import { Injectable, Logger, OnModuleInit, OnModuleDestroy } from '@nestjs/common';
import { PrismaClient } from '@prisma/client';

@Injectable()
export class PrismaService extends PrismaClient implements OnModuleInit, OnModuleDestroy {
  private readonly logger = new Logger(PrismaService.name);

  constructor() {
    super({
      // In production set connection_limit and pool_timeout in DATABASE_URL:
      // ?connection_limit=10&pool_timeout=20&sslmode=require
      log:
        process.env.NODE_ENV === 'development'
          ? [{ emit: 'event', level: 'query' }, { emit: 'stdout', level: 'warn' }, { emit: 'stdout', level: 'error' }]
          : [{ emit: 'stdout', level: 'warn' }, { emit: 'stdout', level: 'error' }],
    });

    if (process.env.NODE_ENV === 'development') {
      (this as any).$on('query', (e: { query: string; duration: number }) => {
        if (e.duration > 500) {
          this.logger.warn(`Slow query (${e.duration}ms): ${e.query}`);
        }
      });
    }
  }

  async onModuleInit() { await this.$connect(); }
  async onModuleDestroy() { await this.$disconnect(); }
}