import { prisma } from '../database'
import { User, Prisma } from '@prisma/client'
import bcrypt from 'bcrypt'

export interface CreateUserData {
  email: string
  name?: string
  password?: string
  image?: string
}

export interface UpdateUserData {
  name?: string
  email?: string
  image?: string
}

export interface UserProfile {
  id: string
  name: string | null
  email: string | null
  image: string | null
  createdAt: Date
  updatedAt: Date
}

export class UserService {
  /**
   * 创建新用户
   */
  static async createUser(data: CreateUserData): Promise<User> {
    const { email, name, password, image } = data

    // 验证邮箱格式
    if (!this.isValidEmail(email)) {
      throw new Error('邮箱格式不正确')
    }

    // 检查邮箱是否已存在
    const existingUser = await prisma.user.findUnique({
      where: { email }
    })

    if (existingUser) {
      throw new Error('邮箱已被注册')
    }

    // 哈希密码（如果提供）
    let hashedPassword: string | undefined
    if (password) {
      if (password.length < 6) {
        throw new Error('密码长度至少6位')
      }
      hashedPassword = await bcrypt.hash(password, 12)
    }

    return prisma.user.create({
      data: {
        email,
        name,
        image,
        hashedPassword
      }
    })
  }

  /**
   * 根据ID获取用户
   */
  static async getUserById(id: string): Promise<UserProfile | null> {
    const user = await prisma.user.findUnique({
      where: { id },
      select: {
        id: true,
        name: true,
        email: true,
        image: true,
        createdAt: true,
        updatedAt: true
      }
    })

    return user
  }

  /**
   * 根据邮箱获取用户
   */
  static async getUserByEmail(email: string): Promise<User | null> {
    return prisma.user.findUnique({
      where: { email }
    })
  }

  /**
   * 更新用户信息
   */
  static async updateUser(id: string, data: UpdateUserData): Promise<UserProfile> {
    const updateData: Prisma.UserUpdateInput = {}

    if (data.name !== undefined) {
      updateData.name = data.name
    }

    if (data.email !== undefined) {
      if (!this.isValidEmail(data.email)) {
        throw new Error('邮箱格式不正确')
      }
      updateData.email = data.email
    }

    if (data.image !== undefined) {
      updateData.image = data.image
    }

    const user = await prisma.user.update({
      where: { id },
      data: updateData,
      select: {
        id: true,
        name: true,
        email: true,
        image: true,
        createdAt: true,
        updatedAt: true
      }
    })

    return user
  }

  /**
   * 验证用户密码
   */
  static async verifyPassword(user: User, password: string): Promise<boolean> {
    if (!user.hashedPassword) {
      return false
    }

    return bcrypt.compare(password, user.hashedPassword)
  }

  /**
   * 删除用户
   */
  static async deleteUser(id: string): Promise<void> {
    await prisma.user.delete({
      where: { id }
    })
  }

  /**
   * 验证邮箱格式
   */
  private static isValidEmail(email: string): boolean {
    const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/
    return emailRegex.test(email)
  }
}