package container

import (
	"fmt"
	"os/exec"
	"strconv"
	"sync"
	"time"

	logging "git.loafle.net/commons/logging-go"
	occp "git.loafle.net/overflow/commons-go/config/probe"
	"git.loafle.net/overflow/probe/config"
)

type OnConnectInfo struct {
	ContainerType occp.ContainerType
	WriteChan     chan<- []byte
}

func NewContainerSession(containerType occp.ContainerType) *ContainerSession {

	cs := &ContainerSession{
		containerType: containerType,
		writeChan:     make(chan []byte, 256),
	}

	return cs
}

type ContainerSession struct {
	containerType      occp.ContainerType
	cmd                *exec.Cmd
	writeChan          chan []byte
	containerWriteChan chan<- []byte

	writeStopChan chan struct{}
	stopWg        sync.WaitGroup
}

func (cs *ContainerSession) Start() error {
	if err := cs.runContainer(); nil != err {
		return err
	}

	cs.writeStopChan = make(chan struct{})
	cs.stopWg.Add(1)
	go cs.handleWrite()

	return nil
}

func (cs *ContainerSession) Stop() {
	close(cs.writeStopChan)

	if err := cs.killContainer(); nil != err {
		logging.Logger().Error(err)
	}

	cs.stopWg.Wait()
}

func (cs *ContainerSession) Connected(writeChan chan<- []byte) {
	logging.Logger().Debugf("Container[%s] has been connected", cs.containerType.String())
	cs.containerWriteChan = writeChan
}

func (cs *ContainerSession) Disconnected() {
	logging.Logger().Debugf("Container[%s] has been disconnected", cs.containerType.String())
	cs.refreshContainer()
}

func (cs *ContainerSession) Send(buff []byte) error {
	select {
	case cs.writeChan <- buff:
		logging.Logger().Debugf("send buffer of Container[%s] has been queued %s", cs.containerType.String(), string(buff))
		return nil
	default:
		return fmt.Errorf("Buffer of Container[%s] is full", cs.containerType.String())
	}
}

func (cs *ContainerSession) handleWrite() {
	defer func() {
		cs.stopWg.Done()
	}()
	var (
		message []byte
		ok      bool
	)

	for {
		select {
		case message, ok = <-cs.writeChan:
			if !ok {
				logging.Logger().Debugf("WriteChan of Container[%s] has been closed", cs.containerType.String())
				return
			}

		LOOP_WRITE:
			for {
				select {
				case cs.containerWriteChan <- message:
					logging.Logger().Debugf("message of Container[%s] has been sended %s", cs.containerType.String(), string(message))
					break LOOP_WRITE
				case <-cs.writeStopChan:
					return
				default:
					time.Sleep(100 * time.Millisecond)
					continue LOOP_WRITE
				}
			}
		case <-cs.writeStopChan:
			return
		}
	}
}

func (cs *ContainerSession) runContainer() error {
	cmd := cotainerCommand(cs.containerType)

	if err := cmd.Start(); nil != err {
		logging.Logger().Errorf("to run Container[%s] failed err %v", cs.containerType.String(), err)
		return err
	}

	cs.cmd = cmd
	logging.Logger().Debugf("Process of Container[%s] has been started", cs.containerType.String())

	return nil
}

func (cs *ContainerSession) killContainer() error {
	defer func() {
		cs.cmd = nil
		logging.Logger().Debugf("Process of Container[%s] has been stopped", cs.containerType.String())
	}()

	if nil == cs.cmd {
		return nil
	}

	if nil == cs.cmd.ProcessState || !cs.cmd.ProcessState.Exited() {
		if err := cs.cmd.Process.Kill(); nil != err {
			return err
		}
	}
	return nil
}

func (cs *ContainerSession) refreshContainer() {
	if err := cs.killContainer(); nil != err {
		logging.Logger().Error(err)
	}
	if err := cs.runContainer(); nil != err {
		logging.Logger().Error(err)
	}

	logging.Logger().Debugf("Process of Container[%s] has been refreshed", cs.containerType.String())
}

func cotainerCommand(containerType occp.ContainerType) (cmd *exec.Cmd) {
	loggingConfigFilePath := config.ContainerLoggingConfigFilePath(containerType)
	binFilePath := config.ContainerBinFilePath(containerType)

	switch containerType {
	case occp.ContainerDiscovery, occp.ContainerNetwork:
		args := []string{
			fmt.Sprintf("-%s=%s", occp.FlagProbePortName, strconv.FormatInt(config.ProbePortNumber, 10)),
			fmt.Sprintf("-%s=%s", occp.FlagLoggingConfigFilePathName, loggingConfigFilePath),
		}
		cmd = exec.Command(binFilePath, args...)
	case occp.ContainerGenernal:
		args := []string{
			"-jar",
			binFilePath,
			strconv.FormatInt(config.ProbePortNumber, 10),
			fmt.Sprintf("-Dlogging.config=%s", loggingConfigFilePath),
		}

		cmd = exec.Command(config.JavaBinPath(), args...)
	}
	return
}