import type { ViewerKind } from "./types.ts";

/** Kind classification only; MIME ownership remains with uploader. */
export const extensions: Record<ViewerKind, readonly string[]> = {
  image: ["jpg", "jpeg", "png", "gif", "webp", "bmp", "ico", "avif"],
  vector: ["svg"],
  pdf: ["pdf"],
  code: [
    "js",
    "jsx",
    "ts",
    "tsx",
    "py",
    "java",
    "cpp",
    "c",
    "h",
    "cs",
    "css",
    "json",
    "xml",
    "sql",
    "sh",
    "yaml",
    "yml",
  ],
  text: ["txt", "md", "log"],
  markup: ["html", "htm"],
  sheet: ["csv", "tsv", "xls", "xlsx", "ods"],
  doc: ["doc", "docx", "dotx", "odt", "rtf", "ppt", "pptx", "ppsx", "potx", "odp"],
  audio: ["mp3", "wav", "aac", "flac", "ogg"],
  video: ["mp4", "webm", "mov", "avi", "mkv"],
  archive: ["zip", "rar", "7z", "tar", "gz", "tgz"],
  binary: ["psd", "ai", "tif", "tiff", "exe", "dll"],
};

export function extensionOf(name: string): string {
  const base = (name.split(/[?#]/)[0] ?? "").split(/[/\\]/).pop() ?? "";
  const dot = base.lastIndexOf(".");
  return dot < 0 ? "" : base.slice(dot).toLowerCase();
}

export function kindOfExtension(ext: string): ViewerKind {
  return (
    (Object.keys(extensions) as ViewerKind[]).find((kind) =>
      extensions[kind].includes(ext.replace(/^\./, "").toLowerCase()),
    ) ?? "binary"
  );
}

export function kindOfMime(mime: string): ViewerKind | undefined {
  const type = mime.split(";")[0]!.trim().toLowerCase();
  if (type === "image/svg+xml") return "vector";
  if (type === "text/html" || type === "application/xhtml+xml") return "markup";
  if (type === "application/pdf") return "pdf";
  if (/^(application|text)\/(json|xml|javascript|x-javascript)$/.test(type) || type === "text/css")
    return "code";
  if (/^text\/(csv|tab-separated-values)$/.test(type) || /spreadsheet|ms-excel/.test(type))
    return "sheet";
  if (/opendocument\.spreadsheet/.test(type)) return "sheet";
  if (/msword|wordprocessing|presentation|powerpoint|opendocument|rtf/.test(type)) return "doc";
  if (/zip|gzip|x-tar|x-7z|rar/.test(type)) return "archive";
  if (/^image\/(png|jpeg|gif|webp|bmp|x-icon|vnd.microsoft.icon|avif)$/.test(type)) return "image";
  if (type.startsWith("audio/")) return "audio";
  if (type.startsWith("video/")) return "video";
  if (type.startsWith("text/")) return "text";
  return undefined;
}