const User = require('../models/userModel');
const Provider = require('../models/providerModel');
const Newsletter = require('../models/newsletterModel');
const bcrypt = require('bcryptjs');

// Get all users (with filtering by role)
exports.getAllUsers = async (req, res) => {
  try {
    const { role, isActive } = req.query;
    let users;

    if (role === 'subscriber') {
      // Find all active newsletter emails
      const subscribers = await Newsletter.find({ isActive: true }).select(
        'email',
      );
      const emails = subscribers.map((s) => s.email);

      // Find users whose email is in the subscribers list (for in-app notifications)
      users = await User.find({ email: { $in: emails } }).select('-password');

      // For the results count, we show the total number of newsletter subscribers
      return res.status(200).json({
        status: 'success',
        results: subscribers.length,
        data: {
          users,
          totalSubscribers: subscribers.length,
        },
      });
    } else {
      const filter = {};
      if (role) filter.role = role;
      if (isActive !== undefined) filter.isActive = isActive === 'true';

      users = await User.find(filter).select('-password');
    }

    res.status(200).json({
      status: 'success',
      results: users.length,
      data: {
        users,
      },
    });
  } catch (err) {
    res.status(500).json({
      status: 'error',
      message: 'Failed to fetch users',
      error: err.message,
    });
  }
};

// Get single user by ID
exports.getUser = async (req, res) => {
  try {
    const user = await User.findById(req.params.id).select('-password');

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

    res.status(200).json({
      status: 'success',
      data: {
        user,
      },
    });
  } catch (err) {
    res.status(500).json({
      status: 'error',
      message: 'Failed to fetch user',
      error: err.message,
    });
  }
};

// Create user with specific role (admin only)
exports.createUser = async (req, res) => {
  try {
    const { name, email, phone, password, role, permissions, providerData } =
      req.body;

    // Validate required fields
    if (!name || !email || !phone || !password) {
      return res.status(400).json({
        status: 'fail',
        message: 'Please provide name, email, phone, and password',
      });
    }

    // Check if email already exists
    const existingUser = await User.findOne({ email });
    if (existingUser) {
      return res.status(400).json({
        status: 'fail',
        message: 'Email already registered',
      });
    }

    // Check if phone already exists
    const existingPhone = await User.findOne({ phone });
    if (existingPhone) {
      return res.status(400).json({
        status: 'fail',
        message: 'Phone number already registered',
      });
    }

    // Create user data object
    const userData = {
      name,
      email,
      phone,
      password,
      role: role || 'customer',
    };

    // Add permissions if role is employee
    if (role === 'employee' && permissions) {
      userData.permissions = permissions;
    }

    // Create the user first
    const newUser = await User.create(userData);

    // If role is vendor, create or link provider
    if (role === 'vendor' && providerData) {
      const provider = await Provider.create({
        ...providerData,
        user: newUser._id,
      });
      newUser.provider = provider._id;
      await newUser.save();
    }

    // Remove password from response
    newUser.password = undefined;

    res.status(201).json({
      status: 'success',
      data: {
        user: newUser,
      },
    });
  } catch (err) {
    res.status(500).json({
      status: 'error',
      message: 'Failed to create user',
      error: err.message,
    });
  }
};

// Update user details (for employees)
exports.updateUser = async (req, res) => {
  try {
    const { name, email, phone, password, permissions, isActive } = req.body;

    const user = await User.findById(req.params.id);

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

    // Update basic fields if provided
    if (name) user.name = name;
    if (email) {
      // Check if email is already taken by another user
      const existingUser = await User.findOne({
        email,
        _id: { $ne: req.params.id },
      });
      if (existingUser) {
        return res.status(400).json({
          status: 'fail',
          message: 'Email already in use',
        });
      }
      user.email = email;
    }
    if (phone) {
      // Check if phone is already taken by another user
      const existingPhone = await User.findOne({
        phone,
        _id: { $ne: req.params.id },
      });
      if (existingPhone) {
        return res.status(400).json({
          status: 'fail',
          message: 'Phone number already in use',
        });
      }
      user.phone = phone;
    }

    // Update password if provided
    if (password) {
      user.password = password; // Will be hashed by pre-save middleware
    }

    // Update permissions if user is employee
    if (user.role === 'employee' && permissions !== undefined) {
      user.permissions = permissions;
    }

    // Update isActive status
    if (isActive !== undefined) {
      user.isActive = isActive;
    }

    await user.save();

    // Remove password from response
    user.password = undefined;

    res.status(200).json({
      status: 'success',
      data: {
        user,
      },
    });
  } catch (err) {
    res.status(500).json({
      status: 'error',
      message: 'Failed to update user',
      error: err.message,
    });
  }
};

// Update user role
exports.updateUserRole = async (req, res) => {
  try {
    const { role } = req.body;

    if (!role || !['customer', 'admin', 'employee', 'vendor'].includes(role)) {
      return res.status(400).json({
        status: 'fail',
        message: 'Please provide a valid role',
      });
    }

    const user = await User.findById(req.params.id);

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

    user.role = role;

    // Clear permissions if changing from employee to another role
    if (role !== 'employee') {
      user.permissions = [];
    }

    await user.save();

    res.status(200).json({
      status: 'success',
      data: {
        user,
      },
    });
  } catch (err) {
    res.status(500).json({
      status: 'error',
      message: 'Failed to update user role',
      error: err.message,
    });
  }
};

// Update employee permissions
exports.updateEmployeePermissions = async (req, res) => {
  try {
    const { permissions } = req.body;

    if (!Array.isArray(permissions)) {
      return res.status(400).json({
        status: 'fail',
        message: 'Permissions must be an array',
      });
    }

    const user = await User.findById(req.params.id);

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

    if (user.role !== 'employee') {
      return res.status(400).json({
        status: 'fail',
        message: 'Permissions can only be set for employees',
      });
    }

    user.permissions = permissions;
    await user.save();

    // Emit socket event to notify the employee of permission changes
    try {
      const io = require('../utils/socket').getIO();
      io.to(user._id.toString()).emit('permissionsUpdated', {
        permissions: user.permissions,
        message: 'تم تحديث صلاحياتك من قبل المسؤول',
      });
    } catch (socketError) {
      console.error('Failed to emit permission update:', socketError);
      // Don't fail the request if socket emission fails
    }

    res.status(200).json({
      status: 'success',
      data: {
        user,
      },
    });
  } catch (err) {
    res.status(500).json({
      status: 'error',
      message: 'Failed to update permissions',
      error: err.message,
    });
  }
};

// Update vendor information
exports.updateVendorInfo = async (req, res) => {
  try {
    const { vendorInfo } = req.body;

    if (!vendorInfo) {
      return res.status(400).json({
        status: 'fail',
        message: 'Please provide vendor information',
      });
    }

    const user = await User.findById(req.params.id);

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

    if (user.role !== 'vendor') {
      return res.status(400).json({
        status: 'fail',
        message: 'Vendor info can only be set for vendors',
      });
    }

    user.vendorInfo = { ...user.vendorInfo, ...vendorInfo };
    await user.save();

    res.status(200).json({
      status: 'success',
      data: {
        user,
      },
    });
  } catch (err) {
    res.status(500).json({
      status: 'error',
      message: 'Failed to update vendor info',
      error: err.message,
    });
  }
};

// Deactivate user account
exports.deactivateUser = async (req, res) => {
  try {
    const user = await User.findById(req.params.id);

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

    user.isActive = false;
    await user.save();

    res.status(200).json({
      status: 'success',
      message: 'User account deactivated successfully',
      data: {
        user,
      },
    });
  } catch (err) {
    res.status(500).json({
      status: 'error',
      message: 'Failed to deactivate user',
      error: err.message,
    });
  }
};

// Activate user account
exports.activateUser = async (req, res) => {
  try {
    const user = await User.findById(req.params.id);

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

    user.isActive = true;
    await user.save();

    res.status(200).json({
      status: 'success',
      message: 'User account activated successfully',
      data: {
        user,
      },
    });
  } catch (err) {
    res.status(500).json({
      status: 'error',
      message: 'Failed to activate user',
      error: err.message,
    });
  }
};

// Delete user (permanent)
exports.deleteUser = async (req, res) => {
  try {
    const user = await User.findByIdAndDelete(req.params.id);

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

    res.status(200).json({
      status: 'success',
      message: 'User deleted successfully',
    });
  } catch (err) {
    res.status(500).json({
      status: 'error',
      message: 'Failed to delete user',
      error: err.message,
    });
  }
};