import { describe, it, expect } from 'vitest';
import {
  isValidRequest,
  parseMessage,
  makeResponse,
  makeError,
  makeEvent,
  ErrorCode,
} from './protocol.js';

describe('protocol', () => {
  describe('isValidRequest', () => {
    it('accepts valid request with params', () => {
      expect(isValidRequest({ id: 1, method: 'agent.send', params: { message: 'hello' } })).toBe(true);
    });

    it('accepts valid request without params', () => {
      expect(isValidRequest({ id: 1, method: 'system.health' })).toBe(true);
    });

    it('rejects missing id', () => {
      expect(isValidRequest({ method: 'test' })).toBe(false);
    });

    it('rejects missing method', () => {
      expect(isValidRequest({ id: 1 })).toBe(false);
    });

    it('rejects non-object', () => {
      expect(isValidRequest('not an object')).toBe(false);
      expect(isValidRequest(null)).toBe(false);
      expect(isValidRequest(42)).toBe(false);
    });

    it('rejects non-numeric id', () => {
      expect(isValidRequest({ id: 'abc', method: 'test' })).toBe(false);
    });

    it('rejects non-string method', () => {
      expect(isValidRequest({ id: 1, method: 42 })).toBe(false);
    });

    it('rejects non-object params', () => {
      expect(isValidRequest({ id: 1, method: 'test', params: 'bad' })).toBe(false);
    });
  });

  describe('parseMessage', () => {
    it('parses valid JSON into GatewayRequest', () => {
      const msg = parseMessage('{"id":1,"method":"agent.send","params":{"message":"hi"}}');
      expect(msg).toEqual({ id: 1, method: 'agent.send', params: { message: 'hi' } });
    });

    it('returns null for invalid JSON', () => {
      expect(parseMessage('not json')).toBeNull();
    });

    it('returns null for valid JSON that is not a valid request', () => {
      expect(parseMessage('{"method":"test"}')).toBeNull();
    });
  });

  describe('makeResponse', () => {
    it('creates a response message', () => {
      expect(makeResponse(1, { status: 'ok' })).toEqual({
        id: 1,
        result: { status: 'ok' },
      });
    });
  });

  describe('makeError', () => {
    it('creates an error message', () => {
      expect(makeError(1, ErrorCode.MethodNotFound, 'Not found')).toEqual({
        id: 1,
        error: { code: -3, message: 'Not found' },
      });
    });
  });

  describe('makeEvent', () => {
    it('creates an event message', () => {
      expect(makeEvent(1, 'content', { text: 'hello' })).toEqual({
        id: 1,
        event: 'content',
        data: { text: 'hello' },
      });
    });

    it('creates an attachment event message', () => {
      const data = { mimeType: 'image/png', data: 'iVBOR...', filename: 'screenshot.png' };
      expect(makeEvent(1, 'attachment', data)).toEqual({
        id: 1,
        event: 'attachment',
        data,
      });
    });

    it('creates an attachment event with url', () => {
      const data = { mimeType: 'application/pdf', url: 'https://example.com/doc.pdf', filename: 'doc.pdf' };
      expect(makeEvent(2, 'attachment', data)).toEqual({
        id: 2,
        event: 'attachment',
        data,
      });
    });
  });
});