import axios from "axios";
const BASE_URL = "https://jsonplaceholder.typicode.com/";
const URI_USERS = 'users/';

/**
* These are the implementation of our functions, which take functions as arguments.
*/

export const _fetchUsers = async function (_makeApiCall, _URI_USERS) {
    return _makeApiCall(_URI_USERS);
}


export const _fetchUser = async function (_makeApiCall, _URI_USERS, id) {
    return _makeApiCall(_URI_USERS + id);
}


export const _fetchUserStrings = async function (_fetchUser, _parseUser, ...ids) {
    const users = await Promise.all(ids.map(id => _fetchUser(id)));
    return users.map(user => _parseUser(user));
}
export const _makeApiCall = async function (uri) {
    try {
        const response = await axios(BASE_URL + uri);
        return response.data;
    } catch (err) {
        throw new Error(err.message);
    }
}

export function _parseUser(user) {
    return `${user.name}:${user.username}`;
}



/**
 * Real exports
 */
export const makeApiCall = _makeApiCall;
export const parseUser = _parseUser;

export const fetchUsers = _fetchUsers.bind(null, _makeApiCall, URI_USERS);
export const fetchUser = _fetchUser.bind(null, _makeApiCall, URI_USERS);
export const fetchUserStrings = _fetchUserStrings.bind(null, _fetchUser, _parseUser);

/**
 * Our most complicated test
 *
 */

describe("_fetchUserStrings", () => {

    describe("happy flow", () => {

        const fetchUserMock = jest.fn((i) => Promise.resolve({
            username: "foo",
            name: "bar"
        }));
        const parseUserMock = jest.fn(user => "string");
        const fetchUserStrings = _fetchUserStrings.bind(null, fetchUserMock, parseUserMock);

        it("returns an array of three strings", async () => {

            expect.assertions(3);
            const result = await fetchUserStrings(1, 2, 3);

            // I'm being a bit lazy here, you could be checking that
            // The strings are actually there etc, but whatevs.

            expect(fetchUserMock).toHaveBeenCalledTimes(3);
            expect(parseUserMock).toHaveBeenCalledTimes(3);
            expect(result).toHaveLength(3);
        })

    });
});