// Prompt loader — reads .md files from lib/llm/prompts/ at runtime.
// Cached in module scope so we only hit the disk once per prompt name.
//
// Lives in a server-only module (uses node:fs); never imported by client code.

import "server-only";
import { readFileSync } from "node:fs";
import { dirname, resolve } from "node:path";
import { fileURLToPath } from "node:url";

const here = dirname(fileURLToPath(import.meta.url));
const cache = new Map<string, string>();

export function loadPrompt(relativePath: string): string {
  const cached = cache.get(relativePath);
  if (cached) return cached;
  const full = resolve(here, "prompts", relativePath);
  const content = readFileSync(full, "utf8");
  cache.set(relativePath, content);
  return content;
}