package gui

import (
	"log"
	"math"
	"slices"
	"strings"
	"sync"

	"github.com/diamondburned/gotk4-adwaita/pkg/adw"
	"github.com/diamondburned/gotk4/pkg/gdk/v4"
	"github.com/diamondburned/gotk4/pkg/gdkpixbuf/v2"
	"github.com/diamondburned/gotk4/pkg/glib/v2"
	"github.com/diamondburned/gotk4/pkg/gtk/v4"
	"suruatoel.xyz/mcg/data"
	"suruatoel.xyz/mcg/internal/client"
	"suruatoel.xyz/mcg/internal/common"
)

type libraryPanel struct {
	*adw.Bin
	toolbar           *gtk.Box
	selectButton      *gtk.ToggleButton
	actionbarRevealer *gtk.Revealer
	toolbarPopover    *gtk.Popover
	searchBar         *gtk.SearchBar
	searchEntry       *gtk.SearchEntry
	sortButtons       map[string]*gtk.CheckButton
	sortDescButton    *gtk.CheckButton
	gridScale         *gtk.Scale
	stack             *gtk.Stack
	progressBox       *gtk.Box
	progressBar       *gtk.ProgressBar
	scroll            *gtk.ScrolledWindow
	libraryGrid       *gtk.GridView
	gridFactory       *pictureItemFactory[string]
	libraryModel      *gtk.StringList
	selectionMulti    *gtk.MultiSelection
	selectionSingle   *gtk.SingleSelection

	headerbarStandalone   *albumHeaderbar
	libraryStack          *gtk.Stack
	panelNormal           *gtk.Box
	panelStandalone       *gtk.Box
	standaloneStack       *gtk.Stack
	standaloneSpinner     *gtk.Spinner
	standaloneScroll      *gtk.ScrolledWindow
	standaloneImage       *gtk.Image
	standalonePlayButton  *gtk.Button
	standaloneQueueButton *gtk.Button
	selectionQueueButton  *gtk.Button
	selectionCancelButton *gtk.Button

	coverLoader      *CoverLoader
	albums           map[string]*common.Album
	pixbufs          map[string]*gdkpixbuf.Pixbuf
	sortField        string
	sortDesc         bool
	itemSize         int
	itemSizeCallback ItemSizeCallback

	libraryLock sync.Mutex
	libraryWait sync.WaitGroup

	standaloneAlbum    *common.Album
	standalonePixbuf   *gdkpixbuf.Pixbuf
	standaloneCallback func(bool)
}

type ItemSizeCallback func(itemSize int)

func newLibraryPanel(config Configuration) *libraryPanel {
	panel := libraryPanel{
		albums:      make(map[string]*common.Album),
		pixbufs:     make(map[string]*gdkpixbuf.Pixbuf),
		sortField:   "year",
		sortDesc:    false,
		libraryLock: sync.Mutex{},
		libraryWait: sync.WaitGroup{},
	}
	panel.loadWidgets(config)
	panel.loadDefaultValues(config)
	panel.connectSignals()

	return &panel
}

func (p *libraryPanel) loadWidgets(config Configuration) {
	builder := gtk.NewBuilderFromString(data.LibraryPanelXML)

	p.toolbar = builder.GetObject("toolbar").Cast().(*gtk.Box)
	p.selectButton = builder.GetObject("select_button").Cast().(*gtk.ToggleButton)
	p.actionbarRevealer = builder.GetObject("actionbar_revealer").Cast().(*gtk.Revealer)
	p.toolbarPopover = builder.GetObject("toolbar_popover").Cast().(*gtk.Popover)

	p.searchBar = builder.GetObject("filter_bar").Cast().(*gtk.SearchBar)
	p.searchEntry = builder.GetObject("filter_entry").Cast().(*gtk.SearchEntry)
	p.sortButtons = make(map[string]*gtk.CheckButton)
	p.sortButtons["artist"] = builder.GetObject("sort_artist").Cast().(*gtk.CheckButton)
	p.sortButtons["title"] = builder.GetObject("sort_title").Cast().(*gtk.CheckButton)
	p.sortButtons["year"] = builder.GetObject("sort_year").Cast().(*gtk.CheckButton)
	p.sortButtons["modified"] = builder.GetObject("sort_modified").Cast().(*gtk.CheckButton)
	p.sortDescButton = builder.GetObject("toolbar_sort_order_button").Cast().(*gtk.CheckButton)
	p.gridScale = builder.GetObject("grid_scale").Cast().(*gtk.Scale)

	p.Bin = builder.GetObject("McgLibraryPanel").Cast().(*adw.Bin)
	p.stack = builder.GetObject("stack").Cast().(*gtk.Stack)
	p.progressBox = builder.GetObject("progress_box").Cast().(*gtk.Box)
	p.progressBar = builder.GetObject("progress_bar").Cast().(*gtk.ProgressBar)
	p.scroll = builder.GetObject("scroll").Cast().(*gtk.ScrolledWindow)
	p.libraryGrid = builder.GetObject("library_grid").Cast().(*gtk.GridView)
	p.libraryModel = gtk.NewStringList(nil)
	p.selectionMulti = gtk.NewMultiSelection(p.libraryModel)
	p.selectionSingle = gtk.NewSingleSelection(p.libraryModel)
	p.libraryGrid.SetModel(p.selectionSingle)

	p.gridFactory = newPictureItemFactory[string](p.itemToModelID, p.modelIDToValue)
	p.libraryGrid.SetFactory(p.gridFactory.ListItemFactory())

	// Headerbar
	p.headerbarStandalone = newAlbumHeaderbar()
	p.libraryStack = builder.GetObject("library_stack").Cast().(*gtk.Stack)
	p.panelNormal = builder.GetObject("panel_normal").Cast().(*gtk.Box)
	p.panelStandalone = builder.GetObject("panel_standalone").Cast().(*gtk.Box)

	p.standaloneStack = builder.GetObject("standalone_stack").Cast().(*gtk.Stack)
	p.standaloneSpinner = builder.GetObject("standalone_spinner").Cast().(*gtk.Spinner)
	p.standaloneScroll = builder.GetObject("standalone_scroll").Cast().(*gtk.ScrolledWindow)
	p.standaloneImage = builder.GetObject("standalone_image").Cast().(*gtk.Image)
	p.standalonePlayButton = builder.GetObject("standalone_play_button").Cast().(*gtk.Button)
	p.standaloneQueueButton = builder.GetObject("standalone_queue_button").Cast().(*gtk.Button)

	// Selection
	p.selectionQueueButton = builder.GetObject("selection_queue_button").Cast().(*gtk.Button)
	p.selectionCancelButton = builder.GetObject("selection_cancel_button").Cast().(*gtk.Button)
}

func (p *libraryPanel) itemToModelID(item *glib.Object) string {
	return item.Cast().(*gtk.StringObject).String()
}

func (p *libraryPanel) modelIDToValue(itemID string) (tooltip string, pixbuf *gdkpixbuf.Pixbuf) {
	if album, ok := p.albums[itemID]; ok {
		tooltip = album.Tooltip()
	}
	pixbuf = p.pixbufs[itemID]

	return
}

func (p *libraryPanel) loadDefaultValues(config Configuration) {
	p.itemSize = config.ItemSize
	p.gridScale.SetValue(float64(config.ItemSize))

	_, found := p.sortButtons[config.SortField]
	if found {
		p.sortField = config.SortField
	}
	p.sortDesc = config.SortDesc

	p.sortButtons[p.sortField].SetActive(true)
	p.sortDescButton.SetActive(p.sortDesc)
}

func (p *libraryPanel) connectSignals() {
	p.selectButton.ConnectToggled(p.onSelectToggled)
	p.searchEntry.ConnectSearchChanged(p.onFilterEntryChanged)
	for field, button := range p.sortButtons {
		button.ConnectToggled(func() {
			p.onSortToggled(field, button)
		})
	}
	p.sortDescButton.ConnectToggled(p.onSortDescToggled)

	p.libraryGrid.ConnectActivate(p.onGridClicked)

	p.headerbarStandalone.ConnectClose(p.onHeaderbarStandaloneClose)
	p.standalonePlayButton.ConnectClicked(p.onStandalonePlayClicked)
	p.standaloneQueueButton.ConnectClicked(p.onStandaloneQueueClicked)

	p.selectionQueueButton.ConnectClicked(p.onSelectionQueue)
	p.selectionCancelButton.ConnectClicked(p.onSelectionCancel)

	buttonController := gtk.NewGestureClick()
	buttonController.ConnectUnpairedRelease(p.onGridScaleReleased)
	p.gridScale.AddController(buttonController)
	p.gridScale.ConnectValueChanged(p.onGridScaleChanged)
}

func (p *libraryPanel) ConnectItemSizeChanged(callback ItemSizeCallback) {
	p.itemSizeCallback = callback
}

func (p *libraryPanel) ConnectStandalone(callback func(bool)) {
	p.standaloneCallback = callback
}

func (p *libraryPanel) onSelectToggled() {
	if p.selectButton.Active() {
		p.actionbarRevealer.SetRevealChild(true)
		p.libraryGrid.SetModel(p.selectionMulti)
		p.libraryGrid.SetSingleClickActivate(false)
		p.libraryGrid.StyleContext().AddClass("selection")
	} else {
		p.actionbarRevealer.SetRevealChild(false)
		p.libraryGrid.SetModel(p.selectionSingle)
		p.libraryGrid.SetSingleClickActivate(true)
		p.libraryGrid.StyleContext().RemoveClass("selection")
	}
}

func (p *libraryPanel) onFilterEntryChanged() {
	p.updateGridModel()
}

func (p *libraryPanel) onSortToggled(field string, button *gtk.CheckButton) {
	if !button.Active() {
		return
	}

	p.sortField = field
	p.updateGridModel()
}

func (p *libraryPanel) onSortDescToggled() {
	p.sortDesc = p.sortDescButton.Active()
	p.updateGridModel()
}

func (p *libraryPanel) onGridScaleChanged() {
	size := math.Floor(p.gridScale.Value())
	gridRange := p.gridScale.Adjustment()
	if size < gridRange.Lower() || size > gridRange.Upper() {
		return
	}

	go p.setGridSize(int(size))
}

func (p *libraryPanel) setGridSize(size int) {
	if size == p.itemSize {
		return
	}

	for i := range p.libraryGrid.Model().NItems() {
		itemObj := p.libraryGrid.Model().Item(i)
		if itemObj != nil {
			itemStr := itemObj.Cast().(*gtk.StringObject)
			albumID := itemStr.String()
			picture, pictureFound := p.gridFactory.Picture(albumID)
			if pictureFound {
				pixbuf, pixbufFound := p.pixbufs[albumID]
				if pixbufFound {
					if pixbuf != nil {
						pixbuf = pixbuf.ScaleSimple(size, size, gdkpixbuf.InterpNearest)
					} else {
					}
					glib.IdleAdd(func() {
						picture.SetPaintable(gdk.NewTextureForPixbuf(pixbuf))
					})
				}
			}
		}
	}
}

func (p *libraryPanel) onGridScaleReleased(x float64, y float64, button uint, sequence *gdk.EventSequence) {
	size := math.Floor(p.gridScale.Value())
	gridRange := p.gridScale.Adjustment()
	if size < gridRange.Lower() || size > gridRange.Upper() {
		return
	}

	p.itemSize = int(size)
	p.redraw()
	glib.IdleAdd(p.toolbarPopover.Popdown)
	if p.itemSizeCallback != nil {
		p.itemSizeCallback(p.itemSize)
	}
}

func (p *libraryPanel) redraw() {
	if len(p.albums) > 0 {
		p.SetAlbums(p.albums)
	}
}

func (p *libraryPanel) onGridClicked(position uint) {
	// Get selected album
	itemObj := p.libraryModel.Item(position)
	if itemObj == nil {
		return
	}
	strObj := itemObj.Cast().(*gtk.StringObject)
	id := strObj.String()
	album, found := p.albums[id]
	if !found {
		return
	}

	// Show standalone album
	if p.libraryGrid.Model().Native() == p.selectionSingle.Native() {
		p.standaloneAlbum = album
		p.headerbarStandalone.SetAlbum(album)
		p.standaloneStack.SetVisibleChild(p.standaloneSpinner)
		p.standaloneSpinner.Start()
		p.openStandalone()
		client.Instance().LoadAlbumart(album)
	}
}

func (p *libraryPanel) onHeaderbarStandaloneClose() {
	p.closeStandalone()
}

func (p *libraryPanel) openStandalone() {
	p.libraryStack.SetVisibleChild(p.panelStandalone)
	if p.standaloneCallback != nil {
		p.standaloneCallback(true)
	}
}

func (p *libraryPanel) closeStandalone() {
	p.libraryStack.SetVisibleChild(p.panelNormal)
	if p.standaloneCallback != nil {
		p.standaloneCallback(false)
	}
}

func (p *libraryPanel) setCoverLoader(loader *CoverLoader) {
	p.coverLoader = loader
}

func (p *libraryPanel) SetAlbumart(album *common.Album, albumart []byte) {
	if album != p.standaloneAlbum {
		return
	}

	p.standalonePixbuf = nil
	if albumart == nil || len(albumart) == 0 {
		return
	}

	loader, loaderErr := loadPixbuf(albumart)
	if loaderErr != nil {
		log.Println("failed to load albumart for ", album.Title(), ":", loaderErr)
		return
	}

	p.standalonePixbuf = loader.Pixbuf()
	glib.IdleAdd(p.showStandaloneImage)
}

func (p *libraryPanel) showStandaloneImage() {
	p.resizeStandaloneImage()
	p.standaloneStack.SetVisibleChild(p.standaloneScroll)
	p.standaloneSpinner.Stop()
}

func (p *libraryPanel) resizeStandaloneImage() {
	newWidth, newHeight := p.getStandaloneSize()
	if p.standalonePixbuf == nil {
		p.standaloneImage.SetPixelSize(min(newWidth, newHeight))
		return
	}

	width, height := p.calculateCoverSize(newWidth, newHeight)
	if width <= 0 || height <= 0 {
		return
	}

	scaledPixbuf := p.standalonePixbuf.ScaleSimple(width, height, gdkpixbuf.InterpHyper)
	p.standaloneImage.SetFromPaintable(gdk.NewTextureForPixbuf(scaledPixbuf))
	p.standaloneImage.SetPixelSize(min(width, height))
}

func (p *libraryPanel) getStandaloneSize() (int, int) {
	return p.standaloneStack.Size(gtk.OrientationHorizontal), p.standaloneStack.Size(gtk.OrientationVertical)
}

func (p *libraryPanel) calculateCoverSize(currentWidth, currentHeight int) (width, height int) {
	ratioWidth := float64(currentWidth) / float64(p.standalonePixbuf.Width())
	ratioHeight := float64(currentHeight) / float64(p.standalonePixbuf.Height())
	ratio := min(min(ratioWidth, ratioHeight), 1)

	width = int(math.Floor(float64(p.standalonePixbuf.Width()) * ratio))
	height = int(math.Floor(float64(p.standalonePixbuf.Height()) * ratio))

	return
}

func (p *libraryPanel) onStandalonePlayClicked() {
	client.Instance().PlayAlbum(p.standaloneAlbum)
	p.closeStandalone()
}

func (p *libraryPanel) onStandaloneQueueClicked() {
	client.Instance().QueueAlbum(p.standaloneAlbum)
	p.closeStandalone()
}

func (p *libraryPanel) onSelectionQueue() {
	albums := p.getSelectedAlbums()
	if len(albums) > 0 {
		client.Instance().QueueAlbums(albums)
	}

	p.selectButton.SetActive(false)
}

func (p *libraryPanel) onSelectionCancel() {
	p.selectButton.SetActive(false)
}

func (p *libraryPanel) getSelectedAlbums() []*common.Album {
	albums := []*common.Album{}
	for i := range p.selectionMulti.NItems() {
		if p.selectionMulti.IsSelected(i) {
			itemObj := p.selectionMulti.Item(i)
			if itemObj != nil {
				itemStr := itemObj.Cast().(*gtk.StringObject)
				albumID := itemStr.String()
				album, found := p.albums[albumID]
				if found {
					albums = append(albums, album)
				}
			}
		}
	}

	return albums
}

func (p *libraryPanel) UpdateConfig(config *Configuration) {
	config.SortField = p.sortField
	config.SortDesc = p.sortDesc
	config.ItemSize = p.itemSize
}

func (p *libraryPanel) updateGridModel() {
	albums := p.filterAlbums()
	p.sortAlbums(albums)
	p.updateGrid(albums)
}

func (p *libraryPanel) filterAlbums() []*common.Album {
	var matchingAlbums []*common.Album
	query := strings.TrimSpace(strings.ToLower(p.searchEntry.Text()))
	for _, album := range p.albums {
		if album.IsMatch(query) {
			matchingAlbums = append(matchingAlbums, album)
		}
	}

	return matchingAlbums
}

func (p *libraryPanel) sortAlbums(filtered []*common.Album) {
	common.SortAlbums(filtered, p.sortField)

	if p.sortDesc {
		slices.Reverse(filtered)
	}
}

func (p *libraryPanel) updateGrid(albums []*common.Album) {
	glib.IdleAdd(func() {
		n := p.libraryModel.NItems()
		if n > 0 {
			p.libraryModel.Splice(0, n, nil)
		}

		ids := make([]string, 0, len(albums))
		for _, item := range albums {
			ids = append(ids, item.ID())
		}

		if len(ids) > 0 {
			p.libraryModel.Splice(0, 0, ids)
		}
	})
}

func (p *libraryPanel) Toolbar() gtk.Widgetter {
	return p.toolbar
}

func (p *libraryPanel) Wait() {
	p.libraryWait.Wait()
}

type LibraryFactory gtk.ListItemFactory

func (p *libraryPanel) SetAlbums(albums map[string]*common.Album) {
	p.libraryWait.Add(1)
	go p.setAlbums(albums)
}

func (p *libraryPanel) setAlbums(albums map[string]*common.Album) {
	p.libraryLock.Lock()
	defer p.libraryLock.Unlock()
	defer p.libraryWait.Done()

	p.albums = albums
	glib.IdleAdd(func() {
		p.stack.SetVisibleChild(p.progressBox)
		p.progressBar.SetFraction(0.0)
	})

	// Create loader loader
	i := 0
	n := len(albums)
	p.pixbufs = make(map[string]*gdkpixbuf.Pixbuf)

	for _, album := range albums {
		if p.coverLoader != nil {
			p.pixbufs[album.ID()] = p.coverLoader.LoadThumbnail(album)
		}

		i++
		glib.IdleAdd(func() {
			p.progressBar.SetFraction(float64(i) / float64(n))
			// FIXME: i18n
			p.progressBar.SetText("Loading images")
		})
	}

	p.updateGridModel()
	glib.IdleAdd(func() {
		p.stack.SetVisibleChild(p.scroll)
	})
}

func (p *libraryPanel) SetWidth(width int) {
	p.resizeStandaloneImage()
	p.setMarks(width)
}

func (p *libraryPanel) setMarks(width int) {
	glib.IdleAdd(func() {
		p.gridScale.ClearMarks()
	})

	lower := p.gridScale.Adjustment().Lower()
	upper := p.gridScale.Adjustment().Upper()
	countMin := int(math.Max(float64(width)/upper, 1))
	countMax := int(math.Max(float64(width)/lower, 1))
	for i := countMin; i <= countMax; i++ {
		pixel := int(float64(width) / float64(i))
		pixel = pixel - (2 * pixel / 100)
		glib.IdleAdd(func() {
			p.gridScale.AddMark(float64(pixel), gtk.PosBottom, "")
		})
	}
}

func (p *libraryPanel) ShowSearch() {
	p.searchBar.SetSearchMode(true)
}

func (p *libraryPanel) HeaderbarStandalone() *albumHeaderbar {
	return p.headerbarStandalone
}