from flask import Flask, request, jsonify, session
from flask_cors import CORS
from werkzeug.security import generate_password_hash, check_password_hash
import json
import os
from datetime import datetime

app = Flask(__name__)
app.secret_key = 'your-secret-key-here-change-in-production'  # needed for sessions
CORS(app, supports_credentials=True)  # allow cookies

# Directories
DATA_DIR = 'data'
USERS_FILE = os.path.join(DATA_DIR, 'users.json')
os.makedirs(DATA_DIR, exist_ok=True)

# ==================== User helpers ====================
def load_users():
    try:
        if os.path.exists(USERS_FILE):
            with open(USERS_FILE, 'r') as f:
                return json.load(f)
    except Exception as e:
        print(f"Error loading users: {e}")
    return []

def save_users(users):
    try:
        with open(USERS_FILE, 'w') as f:
            json.dump(users, f, indent=2)
    except Exception as e:
        print(f"Error saving users: {e}")

def get_next_user_id(users):
    if not users:
        return 1
    return max(u['id'] for u in users) + 1

def get_user_by_username(username):
    users = load_users()
    return next((u for u in users if u['username'] == username), None)

def get_user_by_id(user_id):
    users = load_users()
    return next((u for u in users if u['id'] == user_id), None)

# ==================== Per‑user data helpers ====================
def get_user_data_dir(user_id):
    user_dir = os.path.join(DATA_DIR, 'users', str(user_id))
    os.makedirs(user_dir, exist_ok=True)
    return user_dir

def load_user_journeys(user_id):
    file_path = os.path.join(get_user_data_dir(user_id), 'journeys.json')
    try:
        if os.path.exists(file_path):
            with open(file_path, 'r') as f:
                return json.load(f)
    except Exception as e:
        print(f"Error loading journeys for user {user_id}: {e}")
    return []

def save_user_journeys(user_id, journeys):
    file_path = os.path.join(get_user_data_dir(user_id), 'journeys.json')
    try:
        with open(file_path, 'w') as f:
            json.dump(journeys, f, indent=2)
    except Exception as e:
        print(f"Error saving journeys for user {user_id}: {e}")

def load_user_posts(user_id):
    file_path = os.path.join(get_user_data_dir(user_id), 'posts.json')
    try:
        if os.path.exists(file_path):
            with open(file_path, 'r') as f:
                return json.load(f)
    except Exception as e:
        print(f"Error loading posts for user {user_id}: {e}")
    return []

def save_user_posts(user_id, posts):
    file_path = os.path.join(get_user_data_dir(user_id), 'posts.json')
    try:
        with open(file_path, 'w') as f:
            json.dump(posts, f, indent=2)
    except Exception as e:
        print(f"Error saving posts for user {user_id}: {e}")

# ==================== Authentication endpoints ====================
@app.route('/api/register', methods=['POST'])
def register():
    data = request.get_json()
    username = data.get('username')
    password = data.get('password')

    if not username or not password:
        return jsonify({'error': 'Username and password required'}), 400

    # Check if username already exists
    if get_user_by_username(username):
        return jsonify({'error': 'Username already taken'}), 409

    users = load_users()
    new_id = get_next_user_id(users)

    hashed = generate_password_hash(password)
    new_user = {
        'id': new_id,
        'username': username,
        'password_hash': hashed,
        'created_at': datetime.now().isoformat()
    }
    users.append(new_user)
    save_users(users)

    # Create empty data files for the new user
    save_user_journeys(new_id, [])
    save_user_posts(new_id, [])

    # Log the user in automatically
    session['user_id'] = new_id

    return jsonify({
        'id': new_id,
        'username': username,
        'message': 'Registration successful'
    }), 201

@app.route('/api/login', methods=['POST'])
def login():
    data = request.get_json()
    username = data.get('username')
    password = data.get('password')

    user = get_user_by_username(username)
    if not user or not check_password_hash(user['password_hash'], password):
        return jsonify({'error': 'Invalid username or password'}), 401

    session['user_id'] = user['id']
    return jsonify({
        'id': user['id'],
        'username': user['username'],
        'message': 'Login successful'
    })

@app.route('/api/logout', methods=['POST'])
def logout():
    session.pop('user_id', None)
    return jsonify({'message': 'Logged out'})

@app.route('/api/me', methods=['GET'])
def me():
    user_id = session.get('user_id')
    if not user_id:
        return jsonify({'error': 'Not logged in'}), 401
    user = get_user_by_id(user_id)
    if not user:
        # Should not happen, but clean session
        session.pop('user_id', None)
        return jsonify({'error': 'User not found'}), 401
    return jsonify({
        'id': user['id'],
        'username': user['username']
    })

# ==================== Journey endpoints (protected, user‑specific) ====================
def require_login():
    if 'user_id' not in session:
        return False
    return True

def get_current_user_id():
    return session.get('user_id')

def get_journeys_for_current_user():
    user_id = get_current_user_id()
    if user_id is None:
        return None
    return load_user_journeys(user_id)

@app.route('/api/journeys', methods=['GET'])
def get_journeys():
    if not require_login():
        return jsonify({'error': 'Authentication required'}), 401
    journeys = get_journeys_for_current_user()
    return jsonify(journeys)

def get_next_journey_id(journeys):
    if not journeys:
        return 1
    return max(j['id'] for j in journeys) + 1

@app.route('/api/journeys', methods=['POST'])
def create_journey():
    if not require_login():
        return jsonify({'error': 'Authentication required'}), 401
    data = request.get_json()
    if not data:
        return jsonify({'error': 'No data provided'}), 400

    title = data.get('title')
    if not title:
        return jsonify({'error': 'Journey title is required'}), 400

    user_id = get_current_user_id()
    journeys = get_journeys_for_current_user()
    new_id = get_next_journey_id(journeys)

    new_journey = {
        'id': new_id,
        'title': title,
        'description': data.get('description', ''),
        'markers': data.get('markers', []),
        'created_at': datetime.now().isoformat()
    }

    journeys.append(new_journey)
    save_user_journeys(user_id, journeys)
    return jsonify(new_journey), 201

@app.route('/api/journeys/<int:journey_id>', methods=['GET'])
def get_journey(journey_id):
    if not require_login():
        return jsonify({'error': 'Authentication required'}), 401
    journeys = get_journeys_for_current_user()
    journey = next((j for j in journeys if j['id'] == journey_id), None)
    if journey is None:
        return jsonify({'error': 'Journey not found'}), 404
    return jsonify(journey)

@app.route('/api/journeys/<int:journey_id>', methods=['PUT'])
def update_journey(journey_id):
    if not require_login():
        return jsonify({'error': 'Authentication required'}), 401
    journeys = get_journeys_for_current_user()
    journey = next((j for j in journeys if j['id'] == journey_id), None)
    if journey is None:
        return jsonify({'error': 'Journey not found'}), 404

    data = request.get_json()
    if not data:
        return jsonify({'error': 'No data provided'}), 400

    if 'title' in data:
        journey['title'] = data['title']
    if 'description' in data:
        journey['description'] = data['description']
    if 'markers' in data:
        journey['markers'] = data['markers']

    save_user_journeys(get_current_user_id(), journeys)
    return jsonify(journey)

@app.route('/api/journeys/<int:journey_id>', methods=['DELETE'])
def delete_journey(journey_id):
    if not require_login():
        return jsonify({'error': 'Authentication required'}), 401
    journeys = get_journeys_for_current_user()
    journey = next((j for j in journeys if j['id'] == journey_id), None)
    if journey is None:
        return jsonify({'error': 'Journey not found'}), 404

    journeys = [j for j in journeys if j['id'] != journey_id]
    save_user_journeys(get_current_user_id(), journeys)
    return jsonify({'message': 'Journey deleted successfully', 'journey': journey})

# ==================== Blog Post endpoints (protected, user‑specific) ====================
def get_posts_for_current_user():
    user_id = get_current_user_id()
    if user_id is None:
        return None
    return load_user_posts(user_id)

def get_next_post_id(posts):
    if not posts:
        return 1
    return max(p['id'] for p in posts) + 1

@app.route('/api/blog-posts', methods=['GET'])
def get_blog_posts():
    if not require_login():
        return jsonify({'error': 'Authentication required'}), 401
    posts = get_posts_for_current_user()
    return jsonify(posts)

@app.route('/api/blog-posts/<int:post_id>', methods=['GET'])
def get_blog_post(post_id):
    if not require_login():
        return jsonify({'error': 'Authentication required'}), 401
    posts = get_posts_for_current_user()
    post = next((p for p in posts if p['id'] == post_id), None)
    if not post:
        return jsonify({'error': 'Post not found'}), 404
    return jsonify(post)

@app.route('/api/blog-posts', methods=['POST'])
def create_blog_post():
    if not require_login():
        return jsonify({'error': 'Authentication required'}), 401
    data = request.get_json()
    title = data.get('title')
    if not title:
        return jsonify({'error': 'Title required'}), 400

    user_id = get_current_user_id()
    posts = get_posts_for_current_user()
    new_id = get_next_post_id(posts)

    new_post = {
        'id': new_id,
        'title': title,
        'content': data.get('content', ''),
        'journeyId': data.get('journeyId'),
        'image': data.get('image'),
        'created_at': datetime.now().isoformat()
    }

    posts.append(new_post)
    save_user_posts(user_id, posts)
    return jsonify(new_post), 201

@app.route('/api/blog-posts/<int:post_id>', methods=['PUT'])
def update_blog_post(post_id):
    if not require_login():
        return jsonify({'error': 'Authentication required'}), 401
    posts = get_posts_for_current_user()
    post = next((p for p in posts if p['id'] == post_id), None)
    if not post:
        return jsonify({'error': 'Post not found'}), 404

    data = request.get_json()
    if 'title' in data:
        post['title'] = data['title']
    if 'content' in data:
        post['content'] = data['content']
    if 'journeyId' in data:
        post['journeyId'] = data['journeyId']
    if 'image' in data:
        post['image'] = data['image']

    save_user_posts(get_current_user_id(), posts)
    return jsonify(post)

@app.route('/api/blog-posts/<int:post_id>', methods=['DELETE'])
def delete_blog_post(post_id):
    if not require_login():
        return jsonify({'error': 'Authentication required'}), 401
    posts = get_posts_for_current_user()
    post = next((p for p in posts if p['id'] == post_id), None)
    if not post:
        return jsonify({'error': 'Post not found'}), 404

    posts = [p for p in posts if p['id'] != post_id]
    save_user_posts(get_current_user_id(), posts)
    return jsonify({'message': 'Post deleted'})

# ==================== Health and root ====================
@app.route('/api/journeys/health', methods=['GET'])
def health_check():
    return jsonify({'status': 'healthy', 'timestamp': datetime.now().isoformat()})

@app.route('/')
def index():
    return '''
    <!DOCTYPE html>
    <html>
    <head><title>Journey Mapper API</title></head>
    <body>
        <h1>Journey Mapper API</h1>
        <p>Backend is running. Use <code>/api/journeys</code> endpoints.</p>
        <p>Authentication required: register, login, then use session cookies.</p>
    </body>
    </html>
    '''

if __name__ == '__main__':
    app.run(debug=True, port=5000)