# app.py - COMPLETE VERSION
import os
from dotenv import load_dotenv
from flask import Flask, jsonify, request
import pymysql
import pymysql.cursors
from config import config

# Load environment variables at the start
load_dotenv()

app = Flask(__name__)

# Configure the app
env = os.getenv('FLASK_ENV', 'development')
app.config.from_object(config[env])

print(f"🔧 App configured for: {env}")
print(f"📡 Will run on port: {app.config['FLASK_PORT']}")

# Database configuration
def get_db_connection():
    db_config = {
        'host': app.config['DB_HOST'],
        'user': app.config['DB_USER'],
        'password': app.config['DB_PASSWORD'],
        'database': app.config['DB_NAME'],
        'port': app.config['DB_PORT'],
        'charset': 'utf8mb4',
        'cursorclass': pymysql.cursors.DictCursor
    }
    try:
        return pymysql.connect(**db_config)
    except pymysql.Error as e:
        print(f"Database connection error: {e}")
        return None

def init_users_table():
    """Create users table if it doesn't exist"""
    conn = get_db_connection()
    if conn:
        try:
            with conn.cursor() as cursor:
                cursor.execute('''
                    CREATE TABLE IF NOT EXISTS users (
                        id INT AUTO_INCREMENT PRIMARY KEY,
                        username VARCHAR(80) UNIQUE NOT NULL,
                        email VARCHAR(120) UNIQUE NOT NULL,
                        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
                    )
                ''')
                conn.commit()
                print("✅ Users table is ready")
        except Exception as e:
            print(f"Error creating users table: {e}")
        finally:
            conn.close()

# Initialize the users table when app starts
init_users_table()

# Routes
@app.route('/')
def hello():
    return jsonify({
        "message": "WearWell API is running!", 
        "port": app.config['FLASK_PORT'],
        "endpoints": {
            "health_check": "/health",
            "all_users": "/users",
            "get_user": "/users/<id>",
            "add_user": "/users/add (POST)",
            "delete_user": "/users/delete/<id> (DELETE)",
            "web_interface": "/users/manage"
        }
    })

@app.route('/health')
def health_check():
    conn = get_db_connection()
    if conn:
        conn.close()
        return jsonify({"status": "healthy", "database": "connected"})
    else:
        return jsonify({"status": "unhealthy", "database": "disconnected"}), 500

# User Management Routes
@app.route('/users')
def get_all_users():
    """Get all users"""
    conn = get_db_connection()
    if not conn:
        return jsonify({"error": "Database connection failed"}), 500
    
    try:
        with conn.cursor() as cursor:
            cursor.execute("SELECT * FROM users ORDER BY created_at DESC")
            users = cursor.fetchall()
        return jsonify({"users": users, "count": len(users)})
    except Exception as e:
        return jsonify({"error": str(e)}), 500
    finally:
        conn.close()

@app.route('/users/<int:user_id>')
def get_user(user_id):
    """Get a specific user by ID"""
    conn = get_db_connection()
    if not conn:
        return jsonify({"error": "Database connection failed"}), 500
    
    try:
        with conn.cursor() as cursor:
            cursor.execute("SELECT * FROM users WHERE id = %s", (user_id,))
            user = cursor.fetchone()
        
        if user:
            return jsonify({"user": user})
        else:
            return jsonify({"error": "User not found"}), 404
    except Exception as e:
        return jsonify({"error": str(e)}), 500
    finally:
        conn.close()

@app.route('/users/add', methods=['POST'])
def add_user():
    """Add a new user"""
    conn = get_db_connection()
    if not conn:
        return jsonify({"error": "Database connection failed"}), 500
    
    try:
        # Check if request is JSON
        if not request.is_json:
            return jsonify({"error": "Content-Type must be application/json"}), 400
        
        data = request.get_json()
        
        if not data or not data.get('username') or not data.get('email'):
            return jsonify({"error": "Username and email are required"}), 400
        
        username = data['username'].strip()
        email = data['email'].strip()
        
        # Basic validation
        if len(username) < 3:
            return jsonify({"error": "Username must be at least 3 characters"}), 400
        
        if '@' not in email:
            return jsonify({"error": "Invalid email format"}), 400
        
        with conn.cursor() as cursor:
            cursor.execute(
                "INSERT INTO users (username, email) VALUES (%s, %s)",
                (username, email)
            )
            conn.commit()
            user_id = cursor.lastrowid
        
        return jsonify({
            "message": "User added successfully",
            "user_id": user_id,
            "username": username,
            "email": email
        }), 201
        
    except pymysql.IntegrityError as e:
        if "username" in str(e):
            return jsonify({"error": "Username already exists"}), 400
        elif "email" in str(e):
            return jsonify({"error": "Email already exists"}), 400
        else:
            return jsonify({"error": "Database integrity error"}), 400
    except Exception as e:
        return jsonify({"error": str(e)}), 500
    finally:
        conn.close()

@app.route('/users/delete/<int:user_id>', methods=['DELETE'])
def delete_user(user_id):
    """Delete a user by ID"""
    conn = get_db_connection()
    if not conn:
        return jsonify({"error": "Database connection failed"}), 500
    
    try:
        with conn.cursor() as cursor:
            # First check if user exists
            cursor.execute("SELECT * FROM users WHERE id = %s", (user_id,))
            user = cursor.fetchone()
            
            if not user:
                return jsonify({"error": "User not found"}), 404
            
            # Delete the user
            cursor.execute("DELETE FROM users WHERE id = %s", (user_id,))
            conn.commit()
        
        return jsonify({
            "message": "User deleted successfully",
            "deleted_user": {
                "id": user_id,
                "username": user['username'],
                "email": user['email']
            }
        })
        
    except Exception as e:
        return jsonify({"error": str(e)}), 500
    finally:
        conn.close()

@app.route('/users/update/<int:user_id>', methods=['PUT'])
def update_user(user_id):
    """Update a user's information"""
    conn = get_db_connection()
    if not conn:
        return jsonify({"error": "Database connection failed"}), 500
    
    try:
        if not request.is_json:
            return jsonify({"error": "Content-Type must be application/json"}), 400
        
        data = request.get_json()
        
        if not data or (not data.get('username') and not data.get('email')):
            return jsonify({"error": "At least username or email is required to update"}), 400
        
        # Build update query dynamically based on provided fields
        update_fields = []
        values = []
        
        if 'username' in data and data['username']:
            update_fields.append("username = %s")
            values.append(data['username'].strip())
        
        if 'email' in data and data['email']:
            update_fields.append("email = %s")
            values.append(data['email'].strip())
        
        values.append(user_id)
        
        with conn.cursor() as cursor:
            cursor.execute(
                f"UPDATE users SET {', '.join(update_fields)} WHERE id = %s",
                values
            )
            conn.commit()
            
            if cursor.rowcount == 0:
                return jsonify({"error": "User not found"}), 404
        
        return jsonify({"message": "User updated successfully"})
        
    except pymysql.IntegrityError as e:
        if "username" in str(e):
            return jsonify({"error": "Username already exists"}), 400
        elif "email" in str(e):
            return jsonify({"error": "Email already exists"}), 400
        else:
            return jsonify({"error": "Database integrity error"}), 400
    except Exception as e:
        return jsonify({"error": str(e)}), 500
    finally:
        conn.close()

# Web Interface
@app.route('/users/manage')
def manage_users():
    """Simple web interface to manage users"""
    return '''
    <!DOCTYPE html>
    <html>
    <head>
        <title>User Management - WearWell</title>
        <style>
            body { 
                font-family: 'Arial', sans-serif; 
                margin: 0; 
                padding: 20px; 
                background-color: #f5f5f5;
            }
            .container { 
                max-width: 1000px; 
                margin: 0 auto; 
                background: white;
                padding: 30px;
                border-radius: 10px;
                box-shadow: 0 2px 10px rgba(0,0,0,0.1);
            }
            h1 { 
                color: #333; 
                text-align: center;
                margin-bottom: 30px;
            }
            .section { 
                margin: 30px 0; 
                padding: 25px; 
                border: 1px solid #e0e0e0; 
                border-radius: 8px;
                background: #fafafa;
            }
            h2 {
                color: #555;
                border-bottom: 2px solid #007cba;
                padding-bottom: 10px;
            }
            input, button { 
                margin: 8px; 
                padding: 12px; 
                border: 1px solid #ddd;
                border-radius: 4px;
                font-size: 14px;
            }
            input {
                width: 200px;
            }
            button { 
                background: #007cba;
                color: white;
                border: none;
                cursor: pointer;
                padding: 12px 20px;
            }
            button:hover {
                background: #005a87;
            }
            button.delete {
                background: #dc3545;
            }
            button.delete:hover {
                background: #c82333;
            }
            .user { 
                padding: 15px; 
                border-bottom: 1px solid #eee; 
                display: flex;
                justify-content: space-between;
                align-items: center;
            }
            .user:hover {
                background: #f8f9fa;
            }
            .user-info {
                flex-grow: 1;
            }
            .user-actions {
                display: flex;
                gap: 10px;
            }
            .success { color: #28a745; }
            .error { color: #dc3545; }
            .loading { color: #6c757d; }
            #statusMessage {
                padding: 10px;
                margin: 10px 0;
                border-radius: 4px;
                text-align: center;
            }
            .success-message { background: #d4edda; color: #155724; }
            .error-message { background: #f8d7da; color: #721c24; }
        </style>
    </head>
    <body>
        <div class="container">
            <h1>👥 User Management - WearWell</h1>
            
            <div class="section">
                <h2>➕ Add New User</h2>
                <input type="text" id="username" placeholder="Username (min 3 chars)" required>
                <input type="email" id="email" placeholder="Email address" required>
                <button onclick="addUser()">Add User</button>
                <div id="addStatus"></div>
            </div>
            
            <div class="section">
                <h2>📋 Users List</h2>
                <button onclick="loadUsers()">🔄 Refresh Users</button>
                <div id="usersCount" class="loading">Loading user count...</div>
                <div id="usersList"></div>
            </div>

            <div class="section">
                <h2>🔧 API Testing</h2>
                <p>Test the API endpoints directly:</p>
                <button onclick="testGetUsers()">Test GET /users</button>
                <button onclick="testHealth()">Test GET /health</button>
                <pre id="apiResponse" style="background: #f8f9fa; padding: 15px; border-radius: 4px; margin-top: 10px; display: none;"></pre>
            </div>
        </div>

        <script>
            let currentUsers = [];

            async function loadUsers() {
                showStatus('Loading users...', 'loading');
                try {
                    const response = await fetch('/users');
                    const data = await response.json();
                    
                    if (response.ok) {
                        currentUsers = data.users;
                        const usersList = document.getElementById('usersList');
                        const usersCount = document.getElementById('usersCount');
                        
                        usersCount.innerHTML = `<span class="success">📊 Total Users: ${data.count}</span>`;
                        usersList.innerHTML = '';
                        
                        if (data.users.length === 0) {
                            usersList.innerHTML = '<div class="user">No users found. Add some users above!</div>';
                            return;
                        }
                        
                        data.users.forEach(user => {
                            const userDiv = document.createElement('div');
                            userDiv.className = 'user';
                            userDiv.innerHTML = `
                                <div class="user-info">
                                    <strong>ID: ${user.id}</strong> | 
                                    👤 ${user.username} | 
                                    📧 ${user.email} | 
                                    📅 ${new Date(user.created_at).toLocaleString()}
                                </div>
                                <div class="user-actions">
                                    <button class="delete" onclick="deleteUser(${user.id})">🗑️ Delete</button>
                                </div>
                            `;
                            usersList.appendChild(userDiv);
                        });
                        showStatus('Users loaded successfully!', 'success');
                    } else {
                        showStatus('Error loading users: ' + data.error, 'error');
                    }
                } catch (error) {
                    showStatus('Network error: ' + error.message, 'error');
                }
            }

            async function addUser() {
                const username = document.getElementById('username').value;
                const email = document.getElementById('email').value;
                const addStatus = document.getElementById('addStatus');
                
                if (!username || !email) {
                    showStatus('Please fill in both username and email', 'error', addStatus);
                    return;
                }

                if (username.length < 3) {
                    showStatus('Username must be at least 3 characters', 'error', addStatus);
                    return;
                }

                showStatus('Adding user...', 'loading', addStatus);
                
                try {
                    const response = await fetch('/users/add', {
                        method: 'POST',
                        headers: {'Content-Type': 'application/json'},
                        body: JSON.stringify({username, email})
                    });
                    
                    const data = await response.json();
                    
                    if (response.ok) {
                        showStatus('✅ User added successfully! ID: ' + data.user_id, 'success', addStatus);
                        document.getElementById('username').value = '';
                        document.getElementById('email').value = '';
                        loadUsers();
                    } else {
                        showStatus('❌ Error: ' + data.error, 'error', addStatus);
                    }
                } catch (error) {
                    showStatus('❌ Network error: ' + error.message, 'error', addStatus);
                }
            }

            async function deleteUser(userId) {
                if (!confirm('Are you sure you want to delete this user?')) {
                    return;
                }

                try {
                    const response = await fetch(`/users/delete/${userId}`, {
                        method: 'DELETE'
                    });
                    
                    const data = await response.json();
                    
                    if (response.ok) {
                        showStatus('✅ User deleted successfully!', 'success');
                        loadUsers();
                    } else {
                        showStatus('❌ Error: ' + data.error, 'error');
                    }
                } catch (error) {
                    showStatus('❌ Network error: ' + error.message, 'error');
                }
            }

            async function testGetUsers() {
                try {
                    const response = await fetch('/users');
                    const data = await response.json();
                    document.getElementById('apiResponse').style.display = 'block';
                    document.getElementById('apiResponse').innerHTML = JSON.stringify(data, null, 2);
                } catch (error) {
                    document.getElementById('apiResponse').style.display = 'block';
                    document.getElementById('apiResponse').innerHTML = 'Error: ' + error.message;
                }
            }

            async function testHealth() {
                try {
                    const response = await fetch('/health');
                    const data = await response.json();
                    document.getElementById('apiResponse').style.display = 'block';
                    document.getElementById('apiResponse').innerHTML = JSON.stringify(data, null, 2);
                } catch (error) {
                    document.getElementById('apiResponse').style.display = 'block';
                    document.getElementById('apiResponse').innerHTML = 'Error: ' + error.message;
                }
            }

            function showStatus(message, type, element = null) {
                const targetElement = element || document.getElementById('statusMessage');
                if (!targetElement) return;
                
                targetElement.innerHTML = message;
                targetElement.className = type + '-message';
                targetElement.style.display = 'block';
                
                if (type !== 'loading') {
                    setTimeout(() => {
                        targetElement.style.display = 'none';
                    }, 5000);
                }
            }

            // Create status message element
            const statusElement = document.createElement('div');
            statusElement.id = 'statusMessage';
            statusElement.style.display = 'none';
            document.querySelector('.container').insertBefore(statusElement, document.querySelector('.container').firstChild);

            // Load users when page loads
            loadUsers();
        </script>
    </body>
    </html>
    '''