// Copyright (C) 2020  Raziman

package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"path"
	"path/filepath"
	"time"

	"github.com/gdamore/tcell"
	"github.com/rivo/tview"
	"github.com/spf13/viper"
)

type AudioFile struct {
	Name        string
	Path        string
	IsAudioFile bool
	Length      time.Duration
	Parent      *tview.TreeNode
}

type Playlist struct {
	*tview.TreeView
	prevNode *tview.TreeNode
}

func InitPlaylist() *Playlist {

	rootDir, err := filepath.Abs(expandTilde(viper.GetString("music_dir")))

	if err != nil {
		log(err.Error())
	}

	root := tview.NewTreeNode(path.Base(rootDir)).
		SetColor(accentColor)

	tree := tview.NewTreeView().SetRoot(root)

	playlist := &Playlist{tree, nil}

	rootAudioFile := &AudioFile{
		Name:        root.GetText(),
		Path:        rootDir,
		IsAudioFile: false,
		Parent:      nil,
	}

	root.SetReference(rootAudioFile)

	playlist.SetTitle(" Playlist ").SetBorder(true)

	populate(root, rootDir)

	var firstChild *tview.TreeNode

	if len(root.GetChildren()) == 0 {
		firstChild = root
	} else {
		firstChild = root.GetChildren()[0]
	}

	// firstChild.SetColor(textColor)
	// playlist.SetCurrentNode(firstChild)
	// keep track of prev node so we can remove the color of highlight
	// playlist.prevNode = firstChild.SetColor(accentColor)

	playlist.SetHighlight(firstChild)

	playlist.SetChangedFunc(func(node *tview.TreeNode) {
		playlist.SetHighlight(node)
	})

	playlist.SetSelectedFunc(func(node *tview.TreeNode) {
		node.SetExpanded(!node.IsExpanded())
	})

	playlist.SetInputCapture(func(e *tcell.EventKey) *tcell.EventKey {

		currNode := playlist.GetCurrentNode()

		if currNode == playlist.GetRoot() {
			return e
		}

		audioFile := currNode.GetReference().(*AudioFile)

		switch e.Rune() {

		case 'a':

			name, _ := pages.GetFrontPage()

			if name != "mkdir-popup" {
				CreatePlaylistPopup()
			}

		case 'D':

			var selectedDir *AudioFile

			// gets the parent dir if current focused node is not a dir
			if audioFile.IsAudioFile {
				selectedDir = audioFile.Parent.GetReference().(*AudioFile)
			} else {
				selectedDir = audioFile
			}

			confirmationPopup(
				"Are you sure to delete this directory?", func(_ int, buttonName string) {

					if buttonName == "no" {
						pages.RemovePage("confirmation-popup")
						app.SetFocus(prevPanel.(tview.Primitive))
						return
					}

					err := os.RemoveAll(selectedDir.Path)

					if err != nil {
						timedPopup(
							" Error ",
							"Unable to delete dir "+selectedDir.Name, time.Second*5)
					} else {
						timedPopup(
							" Success ",
							selectedDir.Name+"\nhas been deleted successfully", time.Second*5)

						playlist.Refresh()
					}

					pages.RemovePage("confirmation-popup")
					app.SetFocus(prevPanel.(tview.Primitive))

				})

		case 'd':

			// prevent from deleting a directory
			if !audioFile.IsAudioFile {
				return e
			}

			confirmationPopup(
				"Are you sure to delete this audio file?", func(_ int, buttonName string) {

					if buttonName == "no" {
						pages.RemovePage("confirmation-popup")
						app.SetFocus(prevPanel.(tview.Primitive))
						return
					}

					err := os.Remove(audioFile.Path)

					if err != nil {
						timedPopup(
							" Error ", "Unable to delete "+audioFile.Name, time.Second*5)
					} else {
						timedPopup(
							" Success ",
							audioFile.Name+"\nhas been deleted successfully", time.Second*5)

						playlist.Refresh()
					}

					pages.RemovePage("confirmation-popup")
					app.SetFocus(prevPanel.(tview.Primitive))
				})

		case 'Y':

			if pages.HasPage("download-popup") {
				pages.RemovePage("download-popup")
				return e
			}

			// this ensures it downloads to
			// the correct dir
			if audioFile.IsAudioFile {
				downloadMusic(audioFile.Parent)
			} else {
				downloadMusic(currNode)
			}

		case 'l':

			playlist.addToQueue(audioFile)
			currNode.SetExpanded(true)

		case 'h':

			// if closing node with no children
			// close the node's parent
			// remove the color of the node

			if audioFile.IsAudioFile {
				parent := audioFile.Parent

				playlist.SetHighlight(parent)

				parent.SetExpanded(false)
			}

			currNode.Collapse()

		case 'L':

			if !viper.GetBool("confirm_bulk_add") {
				playlist.addAllToQueue(playlist.GetCurrentNode())
				return e
			}

			confirmationPopup(
				"Are you sure to add this whole directory into queue?",
				func(_ int, label string) {

					if label == "yes" {
						playlist.addAllToQueue(playlist.GetCurrentNode())
					}

					pages.RemovePage("confirmation-popup")
					app.SetFocus(playlist)

				})


		}

		return e
	})

	return playlist

}

// add songs and their directories in Playlist panel
func populate(root *tview.TreeNode, rootPath string) {

	files, err := ioutil.ReadDir(rootPath)

	if err != nil {
		log(err.Error())
	}

	for _, file := range files {

		path := filepath.Join(rootPath, file.Name())
		f, err := os.Open(path)

		if err != nil {
			log(err.Error())
		}

		defer f.Close()

		child := tview.NewTreeNode(file.Name())
		root.AddChild(child)

		if !file.IsDir() {

			filetype, err := GetFileContentType(f)

			if err != nil {
				log(err.Error())
			}

			// skip if not mp3 file
			if filetype != "mpeg" {
				continue
			}

			audioLength, err := GetLength(path)

			if err != nil {
				log(err.Error())
			}

			audioFile := &AudioFile{
				Name:        file.Name(),
				Path:        path,
				IsAudioFile: true,
				Length:      audioLength,
				Parent:      root,
			}

			child.SetReference(audioFile)

		}

		if file.IsDir() {

			audioFile := &AudioFile{
				Name:        file.Name(),
				Path:        path,
				IsAudioFile: false,
				Length:      0,
				Parent:      root,
			}
			child.SetReference(audioFile)
			child.SetColor(accentColor)
			populate(child, path)

		}

	}

}

// add to queue and update queue panel
func (p *Playlist) addToQueue(audioFile *AudioFile) {

	if audioFile.IsAudioFile {

		if !player.IsRunning {

			player.IsRunning = true

			go func() {
				queue.AddItem("", audioFile.Path, 0, nil)
				player.Run()
			}()

			return 

		} 

		songLength, err := GetLength(audioFile.Path)

		if err != nil {
			log(err.Error())
		}

		queueItemView := fmt.Sprintf("[ %s ] %s", fmtDuration(songLength), audioFile.Name)
		queue.AddItem(queueItemView, audioFile.Path, 0, nil)
	}
}

// bulk add a playlist to queue
func (p *Playlist) addAllToQueue(root *tview.TreeNode) {

	var childrens []*tview.TreeNode

	childrens = root.GetChildren()

	// gets the parent if the highlighted item is a file
	if len(childrens) == 0 {
		childrens = root.GetReference().(*AudioFile).Parent.GetChildren()
	}

	for _, v := range childrens {
		currNode := v.GetReference().(*AudioFile)

		go playlist.addToQueue(currNode)
	}

}

// refresh the playlist and read the whole root music dir
func (p *Playlist) Refresh() {

	root := playlist.GetRoot()

	prevFileName := playlist.GetCurrentNode().GetText()

	root.ClearChildren()

	populate(root, root.GetReference().(*AudioFile).Path)

	root.Walk(func(node, parent *tview.TreeNode) bool {

		// to preserve previously highlighted node
		if node.GetReference().(*AudioFile).Name == prevFileName {
			p.SetHighlight(node)
			return false
		}

		return true
	})

}

// adds child while setting reference to audio file
func (p *Playlist) AddSongToPlaylist(audioPath string, selPlaylist *tview.TreeNode) error {

	f, err := os.Open(audioPath)

	if err != nil {
		return err
	}

	defer f.Close()

	node := tview.NewTreeNode(path.Base(audioPath))

	audioLength, err := GetLength(audioPath)

	if err != nil {
		return err
	}

	audioFile := &AudioFile{
		Name:        path.Base(audioPath),
		Path:        audioPath,
		IsAudioFile: true,
		Length:      audioLength,
		Parent:      selPlaylist,
	}

	node.SetReference(audioFile)
	selPlaylist.AddChild(node)
	app.Draw()

	return nil

}

// creates a directory under selected node, returns error if playlist exists
func (p *Playlist) CreatePlaylist(name string) error {

	selectedNode := p.GetCurrentNode()

	parentNode := selectedNode.GetReference().(*AudioFile).Parent

	// if the current node is the root
	// sets the parent to itself
	if parentNode == nil {
		parentNode = selectedNode
	}

	audioFile := parentNode.GetReference().(*AudioFile)

	err := os.Mkdir(path.Join(audioFile.Path, name), 555)

	if err != nil {
		return err
	}

	p.Refresh()

	return nil

}

// this is used to replace default behaviour of SetCurrentNode which
// adds color highlight attributes
func (p *Playlist) SetHighlight(currNode *tview.TreeNode) {

	if p.prevNode != nil {
		p.prevNode.SetColor(textColor)
	}
	currNode.SetColor(accentColor)
	p.SetCurrentNode(currNode)

	if currNode.GetReference().(*AudioFile).IsAudioFile {
		p.prevNode = currNode
	}

}