import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
import { Logger } from '../src/index.js';

describe('Logger', () => {
    const packageName = 'test-pkg';
    let consoleLogSpy: any;
    let consoleWarnSpy: any;
    let consoleErrorSpy: any;

    beforeEach(() => {
        consoleLogSpy = vi.spyOn(console, 'log').mockImplementation(() => { });
        consoleWarnSpy = vi.spyOn(console, 'warn').mockImplementation(() => { });
        consoleErrorSpy = vi.spyOn(console, 'error').mockImplementation(() => { });
        vi.stubEnv('LOG_LEVEL', 'info');
        vi.stubEnv('THROW_ERROR', 'false');
        vi.stubEnv('DEBUG', '');
    });

    afterEach(() => {
        vi.restoreAllMocks();
        vi.unstubAllEnvs();
    });

    describe('Thresholds', () => {
        it('should suppress verbose and debug logs by default (info level)', () => {
            const logger = new Logger({ packageName });
            logger.verbose('v');
            logger.debug('d');
            expect(consoleLogSpy).not.toHaveBeenCalled();
        });

        it('should emit info, warn, and error logs by default', () => {
            const logger = new Logger({ packageName });
            logger.info('i');
            logger.warn('w');
            logger.error('e');
            expect(consoleLogSpy).toHaveBeenCalledWith(expect.stringContaining('[INFO] i'));
            expect(consoleWarnSpy).toHaveBeenCalledWith(expect.stringContaining('[WARN] w'));
            expect(consoleErrorSpy).toHaveBeenCalledWith(expect.stringContaining('[ERROR] e'));
        });

        it('should honor custom LOG_LEVEL', () => {
            vi.stubEnv('LOG_LEVEL', 'warn');
            const logger = new Logger({ packageName });
            logger.info('i');
            logger.warn('w');
            expect(consoleLogSpy).not.toHaveBeenCalled();
            expect(consoleWarnSpy).toHaveBeenCalledWith(expect.stringContaining('[WARN] w'));
        });
    });

    describe('DEBUG Namespace', () => {
        it('should enable debug logs when namespace matches DEBUG', () => {
            vi.stubEnv('DEBUG', 'foo:*');
            const logger = new Logger({ packageName, debugNamespace: 'foo:bar' });
            logger.debug('hello');
            expect(consoleLogSpy).toHaveBeenCalledWith(expect.stringContaining('[DEBUG] hello'));
        });

        it('should NOT enable debug logs when namespace does not match DEBUG', () => {
            vi.stubEnv('DEBUG', 'foo:*');
            const logger = new Logger({ packageName, debugNamespace: 'baz' });
            logger.debug('hello');
            expect(consoleLogSpy).not.toHaveBeenCalled();
        });

        it('should support multiple DEBUG patterns', () => {
            vi.stubEnv('DEBUG', 'foo,bar:*');
            const logger1 = new Logger({ packageName, debugNamespace: 'foo' });
            const logger2 = new Logger({ packageName, debugNamespace: 'bar:baz' });
            logger1.debug('d1');
            logger2.debug('d2');
            expect(consoleLogSpy).toHaveBeenCalledTimes(2);
        });
    });

    describe('Error Throwing', () => {
        it('should throw Error by default when level is error', () => {
            vi.stubEnv('THROW_ERROR', 'true');
            const logger = new Logger({ packageName });
            expect(() => logger.error('failed')).toThrow('failed');
        });

        it('should NOT throw when THROW_ERROR is false', () => {
            vi.stubEnv('THROW_ERROR', 'false');
            const logger = new Logger({ packageName });
            expect(() => logger.error('failed')).not.toThrow();
        });

        it('should throw the provided Error object if available', () => {
            vi.stubEnv('THROW_ERROR', 'true');
            const logger = new Logger({ packageName });
            const customError = new Error('custom');
            expect(() => logger.error('msg', customError)).toThrow(customError);
        });
    });

    describe('Prefixing', () => {
        it('should use custom environment prefix', () => {
            vi.stubEnv('MYAPP_LOG_LEVEL', 'error');
            const logger = new Logger({ packageName, envPrefix: 'MYAPP' });
            logger.warn('w');
            expect(consoleWarnSpy).not.toHaveBeenCalled();

            vi.stubEnv('MYAPP_THROW_ERROR', 'true');
            const logger2 = new Logger({ packageName, envPrefix: 'MYAPP' });
            expect(() => logger2.error('e')).toThrow();
        });
    });
});