"""A2A task endpoint — the single HTTP entry the orchestrator calls per action.

Collects the messages a Session pushes and returns them; the orchestrator forwards
each to the frontend WebSocket. (Same proven adapter as the rest of the mesh.)
"""
import logging
from uuid import uuid4

from fastapi import APIRouter, Depends
from pydantic import BaseModel, Field

from app.a2a.auth import verify_a2a_key
from app.agent.session import MatchmakingAgentSession

logger = logging.getLogger(__name__)
router = APIRouter()


class TaskRequest(BaseModel):
    task_id: str = Field(default_factory=lambda: str(uuid4()))
    action: str = ""
    params: dict = Field(default_factory=dict)
    user_id: str = ""
    user_context: dict | None = None
    session_start: bool = False


class TaskCollector:
    """WebSocket-shaped sink that captures pushed messages into a list."""

    def __init__(self):
        self.messages: list[dict] = []

    async def accept(self):
        pass

    async def send_json(self, data: dict):
        self.messages.append(data)


@router.post("/a2a/tasks")
async def handle_a2a_task(req: TaskRequest, _token: str = Depends(verify_a2a_key)):
    collector = TaskCollector()
    session = MatchmakingAgentSession(websocket=collector, user_id=req.user_id)

    params = {**req.params}
    if req.user_context:
        params["user_context"] = req.user_context

    try:
        if req.session_start:
            await session.on_session_start(params)
        elif req.action:
            await session.on_user_action(req.action, params)
        else:
            return {"task_id": req.task_id, "status": "error", "messages": [], "error": "No action or session_start"}
        return {"task_id": req.task_id, "status": "completed", "messages": collector.messages}
    except Exception as e:  # noqa: BLE001
        logger.error("A2A task %s failed: %s", req.task_id, e, exc_info=True)
        return {"task_id": req.task_id, "status": "error", "messages": collector.messages, "error": str(e)}