package qemuserver

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

	"git.sense-t.eu.org/ACE/ace/drivers/audio"
	"git.sense-t.eu.org/ACE/ace/drivers/video"
	"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/sirupsen/logrus"
)

const waveHeaderSize = audio.FmtHeaderSizeDefault

var waveHeader *audio.WavHeader

func init() {
	waveHeader = audio.DefaultHeader()
}

type Server struct {
	options     *Options
	qemu        *qemu.Domain
	audioHeader chan *audio.WavHeader
	pcm         chan []byte
	ppm         chan io.ReadCloser
}

var DefaultServer *Server

func NewServer(o *Options) (*Server, error) {
	server := &Server{
		options:     o,
		audioHeader: make(chan *audio.WavHeader, 1),
		pcm:         make(chan []byte),
		ppm:         make(chan io.ReadCloser, 60), // to be configured
	}

	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 := &audio.PCMStreamDriver{
		PCM:               server.pcm,
		WaveHeader:        waveHeader,
		BufferSizeByBytes: o.Audio.BufferSize, // to be configured
	}
	if err := driver.GetManager().Register(
		audio,
		driver.Info{
			Label:      "audioFifo",
			DeviceType: driver.Microphone,
			Priority:   driver.PriorityNormal,
		},
	); err != nil {
		return nil, err
	}

	video := &video.PPMStreamDriver{
		Height:   o.Video.Height,
		Width:    o.Video.Width,
		FPS:      o.Video.FPS,
		PPMImage: server.ppm,
	}
	if err := driver.GetManager().Register(
		video,
		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")
	path, err := s.options.MakeFIFO()
	if err != nil {
		return err
	}

	go func() {
		logrus.Debug("screen capture start")
		defer close(s.ppm)
		for range time.Tick(time.Second / time.Duration(s.options.Video.FPS)) { // to be configured
			ppm, err := s.qemu.ScreenDump()
			if err != nil {
				logrus.Error(err)
				continue
			}
			s.ppm <- ppm
		}
	}()

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

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

		logrus.Debug("start reading PCM")
		defer close(s.pcm)
		for {
			b := make([]byte, 2048) // to be configured
			if _, err := f.Read(b[:]); err != nil {
				logrus.Error(err)
			}
			select {
			case s.pcm <- b:
			case <-time.After(waveHeader.GetLatnecy(s.options.Audio.BufferSize)):
			}
		}
	}()

	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",
					path,
					s.options.Audio.Device,
					waveHeader.SampleRate,
					waveHeader.BitsPerSample,
					waveHeader.NumChannels,
				),
			},
		}); err != nil {
			logrus.Fatal("run audio command failed: ", err)
		}
		logrus.Debug("audio capture set")
	}()

	select {}
}

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
}