import { randomUUID } from "node:crypto";
import { writeFileSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";

/**
 * Shell argument limit is often around 128KB or lower depending on the OS.
 * We'll play it safe and use 32KB as our threshold to switch to @file syntax.
 */
const COMMAND_LINE_MAX_LENGTH = 32_768;

/**
 * Automatically detects if a string is too long for shell argument limits.
 * If too long, writes it to a temp file and returns `@<path>`.
 * Otherwise, returns the original string.
 *
 * NOTE: Callers MUST clean up the temp file (unlinkSync) after use.
 * Temp files are written to os.tmpdir() with no automatic cleanup.
 *
 * Works well with tools that support @file syntax (like curl or custom pi tools).
 */
export function wrapLongArg(text: string): string {
  if (text.length < COMMAND_LINE_MAX_LENGTH) {
    return text;
  }

  const tmpPath = join(tmpdir(), `pi-arg-${randomUUID()}.txt`);
  writeFileSync(tmpPath, text, "utf-8");
  return `@${tmpPath}`;
}