From f05febe5d12495bde05524b6554c2b77e767fa28 Mon Sep 17 00:00:00 2001
From: Araozu <fernando@araozu.dev>
Date: Wed, 29 May 2024 17:19:47 -0500
Subject: [PATCH] Cache album covers rewritten

---
 albumCover.go            | 101 +++++++++++++++++++++++++++++++++++++++
 frontend/vite.config.mts |   9 ++++
 frontend/vite.config.ts  |   9 ----
 session.go               |  48 +------------------
 types.go                 |   4 +-
 5 files changed, 114 insertions(+), 57 deletions(-)
 create mode 100644 albumCover.go
 create mode 100644 frontend/vite.config.mts
 delete mode 100644 frontend/vite.config.ts

diff --git a/albumCover.go b/albumCover.go
new file mode 100644
index 0000000..a54cd1f
--- /dev/null
+++ b/albumCover.go
@@ -0,0 +1,101 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"log"
+	"os"
+	"sync"
+
+	"github.com/adrg/xdg"
+)
+
+// Stores information about the album covers cache
+type AlbumCoverInfo struct {
+	Cached    bool
+	Error     error
+	WaitGroup *sync.WaitGroup
+}
+
+// Caches info about the album covers
+var albumCoverCacheInfo = make(map[string]*AlbumCoverInfo)
+var cacheMutex = sync.RWMutex{}
+
+// Loads a single album cover and caches it in XDG_CACHE_HOME
+// First it checks if the cover already exists in XDG_CACHE_HOME
+// If it doesn't, loads it and stores it
+func loadAlbumCover(albumId string) {
+	// Check cache info
+	cacheMutex.Lock()
+	_, ok := albumCoverCacheInfo[albumId]
+	cacheMutex.Unlock()
+	if ok {
+		log.Print("album cover: cache hit: ", albumId)
+		return
+	}
+
+	albumCacheFile, err := xdg.CacheFile(fmt.Sprintf("%s/%s", appname, albumId))
+	if err != nil {
+		panic(fmt.Sprint("error creating cacheFile url: ", err))
+	}
+
+	// Attempt to read file
+	if _, err = os.Stat(albumCacheFile); err != nil {
+		// File exists
+		log.Print("album cover: cache hit (disk): ", albumId)
+		cacheMutex.Lock()
+		albumCoverCacheInfo[albumId] = &AlbumCoverInfo{
+			Cached:    true,
+			WaitGroup: &sync.WaitGroup{},
+		}
+		cacheMutex.Unlock()
+		return
+	}
+
+	// Load cover from network
+	log.Print("load album cover for ", albumId)
+	coverInfo := AlbumCoverInfo{
+		Cached:    false,
+		WaitGroup: &sync.WaitGroup{},
+	}
+	coverInfo.WaitGroup.Add(1)
+	defer coverInfo.WaitGroup.Done()
+
+	cacheMutex.Lock()
+	albumCoverCacheInfo[albumId] = &coverInfo
+	cacheMutex.Unlock()
+
+	response, err := client.R().
+		// TODO: replace `fernando` with the username
+		Get(fmt.Sprintf(
+			"%s/rest/getCoverArt.view?id=%s&u=%s&s=12e7f3&t=%s&v=1.13.0&c=wmusic&size=300",
+			serverUrl,
+			albumId,
+			"fernando",
+			"d7bbe92d7da363aa202ae16136887adc",
+		))
+
+	if err != nil {
+		log.Print("error loadAlbumCover: ", err)
+		return
+	}
+
+	if !response.IsSuccess() {
+		log.Print("error loadAlbumCover")
+		log.Printf("%s", response.Body())
+		coverInfo.Error = errors.New("error loading")
+		return
+	}
+
+	imgBytes := response.Body()
+
+	// Write the image to cache
+	err = os.WriteFile(albumCacheFile, imgBytes, 0644)
+	if err != nil {
+		coverInfo.Error = errors.New("error writing album cover to disk")
+		log.Fatalf("Error writing to cache file for album cover: %s", albumCacheFile)
+		return
+	}
+
+	log.Print("Loading albumCover for ", albumId, " successful")
+}
diff --git a/frontend/vite.config.mts b/frontend/vite.config.mts
new file mode 100644
index 0000000..6ee2282
--- /dev/null
+++ b/frontend/vite.config.mts
@@ -0,0 +1,9 @@
+import { defineConfig } from "vite";
+import solidPlugin from "vite-plugin-solid";
+
+export default defineConfig({
+    plugins: [solidPlugin()],
+    build: {
+        target: "esnext",
+    },
+});
diff --git a/frontend/vite.config.ts b/frontend/vite.config.ts
deleted file mode 100644
index afc5ead..0000000
--- a/frontend/vite.config.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-import { defineConfig } from 'vite';
-import solidPlugin from 'vite-plugin-solid';
-
-export default defineConfig({
-  plugins: [solidPlugin()],
-  build: {
-    target: 'esnext',
-  },
-});
diff --git a/session.go b/session.go
index 4dbcadf..3b61b73 100644
--- a/session.go
+++ b/session.go
@@ -4,10 +4,8 @@ import (
 	"errors"
 	"fmt"
 	"log"
-	"os"
 	"sync"
 
-	"github.com/adrg/xdg"
 	"github.com/go-resty/resty/v2"
 )
 
@@ -15,6 +13,7 @@ type AuthError struct {
 	Error string `json:"error"`
 }
 
+// Name of the app, used to create directories in XDG_<folder> and store files inside
 const appname = "wMusic"
 
 var LoggedUser AuthSuccess
@@ -107,49 +106,4 @@ func loadAlbums(serverUrl string) {
 			go loadAlbumCover(albumId)
 		}
 	}
-
-	// TODO: Do the loading
-}
-
-// Loads a single album cover and caches it in XDG_CACHE_HOME
-func loadAlbumCover(albumId string) {
-	log.Print("Loading albumCover for ", albumId)
-
-	response, err := client.R().
-		// TODO: replace `fernando` with the username
-		Get(fmt.Sprintf(
-			"%s/rest/getCoverArt.view?id=%s&u=fernando&s=12e7f3&t=%s&v=1.13.0&c=wmusic&size=300",
-			serverUrl,
-			albumId,
-			"d7bbe92d7da363aa202ae16136887adc",
-		))
-
-	if err != nil {
-		log.Print("error loadAlbumCover: ", err)
-		return
-	}
-
-	if !response.IsSuccess() {
-		log.Print("error loadAlbumCover")
-		log.Printf("%s", response.Body())
-		return
-	}
-
-	imgBytes := response.Body()
-
-	// Write the image to cache
-	// TODO: Actually check in cache if the album art exists
-	cacheFile, err := xdg.CacheFile(fmt.Sprintf("%s/%s", appname, albumId))
-
-	if err != nil {
-		log.Print("error loadAlbumCover - CacheFile:", err)
-		return
-	}
-
-	err = os.WriteFile(cacheFile, imgBytes, 0666)
-	if err != nil {
-		panic(fmt.Sprintf("Error writing to cache file for album cover: %s", cacheFile))
-	}
-
-	log.Print("Loading albumCover for ", albumId, " successful")
 }
diff --git a/types.go b/types.go
index aef9aa2..9bcd6cb 100644
--- a/types.go
+++ b/types.go
@@ -1,6 +1,8 @@
 package main
 
-import "time"
+import (
+	"time"
+)
 
 // The result of a Login
 type AuthSuccess struct {