const bcrypt = require('bcryptjs');
const jwt = require('jsonwebtoken');
const { User } = require('../models');
const logger = require('../utils/logger');

const generateToken = (userId) => {
  return jwt.sign({ userId }, process.env.JWT_SECRET, {
    expiresIn: process.env.JWT_EXPIRES_IN || '7d'
  });
};

const register = async (req, res) => {
  try {
    const { email, password, firstName, lastName, role = 'user' } = req.body;

    // Validate input
    if (!email || !password || !firstName || !lastName) {
      return res.status(400).json({
        success: false,
        error: 'All fields are required'
      });
    }

    // Check if user already exists
    const existingUser = await User.findOne({ where: { email } });
    if (existingUser) {
      return res.status(400).json({
        success: false,
        error: 'User already exists with this email'
      });
    }

    // Hash password
    const saltRounds = 12;
    const passwordHash = await bcrypt.hash(password, saltRounds);

    // Create user
    const user = await User.create({
      email,
      password_hash: passwordHash,
      first_name: firstName,
      last_name: lastName,
      role
    });

    // Generate token
    const token = generateToken(user.id);

    logger.info(`New user registered: ${email}`);

    res.status(201).json({
      success: true,
      data: {
        user: {
          id: user.id,
          email: user.email,
          firstName: user.first_name,
          lastName: user.last_name,
          role: user.role
        },
        token
      }
    });
  } catch (error) {
    logger.error('Registration error:', error);
    res.status(500).json({
      success: false,
      error: 'Internal server error'
    });
  }
};

const login = async (req, res) => {
  try {
    const { email, password } = req.body;

    // Validate input
    if (!email || !password) {
      return res.status(400).json({
        success: false,
        error: 'Email and password are required'
      });
    }

    // Find user
    const user = await User.findOne({ where: { email } });
    if (!user) {
      return res.status(401).json({
        success: false,
        error: 'Invalid credentials'
      });
    }

    // Check if user is active
    if (!user.is_active) {
      return res.status(401).json({
        success: false,
        error: 'Account is deactivated'
      });
    }

    // Verify password
    const isValidPassword = await bcrypt.compare(password, user.password_hash);
    if (!isValidPassword) {
      return res.status(401).json({
        success: false,
        error: 'Invalid credentials'
      });
    }

    // Update last login
    await user.update({ last_login: new Date() });

    // Generate token
    const token = generateToken(user.id);

    logger.info(`User logged in: ${email}`);

    res.json({
      success: true,
      data: {
        user: {
          id: user.id,
          email: user.email,
          firstName: user.first_name,
          lastName: user.last_name,
          role: user.role
        },
        token
      }
    });
  } catch (error) {
    logger.error('Login error:', error);
    res.status(500).json({
      success: false,
      error: 'Internal server error'
    });
  }
};

const getProfile = async (req, res) => {
  try {
    const user = await User.findByPk(req.user.userId, {
      attributes: { exclude: ['password_hash'] }
    });

    if (!user) {
      return res.status(404).json({
        success: false,
        error: 'User not found'
      });
    }

    res.json({
      success: true,
      data: { user }
    });
  } catch (error) {
    logger.error('Get profile error:', error);
    res.status(500).json({
      success: false,
      error: 'Internal server error'
    });
  }
};

const updateProfile = async (req, res) => {
  try {
    const { firstName, lastName, preferences } = req.body;
    const user = await User.findByPk(req.user.userId);

    if (!user) {
      return res.status(404).json({
        success: false,
        error: 'User not found'
      });
    }

    // Update user
    const updateData = {};
    if (firstName) updateData.first_name = firstName;
    if (lastName) updateData.last_name = lastName;
    if (preferences) updateData.preferences = { ...user.preferences, ...preferences };

    await user.update(updateData);

    res.json({
      success: true,
      data: {
        user: {
          id: user.id,
          email: user.email,
          firstName: user.first_name,
          lastName: user.last_name,
          role: user.role,
          preferences: user.preferences
        }
      }
    });
  } catch (error) {
    logger.error('Update profile error:', error);
    res.status(500).json({
      success: false,
      error: 'Internal server error'
    });
  }
};

module.exports = {
  register,
  login,
  getProfile,
  updateProfile
};