feat: added BusinessAuth implementation

solution/api/v1/auth.py

@@ -1,10 +1,39 @@
+import uuid
+
+import jwt
+from django.conf import settings
 from django.http import HttpRequest
 from ninja.security import HttpBearer
+from pydantic import BaseModel, ValidationError
+
+import apps.business.models
 
 
-class BearerAuth(HttpBearer):
+class BusinessToken(BaseModel):
+    business_id: uuid.UUID
+    token_version: int
+
+
+class BusinessAuth(HttpBearer):
     def authenticate(self, request: HttpRequest, token: str) -> str | None:
-        if token == "will implement later":
-            return token
+        try:
+            decoded_payload = jwt.decode(
+                token,
+                settings.SECRET_KEY,
+                algorithms=["HS256"],
+            )
+            token_payload = BusinessToken(**decoded_payload)
+        except (jwt.PyJWTError, ValidationError):
+            return None
 
-        return None
+        try:
+            business = apps.business.models.Business.objects.get(
+                id=token_payload.business_id
+            )
+        except apps.business.models.Business.DoesNotExist:
+            return None
+
+        if business.token_version != token_payload.token_version:
+            return None
+
+        return business