import {
  INestApplication,
  Injectable,
  Logger,
  OnModuleInit,
} from '@nestjs/common';

import { PrismaClient } from '@prisma/client';

@Injectable()
export class PrismaService extends PrismaClient implements OnModuleInit {
  private readonly logger = new Logger(PrismaService.name);
  constructor() {
    super({
      log: [
        {
          emit: 'stdout',
          level: 'query',
        },
        {
          emit: 'stdout',
          level: 'error',
        },
        {
          emit: 'stdout',
          level: 'info',
        },
        {
          emit: 'stdout',
          level: 'warn',
        },
      ],
      errorFormat: 'pretty',
      transactionOptions: {
        maxWait: 30 * 1000,
        timeout: 60 * 1000,
      },
    });
  }

  async onModuleInit() {
    this.logger.log('Try to connect database...');

    const maxRetry = parseInt(process.env.PRISMA_MAX_RETRY as string) ?? 3;
    const retryDelay = 10000;

    for (let attempt = 1; attempt <= maxRetry; attempt++) {
      try {
        await this.$connect();
        this.logger.log('Connected.');
        return;
      } catch (error) {
        if (attempt < maxRetry) {
          this.logger.warn(
            `Connection attempt ${attempt} failed. Retrying in ${retryDelay}ms...`,
          );
          await this.delay(retryDelay);
        } else {
          this.logger.error(
            `Failed to connect to the database after ${maxRetry} attempts.`,
          );
          throw error;
        }
      }
    }
  }

  private delay(ms: number): Promise<void> {
    return new Promise((resolve) => setTimeout(resolve, ms));
  }

  async enableShutdownHooks(app: INestApplication) {
    this.$on('beforeExit' as never, async () => {
      this.logger.log('Wait for application closing...');
      await app.close();
    });
  }
}