const makeServiceWorkerEnv = require('service-worker-mock');

global.fetch = require('node-fetch');
jest.mock('node-fetch')

describe("plugin: fetch", () => {
  beforeEach(() => {
    global.fetch.mockImplementation((url, init) => {
        const response = new Response(
                        new Blob(
                            [JSON.stringify({ test: "success" })],
                            {type: "application/json"}
                        ),
                        {
                            status: 200,
                            statusText: "OK",
                            headers: {
                            'ETag': 'TestingETagHeader'
                            },
                            url: url
                        });
        return Promise.resolve(response);
    });
      
    Object.assign(global, makeServiceWorkerEnv());
    jest.resetModules();
    global.LibResilientPluginConstructors = new Map()
    LR = {
        log: (component, ...items)=>{
            console.debug(component + ' :: ', ...items)
        }
    }
  })
  
  test("it should register in LibResilientPluginConstructors", () => {
    require("../../plugins/fetch.js");
    expect(LibResilientPluginConstructors.get('fetch')().name).toEqual('fetch');
  });
  
  test("it should return data from fetch()", async () => {
    require("../../plugins/fetch.js");

    const response = await LibResilientPluginConstructors.get('fetch')(LR).fetch('https://resilient.is/test.json');
    
    expect(fetch).toHaveBeenCalled();
    expect(await response.json()).toEqual({test: "success"})
    expect(response.url).toEqual('https://resilient.is/test.json')
  });
  
  test("it should pass the Request() init data to fetch()", async () => {
    require("../../plugins/fetch.js");

    var initTest = {
        method: "GET",
        headers: new Headers({"x-stub": "STUB"}),
        mode: "mode-stub",
        credentials: "credentials-stub",
        cache: "cache-stub",
        referrer: "referrer-stub",
        // these are not implemented by service-worker-mock
        // https://github.com/zackargyle/service-workers/blob/master/packages/service-worker-mock/models/Request.js#L20
        redirect: undefined,
        integrity: undefined,
        cache: undefined
    }
    
    const response = await LibResilientPluginConstructors.get('fetch')(LR).fetch('https://resilient.is/test.json', initTest);
    
    expect(fetch).toHaveBeenCalledWith('https://resilient.is/test.json', initTest);
    expect(await response.json()).toEqual({test: "success"})
    expect(response.url).toEqual('https://resilient.is/test.json')
  });
  
  test("it should set the LibResilient headers", async () => {
    require("../../plugins/fetch.js");

    const response = await LibResilientPluginConstructors.get('fetch')(LR).fetch('https://resilient.is/test.json');
    
    expect(fetch).toHaveBeenCalled();
    expect(await response.json()).toEqual({test: "success"})
    expect(response.url).toEqual('https://resilient.is/test.json')
    expect(response.headers.has('X-LibResilient-Method')).toEqual(true)
    expect(response.headers.get('X-LibResilient-Method')).toEqual('fetch')
    expect(response.headers.has('X-LibResilient-Etag')).toEqual(true)
    expect(response.headers.get('X-LibResilient-ETag')).toEqual('TestingETagHeader')
  });
  
  test("it should throw an error when HTTP status is >= 400", async () => {
    
    global.fetch.mockImplementation((url, init) => {
            const response = new Response(
                                new Blob(
                                  ["Not Found"],
                                  {type: "text/plain"}
                                ),
                                {
                                  status: 404,
                                  statusText: "Not Found",
                                  url: url
                                });
            return Promise.resolve(response);
          });
    
    require("../../plugins/fetch.js");

    expect.assertions(1)
    expect(LibResilientPluginConstructors.get('fetch')(LR).fetch('https://resilient.is/test.json')).rejects.toThrow(Error)
  });
});