from fastapi import APIRouter, Depends, HTTPException

from middleware.auth import require_auth
from sse_starlette.sse import EventSourceResponse
from typing import Dict, Any
import asyncio
import json

from orchestrator.debate_orchestrator import DebateOrchestrator
from models.debate import DebateRequest
from storage.session_manager import SessionManager
from db_models import get_db

router = APIRouter(tags=["debates"])


@router.post("/debate/create", dependencies=[Depends(require_auth)])
async def create_debate(debate_request: DebateRequest, db=Depends(get_db)) -> Dict[str, Any]:
    """
    Create a new debate session with specified parameters
    """
    try:
        orchestrator = DebateOrchestrator(db)
        session_id = await orchestrator.create_session(debate_request)

        return {
            "session_id": session_id,
            "status": "created",
            "message": f"Debate session {session_id} created successfully"
        }
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))


@router.get("/debate/{session_id}")
async def get_debate(session_id: str, db=Depends(get_db)) -> Dict[str, Any]:
    """
    Get the current state of a debate session
    """
    try:
        orchestrator = DebateOrchestrator(db)
        session = await orchestrator.get_session_status(session_id)

        if not session:
            raise HTTPException(status_code=404, detail=f"Debate session {session_id} not found")

        return session.dict()
    except HTTPException:
        raise
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))


@router.post("/debate/{session_id}/start", dependencies=[Depends(require_auth)])
async def start_debate(session_id: str, db=Depends(get_db)) -> Dict[str, Any]:
    """
    Start a debate session and stream the results
    """
    try:
        orchestrator = DebateOrchestrator(db)
        session = await orchestrator.run_debate(session_id)

        return {
            "session_id": session_id,
            "status": session.status,
            "message": f"Debate session {session_id} completed"
        }
    except Exception as e:
        import traceback
        traceback.print_exc()
        raise HTTPException(status_code=500, detail=str(e))


@router.delete("/debate/{session_id}", dependencies=[Depends(require_auth)])
async def end_debate(session_id: str, db=Depends(get_db)) -> Dict[str, Any]:
    """
    End a debate session prematurely
    """
    try:
        orchestrator = DebateOrchestrator(db)
        await orchestrator.terminate_session(session_id)

        return {"session_id": session_id, "status": "terminated"}
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))


@router.get("/debate/{session_id}/stream")
async def stream_debate(session_id: str, db=Depends(get_db)) -> EventSourceResponse:
    """
    Stream debate updates in real-time using Server-Sent Events
    """
    async def event_generator():
        session_manager = SessionManager()

        # Check if the session exists
        session = await session_manager.get_session(db, session_id)
        if not session:
            yield {"event": "error", "data": json.dumps({"error": f"Session {session_id} not found"})}
            return

        # Yield initial state
        yield {"event": "update", "data": json.dumps({
            "session_id": session_id,
            "status": session.status,
            "rounds": [round.dict() for round in session.rounds],
            "evidence_library": [e.dict() for e in session.evidence_library],
            "message": "Debate session initialized"
        }, default=str)}

        last_round_count = len(session.rounds)
        # Poll until debate completes or times out (max 5 min)
        for _ in range(150):  # 150 × 2s = 300s timeout
            await asyncio.sleep(2)

            # Reset transaction so we see commits from the run_debate request
            db.commit()

            updated_session = await session_manager.get_session(db, session_id)
            if not updated_session:
                break

            # Only yield update when rounds actually changed
            if len(updated_session.rounds) != last_round_count or updated_session.status != session.status:
                last_round_count = len(updated_session.rounds)
                session = updated_session
                yield {"event": "update", "data": json.dumps({
                    "session_id": session_id,
                    "status": updated_session.status,
                    "rounds": [round.dict() for round in updated_session.rounds],
                    "evidence_library": [e.dict() for e in updated_session.evidence_library],
                    "current_round": len(updated_session.rounds)
                }, default=str)}

            if updated_session.status in ("completed", "terminated"):
                yield {"event": "complete", "data": json.dumps({
                    "session_id": session_id,
                    "status": updated_session.status,
                    "summary": updated_session.summary,
                    "rounds": [round.dict() for round in updated_session.rounds],
                    "evidence_library": [e.dict() for e in updated_session.evidence_library]
                }, default=str)}
                break

    return EventSourceResponse(event_generator())


@router.get("/sessions")
async def list_sessions(db=Depends(get_db)) -> Dict[str, Any]:
    """
    List all debate sessions
    """
    try:
        session_manager = SessionManager()
        sessions = await session_manager.list_sessions(db)
        return {"sessions": sessions}
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))