tehran_tala/apps/api/src/modules/customer-auth/customer-auth.service.ts

import { HttpException, HttpStatus, Injectable, Logger, UnauthorizedException } from '@nestjs/common';
import { JwtService } from '@nestjs/jwt';
import { MessageAudience } from '@prisma/client';
import * as bcrypt from 'bcryptjs';
import { PrismaService } from '../../prisma/prisma.service';
import { CUSTOMER_TOKEN_TYPE, type CustomerJwtPayload } from './customer-jwt.strategy';
import { faToEn } from './digits';
import { SmsService, smsConfigured } from '../sms/sms.service';

/** Nest 10 has no TooManyRequestsException; 429 with a Persian message. */
class TooManyRequestsException extends HttpException {
  constructor(message: string) {
    super(message, HttpStatus.TOO_MANY_REQUESTS);
  }
}

/** How long a code stays usable. The reference had no expiry at all (D6). */
const OTP_TTL_MS = 2 * 60 * 1000;
/** Wrong guesses allowed against one challenge before it is burned. */
const MAX_ATTEMPTS = 5;
/** Sends allowed per mobile number inside the window. */
const MAX_SENDS_PER_MOBILE = 5;
/** Sends allowed per source IP inside the window. */
const MAX_SENDS_PER_IP = 20;
const SEND_WINDOW_MS = 10 * 60 * 1000;
/** Minimum gap between two sends to the same number. */
const RESEND_COOLDOWN_MS = 60 * 1000;

@Injectable()
export class CustomerAuthService {
  private readonly logger = new Logger(CustomerAuthService.name);

  constructor(
    private readonly prisma: PrismaService,
    private readonly jwt: JwtService,
    private readonly sms: SmsService,
  ) {}

  /**
   * Step 1 — port of ApiMobileController::userAuth (henza_server:39-49).
   *
   * Reference: validate `username`, find an ACTIVE customer by mobile, generate
   * rand(1000,9999), store it, send it by SMS, return `true`.
   *
   * Kept: the active-customer filter, the 4-digit range, the opaque `true`
   * response (it never reveals whether the number exists).
   * Changed: the code is hashed, it expires, and sends are rate limited.
   */
  async requestOtp(rawMobile: string, ip: string | undefined) {
    const mobile = faToEn(rawMobile);

    await this.assertSendAllowed(mobile, ip);

    // Legacy used Customer::active(), and the archived filter matches the
    // customer-list lookup the app login previously relied on.
    const customer = await this.prisma.customer.findFirst({
      where: { mobile, isActive: true, isArchived: false },
      select: { id: true },
    });

    // Deliberately opaque: the reference used firstOrFail() and leaked a 404
    // for unknown numbers, which let anyone enumerate registered customers.
    // Recorded as a deviation in docs/parity/DECISIONS.md.
    if (!customer) {
      this.logger.warn(`OTP requested for unknown or inactive mobile ${mobile}`);
      return { sent: true };
    }

    const code = String(Math.floor(1000 + Math.random() * 9000));

    await this.prisma.customerOtp.create({
      data: {
        mobile,
        customerId: customer.id,
        codeHash: await bcrypt.hash(code, 10),
        expiresAt: new Date(Date.now() + OTP_TTL_MS),
        requestIp: ip ?? null,
      },
    });

    await this.deliver(mobile, code);
    return { sent: true };
  }

  /**
   * Step 2 — port of ApiMobileController::userVerfiy (henza_server:51-64).
   *
   * Reference: `if (faTOen($request->password) != $customer->send_password) abort(422);`
   * then issue a token and return THAT ONE customer.
   *
   * The parity behaviour is the comparison and the rejection. The attempt
   * counter, the expiry check and the single-use consumption are the D6
   * additions.
   */
  async verifyOtp(rawMobile: string, rawCode: string, ip: string | undefined) {
    const mobile = faToEn(rawMobile);
    const code = faToEn(rawCode);

    const challenge = await this.prisma.customerOtp.findFirst({
      where: { mobile, consumedAt: null },
      orderBy: { createdAt: 'desc' },
      include: {
        customer: {
          select: { id: true, mobile: true, isActive: true, isArchived: true },
        },
      },
    });

    // One message for every failure mode below, so a caller cannot tell "no
    // code was sent" from "wrong code" from "expired".
    const reject = () => new UnauthorizedException('کد وارد شده صحیح نیست');

    if (!challenge) throw reject();
    if (challenge.expiresAt.getTime() < Date.now()) throw reject();

    if (challenge.attempts >= MAX_ATTEMPTS) {
      throw new TooManyRequestsException(
        'تعداد تلاش‌های ناموفق بیش از حد مجاز است. لطفاً کد جدیدی درخواست کنید.',
      );
    }

    const ok = await bcrypt.compare(code, challenge.codeHash);
    if (!ok) {
      await this.prisma.customerOtp.update({
        where: { id: challenge.id },
        data: { attempts: { increment: 1 } },
      });
      throw reject();
    }

    if (!challenge.customer.isActive || challenge.customer.isArchived) {
      throw reject();
    }

    // Single use: burn the challenge before issuing the token.
    await this.prisma.customerOtp.update({
      where: { id: challenge.id },
      data: { consumedAt: new Date() },
    });

    const payload: CustomerJwtPayload = {
      sub: challenge.customer.id,
      mobile: challenge.customer.mobile,
      typ: CUSTOMER_TOKEN_TYPE,
    };

    // Reference reused api_token forever once set (:60-62); a fresh token is
    // issued on every verify here (T1).
    const token = await this.jwt.signAsync(payload, {
      secret: customerJwtSecret(),
      // jsonwebtoken types expiresIn as a template-literal union, which a plain
      // string from process.env does not satisfy — same cast AuthModule uses.
      expiresIn: (process.env.JWT_CUSTOMER_EXPIRES_IN ?? '30d') as `${number}d`,
    });

    return {
      token,
      customer: { id: challenge.customer.id, mobile: challenge.customer.mobile },
    };
  }

  /**
   * Per-mobile and per-IP send throttle.
   *
   * Counted off the CustomerOtp rows rather than an in-memory map, so the limit
   * survives a restart and holds across replicas. The reference had no limit:
   * userAuth could be called in a loop, each call sending a real (billed) SMS.
   */
  private async assertSendAllowed(mobile: string, ip: string | undefined) {
    const since = new Date(Date.now() - SEND_WINDOW_MS);

    const lastToMobile = await this.prisma.customerOtp.findFirst({
      where: { mobile },
      orderBy: { createdAt: 'desc' },
      select: { createdAt: true },
    });
    if (lastToMobile && Date.now() - lastToMobile.createdAt.getTime() < RESEND_COOLDOWN_MS) {
      const wait = Math.ceil(
        (RESEND_COOLDOWN_MS - (Date.now() - lastToMobile.createdAt.getTime())) / 1000,
      );
      throw new TooManyRequestsException(`لطفاً ${wait} ثانیه دیگر تلاش کنید`);
    }

    const sentToMobile = await this.prisma.customerOtp.count({
      where: { mobile, createdAt: { gte: since } },
    });
    if (sentToMobile >= MAX_SENDS_PER_MOBILE) {
      throw new TooManyRequestsException(
        'تعداد درخواست‌های کد بیش از حد مجاز است. لطفاً بعداً تلاش کنید.',
      );
    }

    if (ip) {
      const sentFromIp = await this.prisma.customerOtp.count({
        where: { requestIp: ip, createdAt: { gte: since } },
      });
      if (sentFromIp >= MAX_SENDS_PER_IP) {
        throw new TooManyRequestsException(
          'تعداد درخواست‌های کد بیش از حد مجاز است. لطفاً بعداً تلاش کنید.',
        );
      }
    }
  }

  /**
   * Hands the code to the SMS gateway (SmsService -> Trez, per Sms.php:57-82).
   *
   * When no credentials are configured, SmsService does not send and the code
   * is logged instead — development only; production refuses to boot without
   * credentials (assertSmsConfigured in main.ts).
   *
   * A failed send does NOT throw. The reference ignored Sms::Send's result, so
   * a gateway outage never blocked the flow that triggered it; the customer
   * simply retries, and the throttle in assertSendAllowed still applies.
   */
  private async deliver(mobile: string, code: string) {
    // BYTE-IDENTICAL to the reference (ApiMobileController.php:47). The
    // leading "<#> code is <CODE>" line and the trailing "aMo6iFyUQaY" are the
    // Android SMS Retriever app hash — change either and autofill stops
    // working on every installed client. Do not "tidy" this string.
    const smsText =
      `<#> code is ${code}\n` +
      `رمز عبور یکبار مصرف شما جهت ورود به اپلیکشن هنزا گلد ${code} می باشد\n` +
      `aMo6iFyUQaY`;

    // persist:false — the real text carries the live code, and the admin SMS
    // grid lists and searches `body` (SEC-11). The redacted audit row below
    // takes its place.
    await this.sms.send(mobile, smsText, { persist: false });

    // Only outside production, and only when no gateway is configured, so a
    // deployment can never print live codes into its logs.
    if (process.env.NODE_ENV !== 'production' && !smsConfigured()) {
      this.logger.log(`[dev] OTP for ${mobile}: ${code}`);
    }

    // An audit row, NOT the message body.
    //
    // SmsMessage.body is listed and full-text searchable on the admin panel's
    // SMS grid (admin-misc.service.ts:136 allows `body`, :135 searches it), so
    // persisting the real text would show every live OTP to any operator
    // holding the `sms` rid — and the whole point of hashing codeHash is that
    // the code exists nowhere in readable form. The code is redacted here.
    await this.prisma.smsMessage.create({
      data: {
        audience: MessageAudience.SINGLE_NUMBER,
        recipients: mobile,
        body: 'کد یکبار مصرف ورود (متن پیام ثبت نمی‌شود)',
        sentCount: 1,
      },
    });
  }
}

/**
 * Customer tokens are signed with their own secret so an admin token can never
 * validate as a customer token, or the reverse, even if the `typ` check were
 * ever removed (T1).
 */
export function customerJwtSecret(): string {
  return (
    process.env.JWT_CUSTOMER_SECRET ??
    process.env.JWT_SECRET ??
    'dev-only-insecure-customer-secret'
  );
}