package qemu

import (
	"context"
	"fmt"
	"log"
	"os"
	"time"

	"github.com/digitalocean/go-qemu/qmp"
	"github.com/hashicorp/packer/helper/multistep"
	"github.com/hashicorp/packer/packer"
)

// This step configures the VM to enable the QMP listener.
//
// Uses:
//   config *config
//   ui     packer.Ui
//
// Produces:
type stepConfigureQMP struct {
	monitor        *qmp.SocketMonitor
	VNCUsePassword bool
	QMPSocketPath  string
}

func (s *stepConfigureQMP) Run(ctx context.Context, state multistep.StateBag) multistep.StepAction {
	ui := state.Get("ui").(packer.Ui)

	if !s.VNCUsePassword {
		return multistep.ActionContinue
	}

	ui.Say(fmt.Sprintf("QMP socket at: %s", s.QMPSocketPath))

	// Only initialize and open QMP when we have a use for it.
	// Open QMP socket
	var err error
	var cmd []byte
	var result []byte
	s.monitor, err = qmp.NewSocketMonitor("unix", s.QMPSocketPath, 2*time.Second)
	if err != nil {
		err := fmt.Errorf("Error opening QMP socket: %s", err)
		state.Put("error", err)
		ui.Error(err.Error())
		return multistep.ActionHalt
	}
	QMPMonitor := s.monitor
	vncPassword := state.Get("vnc_password")

	// Connect to QMP
	// function automatically calls capabilities so is immediately ready for commands
	err = QMPMonitor.Connect()
	if err != nil {
		err := fmt.Errorf("Error connecting to QMP socket: %s", err)
		state.Put("error", err)
		ui.Error(err.Error())
		return multistep.ActionHalt
	}
	log.Printf("QMP socket open SUCCESS")

	cmd = []byte(fmt.Sprintf("{ \"execute\": \"change-vnc-password\", \"arguments\": { \"password\": \"%s\" } }",
		vncPassword))
	result, err = QMPMonitor.Run(cmd)
	if err != nil {
		err := fmt.Errorf("Error connecting to QMP socket: %s", err)
		state.Put("error", err)
		ui.Error(err.Error())
		return multistep.ActionHalt
	}

	log.Printf("QMP Command: %s\nResult: %s", cmd, result)

	// Put QMP monitor in statebag in case there is a use in a following step
	// Uncomment for future case as it is unused for now
	//state.Put("qmp_monitor", QMPMonitor)

	return multistep.ActionContinue
}

func (s *stepConfigureQMP) Cleanup(multistep.StateBag) {
	if s.monitor != nil {
		err := s.monitor.Disconnect()
		if err != nil {
			log.Printf("failed to disconnect QMP: %v", err)
		}
		// Delete file associated with qmp socket.
		if err := os.Remove(s.QMPSocketPath); err != nil {
			log.Printf("Failed to delete the qmp socket file: %s", err)
		}
	}
}