From 9ea5bce94259b6b003e4d1d85fe8aee2c6738b9b Mon Sep 17 00:00:00 2001
From: Sayem Chowdhury <sayem314@gmail.com>
Date: Fri, 27 Sep 2024 14:53:19 +0600
Subject: [PATCH] album cover

---
 pkg/metadata/album_cover.go      | 63 ++++++++++++++++++++++++++++++++
 pkg/metadata/album_cover_test.go | 30 +++++++++++++++
 2 files changed, 93 insertions(+)
 create mode 100644 pkg/metadata/album_cover.go
 create mode 100644 pkg/metadata/album_cover_test.go

diff --git a/pkg/metadata/album_cover.go b/pkg/metadata/album_cover.go
new file mode 100644
index 0000000..1e2a7d3
--- /dev/null
+++ b/pkg/metadata/album_cover.go
@@ -0,0 +1,63 @@
+package metadata
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/d-fi/GoFi/pkg/request"
+	"github.com/hashicorp/golang-lru/v2/expirable"
+)
+
+const (
+	cacheSize = 50
+	cacheTTL  = 30 * time.Minute
+)
+
+// Valid cover sizes
+const (
+	CoverSize56   = 56
+	CoverSize250  = 250
+	CoverSize500  = 500
+	CoverSize1000 = 1000
+	CoverSize1500 = 1500
+	CoverSize1800 = 1800
+)
+
+var validCoverSizes = map[int]bool{
+	CoverSize56:   true,
+	CoverSize250:  true,
+	CoverSize500:  true,
+	CoverSize1000: true,
+	CoverSize1500: true,
+	CoverSize1800: true,
+}
+
+var albumCoverCache = expirable.NewLRU[string, []byte](cacheSize, nil, cacheTTL)
+
+func DownloadAlbumCover(albumPicture string, albumCoverSize int) ([]byte, error) {
+	if albumPicture == "" {
+		return nil, errors.New("album picture hash is empty")
+	}
+
+	if !validCoverSizes[albumCoverSize] {
+		return nil, fmt.Errorf("invalid cover size: %d", albumCoverSize)
+	}
+
+	cacheKey := fmt.Sprintf("%s%d", albumPicture, albumCoverSize)
+	if cachedData, ok := albumCoverCache.Get(cacheKey); ok {
+		return cachedData, nil
+	}
+
+	url := fmt.Sprintf("https://e-cdns-images.dzcdn.net/images/cover/%s/%dx%d-000000-80-0-0.jpg",
+		albumPicture, albumCoverSize, albumCoverSize)
+
+	resp, err := request.Client.R().Get(url)
+	if err != nil {
+		return nil, fmt.Errorf("failed to download album cover: %w", err)
+	}
+	data := resp.Body()
+
+	albumCoverCache.Add(cacheKey, data)
+	return data, nil
+}
diff --git a/pkg/metadata/album_cover_test.go b/pkg/metadata/album_cover_test.go
new file mode 100644
index 0000000..50d09a5
--- /dev/null
+++ b/pkg/metadata/album_cover_test.go
@@ -0,0 +1,30 @@
+package metadata
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+const ALB_PICTURE = "2e018122cb56986277102d2041a592c8" // Discovery by Daft Punk
+
+func TestDownloadAlbumCover(t *testing.T) {
+	// Test valid cover sizes
+	coverSizes := []int{56, 250, 500, 1000, 1500, 1800}
+	for _, size := range coverSizes {
+		cover, err := DownloadAlbumCover(ALB_PICTURE, size)
+		assert.NoError(t, err)
+		assert.NotNil(t, cover)
+		assert.Greater(t, len(cover), 0)
+	}
+
+	// Test invalid cover sizes
+	_, err := DownloadAlbumCover(ALB_PICTURE, 2000)
+	assert.Error(t, err)
+	assert.Equal(t, "invalid cover size: 2000", err.Error())
+
+	// Test empty album picture hash
+	_, err = DownloadAlbumCover("", 500)
+	assert.Error(t, err)
+	assert.Equal(t, "album picture hash is empty", err.Error())
+}