from flask import Blueprint, request, jsonify, g
from datetime import datetime, timedelta, date
from pydantic import ValidationError

from app.services.reservation_service import ReservationService
from app.schemas.reservation_dto import ReservationCreateDTO, ReservationUpdateDTO
from app.utils.jwt_decorators import jwt_required, jwt_role_required

api_reservations_bp = Blueprint('api_reservations', __name__, url_prefix='/api/v1/reservations')
reservation_service = ReservationService()

@api_reservations_bp.route('', methods=['GET'])
@jwt_required
def list_reservations():
    """Consulta de reservas por rango de fechas y/o aula."""
    start_str = request.args.get('start_date')
    end_str = request.args.get('end_date')
    classroom_id = request.args.get('classroom_id', type=int)

    now = datetime.utcnow()
    try:
        start_dt = datetime.strptime(start_str, '%Y-%m-%d') if start_str else now.replace(hour=0, minute=0, second=0)
    except ValueError:
        return jsonify({'error': 'BadRequest', 'message': 'Formato inválido de start_date (debe ser YYYY-MM-DD).'}), 400

    try:
        end_dt = datetime.strptime(end_str, '%Y-%m-%d').replace(hour=23, minute=59, second=59) if end_str else start_dt + timedelta(days=7)
    except ValueError:
        return jsonify({'error': 'BadRequest', 'message': 'Formato inválido de end_date (debe ser YYYY-MM-DD).'}), 400

    reservations = reservation_service.list_reservations(start_dt, end_dt, classroom_id=classroom_id)
    result = []
    for r in reservations:
        result.append({
            'id': r.id,
            'classroom_id': r.classroom_id,
            'classroom_name': r.classroom.code if r.classroom else None,
            'commission_id': r.commission_id,
            'teacher_name': r.user.name if r.user else None,
            'start_time': r.start_time.isoformat(),
            'end_time': r.end_time.isoformat(),
            'purpose': r.purpose,
            'status': str(r.status),
            'shift': r.shift,
            'virtual_link': r.virtual_link,
            'expected_attendees': r.expected_attendees
        })

    return jsonify({
        'total': len(result),
        'start_date': start_dt.strftime('%Y-%m-%d'),
        'end_date': end_dt.strftime('%Y-%m-%d'),
        'reservations': result
    }), 200

@api_reservations_bp.route('/<int:reservation_id>', methods=['GET'])
@jwt_required
def get_reservation(reservation_id: int):
    """Obtiene el detalle de una reserva específica."""
    r = reservation_service.get_reservation(reservation_id)
    if not r:
        return jsonify({'error': 'NotFound', 'message': f'Reserva {reservation_id} no encontrada.'}), 404

    return jsonify({
        'id': r.id,
        'classroom_id': r.classroom_id,
        'classroom_name': r.classroom.code if r.classroom else None,
        'location_display': r.classroom.location_display if r.classroom else None,
        'commission_id': r.commission_id,
        'teacher_id': r.user_id,
        'teacher_name': r.user.name if r.user else None,
        'start_time': r.start_time.isoformat(),
        'end_time': r.end_time.isoformat(),
        'purpose': r.purpose,
        'status': str(r.status),
        'shift': r.shift,
        'virtual_link': r.virtual_link,
        'expected_attendees': r.expected_attendees,
        'notes': r.notes
    }), 200

@api_reservations_bp.route('', methods=['POST'])
@jwt_required
def create_reservation():
    """Crea una reserva aplicando validación DTO y detección de colisiones."""
    data = request.get_json(silent=True) or {}
    
    # Inyectar usuario autenticado si no se especifica
    if 'user_id' not in data:
        data['user_id'] = g.jwt_user.id

    try:
        dto = ReservationCreateDTO(**data)
    except ValidationError as e:
        return jsonify({'error': 'ValidationError', 'details': e.errors()}), 400

    try:
        reservation = reservation_service.create_reservation(dto)
        return jsonify({
            'message': 'Reserva creada exitosamente.',
            'id': reservation.id,
            'classroom_id': reservation.classroom_id,
            'start_time': reservation.start_time.isoformat(),
            'end_time': reservation.end_time.isoformat(),
            'status': str(reservation.status)
        }), 201
    except ValueError as e:
        return jsonify({'error': 'ConflictOrValidation', 'message': str(e)}), 409

@api_reservations_bp.route('/<int:reservation_id>', methods=['PUT'])
@jwt_required
def update_reservation(reservation_id: int):
    """Modifica una reserva existente."""
    data = request.get_json(silent=True) or {}
    try:
        dto = ReservationUpdateDTO(**data)
    except ValidationError as e:
        return jsonify({'error': 'ValidationError', 'details': e.errors()}), 400

    try:
        reservation = reservation_service.update_reservation(reservation_id, dto)
        return jsonify({
            'message': 'Reserva actualizada exitosamente.',
            'id': reservation.id,
            'start_time': reservation.start_time.isoformat(),
            'end_time': reservation.end_time.isoformat(),
            'status': str(reservation.status)
        }), 200
    except ValueError as e:
        return jsonify({'error': 'ConflictOrValidation', 'message': str(e)}), 409

@api_reservations_bp.route('/<int:reservation_id>', methods=['DELETE'])
@jwt_required
def cancel_reservation(reservation_id: int):
    """Cancela una reserva."""
    cancelled = reservation_service.cancel_reservation(reservation_id)
    if not cancelled:
        return jsonify({'error': 'NotFound', 'message': f'Reserva {reservation_id} no encontrada.'}), 404

    return jsonify({'message': f'Reserva {reservation_id} cancelada correctamente.'}), 200