/**
 * Auth Service
 * 
 * 认证业务逻辑
 * 
 * 支持两种登录方式：
 * 1. 手机号 + 验证码
 * 2. 手机号 + 密码
 */

import bcrypt from 'bcryptjs';
import { prisma } from '../../config/database.js';
import { jwtService } from './jwt.service.js';
import type { JWTPayload, TokenResponse } from './jwt.service.js';
import { logger } from '../logging/index.js';

/**
 * 登录请求 - 密码方式
 */
export interface PasswordLoginRequest {
  phone: string;
  password: string;
}

/**
 * 登录请求 - 验证码方式
 */
export interface VerificationCodeLoginRequest {
  phone: string;
  code: string;
}

/**
 * 修改密码请求
 */
export interface ChangePasswordRequest {
  oldPassword?: string;  // 如果用验证码修改，可不提供
  newPassword: string;
  confirmPassword: string;
}

/**
 * 用户信息响应
 */
export interface UserInfoResponse {
  id: string;
  phone: string;
  name: string;
  email?: string | null;
  role: string;
  tenantId: string;
  tenantCode?: string;
  tenantName?: string;
  departmentId?: string | null;
  departmentName?: string | null;
  isDefaultPassword: boolean;
  permissions: string[];
  modules: string[];  // 用户可访问的模块代码列表
}

/**
 * 登录响应
 */
export interface LoginResponse {
  user: UserInfoResponse;
  tokens: TokenResponse;
}

/**
 * Auth Service 类
 */
export class AuthService {
  
  /**
   * 密码登录
   */
  async loginWithPassword(request: PasswordLoginRequest): Promise<LoginResponse> {
    const { phone, password } = request;

    // 1. 查找用户
    const user = await prisma.user.findUnique({
      where: { phone },
      include: {
        tenants: true,
        departments: true,
      },
    });

    if (!user) {
      logger.warn('登录失败：用户不存在', { phone });
      throw new Error('手机号或密码错误');
    }

    // 2. 验证密码
    const isValidPassword = await bcrypt.compare(password, user.password);
    if (!isValidPassword) {
      logger.warn('登录失败：密码错误', { phone, userId: user.id });
      throw new Error('手机号或密码错误');
    }

    // 3. 检查用户状态
    if (user.status !== 'active') {
      logger.warn('登录失败：用户已禁用', { phone, userId: user.id, status: user.status });
      throw new Error('账号已被禁用，请联系管理员');
    }

    // 4. 获取用户权限和模块列表
    const permissions = await this.getUserPermissions(user.role);
    const modules = await this.getUserModules(user.id);

    // 5. 生成 JWT
    const jwtPayload: JWTPayload = {
      userId: user.id,
      phone: user.phone,
      role: user.role,
      tenantId: user.tenant_id,
      tenantCode: user.tenants?.code,
      isDefaultPassword: user.is_default_password,
    };

    const tokens = jwtService.generateTokens(jwtPayload);

    // 6. 更新最后登录时间
    await prisma.user.update({
      where: { id: user.id },
      data: { lastLoginAt: new Date() },
    });

    logger.info('用户登录成功（密码方式）', { 
      userId: user.id, 
      phone: user.phone,
      role: user.role,
      tenantId: user.tenant_id,
      modules: modules.length,
    });

    return {
      user: {
        id: user.id,
        phone: user.phone,
        name: user.name,
        email: user.email,
        role: user.role,
        tenantId: user.tenant_id,
        tenantCode: user.tenants?.code,
        tenantName: user.tenants?.name,
        departmentId: user.department_id,
        departmentName: user.departments?.name,
        isDefaultPassword: user.is_default_password,
        permissions,
        modules,  // 新增：返回模块列表
      },
      tokens,
    };
  }

  /**
   * 验证码登录
   */
  async loginWithVerificationCode(request: VerificationCodeLoginRequest): Promise<LoginResponse> {
    const { phone, code } = request;

    // 1. 验证验证码
    const verificationCode = await prisma.verification_codes.findFirst({
      where: {
        phone,
        code,
        type: 'LOGIN',
        is_used: false,
        expires_at: { gt: new Date() },
      },
      orderBy: { created_at: 'desc' },
    });

    if (!verificationCode) {
      logger.warn('登录失败：验证码无效', { phone });
      throw new Error('验证码无效或已过期');
    }

    // 2. 标记验证码已使用
    await prisma.verification_codes.update({
      where: { id: verificationCode.id },
      data: { is_used: true },
    });

    // 3. 查找用户
    const user = await prisma.user.findUnique({
      where: { phone },
      include: {
        tenants: true,
        departments: true,
      },
    });

    if (!user) {
      logger.warn('登录失败：用户不存在', { phone });
      throw new Error('用户不存在');
    }

    // 4. 检查用户状态
    if (user.status !== 'active') {
      logger.warn('登录失败：用户已禁用', { phone, userId: user.id, status: user.status });
      throw new Error('账号已被禁用，请联系管理员');
    }

    // 5. 获取用户权限和模块列表
    const permissions = await this.getUserPermissions(user.role);
    const modules = await this.getUserModules(user.id);

    // 6. 生成 JWT
    const jwtPayload: JWTPayload = {
      userId: user.id,
      phone: user.phone,
      role: user.role,
      tenantId: user.tenant_id,
      tenantCode: user.tenants?.code,
      isDefaultPassword: user.is_default_password,
    };

    const tokens = jwtService.generateTokens(jwtPayload);

    logger.info('用户登录成功（验证码方式）', { 
      userId: user.id, 
      phone: user.phone,
      role: user.role,
      modules: modules.length,
    });

    return {
      user: {
        id: user.id,
        phone: user.phone,
        name: user.name,
        email: user.email,
        role: user.role,
        tenantId: user.tenant_id,
        tenantCode: user.tenants?.code,
        tenantName: user.tenants?.name,
        departmentId: user.department_id,
        departmentName: user.departments?.name,
        isDefaultPassword: user.is_default_password,
        permissions,
        modules,  // 新增：返回模块列表
      },
      tokens,
    };
  }

  /**
   * 获取当前用户信息
   */
  async getCurrentUser(userId: string): Promise<UserInfoResponse> {
    const user = await prisma.user.findUnique({
      where: { id: userId },
      include: {
        tenants: true,
        departments: true,
      },
    });

    if (!user) {
      throw new Error('用户不存在');
    }

    const permissions = await this.getUserPermissions(user.role);

    return {
      id: user.id,
      phone: user.phone,
      name: user.name,
      email: user.email,
      role: user.role,
      tenantId: user.tenant_id,
      tenantCode: user.tenants?.code,
      tenantName: user.tenants?.name,
      departmentId: user.department_id,
      departmentName: user.departments?.name,
      isDefaultPassword: user.is_default_password,
      permissions,
    };
  }

  /**
   * 修改密码
   */
  async changePassword(userId: string, request: ChangePasswordRequest): Promise<void> {
    const { oldPassword, newPassword, confirmPassword } = request;

    // 1. 验证新密码
    if (newPassword !== confirmPassword) {
      throw new Error('两次输入的密码不一致');
    }

    if (newPassword.length < 6) {
      throw new Error('密码长度至少为6位');
    }

    // 2. 获取用户
    const user = await prisma.user.findUnique({
      where: { id: userId },
    });

    if (!user) {
      throw new Error('用户不存在');
    }

    // 3. 如果提供了旧密码，验证旧密码
    if (oldPassword) {
      const isValidPassword = await bcrypt.compare(oldPassword, user.password);
      if (!isValidPassword) {
        throw new Error('原密码错误');
      }
    }

    // 4. 加密新密码
    const hashedPassword = await bcrypt.hash(newPassword, 10);

    // 5. 更新密码
    await prisma.user.update({
      where: { id: userId },
      data: {
        password: hashedPassword,
        is_default_password: false,
        password_changed_at: new Date(),
      },
    });

    logger.info('用户修改密码成功', { userId });
  }

  /**
   * 发送验证码
   */
  async sendVerificationCode(phone: string, type: 'LOGIN' | 'RESET_PASSWORD'): Promise<{ expiresIn: number }> {
    // 1. 检查用户是否存在
    const user = await prisma.user.findUnique({
      where: { phone },
    });

    if (!user) {
      throw new Error('用户不存在');
    }

    // 2. 检查是否频繁发送（1分钟内只能发一次）
    const recentCode = await prisma.verification_codes.findFirst({
      where: {
        phone,
        created_at: { gt: new Date(Date.now() - 60 * 1000) },
      },
    });

    if (recentCode) {
      throw new Error('验证码发送过于频繁，请稍后再试');
    }

    // 3. 生成6位验证码
    const code = Math.floor(100000 + Math.random() * 900000).toString();
    
    // 4. 设置5分钟过期
    const expiresAt = new Date(Date.now() + 5 * 60 * 1000);

    // 5. 保存验证码
    await prisma.verification_codes.create({
      data: {
        phone,
        code,
        type: type as any,  // VerificationType enum
        expires_at: expiresAt,
      },
    });

    // TODO: 实际发送短信
    // 开发环境直接打印验证码
    logger.info('📱 验证码已生成', { phone, code, type, expiresAt });
    console.log(`\n📱 验证码: ${code} (有效期5分钟)\n`);

    return { expiresIn: 300 };  // 5分钟
  }

  /**
   * 刷新 Token
   */
  async refreshToken(refreshToken: string): Promise<TokenResponse> {
    return jwtService.refreshToken(refreshToken, async (userId) => {
      const user = await prisma.user.findUnique({
        where: { id: userId },
        include: { tenants: true },
      });

      if (!user) {
        return null;
      }

      return {
        userId: user.id,
        phone: user.phone,
        role: user.role,
        tenantId: user.tenant_id,
        tenantCode: user.tenants?.code,
        isDefaultPassword: user.is_default_password,
      };
    });
  }

  /**
   * 获取用户权限列表
   */
  private async getUserPermissions(role: string): Promise<string[]> {
    const rolePermissions = await prisma.role_permissions.findMany({
      where: { role: role as any },
      include: { permissions: true },
    });

    return rolePermissions.map(rp => rp.permissions.code);
  }

  /**
   * 获取用户可访问的模块列表
   * 
   * 逻辑：
   * 1. 查询用户所有租户关系
   * 2. 对每个租户，检查租户订阅的模块
   * 3. 如果用户有自定义模块权限，使用自定义权限
   * 4. 否则继承租户的全部模块权限
   * 5. 去重后返回所有可访问模块
   */
  private async getUserModules(userId: string): Promise<string[]> {
    // 获取用户的所有租户关系
    const tenantMembers = await prisma.tenant_members.findMany({
      where: { user_id: userId },
    });

    const allAccessibleModules = new Set<string>();

    for (const tm of tenantMembers) {
      // 获取租户订阅的模块
      const tenantModules = await prisma.tenant_modules.findMany({
        where: { 
          tenant_id: tm.tenant_id,
          is_enabled: true,
        },
      });

      // 获取用户在该租户的自定义模块权限
      const userModules = await prisma.user_modules.findMany({
        where: {
          user_id: userId,
          tenant_id: tm.tenant_id,
          is_enabled: true,
        },
      });

      if (userModules.length > 0) {
        // 有自定义权限，使用自定义权限
        userModules.forEach(um => allAccessibleModules.add(um.module_code));
      } else {
        // 无自定义权限，继承租户所有模块
        tenantModules.forEach(tm => allAccessibleModules.add(tm.module_code));
      }
    }

    return Array.from(allAccessibleModules).sort();
  }

  /**
   * 根据用户ID获取JWT Payload（用于刷新Token）
   */
  async getUserPayloadById(userId: string): Promise<JWTPayload | null> {
    const user = await prisma.user.findUnique({
      where: { id: userId },
      include: { tenants: true },
    });

    if (!user) {
      return null;
    }

    return {
      userId: user.id,
      phone: user.phone,
      role: user.role,
      tenantId: user.tenant_id,
      tenantCode: user.tenants?.code,
      isDefaultPassword: user.is_default_password,
    };
  }
}

// 导出单例
export const authService = new AuthService();