from flask import Blueprint, request, jsonify
from flask_jwt_extended import jwt_required, get_jwt_identity
from .database import db, PushDevice, User

device_bp = Blueprint('devices', __name__, url_prefix='/api/devices')

@device_bp.route('', methods=['POST'])
@jwt_required()
def register_device():
    current_user_id = get_jwt_identity()
    data = request.get_json()
    if not data: return jsonify({"error": "Request must be JSON"}), 400

    device_type = data.get('type')
    token = data.get('token')

    if not device_type or not token:
        return jsonify({"error": "Missing 'type' or 'token'"}), 400
    if device_type not in ['web', 'ios', 'android']:
        return jsonify({"error": "Invalid device type"}), 400

    # Check if token already exists to prevent duplicates
    existing = PushDevice.query.filter_by(token=token).first()
    if existing:
        # Optional: Update user_id if token somehow got registered by another user?
        # Or just return OK indicating it's known
        if existing.user_id != current_user_id:
             # Decide handling: update owner or error? Let's update.
             existing.user_id = current_user_id
             db.session.commit()
             print(f"Warning: Push token {token[:10]}... re-assigned to user {current_user_id}")
        return jsonify({"message": "Device already registered"}), 200

    new_device = PushDevice(
        user_id=current_user_id,
        device_type=device_type,
        token=token
    )
    db.session.add(new_device)
    try:
        db.session.commit()
        return jsonify({"message": "Device registered successfully"}), 201
    except Exception as e:
        db.session.rollback()
        # Could be unique constraint violation if race condition, or DB error
        print(f"Error registering device: {e}")
        # Check again if it exists now (due to race condition)
        existing = PushDevice.query.filter_by(token=token).first()
        if existing: return jsonify({"message": "Device already registered"}), 200
        return jsonify({"error": "Failed to register device"}), 500


@device_bp.route('/<string:token_prefix>', methods=['DELETE'])
@jwt_required()
def unregister_device(token_prefix):
    # Note: Deleting by full token in URL can be problematic (length, encoding).
    # A better approach might be POST /api/devices/unregister { "token": "..." }
    # Or require the client to store the device ID returned on registration and use that.
    # For simplicity now, we'll assume we search by token.

    current_user_id = get_jwt_identity()
    # This is inefficient if tokens are long. A dedicated device ID is better.
    # Let's simulate finding based on a prefix if needed, but ideally use full token from body
    # device = PushDevice.query.filter(PushDevice.token.like(f'{token_prefix}%'), PushDevice.user_id==current_user_id).first()

    # --- Alternative using request body ---
    data = request.get_json()
    token_to_delete = data.get('token') if data else None
    if not token_to_delete:
        return jsonify({"error": "Token required in request body for deletion"}), 400

    device = PushDevice.query.filter_by(token=token_to_delete, user_id=current_user_id).first()

    if not device:
        return jsonify({"error": "Device not found or not owned by user"}), 404

    db.session.delete(device)
    db.session.commit()
    return '', 204