from __future__ import annotations

import logging
from typing import Dict, Optional

from flask import url_for

from models import Display, EventDisplayMap, Video, db
from sync import ActiveEventState, server_time_ms, set_trigger_event


logger = logging.getLogger(__name__)


def _build_assignments(event_id: int) -> Dict[str, str]:
    maps = (
        db.session.query(EventDisplayMap)
        .filter_by(event_id=event_id)
        .join(Display, EventDisplayMap.display_id == Display.id)
        .join(Video, EventDisplayMap.video_id == Video.id)
        .all()
    )
    assignments: Dict[str, str] = {}
    for m in maps:
        assignments[m.display.public_id] = url_for("main.media", filename=m.video.filename)
    return assignments


def broadcast_trigger_state(state: ActiveEventState) -> None:
    # Lazy import to avoid circular import (sockets -> event_manager -> sockets)
    from sockets import socketio

    for public_id, video_url in state.assignments.items():
        socketio.emit(
            "event_start",
            {
                "event_id": state.event_id,
                "event_name": state.name,
                "video_url": video_url,
                "start_time_ms": state.start_time_ms,
                "server_time_ms": server_time_ms(),
            },
            room=f"display:{public_id}",
        )


def activate_trigger_event(event_id: int, start_ms: float, end_ms: float, name: str) -> Optional[ActiveEventState]:
    """Activate a triggered event, store it in-memory, and broadcast it to displays."""
    assignments = _build_assignments(event_id)
    if not assignments:
        return None

    state = ActiveEventState(
        event_id=event_id,
        name=name,
        start_time_ms=start_ms,
        end_time_ms=end_ms,
        assignments=assignments,
    )
    set_trigger_event(state)
    broadcast_trigger_state(state)
    logger.info("Activated trigger event %s (%s)", event_id, name)
    return state