import crypto from "node:crypto";
import os from "node:os";
import path from "node:path";

function sanitizePrefix(prefix: string): string {
  const normalized = prefix.replace(/[^a-zA-Z0-9_-]+/g, "-").replace(/^-+|-+$/g, "");
  return normalized || "tmp";
}

function sanitizeExtension(extension?: string): string {
  if (!extension) {
    return "";
  }
  const normalized = extension.startsWith(".") ? extension : `.${extension}`;
  const suffix = normalized.match(/[a-zA-Z0-9._-]+$/)?.[0] ?? "";
  const token = suffix.replace(/^[._-]+/, "");
  if (!token) {
    return "";
  }
  return `.${token}`;
}

export function buildRandomTempFilePath(params: {
  prefix: string;
  extension?: string;
  tmpDir?: string;
  now?: number;
  uuid?: string;
}): string {
  const prefix = sanitizePrefix(params.prefix);
  const extension = sanitizeExtension(params.extension);
  const nowCandidate = params.now;
  const now =
    typeof nowCandidate === "number" && Number.isFinite(nowCandidate)
      ? Math.trunc(nowCandidate)
      : Date.now();
  const uuid = params.uuid?.trim() || crypto.randomUUID();
  return path.join(params.tmpDir ?? os.tmpdir(), `${prefix}-${now}-${uuid}${extension}`);
}