const DOCUMENT_PREVIEW_EXTENSIONS = new Set([
  "pdf",
  "jpg",
  "jpeg",
  "png",
  "gif",
  "webp",
  "svg",
  "bmp",
  "ico",
  "avif",
  "docx",
  "xls",
  "xlsx",
  "xlsm",
  "xlsb",
  "ods",
  "csv",
  "tsv",
  "txt",
  "text",
  "md",
  "markdown",
  "json",
  "xml",
  "html",
  "htm",
  "css",
  "scss",
  "sass",
  "less",
  "js",
  "jsx",
  "ts",
  "tsx",
  "mjs",
  "cjs",
  "yml",
  "yaml",
  "ini",
  "conf",
  "cfg",
  "log",
  "sql",
  "py",
  "java",
  "c",
  "cpp",
  "h",
  "hpp",
  "cs",
  "go",
  "rs",
  "php",
  "rb",
  "kt",
  "kts",
  "swift",
  "sh",
  "bash",
  "zsh",
  "ps1",
  "bat",
  "cmd",
  "properties",
  "env",
  "rtf",
  "mp4",
  "webm",
  "ogg",
  "ogv",
  "mov",
  "m4v",
  "mp3",
  "wav",
  "oga",
  "m4a",
  "aac",
  "flac",
]);

const DOCUMENT_PREVIEW_FILE_NAMES = new Set([
  "dockerfile",
  "makefile",
  "readme",
  "license",
  ".gitignore",
  ".env",
]);

export function getDocumentFileExtension(fileName?: string | null): string {
  const cleanName = (fileName || "").toLowerCase().split("?")[0].split("#")[0];
  return cleanName.match(/\.([^.]+)$/)?.[1] || "";
}

export function canPreviewDocument(fileName?: string | null): boolean {
  const lowerName = (fileName || "").toLowerCase();
  const extension = getDocumentFileExtension(fileName);
  return DOCUMENT_PREVIEW_EXTENSIONS.has(extension) || DOCUMENT_PREVIEW_FILE_NAMES.has(lowerName);
}