1 files changed, 30 insertions, 0 deletions
diff --git a/src/scripts/sidebarImage.ts b/src/scripts/sidebarImage.ts
new file mode 100644
index 0000000..456059e
--- /dev/null
+++ b/src/scripts/sidebarImage.ts
@@ -0,0 +1,30 @@
+document.addEventListener("DOMContentLoaded", (): void => {
+  const currentMinute: number = Math.floor(Date.now() / 60000);
+  const sidebarImagePathPrefix: string = "/images/internal/sidebar";
+
+  type ImageRule = {
+    divisor: number;
+    filename: string;
+  };
+
+  const imageRules: ImageRule[] = [
+    { divisor: 7, filename: "7.gif" },
+    { divisor: 5, filename: "5.gif" },
+    { divisor: 3, filename: "3.gif" },
+    { divisor: 2, filename: "2.gif" },
+  ];
+
+  const matchedRule: ImageRule | undefined = imageRules.find(
+    (rule: ImageRule): boolean => currentMinute % rule.divisor === 0
+  );
+
+  const imageName: string = matchedRule ? matchedRule.filename : "default.gif";
+  const sidebarImage: string = `${sidebarImagePathPrefix}/${imageName}`;
+
+  const imageElement: HTMLImageElement | null = document.getElementById(
+    "sidebar-image"
+  ) as HTMLImageElement;
+  if (imageElement) {
+    imageElement.src = sidebarImage;
+  }
+});