import { describe, it, expect, beforeEach } from 'vitest';
import { createLogger, setLogLevel, getRecentLogs, clearRecentLogs, dumpLogs } from './logger';

describe('logger', () => {
	beforeEach(() => {
		clearRecentLogs();
		setLogLevel('debug');
	});

	it('createLogger returns scoped logger with all levels', () => {
		const log = createLogger('test.context');
		expect(log.debug).toBeTypeOf('function');
		expect(log.info).toBeTypeOf('function');
		expect(log.warn).toBeTypeOf('function');
		expect(log.error).toBeTypeOf('function');
	});

	it('logs are stored in recent logs buffer', () => {
		const log = createLogger('test');
		log.info('hello');
		log.warn('warning');

		const recent = getRecentLogs();
		expect(recent).toHaveLength(2);
		expect(recent[0].level).toBe('info');
		expect(recent[0].context).toBe('test');
		expect(recent[0].message).toBe('hello');
		expect(recent[1].level).toBe('warn');
	});

	it('clearRecentLogs empties the buffer', () => {
		const log = createLogger('test');
		log.info('msg');
		expect(getRecentLogs()).toHaveLength(1);

		clearRecentLogs();
		expect(getRecentLogs()).toHaveLength(0);
	});

	it('setLogLevel filters lower-priority logs', () => {
		setLogLevel('warn');
		const log = createLogger('test');
		log.debug('should be filtered');
		log.info('should be filtered');
		log.warn('should appear');
		log.error('should appear');

		const recent = getRecentLogs();
		expect(recent).toHaveLength(2);
		expect(recent[0].level).toBe('warn');
		expect(recent[1].level).toBe('error');
	});

	it('log entries include structured data', () => {
		const log = createLogger('test');
		log.info('with data', { data: { userId: '123' } });

		const recent = getRecentLogs();
		expect(recent[0].data).toEqual({ userId: '123' });
	});

	it('log entries include error objects', () => {
		const log = createLogger('test');
		const err = new Error('test error');
		log.error('failed', { error: err });

		const recent = getRecentLogs();
		expect(recent[0].error).toBe(err);
	});

	it('log entries have ISO timestamp', () => {
		const log = createLogger('test');
		log.info('timestamped');

		const recent = getRecentLogs();
		expect(recent[0].timestamp).toMatch(/^\d{4}-\d{2}-\d{2}T/);
	});

	it('dumpLogs formats entries as readable string', () => {
		const log = createLogger('ctx');
		log.info('message one', { data: { key: 'val' } });
		log.error('message two');

		const dump = dumpLogs();
		expect(dump).toContain('[INFO]');
		expect(dump).toContain('[ctx]');
		expect(dump).toContain('message one');
		expect(dump).toContain('"key": "val"');
		expect(dump).toContain('[ERROR]');
		expect(dump).toContain('message two');
	});

	it('getRecentLogs returns a copy, not the internal buffer', () => {
		const log = createLogger('test');
		log.info('msg');

		const copy = getRecentLogs();
		copy.push({ level: 'debug', context: 'fake', message: 'injected', timestamp: '' });

		expect(getRecentLogs()).toHaveLength(1);
	});

	it('buffer caps at 100 entries', () => {
		const log = createLogger('test');
		for (let i = 0; i < 110; i++) {
			log.info(`msg ${i}`);
		}

		const recent = getRecentLogs();
		expect(recent).toHaveLength(100);
		expect(recent[0].message).toBe('msg 10');
		expect(recent[99].message).toBe('msg 109');
	});
});