package qemuserver

import (
	"fmt"
	"net/url"
	"os"
	"time"

	"git.sense-t.eu.org/ACE/ace/lib/audiodriver"
	"git.sense-t.eu.org/ACE/ace/lib/qemuconnection"
	"github.com/digitalocean/go-qemu/qemu"
	"github.com/digitalocean/go-qemu/qmp"
	"github.com/pion/mediadevices/pkg/driver"
	"github.com/pion/mediadevices/pkg/driver/vncdriver"
	"github.com/sirupsen/logrus"
)

const waveHeaderSize = 16

var waveHeader = &audiodriver.WavHeader{
	Size:          waveHeaderSize,
	AudioFormat:   1,
	NumChannels:   2,
	SampleRate:    44100,
	BlockAlign:    4,
	BitsPerSample: 16,
}

type Server struct {
	options     *Options
	qemu        *qemu.Domain
	audioHeader chan *audiodriver.WavHeader
	pcm         chan [audiodriver.BufferSize]byte
}

var DefaultServer *Server

func NewServer(o *Options) (*Server, error) {
	if err := o.MakeFIFO(); err != nil {
		return nil, err
	}

	server := &Server{
		options:     o,
		audioHeader: make(chan *audiodriver.WavHeader, 1),
		pcm:         make(chan [audiodriver.BufferSize]byte),
	}

	u, err := url.Parse(o.QmpAddress)
	if err != nil {
		return nil, err
	}
	var address string
	if u.Scheme == "unix" {
		address = u.Path
	} else {
		address = u.Host
	}
	logrus.Debugf("trying to connect qmp with %s://%s", u.Scheme, address)
	qmpConnection, err := qmp.NewSocketMonitor(u.Scheme, address, o.Timeout)
	if err != nil {
		return nil, err
	}

	if err := qmpConnection.Connect(); err != nil {
		return nil, err
	}
	logrus.Debug("qmp connected")

	qemu, err := qemu.NewDomain(qmpConnection, o.Name)
	if err != nil {
		return nil, err
	}
	server.qemu = qemu

	audio := audiodriver.New()
	if err := driver.GetManager().Register(
		audio,
		driver.Info{
			Label:      "audioFifo",
			DeviceType: driver.Microphone,
			Priority:   driver.PriorityNormal,
		},
	); err != nil {
		return nil, err
	}
	audio.PCM = server.pcm
	audio.WaveHeader = waveHeader

	if err := driver.GetManager().Register(
		vncdriver.NewVnc(o.VNCAddress),
		driver.Info{
			Label:      "vnc",
			DeviceType: driver.Camera,
			Priority:   driver.PriorityNormal,
		},
	); err != nil {
		return nil, err
	}

	return server, nil
}

func (s *Server) Run() error {
	logrus.Debug("qemu server running")

	f, err := os.Open(s.options.AudioPipe)
	if err != nil {
		logrus.Fatal(err)
	}
	defer f.Close()
	logrus.Debug("start reading fifo")

	go func() {
		logrus.Debug("setting audio capture")
		if _, err := s.qemu.Run(qmp.Command{
			Execute: "human-monitor-command",
			Args: map[string]string{
				"command-line": fmt.Sprintf(
					"wavcapture %s %s %d %d %d",
					s.options.AudioPipe,
					s.options.AudioDevice,
					waveHeader.SampleRate,
					waveHeader.BitsPerSample,
					waveHeader.NumChannels,
				),
			},
		}); err != nil {
			logrus.Fatal("run audio command failed: ", err)
		}
		logrus.Debug("audio capture set")
	}()

	logrus.Debug("skip wave headers, to the PCM!")
	// skip to pcm data, for 44 bytes.
	var _dataChunkHeader [audiodriver.FmtHeaderOffset +
		audiodriver.FmtHeaderIDSize + audiodriver.FmtHeaderChunkSizeSize + waveHeaderSize +
		audiodriver.DataChunkIDSize + audiodriver.DataChunkSizeSize]byte
	if _, err := f.Read(_dataChunkHeader[:]); err != nil {
		logrus.Fatal(err)
	}

	defer close(s.pcm)
	for {
		var b [audiodriver.BufferSize]byte
		if _, err := f.Read(b[:]); err != nil {
			logrus.Error(err)
		}
		select {
		case s.pcm <- b:
		case <-time.After(waveHeader.GetLatnecy()):
		}
	}
}

func (s *Server) SendEvent(b []byte) error {
	ev, err := qemuconnection.ParseEvent(b)
	if err != nil {
		return err
	}
	for _, cmd := range ev.ToQemuCommand() {
		_, err := s.qemu.Run(cmd)
		if err != nil {
			return err
		}
	}
	return nil
}

func (s *Server) GetStatus() qemu.Status {
	status, err := s.qemu.Status()
	if err != nil {
		return qemu.StatusIOError
	}
	return status
}