const http = require('http');
const LC = require('../src/client');

describe('λ-calculator', () => {
  let challenger, port;

  beforeEach((done) => {
    challenger = http.createServer();
    challenger.listen(0, () => {
      port = challenger.address().port;
      done();
    });
  });

  afterEach((done) => {
    challenger.close(() => done());
  });

  it('registers to challenger', () => {
    challenger.on('request', (request, response) => {
      expect(request.method).toBe('POST');
      expect(request.url).toBe('/api/register');
      expect(request.headers).toHaveProperty('content-type', 'application/json;charset=utf-8');

      let payload = '';
      request.on('data', (d) => (payload += d));
      request.on('end', () => {
        expect(payload).toEqual('"John Smith"');
      });

      response.end('SomeToken');
    });

    const client = LC.newClient({
      playerName: 'John Smith',
      challengerURL: `http://localhost:${port}`,
    });
    return client.start()
      .then((token) => expect(token).toBe('SomeToken'));
  });

  it('retrieves next challenge', () => {

    challenger.on('request', (request, response) => {
      expect(request.method).toBe('GET');
      expect(request.url).toBe('/api/challenge?token=SomeToken');
      response.end(JSON.stringify({ expr: 'SomeChallenge' }));
    });

    const client = LC.newClient({
      playerName: 'John Smith',
      challengerURL: `http://localhost:${port}`,
    });
    return client.nextChallenge('SomeToken')
      .then((challenge) => expect(challenge).toBe('SomeChallenge'));
  });

  it('solves challenges', () => {
    const parser = {
      parse: (challenge) => {
        expect(challenge).toBe('Some challenge');
        return 'Parsed expression';
      },
    };

    const interpreter = {
      evaluate: (parsedExpression) => {
        expect(parsedExpression).toBe('Parsed expression');
        return 'Evaluated expression';
      },
    };

    const printer = {
      print: (evaluatedExpression) => {
        expect(evaluatedExpression).toBe('Evaluated expression');
        return 'Expression to print';
      },
    };

    const client = LC.newClient({ parser, interpreter, printer });
    expect(client.solve('Some challenge')).toBe('Expression to print');
  });
});