package httpserver

import (
	"context"
	"fmt"
	"net/http"
	"os"
	"os/exec"
	"os/signal"
	"service/library/configcenter"
	"service/library/servicediscovery"
	"syscall"
	"time"

	"service/library/logger"
)

const (
	ServerStatusFDRun  = "RUN"  // 服务运行中
	ServerStatusFDStop = "STOP" // 服务停止
)

func StartHttpServer(srv *http.Server, cfg *configcenter.DefaultConfig, ip string, port int) {
	go func() {
		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			logger.Fatal("listen: %v", err)
			return
		}
	}()

	// 注册服务
	go func() {
		err := registerSD(ip, port)
		if err != nil {
			logger.Fatal("registerSD: %v", err)
			return
		}
		setServerStatusFD(ServerStatusFDRun)
	}()

	quit := make(chan os.Signal, 1)
	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
	<-quit
	logger.Info("Shutdown Server ...")

	if err := servicediscovery.DeRegister(ip, port); err != nil {
		logger.Fatal("DeRegister fail: %v", err)
	}

	ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
	if err := srv.Shutdown(ctx); err != nil {
		logger.Fatal("Server Shutdown:", err)
	}
	defer cancel()

	select {
	case <-ctx.Done():
		logger.Info("timeout of 1 seconds.")
	}

	logger.Info("Server exited")
	setServerStatusFD(ServerStatusFDStop)
}

func registerSD(ip string, port int) error {
	// 要等服务起来后再注册到consul，否则会有问题
	// 方法：调用 healthcheck
	idx := 0
	timer := time.NewTimer(time.Second * 5)
	timerRetry := time.NewTicker(time.Second * 1)
	for {
		select {
		case <-timer.C:
			return fmt.Errorf("registerSD fail, ip: %v, port: %v", ip, port)
		case <-timerRetry.C:
			idx += 1
			resp, err := http.Get(fmt.Sprintf("http://%s:%v/healthcheck", ip, port))
			if err != nil {
				logger.Error("healthcheck fail, err: %v", err)
				continue
			}
			if resp.StatusCode == http.StatusOK {
				if err := servicediscovery.Register(ip, port); err != nil {
					logger.Error("registerSD fail, ip: %v, port: %v, err: %v", ip, port, err)
					continue
				}
				return nil
			}
		}
	}
}

func setServerStatusFD(status string) {
	serverStatusFdPath := "/app/SERVER_STATUS_FD"
	cmd := exec.Command("sh", "-c", fmt.Sprintf("echo %s > %s", status, serverStatusFdPath))
	err := cmd.Run()
	if err != nil {
		logger.Info("run cmd fail, p: %v, err: %v", serverStatusFdPath, err)
		return
	}
	logger.Info("SetServerStatusFD success: %v", status)
}