subsonic-tui/internal/client/artwork_cache.go

package client

import (
	"fmt"
	"image"
	"image/jpeg"
	"io/fs"
	"os"
	"path"
)

type artcache struct {
	artPaths map[string]string
	cacheDir string
}

var ArtCache *artcache

func (c *artcache) saveArt(id string, img image.Image) *string {
	path := c.GetPath(id)
	if path != nil {
		return path
	}

	path = c.saveImage(id, img)
	if path != nil {
		c.artPaths[id] = *path
	}

	return path
}

func (c *artcache) saveImage(id string, img image.Image) *string {
	filePath := c.filepath(id)
	f, err := os.Create(filePath)

	defer func() {
		_ = f.Close()
	}()

	if err != nil {
		return nil
	}

	err = jpeg.Encode(f, img, nil)
	if err != nil {
		return nil
	}

	return &filePath
}

func (c *artcache) GetPath(id string) *string {
	if path, ok := c.artPaths[id]; ok {
		return &path
	}

	return nil
}

func (c *artcache) GetImage(id string) *image.Image {
	path := c.GetPath(id)
	if path == nil {
		return nil
	}

	f, err := os.Open(*path)
	if err != nil {
		return nil
	}

	defer func() {
		_ = f.Close()
	}()

	img, err := jpeg.Decode(f)
	if err != nil {
		return nil
	}

	return &img
}

func (c *artcache) filepath(id string) string {
	return path.Join(c.cacheDir, id+".jpg")
}

func (c *artcache) Destroy() {
	os.RemoveAll(c.cacheDir)
}

func init() {
	tmpDir := os.TempDir()
	cacheDir := path.Join(tmpDir, fmt.Sprintf("subsonic-tui-%d", os.Getpid()))

	var permissions fs.FileMode = 0o777

	err := os.Mkdir(cacheDir, permissions)
	if err != nil {
		panic("Failed to create cacheDir")
	}

	ArtCache = &artcache{
		cacheDir: cacheDir,
		artPaths: make(map[string]string),
	}
}