"""
Chat API - Main endpoint for interacting with Grimlock
"""

from fastapi import APIRouter, Depends, HTTPException
from fastapi.responses import StreamingResponse
from pydantic import BaseModel
from typing import List, Optional
import logging

from core.context_manager import ContextManager
from core.ai_client import AIClient
import main

logger = logging.getLogger(__name__)

router = APIRouter()

class Message(BaseModel):
    role: str
    content: str

class ChatRequest(BaseModel):
    messages: List[Message]
    role: Optional[str] = None
    stream: bool = False

class ChatResponse(BaseModel):
    response: str
    context_used: bool

@router.post("/", response_model=ChatResponse)
async def chat(
    request: ChatRequest,
    context_manager: ContextManager = Depends(main.get_context_manager),
    ai_client: AIClient = Depends(main.get_ai_client)
):
    """
    Chat with Grimlock
    
    Args:
        request: Chat request with messages and optional role
        
    Returns:
        ChatResponse with AI response
    """
    try:
        # Get the last user message for context
        user_message = None
        for msg in reversed(request.messages):
            if msg.role == "user":
                user_message = msg.content
                break
        
        # Get relevant context
        context = ""
        if user_message:
            context = context_manager.get_context_for_query(
                user_message,
                role=request.role
            )
        
        # Build system prompt
        system_prompt = context_manager.get_system_prompt(role=request.role)
        
        # Add context to system prompt if available
        if context:
            system_prompt += f"\n\n# Company Context\n{context}"
        
        # Convert messages to API format
        api_messages = [
            {"role": msg.role, "content": msg.content}
            for msg in request.messages
        ]
        
        # Get response from AI
        response = await ai_client.chat(
            messages=api_messages,
            system_prompt=system_prompt
        )
        
        return ChatResponse(
            response=response,
            context_used=bool(context)
        )
        
    except Exception as e:
        logger.error(f"Error in chat endpoint: {e}")
        raise HTTPException(status_code=500, detail=str(e))

@router.post("/stream")
async def chat_stream(
    request: ChatRequest,
    context_manager: ContextManager = Depends(main.get_context_manager),
    ai_client: AIClient = Depends(main.get_ai_client)
):
    """Stream chat response from Grimlock"""
    
    try:
        # Get context
        user_message = None
        for msg in reversed(request.messages):
            if msg.role == "user":
                user_message = msg.content
                break
        
        context = ""
        if user_message:
            context = context_manager.get_context_for_query(
                user_message,
                role=request.role
            )
        
        # Build system prompt
        system_prompt = context_manager.get_system_prompt(role=request.role)
        if context:
            system_prompt += f"\n\n# Company Context\n{context}"
        
        # Convert messages
        api_messages = [
            {"role": msg.role, "content": msg.content}
            for msg in request.messages
        ]
        
        # Stream response
        async def generate():
            async for chunk in ai_client.chat_stream(
                messages=api_messages,
                system_prompt=system_prompt
            ):
                yield chunk
        
        return StreamingResponse(generate(), media_type="text/plain")
        
    except Exception as e:
        logger.error(f"Error in chat stream: {e}")
        raise HTTPException(status_code=500, detail=str(e))