// Request utils,
// feel free to replace with your code
// (get, post are used in ApiServices)


import {getLocalToken} from 'api/AuthSvc';
import config from 'config'

window.BASE_API = config.BASE_API

function requestWrapper(method) {
    return async function (url, data = null, params = {}) {
        if (method === 'GET') {
            // is it a GET?
            // GET doesn't have data
            params = data;
            data = null;
        } else if (data === Object(data)) {
            // (data === Object(data)) === _.isObject(data)
            data = JSON.stringify(data)
        } else {
            throw new Error(`XHR invalid, check ${method} on ${url}`)
        }

        // default params for fetch = method + (Content-Type)
        let defaults = {
            method: method,
            headers: {
                'Content-Type': 'application/json; charset=UTF-8'
            }
        }

        // check that req url is relative and request was sent to our domain
        if (url.match(/^https?:\/\//gi) > -1) {
            let token = getLocalToken();
            if (token) {
                defaults.headers['Authorization'] = `JWT ${token}`;
            }
            url = window.BASE_API + url;
        }

        if (data) {
            defaults.body = data;
        }

        let paramsObj = {...defaults, headers: {...params, ...defaults.headers}}

        return await fetch(url, paramsObj)
            .then(parseJSON)
            .catch((err) => {
                console.error(err)
            });
    }
}

// middlewares
// parse fetch json, add ok property and return request result

/**
 * 1. parse response
 * 2. add "ok" property to result
 * 3. return request result
 * @param  {Object} res - response from server
 * @return {Object} response result with "ok" property
 */
async function parseJSON(res) {
    let json;
    try {
        json = await res.json()
    } catch (e) {
        return {data: {}, ok: false}
    }

    // simplest validation ever, ahah :)
    if (!res.ok) {
        return {data: json, ok: false}
    }
    // resultOK - is a function with side effects
    // It removes ok property from result object
    return {data: json, ok: true}
}


export const get = requestWrapper('GET')
export const post = requestWrapper('POST')
export const put = requestWrapper('PUT')
export const patch = requestWrapper('PATCH')
export const del = requestWrapper('DELETE')

// USAGE:
// get('https://www.google.com', {
//     Authorization: 'JWT LOL',
//     headers: {
//         'Content-Type': 'text/html'
//     }
// })

// FUNCTION WITH SIDE-EFFECTS
/**
 * `parseJSON()` adds property "ok"
 * that identicates that response is OK
 *
 * `resultOK`removes result.ok from result and returns "ok" property
 *  It widely used in `/actions/*`
 *  for choosing action to dispatch after request to API
 *
 * @param  {Object} result - response result that
 * @return {bool} - indicates was request successful or not
 */
export function resultOK(result) {
    if (result) {
        let ok = result.ok
        delete result.ok
        return ok //look at parseJSON
    } else {
        return false
    }
}