import json

from fastapi import APIRouter, Query
from sse_starlette.sse import EventSourceResponse

from app.services.dialogue_service import DialogueService

router = APIRouter(prefix="/api/v1/dialogue", tags=["dialogue"])
dialogue_service = DialogueService()


@router.get("/stream")
async def stream_dialogue(
    dialogue_id: str | None = Query(default=None),
    user_text: str | None = Query(default=None),
    scene_prompt: str | None = Query(default=None),
    difficulty: str = Query(default="A2"),
) -> EventSourceResponse:
    resolved_id = dialogue_id or dialogue_service.create_dialogue_id()

    async def event_generator():
        async for chunk in dialogue_service.stream_dialogue(
            dialogue_id=resolved_id,
            user_text=user_text,
            scene_prompt=scene_prompt,
            difficulty=difficulty,
        ):
            yield {"event": "message", "data": json.dumps(chunk, ensure_ascii=False)}
        yield {"event": "done", "data": json.dumps({"dialogue_id": resolved_id})}

    return EventSourceResponse(event_generator())