package main

import (
	"embed"
	"io/ioutil"
	"path"
	"strings"
)

// Embed the built-in icons into the binary.
//
//go:embed icons/*
var fs embed.FS

// Icon implements a fyne.Resource and provides built-in icon data.
type Icon struct {
	name string
	data []byte
}

func (i Icon) Empty() bool {
	return len(i.data) == 0
}

func (i Icon) Name() string {
	return i.name
}

func (i Icon) Content() []byte {
	return i.data
}

// A map of all the built-in icons by name.
var (
	icons     = map[string]Icon{}
	iconNames = []string{}
)

// LoadIcons parses the built-in icons into memory.
func LoadIcons() {
	filenames, err := fs.ReadDir("icons")
	if err != nil {
		panic(err)
	}

	for _, icon := range filenames {
		basename := strings.TrimSuffix(icon.Name(), ".png")
		iconNames = append(iconNames, basename)

		// Populate the icons map too.
		if _, ok := icons[basename]; !ok {
			bin, err := fs.ReadFile("icons/" + icon.Name())
			if err != nil {
				panic(err)
			}

			i := Icon{
				name: basename,
				data: bin,
			}
			icons[basename] = i
		}
	}
}

// LoadCustomIcon adds a custom icon (PNG image) from disk.
func LoadCustomIcon(filename string) (basename string, err error) {
	basename = path.Base(filename)
	data, err := ioutil.ReadFile(filename)
	if err != nil {
		return
	}

	i := Icon{
		name: basename,
		data: data,
	}
	icons[basename] = i
	return
}