first commit

2026-07-12 15:55:18 +05:30
commit ee98026cc5
404 changed files with 44522 additions and 0 deletions
@@ -0,0 +1,81 @@
+/**
+ * Minimal extension ↔ MIME mapping + `accept` matching. Zero-dep: just a table
+ * big enough for the common upload types (images, docs, media, archives).
+ */
+
+const BY_EXT: Record<string, string> = {
+  // images
+  png: "image/png",
+  jpg: "image/jpeg",
+  jpeg: "image/jpeg",
+  gif: "image/gif",
+  webp: "image/webp",
+  avif: "image/avif",
+  svg: "image/svg+xml",
+  ico: "image/x-icon",
+  bmp: "image/bmp",
+  // documents
+  pdf: "application/pdf",
+  txt: "text/plain",
+  html: "text/html",
+  htm: "text/html",
+  csv: "text/csv",
+  json: "application/json",
+  xml: "application/xml",
+  doc: "application/msword",
+  docx: "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+  xls: "application/vnd.ms-excel",
+  xlsx: "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
+  ppt: "application/vnd.ms-powerpoint",
+  pptx: "application/vnd.openxmlformats-officedocument.presentationml.presentation",
+  // media
+  mp3: "audio/mpeg",
+  wav: "audio/wav",
+  ogg: "audio/ogg",
+  mp4: "video/mp4",
+  webm: "video/webm",
+  mov: "video/quicktime",
+  // archives / misc
+  zip: "application/zip",
+  gz: "application/gzip",
+  tar: "application/x-tar",
+};
+
+/** Lowercased extension WITHOUT the dot (e.g. "png"), or "" if none. */
+export function extOf(name: string): string {
+  const clean = name.split(/[?#]/)[0] ?? "";
+  const dot = clean.lastIndexOf(".");
+  return dot >= 0 ? clean.slice(dot + 1).toLowerCase() : "";
+}
+
+/** MIME type for a filename/key by its extension, or a safe default. */
+export function contentTypeOf(name: string, fallback = "application/octet-stream"): string {
+  return BY_EXT[extOf(name)] ?? fallback;
+}
+
+/** The conventional extension for a MIME type, or "" (used to name S3 keys). */
+export function extForType(type: string): string {
+  const t = type.split(";")[0]!.trim().toLowerCase();
+  for (const [ext, mime] of Object.entries(BY_EXT)) if (mime === t) return ext;
+  return "";
+}
+
+/**
+ * Does `file` (its MIME `type` + `name`) satisfy an `accept` list? Each accept
+ * entry is a MIME type (`"image/png"`), a wildcard MIME (`"image/*"`), or a
+ * dotted extension (`".pdf"`). An empty/omitted list accepts everything.
+ */
+export function accepts(
+  accept: string[] | undefined,
+  file: { type: string; name: string },
+): boolean {
+  if (!accept || accept.length === 0) return true;
+  const type = (file.type || contentTypeOf(file.name)).toLowerCase();
+  const ext = "." + extOf(file.name);
+  return accept.some((raw) => {
+    const rule = raw.trim().toLowerCase();
+    if (rule.startsWith(".")) return rule === ext;
+    if (rule.endsWith("/*")) return type.startsWith(rule.slice(0, -1)); // "image/" prefix
+    return rule === type;
+  });
+}