package cmd

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

	"github.com/dexterlb/mpvipc"
)

type MPVPLayer struct {
	entries         []*feedEntry
	finishedEntries []*feedEntry

	c *mpvipc.Connection
	f *os.File

	videoPosition time.Duration
	videoDuration time.Duration
	isPlaying     bool

	sync.RWMutex
}

func NewMPVPlayer() *MPVPLayer {
	return &MPVPLayer{}
}

func (mpv *MPVPLayer) Exit() error {
	return nil
}

func (mpv *MPVPLayer) Queue(e feedEntry) error {
	mpv.Lock()
	defer mpv.Unlock()

	// TODO(eyJhb): implement checking
	mpv.entries = append(mpv.entries, &e)

	if len(mpv.entries) == 1 {
		return mpv.play(e.Link)
	}

	return nil
}

func (mpv *MPVPLayer) FinishedPlaying() []*feedEntry {
	mpv.Lock()
	defer mpv.Unlock()

	f := mpv.finishedEntries
	mpv.finishedEntries = nil

	return f
}

func (mpv *MPVPLayer) CurrentlyPlaying() *feedEntry {
	mpv.Lock()
	defer mpv.Unlock()

	if !mpv.isPlaying {
		return nil
	}

	return mpv.entries[0]
}

func (mpv *MPVPLayer) play(url string) error {
	if err := mpv.ensurePlayer(); err != nil {
		return err
	}

	_, err := mpv.c.Call("loadfile", url)
	if err != nil {
		return err
	}

	mpv.isPlaying = true

	return err
}

func (mpv *MPVPLayer) Stop() error {
	mpv.Lock()
	defer mpv.Unlock()
	if mpv.c == nil {
		return nil
	}

	err := mpv.c.Set("pause", true)
	return err
}

func (mpv *MPVPLayer) VideoDuration() time.Duration {
	mpv.RLock()
	defer mpv.RUnlock()

	return mpv.videoDuration
}

func (mpv *MPVPLayer) VideoPosition() time.Duration {
	mpv.RLock()
	defer mpv.RUnlock()

	return mpv.videoPosition
}

func (mpv *MPVPLayer) IsPlaying() bool {
	mpv.Lock()
	defer mpv.Unlock()

	if mpv.c == nil || mpv.c.IsClosed() {
		if mpv.isPlaying == true {
			mpv.finishedVideo()
		}
		return false
	}

	return mpv.isPlaying
}

func (mpv *MPVPLayer) finishedVideo() (bool, error) {
	if len(mpv.entries) > 0 {
		mpv.finishedEntries = append(mpv.finishedEntries, mpv.entries[0])
		mpv.entries = mpv.entries[1:]
	}
	mpv.isPlaying = false

	if len(mpv.entries) == 1 {
		if err := mpv.play(mpv.entries[0].Link); err != nil {
			return false, err
		}
	}

	return false, nil
}

func (mpv *MPVPLayer) ensurePlayer() error {
	if mpv.c != nil && !mpv.c.IsClosed() {
		return nil
	}

	var err error
	mpv.f, err = os.CreateTemp("", "example")
	if err != nil {
		return err
	}

	// close and delete file
	defer func() {
		if mpv.f == nil {
			return
		}

		filename := mpv.f.Name()
		mpv.f.Close()
		os.Remove(filename)
	}()

	// defer mpv.finishedVideo()

	ctx := context.TODO()
	cmd := exec.CommandContext(ctx,
		"mpv",
		"--keep-open=yes",
		"--idle",
		fmt.Sprintf("--input-ipc-server=%s", mpv.f.Name()),
	)

	// start
	err = cmd.Start()
	if err != nil {
		return err
	}

	time.Sleep(100 * time.Millisecond)
	mpv.c = mpvipc.NewConnection(mpv.f.Name())
	if err := mpv.c.Open(); err != nil {
		return err
	}

	// setup observe properties
	events, _ := mpv.c.NewEventListener()
	if _, err = mpv.c.Call("observe_property", 1, "duration"); err != nil {
		return err
	}
	if _, err = mpv.c.Call("observe_property", 2, "time-pos"); err != nil {
		return err
	}
	if _, err = mpv.c.Call("observe_property", 3, "eof-reached"); err != nil {
		return err
	}

	go func() {
		for event := range events {
			if event.ID == 1 {
				if event.Data != nil {
					mpv.Lock()
					mpv.videoDuration = time.Duration(event.Data.(float64)) * time.Second
					mpv.Unlock()
				}
			} else if event.ID == 2 {
				if event.Data != nil {
					mpv.Lock()
					mpv.videoPosition = time.Duration(event.Data.(float64)) * time.Second
					mpv.Unlock()
				}
			} else if event.ID == 3 {
				if event.Data != nil {
					if event.Data.(bool) == true {
						mpv.Lock()
						mpv.finishedVideo()
						mpv.Unlock()
					}
				}
			}
		}
	}()

	return nil
	// return cmd.Wait()
}