import process from 'node:process';

export function logJson(event) {
  process.stdout.write(`${JSON.stringify(compact({
    ts: new Date().toISOString(),
    ...event,
  }))}\n`);
}

export function createLogger(bindings = {}) {
  const base = compact(bindings);

  return {
    child(extraBindings = {}) {
      return createLogger({ ...base, ...extraBindings });
    },
    info(event, fields = {}) {
      logJson({ level: 'info', ...base, event, ...compact(fields) });
    },
    warn(event, fields = {}) {
      logJson({ level: 'warn', ...base, event, ...compact(fields) });
    },
    error(event, fields = {}) {
      logJson({ level: 'error', ...base, event, ...compact(fields) });
    },
  };
}

export function serializeError(error) {
  if (!error) return null;
  if (error instanceof Error) {
    return compact({
      name: error.name,
      message: error.message,
      stack: error.stack,
      code: error.code,
    });
  }
  if (typeof error === 'object') return compact(error);
  return { message: String(error) };
}

function compact(value) {
  if (Array.isArray(value)) {
    return value.map((item) => compact(item));
  }

  if (!value || typeof value !== 'object') return value;

  const entries = Object.entries(value)
    .filter(([, entry]) => entry !== undefined)
    .map(([key, entry]) => [key, compact(entry)]);

  return Object.fromEntries(entries);
}