refactor: chat_routes (#1512)

# Description

Please include a summary of the changes and the related issue. Please
also include relevant motivation and context.

## Checklist before requesting a review

Please delete options that are not relevant.

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my code
- [ ] I have commented hard-to-understand areas
- [ ] I have ideally added tests that prove my fix is effective or that
my feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged

## Screenshots (if appropriate):

backend/routes/chat/brainful_chat.py

@@ -0,0 +1,43 @@
+from llm.qa_base import QABaseBrainPicking
+from routes.authorizations.brain_authorization import validate_brain_authorization
+from routes.authorizations.types import RoleEnum
+from routes.chat.interface import ChatInterface
+
+from repository.brain import get_brain_details
+
+
+class BrainfulChat(ChatInterface):
+    def validate_authorization(self, user_id, brain_id):
+        if brain_id:
+            validate_brain_authorization(
+                brain_id=brain_id,
+                user_id=user_id,
+                required_roles=[RoleEnum.Viewer, RoleEnum.Editor, RoleEnum.Owner],
+            )
+
+    def get_openai_api_key(self, brain_id, user_id):
+        brain_details = get_brain_details(brain_id)
+        if brain_details:
+            return brain_details.openai_api_key
+
+    def get_answer_generator(
+        self,
+        brain_id,
+        chat_id,
+        model,
+        max_tokens,
+        temperature,
+        user_openai_api_key,
+        streaming,
+        prompt_id,
+    ):
+        return QABaseBrainPicking(
+            chat_id=chat_id,
+            model=model,
+            max_tokens=max_tokens,
+            temperature=temperature,
+            brain_id=brain_id,
+            user_openai_api_key=user_openai_api_key,
+            streaming=streaming,
+            prompt_id=prompt_id,
+        )

backend/routes/chat/brainless_chat.py

@@ -0,0 +1,36 @@
+from llm.qa_headless import HeadlessQA
+from routes.chat.interface import ChatInterface
+
+from repository.user_identity import get_user_identity
+
+
+class BrainlessChat(ChatInterface):
+    def validate_authorization(self, user_id, brain_id):
+        pass
+
+    def get_openai_api_key(self, brain_id, user_id):
+        user_identity = get_user_identity(user_id)
+
+        if user_identity is not None:
+            return user_identity.openai_api_key
+
+    def get_answer_generator(
+        self,
+        brain_id,
+        chat_id,
+        model,
+        max_tokens,
+        temperature,
+        user_openai_api_key,
+        streaming,
+        prompt_id,
+    ):
+        return HeadlessQA(
+            chat_id=chat_id,
+            model=model,
+            max_tokens=max_tokens,
+            temperature=temperature,
+            user_openai_api_key=user_openai_api_key,
+            streaming=streaming,
+            prompt_id=prompt_id,
+        )

backend/routes/chat/factory.py

@@ -0,0 +1,11 @@
+from uuid import UUID
+
+from .brainful_chat import BrainfulChat
+from .brainless_chat import BrainlessChat
+
+
+def get_chat_strategy(brain_id: UUID | None = None):
+    if brain_id:
+        return BrainfulChat()
+    else:
+        return BrainlessChat()

backend/routes/chat/interface.py

@@ -0,0 +1,25 @@
+from abc import ABC, abstractmethod
+
+
+class ChatInterface(ABC):
+    @abstractmethod
+    def validate_authorization(self, user_id, required_roles):
+        pass
+
+    @abstractmethod
+    def get_openai_api_key(self, brain_id, user_id):
+        pass
+
+    @abstractmethod
+    def get_answer_generator(
+        self,
+        brain_id,
+        chat_id,
+        model,
+        max_tokens,
+        temperature,
+        user_openai_api_key,
+        streaming,
+        prompt_id,
+    ):
+        pass

backend/routes/chat/utils.py

@@ -0,0 +1,57 @@
+import time
+from uuid import UUID
+
+from fastapi import HTTPException
+from models import UserIdentity, UserUsage
+from models.databases.supabase.supabase import SupabaseDB
+
+
+class NullableUUID(UUID):
+    @classmethod
+    def __get_validators__(cls):
+        yield cls.validate
+
+    @classmethod
+    def validate(cls, v) -> UUID | None:
+        if v == "":
+            return None
+        try:
+            return UUID(v)
+        except ValueError:
+            return None
+
+
+def delete_chat_from_db(supabase_db: SupabaseDB, chat_id):
+    try:
+        supabase_db.delete_chat_history(chat_id)
+    except Exception as e:
+        print(e)
+        pass
+    try:
+        supabase_db.delete_chat(chat_id)
+    except Exception as e:
+        print(e)
+        pass
+
+
+def check_user_requests_limit(
+    user: UserIdentity,
+):
+    userDailyUsage = UserUsage(
+        id=user.id, email=user.email, openai_api_key=user.openai_api_key
+    )
+
+    userSettings = userDailyUsage.get_user_settings()
+
+    date = time.strftime("%Y%m%d")
+    userDailyUsage.handle_increment_user_request_count(date)
+
+    if user.openai_api_key is None:
+        daily_chat_credit = userSettings.get("daily_chat_credit", 0)
+        if int(userDailyUsage.daily_requests_count) >= int(daily_chat_credit):
+            raise HTTPException(
+                status_code=429,  # pyright: ignore reportPrivateUsage=none
+                detail="You have reached the maximum number of requests for today.",  # pyright: ignore reportPrivateUsage=none
+            )
+    else:
+        pass