import { Controller, Get } from '@nestjs/common';
import {
  HealthCheck,
  HealthCheckService,
  HttpHealthIndicator,
  DiskHealthIndicator,
  MemoryHealthIndicator,
} from '@nestjs/terminus';
import { TypeOrmHealthIndicator } from './indicators/typeorm.health';
import { DbPoolStatsIndicator } from './indicators/db-pool-stats.health';
import { ConfigService } from '@nestjs/config';
import { ApiTags, ApiOperation } from '@nestjs/swagger';
import * as os from 'os';

@ApiTags('Health Check')
@Controller('health')
export class HealthController {
  private readonly diskPath: string;

  constructor(
    private health: HealthCheckService,
    private http: HttpHealthIndicator,
    private disk: DiskHealthIndicator,
    private memory: MemoryHealthIndicator,
    private typeOrmHealth: TypeOrmHealthIndicator,
    private dbPoolStats: DbPoolStatsIndicator,
    private configService: ConfigService,
  ) {
    // Define o caminho correto para o disco, baseado no sistema operacional
    this.diskPath = os.platform() === 'win32' ? 'C:\\' : '/';
  }

  @Get()
  @HealthCheck()
  @ApiOperation({ summary: 'Verificar saúde geral da aplicação' })
  check() {
    return this.health.check([
      // Verifica o status da própria aplicação
      () => this.http.pingCheck('api', 'http://localhost:8066/docs'),
      
      // Verifica espaço em disco (espaço livre < 80%)
      () => this.disk.checkStorage('disk_percent', { 
        path: this.diskPath, 
        thresholdPercent: 0.8, // 80%
      }),
      
      // Verifica espaço em disco (pelo menos 500MB livres)
      () => this.disk.checkStorage('disk_space', { 
        path: this.diskPath, 
        threshold: 500 * 1024 * 1024, // 500MB em bytes
      }),
      
      // Verifica uso de memória (heap <150MB)
      () => this.memory.checkHeap('memory_heap', 150 * 1024 * 1024), // 150MB
      
      // Verifica as conexões de banco de dados 
      () => this.typeOrmHealth.checkOracle(),
      () => this.typeOrmHealth.checkPostgres(),
    ]);
  }

  @Get('db')
  @HealthCheck()
  @ApiOperation({ summary: 'Verificar saúde das conexões de banco de dados' })
  checkDatabase() {
    return this.health.check([
      () => this.typeOrmHealth.checkOracle(),
      () => this.typeOrmHealth.checkPostgres(),
    ]);
  }

  @Get('memory')
  @HealthCheck()
  @ApiOperation({ summary: 'Verificar uso de memória' })
  checkMemory() {
    return this.health.check([
      () => this.memory.checkHeap('memory_heap', 150 * 1024 * 1024),
      () => this.memory.checkRSS('memory_rss', 300 * 1024 * 1024),
    ]);
  }

  @Get('disk')
  @HealthCheck()
  @ApiOperation({ summary: 'Verificar espaço em disco' })
  checkDisk() {
    return this.health.check([
      // Verificar espaço em disco usando porcentagem
      () => this.disk.checkStorage('disk_percent', { 
        path: this.diskPath, 
        thresholdPercent: 0.8,
      }),
      // Verificar espaço em disco usando valor absoluto
      () => this.disk.checkStorage('disk_space', { 
        path: this.diskPath, 
        threshold: 500 * 1024 * 1024,
      }),
    ]);
  }

  @Get('pool')
  @HealthCheck()
  @ApiOperation({ summary: 'Verificar estatísticas do pool de conexões' })
  checkPoolStats() {
    return this.health.check([
      () => this.dbPoolStats.checkOraclePoolStats(),
      () => this.dbPoolStats.checkPostgresPoolStats(),
    ]);
  }
}