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 with category preferences"""
    data = request.json
    email = data.get('email', '').strip().lower()
    # Get valid categories from RSS feeds
    from database import rss_feeds_collection
    valid_categories = rss_feeds_collection.distinct('category')
    
    categories = data.get('categories', valid_categories)  # Default: all categories
    
    if not email or '@' not in email:
        return jsonify({'error': 'Invalid email address'}), 400
    
    # Validate categories
    if not isinstance(categories, list) or not categories:
        categories = valid_categories  # Default to all if invalid
    else:
        # Filter to only valid categories (categories that exist in RSS feeds)
        categories = [c for c in categories if c in valid_categories]
        if not categories:
            categories = valid_categories  # Default to all if none valid
    
    try:
        subscriber_doc = {
            'email': email,
            'subscribed_at': datetime.utcnow(),
            'status': 'active',
            'categories': categories
        }
        
        # Try to insert, if duplicate key error, subscriber already exists
        try:
            subscribers_collection.insert_one(subscriber_doc)
            return jsonify({
                'message': 'Successfully subscribed!',
                'categories': categories
            }), 201
        except DuplicateKeyError:
            # Check if subscriber is active
            existing = subscribers_collection.find_one({'email': email})
            if existing and existing.get('status') == 'active':
                # Update categories even if already subscribed
                subscribers_collection.update_one(
                    {'email': email},
                    {'$set': {'categories': categories}}
                )
                return jsonify({
                    'message': 'Email already subscribed. Preferences updated!',
                    'categories': categories
                }), 200
            else:
                # Reactivate if previously unsubscribed
                subscribers_collection.update_one(
                    {'email': email},
                    {'$set': {
                        'status': 'active',
                        'subscribed_at': datetime.utcnow(),
                        'categories': categories
                    }}
                )
                return jsonify({
                    'message': 'Successfully re-subscribed!',
                    'categories': categories
                }), 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=['GET'])
def get_subscriber(email):
    """Get a single subscriber's information"""
    try:
        email = email.strip().lower()
        
        subscriber = subscribers_collection.find_one(
            {'email': email},
            {'_id': 0, 'email': 1, 'categories': 1, 'status': 1, 'subscribed_at': 1}
        )
        
        if subscriber:
            # Convert datetime to ISO format
            if 'subscribed_at' in subscriber:
                subscriber['subscribed_at'] = subscriber['subscribed_at'].isoformat()
            
            # Ensure categories field exists
            if 'categories' not in subscriber:
                subscriber['categories'] = ['general', 'local', 'sports']
            
            return jsonify(subscriber), 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/<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


@subscription_bp.route('/api/admin/subscribers/delete-all', methods=['DELETE'])
def delete_all_subscribers():
    """Delete all subscribers (admin only)"""
    try:
        result = subscribers_collection.delete_many({})
        
        return jsonify({
            'message': f'Successfully deleted {result.deleted_count} subscribers',
            'deleted_count': result.deleted_count
        }), 200
            
    except Exception as e:
        return jsonify({'error': str(e)}), 500


@subscription_bp.route('/api/categories', methods=['GET'])
def get_categories():
    """Get available newsletter categories from RSS feeds"""
    from database import rss_feeds_collection
    
    # Get unique categories from RSS feeds
    categories_from_db = rss_feeds_collection.distinct('category')
    
    # Category metadata
    category_info = {
        'general': {
            'name': 'Top Trending',
            'description': 'Top trending news and updates',
            'icon': '🔥'
        },
        'local': {
            'name': 'Local Events',
            'description': 'Local events, culture, and community news',
            'icon': '🏛️'
        },
        'sports': {
            'name': 'Sports',
            'description': 'Sports news and updates',
            'icon': '⚽'
        },
        'science': {
            'name': 'Science & Tech',
            'description': 'Science and technology news',
            'icon': '🔬'
        }
    }
    
    # Build category list
    categories = []
    for cat_id in sorted(categories_from_db):
        info = category_info.get(cat_id, {
            'name': cat_id.title(),
            'description': f'{cat_id.title()} news',
            'icon': '📄'
        })
        categories.append({
            'id': cat_id,
            'name': info['name'],
            'description': info['description'],
            'icon': info['icon']
        })
    
    return jsonify({'categories': categories}), 200