import { describe, it, expect, beforeEach } from 'vitest';
import { createLogger } from '../core/logger';

describe('logger', () => {
  let writes: string[];
  let write: (s: string) => boolean;

  beforeEach(() => {
    writes = [];
    write = (s: string) => {
      writes.push(s);
      return true;
    };
  });

  it('emits a JSON line per call with level and msg', () => {
    const log = createLogger({ runId: 'r1', write });
    log.info('hello');
    expect(writes).toHaveLength(1);
    const parsed = JSON.parse(writes[0]);
    expect(parsed.level).toBe('info');
    expect(parsed.msg).toBe('hello');
    expect(parsed.runId).toBe('r1');
    expect(parsed.timestamp).toBeTypeOf('string');
  });

  it('merges meta into the log line', () => {
    const log = createLogger({ runId: 'r1', write });
    log.warn('slow', { turnMs: 3000 });
    const parsed = JSON.parse(writes[0]);
    expect(parsed.turnMs).toBe(3000);
    expect(parsed.level).toBe('warn');
  });

  it('child logger inherits parent meta', () => {
    const log = createLogger({ runId: 'r1', write });
    const roomLog = log.child({ room: 'room-1' });
    roomLog.info('game_start');
    const parsed = JSON.parse(writes[0]);
    expect(parsed.room).toBe('room-1');
    expect(parsed.runId).toBe('r1');
  });

  it('respects minimum level', () => {
    const log = createLogger({ runId: 'r1', write, minLevel: 'warn' });
    log.debug('nope');
    log.info('nope');
    log.warn('yes');
    log.error('yes');
    expect(writes).toHaveLength(2);
  });
});