import { Injectable, BadRequestException } from '@nestjs/common';
import { randomInt } from 'node:crypto';
import { PinoLogger } from 'nestjs-pino';
import { PrismaService } from '../prisma/prisma.service';
import { MailService } from '../mail/mail.service';

@Injectable()
export class VerificationService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly mailService: MailService,
    private readonly logger: PinoLogger,
  ) {
    this.logger.setContext(VerificationService.name);
  }

  generateCode(): string {
    return randomInt(100000, 999999).toString();
  }

  async sendEmailCode(email: string): Promise<void> {
    const code = this.generateCode();
    await this.prisma.verificationCode.create({
      data: {
        target: email,
        channel: 'EMAIL',
        code,
        purpose: 'AUTH',
        expiresAt: new Date(Date.now() + 5 * 60 * 1000),
      },
    });
    await this.mailService.sendCode(email, code, 'AUTH');
    this.logger.info({ email }, 'Email verification code sent');
  }

  async sendPhoneCode(phone: string): Promise<void> {
    const code = this.generateCode();
    await this.prisma.verificationCode.create({
      data: {
        target: phone,
        channel: 'SMS',
        code,
        purpose: 'AUTH',
        expiresAt: new Date(Date.now() + 5 * 60 * 1000),
      },
    });
    this.logger.info({ phone }, 'SMS verification code would be sent (mock)');
  }

  async verifyCode(target: string, code: string): Promise<boolean> {
    const record = await this.prisma.verificationCode.findFirst({
      where: {
        target,
        code,
        usedAt: null,
        expiresAt: { gt: new Date() },
      },
      orderBy: { createdAt: 'desc' },
    });

    if (!record) {
      throw new BadRequestException('Invalid or expired code');
    }

    await this.prisma.verificationCode.update({
      where: { id: record.id },
      data: { usedAt: new Date() },
    });

    return true;
  }
}