Add simple HanchuESS Helper

backend/requirements.txt

@@ -1,2 +1,5 @@
 fastapi
-uvicorn[standard]
+uvicorn[standard]
+requests>=2.31.0
+pycryptodome>=3.20.0
+python-dotenv>=1.0.1

backend/src/main.py

@@ -6,6 +6,17 @@ app = FastAPI(title="HanchuESS Solar Backend API")
 def root():
     return {"message": "Welcome to the HanchuESS Solar Backend API!"}
 
+@app.get("/get_access_token", tags=["HanchuESS"])
+def get_access_token():
+    from service.hanchu_service import HanchuESSService
+
+    hanchu_service = HanchuESSService()
+    try:
+        access_token = hanchu_service.get_access_token()
+        return {"access_token": access_token}
+    except Exception as e:
+        return {"error": str(e)}
+
 if __name__ == "__main__":
     import uvicorn
     uvicorn.run(app, host="0.0.0.0", port=8050)

backend/src/service/hanchu_service.py

@@ -0,0 +1,80 @@
+import base64
+import json
+import os
+import requests
+
+from Crypto.Cipher import AES
+from Crypto.Util.Padding import pad
+from dotenv import load_dotenv
+
+
+load_dotenv()
+
+
+class HanchuESSService:
+    def __init__(self):
+        self.name = "HanchuESS Service"
+
+        # Load config from environment
+        self.aes_key = os.environ["HANCHU_AES_KEY"].encode("utf-8")
+        self.aes_iv = os.environ["HANCHU_AES_IV"].encode("utf-8")
+        self.login_url = os.environ["HANCHU_LOGIN_URL"]
+        self.login_type = os.getenv("HANCHU_LOGIN_TYPE", "ACCOUNT")
+        self.timeout = int(os.getenv("HANCHU_HTTP_TIMEOUT", "10"))
+        self.verify_ssl = os.getenv("HANCHU_VERIFY_SSL", "true").lower() == "true"
+        self.hanchu_username = os.getenv("HANCHU_USERNAME", "")
+        self.hanchu_password = os.getenv("HANCHU_PASSWORD", "")
+
+        # Safety checks
+        if len(self.aes_key) not in (16, 24, 32):
+            raise ValueError("AES key must be 16, 24, or 32 bytes")
+        if len(self.aes_iv) != 16:
+            raise ValueError("AES IV must be exactly 16 bytes")
+
+    def encrypt_payload(self, data: dict | str) -> str:
+        """
+        Encrypt payload using AES-CBC and return base64 string.
+        """
+        if not isinstance(data, str):
+            data = json.dumps(data, separators=(",", ":"))
+
+        cipher = AES.new(self.aes_key, AES.MODE_CBC, self.aes_iv)
+        ciphertext = cipher.encrypt(pad(data.encode("utf-8"), AES.block_size))
+        return base64.b64encode(ciphertext).decode("utf-8")
+
+    def get_access_token(self) -> str:
+        """
+        Authenticate with Hanchu ESS and return access token.
+        """
+
+        payload = {
+            "account": self.hanchu_username,
+            "password": self.hanchu_password,
+            "loginType": self.login_type,
+        }
+
+        encrypted_payload = self.encrypt_payload(payload)
+
+        headers = {
+            "Content-Type": "application/json",
+            "Accept": "application/json",
+            "User-Agent": "Mozilla/5.0",
+        }
+
+        response = requests.post(
+            self.login_url,
+            json={"data": encrypted_payload},
+            headers=headers,
+            timeout=self.timeout,
+            verify=self.verify_ssl,
+        )
+
+        response.raise_for_status()
+        result = response.json()
+
+        try:
+            return result["data"]["accessToken"]
+        except (KeyError, TypeError):
+            raise RuntimeError(
+                f"Hanchu login failed: {json.dumps(result, ensure_ascii=False)}"
+            )