import {
  BadRequestException,
  Body,
  Controller,
  Delete,
  ForbiddenException,
  NotFoundException,
  Get,
  Param,
  Post,
  Put,
  Request,
  UseGuards,
} from '@nestjs/common';
import { UserService } from './user.service';
import { CombinedAuthGuard } from '../auth/combined-auth.guard';
import { UpdateUserDto } from './dto/update-user.dto';
import { I18nService } from '../i18n/i18n.service';

@Controller('users')
@UseGuards(CombinedAuthGuard)
export class UserController {
  constructor(
    private readonly userService: UserService,
    private readonly i18nService: I18nService,
  ) { }

  // --- API Key Management ---
  @Get('api-key')
  async getApiKey(@Request() req) {
    const apiKey = await this.userService.getOrCreateApiKey(req.user.id);
    return { apiKey };
  }

  @Post('api-key/rotate')
  async rotateApiKey(@Request() req) {
    const apiKey = await this.userService.regenerateApiKey(req.user.id);
    return { apiKey };
  }

  // --- Profile ---
  @Get('me')
  async getMe(@Request() req) {
    const user = await this.userService.findOneById(req.user.id);
    if (!user) throw new NotFoundException(this.i18nService.getErrorMessage('userNotFound'));

    let isNotebookEnabled = true;
    if (user.tenantId) {
      const settings = await this.userService.getTenantSettings(user.tenantId);
      isNotebookEnabled = settings?.isNotebookEnabled ?? true;
    }

    return {
      id: user.id,
      username: user.username,
      role: user.role,
      tenantId: user.tenantId,
      isAdmin: user.isAdmin,
      isNotebookEnabled,
    };
  }

  @Get()
  async findAll(@Request() req) {
    const callerRole = req.user.role;
    if (callerRole !== 'SUPER_ADMIN' && callerRole !== 'TENANT_ADMIN') {
      throw new ForbiddenException(this.i18nService.getErrorMessage('adminOnlyViewList'));
    }

    if (callerRole === 'SUPER_ADMIN') {
      return this.userService.findAll();
    } else {
      return this.userService.findByTenantId(req.user.tenantId);
    }
  }

  @Put('password')
  async changePassword(
    @Request() req,
    @Body() body: { currentPassword: string; newPassword: string },
  ) {
    const { currentPassword, newPassword } = body;

    if (!currentPassword || !newPassword) {
      throw new BadRequestException(this.i18nService.getErrorMessage('passwordsRequired'));
    }

    if (newPassword.length < 6) {
      throw new BadRequestException(this.i18nService.getErrorMessage('newPasswordMinLength'));
    }

    return this.userService.changePassword(
      req.user.id,
      currentPassword,
      newPassword,
    );
  }

  @Post()
  async createUser(
    @Request() req,
    @Body() body: { username: string; password: string; role?: string },
  ) {
    const callerRole = req.user.role;
    if (callerRole !== 'SUPER_ADMIN' && callerRole !== 'TENANT_ADMIN') {
      throw new ForbiddenException(this.i18nService.getErrorMessage('adminOnlyCreateUser'));
    }

    const { username, password } = body;

    if (!username || !password) {
      throw new BadRequestException(this.i18nService.getErrorMessage('usernamePasswordRequired'));
    }

    if (password.length < 6) {
      throw new BadRequestException(this.i18nService.getErrorMessage('passwordMinLength'));
    }

    // Determine target role based on caller's role and requested role
    let targetRole = 'USER';
    let isAdmin = false;

    if (callerRole === 'SUPER_ADMIN') {
      // Super Admin can create TENANT_ADMIN or USER. Default to requested role, fallback to USER.
      targetRole = body.role === 'TENANT_ADMIN' ? 'TENANT_ADMIN' : 'USER';
      isAdmin = targetRole === 'TENANT_ADMIN';
    } else if (callerRole === 'TENANT_ADMIN') {
      // Tenant Admin can ONLY create regular users.
      targetRole = 'USER';
      isAdmin = false;
    }

    // Pass the calculated params to the service
    return this.userService.createUser(username, password, isAdmin, req.user.tenantId, targetRole as any);
  }

  @Put(':id')
  async updateUser(
    @Request() req,
    @Body() body: UpdateUserDto,
    @Param('id') id: string,
  ) {
    const callerRole = req.user.role;
    if (callerRole !== 'SUPER_ADMIN' && callerRole !== 'TENANT_ADMIN') {
      throw new ForbiddenException(this.i18nService.getErrorMessage('adminOnlyUpdateUser'));
    }

    // 更新するユーザー情報を取得
    const userToUpdate = await this.userService.findOneById(id);
    if (!userToUpdate) {
      throw new NotFoundException(this.i18nService.getErrorMessage('userNotFound'));
    }

    if (callerRole === 'TENANT_ADMIN' && userToUpdate.tenantId !== req.user.tenantId) {
      throw new ForbiddenException('Cannot modify users outside your tenant');
    }

    // Prevent modifying the builtin admin account
    if (userToUpdate.username === 'admin') {
      throw new ForbiddenException(this.i18nService.getErrorMessage('cannotModifyBuiltinAdmin'));
    }

    // Role modification logic
    if (body.role && userToUpdate.role !== body.role) {
      if (callerRole !== 'SUPER_ADMIN') {
        throw new ForbiddenException('Only Super Admins can change user roles.');
      }
      if (userToUpdate.role === 'SUPER_ADMIN') {
        throw new ForbiddenException('Cannot modify the role of another Super Admin.');
      }

      // Sync isAdmin based on the newly selected role
      if (body.role === 'TENANT_ADMIN' || body.role === 'SUPER_ADMIN') {
        body.isAdmin = true;
      } else {
        body.isAdmin = false;
      }
    }

    return this.userService.updateUser(id, body);
  }

  @Delete(':id')
  async deleteUser(
    @Request() req,
    @Param('id') id: string,
  ) {
    const callerRole = req.user.role;
    if (callerRole !== 'SUPER_ADMIN' && callerRole !== 'TENANT_ADMIN') {
      throw new ForbiddenException(this.i18nService.getErrorMessage('adminOnlyDeleteUser'));
    }

    // 管理者が自身を削除するのを防止
    if (req.user.id === id) {
      throw new BadRequestException(this.i18nService.getErrorMessage('cannotDeleteSelf'));
    }

    // 削除するユーザー情報を取得
    const userToDelete = await this.userService.findOneById(id);
    if (!userToDelete) {
      throw new NotFoundException(this.i18nService.getErrorMessage('userNotFound'));
    }

    if (callerRole === 'TENANT_ADMIN' && userToDelete.tenantId !== req.user.tenantId) {
      throw new ForbiddenException('Cannot delete users outside your tenant');
    }

    // ビルトインadminアカウントの削除を阻止
    if (userToDelete.username === 'admin') {
      throw new ForbiddenException(this.i18nService.getErrorMessage('cannotDeleteBuiltinAdmin'));
    }

    return this.userService.deleteUser(id);
  }
}