from flask import Blueprint, request, jsonify
from datetime import datetime
from pymongo.errors import DuplicateKeyError
from database import subscribers_collection

subscription_bp = Blueprint('subscription', __name__)


@subscription_bp.route('/api/subscribe', methods=['POST'])
def subscribe():
    """Subscribe a user to the newsletter"""
    data = request.json
    email = data.get('email', '').strip().lower()
    
    if not email or '@' not in email:
        return jsonify({'error': 'Invalid email address'}), 400
    
    try:
        subscriber_doc = {
            'email': email,
            'subscribed_at': datetime.utcnow(),
            'status': 'active'
        }
        
        # Try to insert, if duplicate key error, subscriber already exists
        try:
            subscribers_collection.insert_one(subscriber_doc)
            return jsonify({'message': 'Successfully subscribed!'}), 201
        except DuplicateKeyError:
            # Check if subscriber is active
            existing = subscribers_collection.find_one({'email': email})
            if existing and existing.get('status') == 'active':
                return jsonify({'message': 'Email already subscribed'}), 200
            else:
                # Reactivate if previously unsubscribed
                subscribers_collection.update_one(
                    {'email': email},
                    {'$set': {'status': 'active', 'subscribed_at': datetime.utcnow()}}
                )
                return jsonify({'message': 'Successfully re-subscribed!'}), 200
                
    except Exception as e:
        return jsonify({'error': str(e)}), 500


@subscription_bp.route('/api/unsubscribe', methods=['POST'])
def unsubscribe():
    """Unsubscribe a user from the newsletter"""
    data = request.json
    email = data.get('email', '').strip().lower()
    
    try:
        result = subscribers_collection.update_one(
            {'email': email},
            {'$set': {'status': 'inactive'}}
        )
        
        if result.matched_count > 0:
            return jsonify({'message': 'Successfully unsubscribed'}), 200
        else:
            return jsonify({'error': 'Email not found in subscribers'}), 404
    except Exception as e:
        return jsonify({'error': str(e)}), 500


@subscription_bp.route('/api/subscribers', methods=['GET'])
def list_subscribers():
    """List all subscribers with optional status filter"""
    try:
        # Get status filter from query params (default: all)
        status = request.args.get('status', None)
        
        # Build query
        query = {}
        if status:
            query['status'] = status
        
        # Fetch subscribers
        subscribers = list(subscribers_collection.find(
            query,
            {'_id': 0, 'email': 1, 'subscribed_at': 1, 'status': 1}
        ).sort('subscribed_at', -1))
        
        # Convert datetime to ISO format
        for sub in subscribers:
            if 'subscribed_at' in sub:
                sub['subscribed_at'] = sub['subscribed_at'].isoformat()
        
        return jsonify({
            'subscribers': subscribers,
            'total': len(subscribers)
        }), 200
        
    except Exception as e:
        return jsonify({'error': str(e)}), 500


@subscription_bp.route('/api/subscribers/<email>', methods=['DELETE'])
def remove_subscriber(email):
    """Permanently remove a subscriber from the database"""
    try:
        email = email.strip().lower()
        
        result = subscribers_collection.delete_one({'email': email})
        
        if result.deleted_count > 0:
            return jsonify({'message': f'Subscriber {email} permanently removed'}), 200
        else:
            return jsonify({'error': 'Email not found in subscribers'}), 404
            
    except Exception as e:
        return jsonify({'error': str(e)}), 500