import { Inject, Injectable } from '@nestjs/common';
import { Repository } from 'typeorm';
import { UserToken, UserTokenType } from './user-token.entity';
import { UserTOTPToken } from './user-totp-token.entity';
import { User } from './user.entity';
import speakeasy from '@levminer/speakeasy';

import * as bcrypt from 'bcrypt';
import { TokenService } from 'src/modules/utility/services/token.service';

@Injectable()
export class UserService {
  constructor(
    @Inject('USER_REPOSITORY')
    private userRepository: Repository<User>,
    @Inject('USER_TOKEN_REPOSITORY')
    private userTokenRepository: Repository<UserToken>,
    @Inject('USER_TOTP_TOKEN_REPOSITORY')
    private userTOTPTokenRepository: Repository<UserTOTPToken>,
    private token: TokenService,
  ) {}

  public async getById(id: number): Promise<User> {
    return this.userRepository.findOne({ id });
  }

  public async getByUUID(uuid: string): Promise<User> {
    return this.userRepository.findOne({ uuid });
  }

  public async getByEmail(email: string): Promise<User> {
    return this.userRepository.findOne({ email });
  }

  public async getByUsername(username: string): Promise<User> {
    return this.userRepository.findOne({ username });
  }

  public async get(input: string | number): Promise<User> {
    if (typeof input === 'number') {
      return this.getById(input);
    }

    if (input.includes('@')) {
      return this.getByEmail(input);
    }

    if (input.length === 36 && input.includes('-')) {
      return this.getByUUID(input);
    }

    return this.getByUsername(input);
  }

  public async comparePasswords(
    hash: string,
    password: string,
  ): Promise<boolean> {
    return bcrypt.compare(password, hash);
  }

  public async hashPassword(password: string): Promise<string> {
    const salt = await bcrypt.genSalt(10);
    return bcrypt.hash(password, salt);
  }

  /**
   * Check if the user has TOTP enabled
   * @param user User object
   * @returns true if the user has TOTP enabled
   */
  public async userHasTOTP(user: User): Promise<boolean> {
    return !!(await this.getUserTOTP(user));
  }

  /**
   * Get the TOTP token of a user
   * @param user User object
   * @returns TOTP token
   */
  public async getUserTOTP(user: User): Promise<UserTOTPToken> {
    return this.userTOTPTokenRepository.findOne({
      user,
      activated: true,
    });
  }

  public validateTOTP(secret: string, token: string): boolean {
    return speakeasy.totp.verify({
      secret,
      encoding: 'base32',
      token,
      window: 6,
    });
  }

  public async createUserToken(
    user: User,
    type: UserTokenType,
    expiresAt?: Date,
  ): Promise<UserToken> {
    const token = new UserToken();
    token.token = this.token.generateString(64);
    token.user = user;
    token.type = type;
    token.expires_at = expiresAt;
    await this.userTokenRepository.save(token);
    return token;
  }

  public async sendActivationEmail(user: User): Promise<void> {
    const activationToken = await this.createUserToken(
      user,
      UserTokenType.ACTIVATION,
      new Date(Date.now() + 3600 * 1000),
    );
  }

  public async userRegistration(newUserInfo: {
    username: string;
    display_name: string;
    email: string;
    password: string;
  }): Promise<User> {
    if (!!(await this.getByEmail(newUserInfo.email))) {
      throw new Error('Email is already in use!');
    }

    if (!!(await this.getByUsername(newUserInfo.username))) {
      throw new Error('Username is already in use!');
    }

    const hashword = await this.hashPassword(newUserInfo.password);
    const user = new User();
    user.email = newUserInfo.email;
    user.uuid = this.token.createUUID();
    user.username = newUserInfo.username;
    user.display_name = newUserInfo.display_name;
    user.password = hashword;
    await this.userRepository.insert(user);

    // TODO: activation email

    return user;
  }
}