From 0afb3207281f3caab9f37efc12742d4adf6fff3a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tom=C3=A1=C5=A1=20Ml=C3=A1dek?= <t@mldk.cz>
Date: Sun, 27 Jul 2025 20:43:34 +0200
Subject: [PATCH] feat: implement image queue service and audio preloading to
 prevent connection limits

---
 src/components/AudioArea.vue   | 31 ++++++++++++-
 src/components/VideoScroll.vue | 42 +++++++++++-------
 src/services/ImageLoader.ts    | 80 ++++++++++++++++++++++++++++++++++
 3 files changed, 137 insertions(+), 16 deletions(-)
 create mode 100644 src/services/ImageLoader.ts

diff --git a/src/components/AudioArea.vue b/src/components/AudioArea.vue
index 2075a10..2be1cad 100644
--- a/src/components/AudioArea.vue
+++ b/src/components/AudioArea.vue
@@ -1,5 +1,5 @@
 <template>
-  <audio ref="audio" :src="definition.src" loop preload="auto" />
+  <audio ref="audio" :src="audioSrc" loop preload="auto" />
 </template>
 
 <script lang="ts">
@@ -20,9 +20,37 @@ export default defineComponent({
   },
   setup(props) {
     const audio = ref<HTMLAudioElement | null>(null);
+    const audioSrc = ref<string>(""); // Ref to hold audio source after preloading
+    const isPreloaded = ref<boolean>(false);
 
     console.debug(`[AUDIOAREA] Initializing ${props.definition.src}...`);
     console.debug(props.definition);
+    
+    // Preload the audio file completely to avoid keeping connections open
+    const preloadAudio = async (src: string) => {
+      console.debug(`[AUDIOAREA] Preloading audio: ${src}`);
+      try {
+        // Fetch the entire audio file
+        const response = await fetch(src);
+        if (!response.ok) throw new Error(`Failed to load audio: ${response.statusText}`);
+        
+        // Convert to blob to ensure full download
+        const blob = await response.blob();
+        
+        // Create a blob URL to use as the audio source
+        const blobUrl = URL.createObjectURL(blob);
+        audioSrc.value = blobUrl;
+        isPreloaded.value = true;
+        console.debug(`[AUDIOAREA] Successfully preloaded audio: ${src}`);
+      } catch (error) {
+        console.error(`[AUDIOAREA] Error preloading audio: ${error}`);
+        // Fall back to original source if preloading fails
+        audioSrc.value = src;
+      }
+    };
+    
+    // Start preloading when component is created
+    preloadAudio(props.definition.src);
 
     const MIN_SCALE = 0.02;
     const MIN_VOLUME_MULTIPLIER = 0.33;
@@ -61,6 +89,7 @@ export default defineComponent({
 
     return {
       audio,
+      audioSrc,
     };
   },
 });
diff --git a/src/components/VideoScroll.vue b/src/components/VideoScroll.vue
index 9ebcafb..9f69145 100644
--- a/src/components/VideoScroll.vue
+++ b/src/components/VideoScroll.vue
@@ -31,6 +31,7 @@
 <script lang="ts">
 import { defineComponent, PropType } from "vue";
 import { rotate } from "@/utils";
+import { queueImageForLoading } from "@/services/ImageLoader";
 
 export default defineComponent({
   name: "VideoScroll",
@@ -87,35 +88,46 @@ export default defineComponent({
         : -1;
     },
   },
+  methods: {
+    handleImageLoad(element: HTMLImageElement) {
+      // Setup image display when loaded
+      element.classList.add("displayed");
+      element.classList.add("loaded");
+      
+      // Adjust dimensions based on scroll direction
+      if (this.isHorizontal) {
+        element.style.height = "auto";
+      } else {
+        element.style.width = "auto";
+      }
+    }
+  },
   mounted() {
     const observer = new IntersectionObserver((entries, _) => {
       entries.forEach((entry) => {
         const element = entry.target as HTMLImageElement;
         if (entry.isIntersecting) {
           element.classList.add("visible");
-          if (!element.src) {
-            console.debug(
-              `[VIDEOSCROLL] Intersected, loading ${element.dataset.src}`
-            );
-            element.src = element.dataset.src!;
+          if (!element.src && element.dataset.src) {
+            // Queue the image for loading through the global service
+            const self = this;
+            queueImageForLoading(element, function() {
+              self.handleImageLoad(element);
+            });
+            
+            // Add a fallback to show the image after a timeout even if not fully loaded
             setTimeout(() => {
-              element.classList.add("displayed");
-            }, 3000);
-            element.onload = () => {
-              element.classList.add("displayed");
-              element.classList.add("loaded");
-              if (this.isHorizontal) {
-                element.style.height = "auto";
-              } else {
-                element.style.width = "auto";
+              if (!element.classList.contains("loaded")) {
+                element.classList.add("displayed");
               }
-            };
+            }, 3000);
           }
         } else {
           element.classList.remove("visible");
         }
       });
     });
+
     if (this.$refs.root) {
       Array.from((this.$refs.root as Element).children).forEach((el) => {
         observer.observe(el);
diff --git a/src/services/ImageLoader.ts b/src/services/ImageLoader.ts
new file mode 100644
index 0000000..6c7dddd
--- /dev/null
+++ b/src/services/ImageLoader.ts
@@ -0,0 +1,80 @@
+/**
+ * Global image loading queue service to prevent hitting browser connection limits
+ */
+
+// Configuration
+const MAX_CONCURRENT_LOADS = 5;
+
+// State
+let activeLoads = 0;
+const imageQueue: Array<{
+  element: HTMLImageElement;
+  onComplete: () => void;
+}> = [];
+
+/**
+ * Queue an image for loading, respecting the global concurrent loading limit
+ */
+export function queueImageForLoading(
+  element: HTMLImageElement,
+  onComplete?: () => void
+) {
+  if (!element.dataset.src) {
+    console.warn("[ImageLoader] Element has no data-src attribute");
+    return;
+  }
+
+  // Add to queue
+  imageQueue.push({
+    element,
+    onComplete: onComplete || (() => {}),
+  });
+
+  // Try to process queue
+  processQueue();
+}
+
+/**
+ * Process the next items in the queue if we have capacity
+ */
+function processQueue() {
+  // Load more images if we have capacity and images in the queue
+  while (activeLoads < MAX_CONCURRENT_LOADS && imageQueue.length > 0) {
+    const next = imageQueue.shift();
+    if (next) {
+      loadImage(next.element, next.onComplete);
+    }
+  }
+}
+
+/**
+ * Internal function to handle the actual image loading
+ */
+function loadImage(element: HTMLImageElement, onComplete: () => void) {
+  // Increment active loads counter
+  activeLoads++;
+
+  const src = element.dataset.src;
+  console.debug(`[ImageLoader] Loading ${src}`);
+
+  // Start loading the image
+  element.src = src!;
+
+  // Handle load completion
+  const handleCompletion = () => {
+    activeLoads--;
+    onComplete();
+    processQueue();
+  };
+
+  // Set handlers
+  element.onload = () => {
+    console.debug(`[ImageLoader] Loaded ${src}`);
+    handleCompletion();
+  };
+
+  element.onerror = () => {
+    console.error(`[ImageLoader] Failed to load ${src}`);
+    handleCompletion();
+  };
+}