package view

import (
	"errors"
	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/canvas"
	"fyne.io/fyne/v2/container"
	"fyne.io/fyne/v2/lang"
	"fyne.io/fyne/v2/storage"
	"fyne.io/fyne/v2/widget"
	"git.kor-elf.net/kor-elf/gui-for-ffmpeg/internal/ffmpeg"
	"git.kor-elf.net/kor-elf/gui-for-ffmpeg/internal/gui/window"
	"git.kor-elf.net/kor-elf/gui-for-ffmpeg/internal/utils"
	"git.kor-elf.net/kor-elf/gui-for-ffmpeg/kernel"
	"image/color"
	"os"
	"path/filepath"
)

func Convertor(
	window window.WindowContract,
	addFileForConversion func(file ffmpeg.File),
	directoryForSavingPath string,
	directoryForSaving func(path string),
) fyne.CanvasObject {
	form := newFormConvertor(
		window,
		addFileForConversion,
		directoryForSavingPath,
		directoryForSaving,
	)

	converterVideoFilesTitle := lang.L("converterVideoFilesTitle")
	return widget.NewCard(converterVideoFilesTitle, "", container.NewVScroll(form.getForm()))
}

type formConvertor struct {
	form  *widget.Form
	items []*widget.FormItem

	window               window.WindowContract
	addFileForConversion func(file ffmpeg.File)
	directoryForSaving   func(path string)
}

func newFormConvertor(
	window window.WindowContract,
	addFileForConversion func(file ffmpeg.File),
	directoryForSavingPath string,
	directoryForSaving func(path string),
) *formConvertor {
	f := widget.NewForm()
	f.SubmitText = lang.L("converterVideoFilesSubmitTitle")

	formConvertor := &formConvertor{
		form:                 f,
		window:               window,
		addFileForConversion: addFileForConversion,
		directoryForSaving:   directoryForSaving,
	}

	fileForConversion := formConvertor.newFileForConversion()
	directoryForSavingButton := formConvertor.newDirectoryForSaving(directoryForSavingPath)

	items := []*widget.FormItem{
		{
			Text:   lang.L("fileForConversionTitle"),
			Widget: fileForConversion.button,
		},
		{
			Widget: container.NewHScroll(fileForConversion.message),
		},

		{
			Text:   lang.L("buttonForSelectedDirTitle"),
			Widget: directoryForSavingButton.button,
		},
		{
			Widget: container.NewHScroll(directoryForSavingButton.message),
		},
	}
	formConvertor.form.Items = items
	formConvertor.items = items

	return formConvertor
}

func (f *formConvertor) getForm() *widget.Form {
	return f.form
}

type fileForConversion struct {
	button  *widget.Button
	message *canvas.Text
	file    *kernel.File

	changeCallbacks map[int]func(err error)
}

func (f *formConvertor) newFileForConversion() *fileForConversion {
	message := canvas.NewText("", color.RGBA{R: 255, G: 0, B: 0, A: 255})
	fileForConversion := &fileForConversion{
		message: message,

		changeCallbacks: map[int]func(err error){},
	}

	buttonTitle := lang.L("choose") + "\n" +
		lang.L("or") + "\n" +
		lang.L("dragAndDropFiles")

	var locationURI fyne.ListableURI

	fileForConversion.button = widget.NewButton(buttonTitle, func() {
		f.window.NewFileOpen(func(r fyne.URIReadCloser, err error) {
			fyne.Do(func() {
				fileForConversion.message.Text = ""
				fileForConversion.message.Refresh()
			})

			if err != nil {
				fyne.Do(func() {
					fileForConversion.message.Text = err.Error()
					fileForConversion.message.Refresh()
				})
				fileForConversion.eventSelectFile(err)
				return
			}
			if r == nil {
				return
			}

			f.addFileForConversion(ffmpeg.File{
				Path: r.URI().Path(),
				Name: r.URI().Name(),
				Ext:  r.URI().Extension(),
			})

			fileForConversion.eventSelectFile(nil)

			listableURI := storage.NewFileURI(filepath.Dir(r.URI().Path()))
			locationURI, _ = storage.ListerForURI(listableURI)
		}, locationURI)
	})

	f.window.SetOnDropped(func(position fyne.Position, uris []fyne.URI) {
		if len(uris) == 0 {
			return
		}

		isError := false
		for _, uri := range uris {
			info, err := os.Stat(uri.Path())
			if err != nil {
				isError = true
				continue
			}
			if info.IsDir() {
				isError = true
				continue
			}

			f.addFileForConversion(ffmpeg.File{
				Path: uri.Path(),
				Name: uri.Name(),
				Ext:  uri.Extension(),
			})

			fileForConversion.eventSelectFile(nil)

			listableURI := storage.NewFileURI(filepath.Dir(uri.Path()))
			locationURI, _ = storage.ListerForURI(listableURI)
		}

		if isError {
			fileForConversion.message.Text = lang.L("errorDragAndDropFile")
			utils.SetStringErrorStyle(fileForConversion.message)
			fileForConversion.eventSelectFile(errors.New(fileForConversion.message.Text))
		} else {
			fyne.Do(func() {
				fileForConversion.message.Text = ""
				fileForConversion.message.Refresh()
			})
		}
	})

	return fileForConversion
}

type directoryForSaving struct {
	button  *widget.Button
	message *canvas.Text
	path    string
}

func (f *formConvertor) newDirectoryForSaving(directoryForSavingPath string) *directoryForSaving {
	directoryForSaving := &directoryForSaving{
		path: "",
	}

	directoryForSaving.message = canvas.NewText("", color.RGBA{R: 255, G: 0, B: 0, A: 255})
	directoryForSaving.message.TextSize = 16
	directoryForSaving.message.TextStyle = fyne.TextStyle{Bold: true}

	buttonTitle := lang.L("choose")

	locationURI, err := utils.PathToListableURI(directoryForSavingPath)
	if err == nil {
		directoryForSaving.path = locationURI.Path()
		directoryForSaving.message.Text = locationURI.Path()
		utils.SetStringSuccessStyle(directoryForSaving.message)
	}

	directoryForSaving.button = widget.NewButton(buttonTitle, func() {
		f.window.NewFolderOpen(func(r fyne.ListableURI, err error) {
			if err != nil {
				directoryForSaving.message.Text = err.Error()
				utils.SetStringErrorStyle(directoryForSaving.message)
				return
			}
			if r == nil {
				return
			}

			directoryForSaving.path = r.Path()

			directoryForSaving.message.Text = r.Path()
			utils.SetStringSuccessStyle(directoryForSaving.message)
			locationURI, err = storage.ListerForURI(r)

			if err == nil {
				f.directoryForSaving(locationURI.Path())
			}

		}, locationURI)
	})

	return directoryForSaving
}

func (c *fileForConversion) addChangeCallback(callback func(err error)) {
	c.changeCallbacks[len(c.changeCallbacks)] = callback
}

func (c *fileForConversion) eventSelectFile(err error) {
	for _, changeCallback := range c.changeCallbacks {
		changeCallback(err)
	}
}