/**
 * User API handlers
 */

import type { IApiContext, IApiResponse } from '../router.ts';
import { PermissionService } from '../../services/permission.service.ts';
import { AuthService } from '../../services/auth.service.ts';
import { User } from '../../models/user.ts';

export class UserApi {
  private permissionService: PermissionService;

  constructor(permissionService: PermissionService) {
    this.permissionService = permissionService;
  }

  /**
   * GET /api/v1/users
   */
  public async list(ctx: IApiContext): Promise<IApiResponse> {
    if (!ctx.actor?.userId) {
      return { status: 401, body: { error: 'Authentication required' } };
    }

    // Only system admins can list all users
    if (!ctx.actor.user?.isSystemAdmin) {
      return { status: 403, body: { error: 'System admin access required' } };
    }

    try {
      const users = await User.getInstances({});
      return {
        status: 200,
        body: {
          users: users.map((u) => ({
            id: u.id,
            email: u.email,
            username: u.username,
            displayName: u.displayName,
            isSystemAdmin: u.isSystemAdmin,
            isActive: u.isActive,
            createdAt: u.createdAt,
            lastLoginAt: u.lastLoginAt,
          })),
        },
      };
    } catch (error) {
      console.error('[UserApi] List error:', error);
      return { status: 500, body: { error: 'Failed to list users' } };
    }
  }

  /**
   * GET /api/v1/users/:id
   */
  public async get(ctx: IApiContext): Promise<IApiResponse> {
    if (!ctx.actor?.userId) {
      return { status: 401, body: { error: 'Authentication required' } };
    }

    const { id } = ctx.params;

    // Users can view their own profile, admins can view any
    if (id !== ctx.actor.userId && !ctx.actor.user?.isSystemAdmin) {
      return { status: 403, body: { error: 'Access denied' } };
    }

    try {
      const user = await User.findById(id);
      if (!user) {
        return { status: 404, body: { error: 'User not found' } };
      }

      return {
        status: 200,
        body: {
          id: user.id,
          email: user.email,
          username: user.username,
          displayName: user.displayName,
          avatarUrl: user.avatarUrl,
          isSystemAdmin: user.isSystemAdmin,
          isActive: user.isActive,
          createdAt: user.createdAt,
          lastLoginAt: user.lastLoginAt,
        },
      };
    } catch (error) {
      console.error('[UserApi] Get error:', error);
      return { status: 500, body: { error: 'Failed to get user' } };
    }
  }

  /**
   * POST /api/v1/users
   */
  public async create(ctx: IApiContext): Promise<IApiResponse> {
    if (!ctx.actor?.userId) {
      return { status: 401, body: { error: 'Authentication required' } };
    }

    // Only system admins can create users
    if (!ctx.actor.user?.isSystemAdmin) {
      return { status: 403, body: { error: 'System admin access required' } };
    }

    try {
      const body = await ctx.request.json();
      const { email, username, password, displayName, isSystemAdmin } = body;

      if (!email || !username || !password) {
        return {
          status: 400,
          body: { error: 'Email, username, and password are required' },
        };
      }

      // Check if email already exists
      const existing = await User.findByEmail(email);
      if (existing) {
        return { status: 409, body: { error: 'Email already in use' } };
      }

      // Check if username already exists
      const existingUsername = await User.findByUsername(username);
      if (existingUsername) {
        return { status: 409, body: { error: 'Username already in use' } };
      }

      // Hash password
      const passwordHash = await AuthService.hashPassword(password);

      // Create user
      const user = new User();
      user.id = await User.getNewId();
      user.email = email;
      user.username = username;
      user.passwordHash = passwordHash;
      user.displayName = displayName || username;
      user.isSystemAdmin = isSystemAdmin || false;
      user.isActive = true;
      user.createdAt = new Date();

      await user.save();

      return {
        status: 201,
        body: {
          id: user.id,
          email: user.email,
          username: user.username,
          displayName: user.displayName,
          isSystemAdmin: user.isSystemAdmin,
          createdAt: user.createdAt,
        },
      };
    } catch (error) {
      console.error('[UserApi] Create error:', error);
      return { status: 500, body: { error: 'Failed to create user' } };
    }
  }

  /**
   * PUT /api/v1/users/:id
   */
  public async update(ctx: IApiContext): Promise<IApiResponse> {
    if (!ctx.actor?.userId) {
      return { status: 401, body: { error: 'Authentication required' } };
    }

    const { id } = ctx.params;

    // Users can update their own profile, admins can update any
    if (id !== ctx.actor.userId && !ctx.actor.user?.isSystemAdmin) {
      return { status: 403, body: { error: 'Access denied' } };
    }

    try {
      const user = await User.findById(id);
      if (!user) {
        return { status: 404, body: { error: 'User not found' } };
      }

      const body = await ctx.request.json();
      const { displayName, avatarUrl, password, isActive, isSystemAdmin } = body;

      if (displayName !== undefined) user.displayName = displayName;
      if (avatarUrl !== undefined) user.avatarUrl = avatarUrl;

      // Only admins can change these
      if (ctx.actor.user?.isSystemAdmin) {
        if (isActive !== undefined) user.isActive = isActive;
        if (isSystemAdmin !== undefined) user.isSystemAdmin = isSystemAdmin;
      }

      // Password change
      if (password) {
        user.passwordHash = await AuthService.hashPassword(password);
      }

      await user.save();

      return {
        status: 200,
        body: {
          id: user.id,
          email: user.email,
          username: user.username,
          displayName: user.displayName,
          avatarUrl: user.avatarUrl,
          isSystemAdmin: user.isSystemAdmin,
          isActive: user.isActive,
        },
      };
    } catch (error) {
      console.error('[UserApi] Update error:', error);
      return { status: 500, body: { error: 'Failed to update user' } };
    }
  }

  /**
   * DELETE /api/v1/users/:id
   */
  public async delete(ctx: IApiContext): Promise<IApiResponse> {
    if (!ctx.actor?.userId) {
      return { status: 401, body: { error: 'Authentication required' } };
    }

    // Only system admins can delete users
    if (!ctx.actor.user?.isSystemAdmin) {
      return { status: 403, body: { error: 'System admin access required' } };
    }

    const { id } = ctx.params;

    // Cannot delete yourself
    if (id === ctx.actor.userId) {
      return { status: 400, body: { error: 'Cannot delete your own account' } };
    }

    try {
      const user = await User.findById(id);
      if (!user) {
        return { status: 404, body: { error: 'User not found' } };
      }

      // Soft delete - deactivate instead of removing
      user.isActive = false;
      await user.save();

      return {
        status: 200,
        body: { message: 'User deactivated successfully' },
      };
    } catch (error) {
      console.error('[UserApi] Delete error:', error);
      return { status: 500, body: { error: 'Failed to delete user' } };
    }
  }
}