from __future__ import annotations

from datetime import datetime, timezone

from fastapi import APIRouter, Depends, Request
from fastapi.responses import JSONResponse, StreamingResponse

from app_dependencies import get_runtime
from message_pipeline import (
    context_label_from_message_metadata,
    encode_sse_data,
    typed_message_from_api_notification,
)
from nanobot_api_client import stream_nanobot_agent_turn
from route_helpers import read_json_request
from session_store import normalize_session_chat_id
from web_runtime import WebAppRuntime

router = APIRouter()


@router.post("/message")
async def post_message(
    request: Request,
    runtime: WebAppRuntime = Depends(get_runtime),
) -> JSONResponse:
    try:
        payload = await read_json_request(request)
    except ValueError as exc:
        return JSONResponse({"error": str(exc)}, status_code=400)
    text = str(payload.get("text", "")).strip()
    metadata = payload.get("metadata", {})
    chat_id = normalize_session_chat_id(str(payload.get("chat_id", "web") or "web"))
    if not text:
        return JSONResponse({"error": "empty message"}, status_code=400)
    if not chat_id:
        return JSONResponse({"error": "invalid chat id"}, status_code=400)
    if not isinstance(metadata, dict):
        metadata = {}
    try:
        await runtime.gateway.send_user_message(text, metadata=metadata, chat_id=chat_id)
    except RuntimeError as exc:
        return JSONResponse({"error": str(exc)}, status_code=503)
    return JSONResponse({"status": "ok"})


@router.post("/message/stream")
async def stream_message(
    request: Request,
    runtime: WebAppRuntime = Depends(get_runtime),
):
    try:
        payload = await read_json_request(request)
    except ValueError as exc:
        return JSONResponse({"error": str(exc)}, status_code=400)

    text = str(payload.get("text", "")).strip()
    metadata = payload.get("metadata", {})
    chat_id = normalize_session_chat_id(str(payload.get("chat_id", "web") or "web"))
    if not text:
        return JSONResponse({"error": "empty message"}, status_code=400)
    if not chat_id:
        return JSONResponse({"error": "invalid chat id"}, status_code=400)
    if not isinstance(metadata, dict):
        metadata = {}
    context_label = context_label_from_message_metadata(metadata)

    async def stream_turn():
        try:
            yield ": stream-open\n\n"
            yield encode_sse_data(
                {
                    "type": "message",
                    "role": "user",
                    "content": text,
                    "is_progress": False,
                    "is_tool_hint": False,
                    "timestamp": datetime.now(timezone.utc).isoformat(),
                    "context_label": context_label or None,
                }
            )

            async for typed_event in stream_nanobot_agent_turn(
                text,
                chat_id=chat_id,
                metadata=metadata,
                timeout_seconds=60.0,
                notification_to_event=lambda obj: typed_message_from_api_notification(
                    obj,
                    default_chat_id=chat_id,
                ),
            ):
                if typed_event.get("type") == "card":
                    await runtime.publish_cards_changed(
                        typed_event.get("chat_id") if isinstance(typed_event, dict) else chat_id
                    )
                elif typed_event.get("type") == "workbench":
                    await runtime.publish_workbench_changed(
                        typed_event.get("chat_id") if isinstance(typed_event, dict) else chat_id
                    )
                yield encode_sse_data(typed_event)
            await runtime.publish_sessions_changed()
        except RuntimeError as exc:
            yield encode_sse_data({"type": "error", "error": str(exc)})

    return StreamingResponse(
        stream_turn(),
        media_type="text/event-stream",
        headers={
            "Cache-Control": "no-cache",
            "Connection": "keep-alive",
            "X-Accel-Buffering": "no",
        },
    )