import { readFileSync, existsSync } from "node:fs";
import { resolve } from "node:path";
import { parse as parseYaml } from "yaml";

function findConfigPath(explicit?: string): string | null {
  const candidates = [
    explicit,
    "pipeline.config.yaml",
    "pipeline.config.yml",
    "config/default.yaml",
  ].filter(Boolean) as string[];

  // Walk up from cwd so the lookup works in both dev (cwd = apps/web) and
  // Docker production (cwd = /app/apps/web), where the bundled import.meta.url
  // points inside .next rather than the source tree.
  let dir = process.cwd();
  for (let i = 0; i < 6; i++) {
    for (const c of candidates) {
      const p = resolve(dir, c);
      if (existsSync(p)) return p;
    }
    if (dir === "/") break;
    dir = resolve(dir, "..");
  }
  return null;
}

export function loadConfig(configPath?: string): Record<string, any> | null {
  const p = findConfigPath(configPath);
  if (!p) return null;
  const content = readFileSync(p, "utf-8");
  return parseYaml(content);
}