package server

import (
	"context"
	"log/slog"
	"os"
	"os/signal"
	"proxy-server/pkg/utils"
	"proxy-server/server/debug"
	"proxy-server/server/fwd"
	"proxy-server/server/pkg/env"
	"proxy-server/server/pkg/log"
	"proxy-server/server/pkg/orm"
	"proxy-server/server/report"
	"proxy-server/server/web"
	"sync"
	"syscall"
	"time"

	"github.com/google/uuid"

	"github.com/joho/godotenv"

	_ "net/http/pprof"
)

const (
	Version      = 1
	RestoreMagic = 0x72
)

type server struct {
	id   int32
	name string
}

func New() *server {
	return &server{}
}

func (s *server) Run() (err error) {

	// 初始化
	err = s.init()
	if err != nil {
		return err
	}

	// 恢复服务状态
	err = s.restore()
	if err != nil {
		return err
	}

	// 准备子服务
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	wg := sync.WaitGroup{}

	// 转发服务
	wg.Add(1)
	fwdQuit := make(chan error, 1)
	defer close(fwdQuit)
	go func() {
		defer wg.Done()
		err = s.startFwd(ctx)
		fwdQuit <- err
	}()

	// 接口服务
	wg.Add(1)
	apiQuit := make(chan error, 1)
	defer close(apiQuit)
	go func() {
		defer wg.Done()
		err := s.startWeb(ctx)
		apiQuit <- err
	}()

	// debug
	go func() {
		debug.Start(ctx)
	}()

	// 性能监控
	// go func() {
	// 	runtime.SetBlockProfileRate(1)
	// 	err := http.ListenAndServe(":6060", nil)
	// 	if err != nil {
	// 		slog.Error("性能监控服务发生错误", "err", err)
	// 	}
	// }()

	// 报告上线
	slog.Debug("报告服务上线")
	var reportErrCh = make(chan error, 1)
	defer close(reportErrCh)
	go func() {
		id, err := report.Online(ctx, s.name)
		if err != nil {
			reportErrCh <- err
			return
		}
		s.id = id
	}()

	// 等待退出信号
	osQuit := make(chan os.Signal, 1)
	signal.Notify(osQuit, os.Interrupt, syscall.SIGTERM)

	var reportErr error
	select {
	case <-osQuit:
		slog.Info("服务主动退出")
	case err := <-fwdQuit:
		slog.Warn("fwd 服务异常退出", "err", err)
	case err := <-apiQuit:
		slog.Warn("web 服务异常退出", "err", err)
	case reportErr = <-reportErrCh:
		slog.Warn("报告服务上线发生错误", "err", reportErr)
	}
	cancel()

	// 报告下线
	if reportErr == nil {
		slog.Debug("报告服务下线")
		go func() {
			err := report.Offline(ctx, s.name)
			if err != nil {
				slog.Error("报告服务下线发生错误", "err", err)
			}
		}()
	}

	// 等待其它服务关闭
	timeout, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	select {
	case <-utils.ChanWgWait(timeout, &wg):
		slog.Info("服务正常关闭")
	case <-timeout.Done():
		slog.Warn("超时强制关闭")
	}

	return nil
}

func (s *server) init() error {

	err := godotenv.Load()
	if err != nil {
		println("没有本地环境变量文件")
	}

	log.Init()
	env.Init()
	orm.Init()

	return nil
}

func (s *server) restore() error {
	var file = "proxy.lock"

	bytes, err := os.ReadFile(file)
	if err != nil {
		return err
	}

	if len(bytes) == 17 && bytes[0] == RestoreMagic {
		s.name = uuid.UUID(bytes[1:]).String()
		slog.Info("恢复服务名称", "name", s.name)
	} else {
		var u = uuid.New()
		s.name = u.String()

		bytes = make([]byte, 17)
		bytes[0] = RestoreMagic
		copy(bytes[1:], u[:])
		err := os.WriteFile(file, bytes, 0644)
		if err != nil {
			return err
		}

		slog.Info("生成服务名称", "name", s.name)
	}

	return nil
}

func (s *server) startFwd(ctx context.Context) error {
	server := fwd.New(&fwd.Config{
		Id: &s.id,
	})
	go func() {
		<-ctx.Done()
		server.Stop()
	}()
	return server.Run()
}

func (s *server) startWeb(ctx context.Context) error {
	server := web.New()
	go func() {
		<-ctx.Done()
		err := server.Stop()
		if err != nil {
			slog.Error("web 服务关闭发生错误", "err", err)
		}
	}()
	return server.Run()
}