import { Response } from 'express';
import { AuthenticatedRequest } from '../middleware/auth.middleware';
import * as userService from '../services/user.service';
import {
  CreateUserInput,
  UpdateUserInput,
  ChangePasswordInput,
} from '../validators/user.validator';

/**
 * GET /users
 * List all users (admin only)
 * Supports filtering by role_id, is_active, and search
 * Supports pagination with page, limit, sortBy, sortOrder
 */
export async function getAllUsers(
  req: AuthenticatedRequest,
  res: Response
): Promise<void> {
  try {
    // Parse query parameters for filters
    const filters: userService.UserFilter = {};

    if (req.query.role_id) {
      filters.role_id = parseInt(req.query.role_id as string, 10);
    }

    if (req.query.is_active !== undefined) {
      filters.is_active = req.query.is_active === 'true';
    }

    if (req.query.search) {
      filters.search = req.query.search as string;
    }

    // Parse pagination parameters
    const pagination = {
      page: parseInt(req.query.page as string, 10) || 1,
      limit: parseInt(req.query.limit as string, 10) || 10,
      sortBy: (req.query.sortBy as string) || 'created_at',
      sortOrder: (req.query.sortOrder as 'asc' | 'desc') || 'desc',
    };

    const result = await userService.getAll(filters, pagination);

    res.status(200).json({
      success: true,
      message: 'Users retrieved successfully',
      data: result.users,
      pagination: result.pagination,
    });
  } catch (error) {
    const message = error instanceof Error ? error.message : 'Failed to retrieve users';
    res.status(500).json({
      success: false,
      error: message,
    });
  }
}

/**
 * GET /users/:id
 * Get a single user by ID (admin or self)
 */
export async function getUserById(
  req: AuthenticatedRequest,
  res: Response
): Promise<void> {
  try {
    const userId = req.params.id;

    if (!userId) {
      res.status(400).json({
        success: false,
        error: 'Invalid user ID',
      });
      return;
    }

    // Check if user is admin or requesting their own data
    const requestingUser = req.user;
    const isAdmin = requestingUser?.roleName === 'ADMIN';
    const isSelf = requestingUser?.userId === userId;

    if (!isAdmin && !isSelf) {
      res.status(403).json({
        success: false,
        error: 'Insufficient permissions',
      });
      return;
    }

    const user = await userService.getById(userId);

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

    res.status(200).json({
      success: true,
      message: 'User retrieved successfully',
      data: user,
    });
  } catch (error) {
    const message = error instanceof Error ? error.message : 'Failed to retrieve user';
    res.status(500).json({
      success: false,
      error: message,
    });
  }
}

/**
 * POST /users
 * Create a new user (admin only)
 */
export async function createUser(
  req: AuthenticatedRequest,
  res: Response
): Promise<void> {
  try {
    const data = req.body as CreateUserInput;

    const user = await userService.create({
      email: data.email,
      password: data.password,
      name: data.name,
      avatar_url: data.avatar_url,
      role_id: data.role_id,
      is_active: data.is_active,
    });

    res.status(201).json({
      success: true,
      message: 'User created successfully',
      data: user,
    });
  } catch (error) {
    const message = error instanceof Error ? error.message : 'Failed to create user';

    if (message === 'Email already in use') {
      res.status(409).json({
        success: false,
        error: message,
      });
      return;
    }

    res.status(500).json({
      success: false,
      error: message,
    });
  }
}

/**
 * PUT /users/:id
 * Update a user (admin can update all fields, regular users can only update limited fields on self)
 */
export async function updateUser(
  req: AuthenticatedRequest,
  res: Response
): Promise<void> {
  try {
    const userId = req.params.id;

    if (!userId) {
      res.status(400).json({
        success: false,
        error: 'Invalid user ID',
      });
      return;
    }

    const requestingUser = req.user;
    const isAdmin = requestingUser?.roleName === 'ADMIN';
    const isSelf = requestingUser?.userId === userId;

    if (!isAdmin && !isSelf) {
      res.status(403).json({
        success: false,
        error: 'Insufficient permissions',
      });
      return;
    }

    const data = req.body as UpdateUserInput;

    // Non-admin users can only update their own profile fields (not role_id or is_active)
    if (!isAdmin) {
      if (data.role_id !== undefined || data.is_active !== undefined) {
        res.status(403).json({
          success: false,
          error: 'You can only update your profile information',
        });
        return;
      }
    }

    const user = await userService.update(userId, data);

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

    res.status(200).json({
      success: true,
      message: 'User updated successfully',
      data: user,
    });
  } catch (error) {
    const message = error instanceof Error ? error.message : 'Failed to update user';

    if (message === 'Email already in use') {
      res.status(409).json({
        success: false,
        error: message,
      });
      return;
    }

    res.status(500).json({
      success: false,
      error: message,
    });
  }
}

/**
 * DELETE /users/:id
 * Deactivate a user (soft delete, admin only)
 */
export async function deleteUser(
  req: AuthenticatedRequest,
  res: Response
): Promise<void> {
  try {
    const userId = req.params.id;

    if (!userId) {
      res.status(400).json({
        success: false,
        error: 'Invalid user ID',
      });
      return;
    }

    // Prevent admin from deleting themselves
    if (req.user?.userId === userId) {
      res.status(400).json({
        success: false,
        error: 'Cannot deactivate your own account',
      });
      return;
    }

    const deleted = await userService.deleteUser(userId);

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

    res.status(200).json({
      success: true,
      message: 'User deactivated successfully',
    });
  } catch (error) {
    const message = error instanceof Error ? error.message : 'Failed to deactivate user';
    res.status(500).json({
      success: false,
      error: message,
    });
  }
}

/**
 * PUT /users/:id/password
 * Change user password (self only)
 */
export async function changePassword(
  req: AuthenticatedRequest,
  res: Response
): Promise<void> {
  try {
    const userId = req.params.id;

    if (!userId) {
      res.status(400).json({
        success: false,
        error: 'Invalid user ID',
      });
      return;
    }

    // Only allow users to change their own password
    if (req.user?.userId !== userId) {
      res.status(403).json({
        success: false,
        error: 'You can only change your own password',
      });
      return;
    }

    const data = req.body as ChangePasswordInput;

    await userService.changePassword(
      userId,
      data.current_password,
      data.new_password
    );

    res.status(200).json({
      success: true,
      message: 'Password changed successfully',
    });
  } catch (error) {
    const message = error instanceof Error ? error.message : 'Failed to change password';

    if (message === 'Current password is incorrect') {
      res.status(401).json({
        success: false,
        error: message,
      });
      return;
    }

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

    res.status(500).json({
      success: false,
      error: message,
    });
  }
}