP 429)."""
+    pass
+
+class AEBadRequestError(AEAPIError):
+    """Raised when API returns HTTP 400 or 422."""
+    pass
+
+class AENotFoundError(AEAPIError):
+    """Raised when API returns HTTP 404."""
+    pass

backend/ae_api/services/products.py

@@ -0,0 +1,30 @@
+from typing import Dict, Any, Optional
+from ..client import AEClient
+
+class ProductsService:
+    """Service to handle AE Platform Products and Links."""
+    
+    def __init__(self, client: AEClient):
+        self.client = client
+
+    def get_link_info(self, link: str, user_id: Optional[str] = None, user_sub_id: Optional[str] = None) -> Dict[str, Any]:
+        """
+        Get information about a product/link including commission rates.
+        Endpoint: POST /users/{userId}/link/info
+        """
+        uid = user_id or self.client.user_id
+        if not uid:
+            raise ValueError("user_id must be provided either in the method call or client initialization.")
+            
+        payload = {"link": link}
+        if user_sub_id:
+            payload["userSubId"] = user_sub_id
+            
+        return self.client.post(f"/users/{uid}/link/info", data=payload)
+
+    def get_products_feeds(self, limit: int = 30) -> Dict[str, Any]:
+        """
+        Get product feeds.
+        Endpoint: GET /productsfeeds/feeds
+        """
+        return self.client.get("/productsfeeds/feeds", params={"limit": limit})

backend/ae_api/services/transactions.py

@@ -0,0 +1,19 @@
+from typing import Dict, Any, Optional
+from ..client import AEClient
+
+class TransactionsService:
+    """Service to handle AE Platform Transactions (Orders)."""
+    
+    def __init__(self, client: AEClient):
+        self.client = client
+
+    def get_list(self, user_id: Optional[str] = None, params: Optional[Dict[str, Any]] = None) -> Dict[str, Any]:
+        """
+        Get list of transactions (orders) for a user.
+        Endpoint: GET /users/{user_id}/transactions
+        """
+        uid = user_id or self.client.user_id
+        if not uid:
+            raise ValueError("user_id must be provided either in the method call or client initialization.")
+            
+        return self.client.get(f"/users/{uid}/transactions", params=params)