import json

from fastapi import APIRouter, Depends, HTTPException, status
from fastapi.responses import StreamingResponse

from ..config import settings
from ..middleware.auth import require_auth
from ..models.schemas import ChatRequest, ChatResponse, ProviderListResponse
from ..services.provider_manager import provider_manager

router = APIRouter(prefix="/api/chat", tags=["chat"])


@router.post("/", response_model=ChatResponse)
async def chat(request: ChatRequest, user: dict = Depends(require_auth)):
    """
    Non-streaming chat endpoint
    """
    try:
        provider = provider_manager.get_provider(request.provider)
        response = await provider.chat(request.message)

        return ChatResponse(message=response, provider=provider.get_provider_name())
    except ValueError as e:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(e))
    except Exception as e:
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Error processing request: {str(e)}",
        )


@router.post("/stream")
async def chat_stream(request: ChatRequest, user: dict = Depends(require_auth)):
    """
    Streaming chat endpoint - returns SSE (Server-Sent Events)
    """
    try:
        provider = provider_manager.get_provider(request.provider)

        async def event_generator():
            try:
                async for chunk in provider.chat_stream(request.message):
                    yield f"data: {json.dumps({'chunk': chunk})}\n\n"

                yield f"data: {json.dumps({'done': True})}\n\n"
            except Exception as e:
                yield f"data: {json.dumps({'error': str(e)})}\n\n"

        return StreamingResponse(
            event_generator(),
            media_type="text/event-stream",
            headers={
                "Cache-Control": "no-cache",
                "Connection": "keep-alive",
            },
        )
    except ValueError as e:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(e))


@router.get("/providers", response_model=ProviderListResponse)
async def list_providers():
    """
    List available providers
    """
    return ProviderListResponse(
        providers=provider_manager.get_available_providers(),
        default=settings.DEFAULT_PROVIDER,
    )