improvement: finish address changes

backend/src/lib/base64/index.ts

@@ -0,0 +1,40 @@
+// Credit: https://github.com/miguelmota/is-base64
+export const isBase64 = (
+  v: string,
+  opts = { allowEmpty: false, mimeRequired: false, allowMime: true, paddingRequired: false }
+) => {
+  if (opts.allowEmpty === false && v === "") {
+    return false;
+  }
+
+  let regex = "(?:[A-Za-z0-9+\\/]{4})*(?:[A-Za-z0-9+\\/]{2}==|[A-Za-z0-9+/]{3}=)?";
+  const mimeRegex = "(data:\\w+\\/[a-zA-Z\\+\\-\\.]+;base64,)";
+
+  if (opts.mimeRequired === true) {
+    regex = mimeRegex + regex;
+  } else if (opts.allowMime === true) {
+    regex = `${mimeRegex}?${regex}`;
+  }
+
+  if (opts.paddingRequired === false) {
+    regex = "(?:[A-Za-z0-9+\\/]{4})*(?:[A-Za-z0-9+\\/]{2}(==)?|[A-Za-z0-9+\\/]{3}=?)?";
+  }
+
+  return new RegExp(`^${regex}$`, "gi").test(v);
+};
+
+export const getBase64SizeInBytes = (base64String: string) => {
+  // Remove data URI scheme if present
+  const base64 = base64String.replace(/^data:.*?;base64,/, "");
+
+  // Remove padding characters
+  const withoutPadding = base64.replace(/=+$/, "");
+
+  // Calculate bits: each base64 character represents 6 bits
+  const totalBits = withoutPadding.length * 6;
+
+  // Convert bits to bytes (8 bits = 1 byte)
+  const bytes = totalBits / 8;
+
+  return bytes;
+};