import json
from typing import List, Optional
from sqlalchemy.orm import Session
from src.core.ports.chat_history_port import ChatHistoryPort, ChatMessage

class Message(ChatMessage):
    def __init__(self, role: str, content: str):
        self.role = role
        self.content = content

class PostgresAdapter(ChatHistoryPort):
    def __init__(self, db_session: Session):
        self.db = db_session

    def get_history(self, session_id: str, limit: int = 6) -> List[ChatMessage]:
        from src.core.domain.db_models import ChatHistory
        past_messages = (
            self.db.query(ChatHistory)
            .filter(ChatHistory.session_id == session_id)
            .order_by(ChatHistory.timestamp.asc())
            .limit(limit)
            .all()
        )
        return [Message(role=msg.role, content=msg.content) for msg in past_messages]

    def save_interaction(self, session_id: str, user_query: str, ai_response: str,
                         retrieved_doc_ids: List[str], user_id: Optional[int] = None):
        from src.core.domain.db_models import ChatHistory
        user_msg = ChatHistory(session_id=session_id, role="user", content=user_query, user_id=user_id)
        ai_msg = ChatHistory(
            session_id=session_id,
            role="assistant",
            content=ai_response,
            retrieved_doc_ids=json.dumps(retrieved_doc_ids),
            user_id=user_id
        )
        self.db.add(user_msg)
        self.db.add(ai_msg)
        self.db.commit()