/*
 * SonarQube
 * Copyright (C) 2009-2016 SonarSource SA
 * mailto:contact AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
import { stringify } from 'querystring';
import { getCookie } from './cookies';

export function getCSRFTokenName () {
  return 'X-XSRF-TOKEN';
}

export function getCSRFTokenValue () {
  const cookieName = 'XSRF-TOKEN';
  const cookieValue = getCookie(cookieName);
  if (!cookieValue) {
    return '';
  }
  return cookieValue;
}

/**
 * Return an object containing a special http request header used to prevent CSRF attacks.
 * @returns {Object}
 */
export function getCSRFToken () {
  // Fetch API in Edge doesn't work with empty header,
  // so we ensure non-empty value
  const value = getCSRFTokenValue();
  return value ? { [getCSRFTokenName()]: value } : {};
}

/**
 * Default options for any request
 */
const DEFAULT_OPTIONS = {
  method: 'GET',
  credentials: 'same-origin'
};

/**
 * Default request headers
 */
const DEFAULT_HEADERS = {
  'Accept': 'application/json'
};

/**
 * Request
 */
class Request {
  constructor (url) {
    this.url = url;
    this.options = {};
    this.headers = {};
  }

  submit () {
    let url = this.url;

    const options = { ...DEFAULT_OPTIONS, ...this.options };
    const customHeaders = {};

    if (this.data) {
      if (this.data instanceof FormData) {
        options.body = this.data;
      } else if (options.method === 'GET') {
        url += '?' + stringify(this.data);
      } else {
        customHeaders['Content-Type'] = 'application/x-www-form-urlencoded';
        options.body = stringify(this.data);
      }
    }

    options.headers = {
      ...DEFAULT_HEADERS,
      ...customHeaders,
      ...this.headers,
      ...getCSRFToken()
    };

    return window.fetch(window.baseUrl + url, options);
  }

  setMethod (method) {
    this.options.method = method;
    return this;
  }

  setData (data) {
    this.data = data;
    return this;
  }

  setHeader (name, value) {
    this.headers[name] = value;
    return this;
  }
}

/**
 * Make a request
 * @param {string} url
 * @returns {Request}
 */
export function request (url) {
  return new Request(url);
}

/**
 * Check that response status is ok
 * @param response
 * @returns {*}
 */
export function checkStatus (response) {
  if (response.status === 401) {
    window.location = window.baseUrl + '/sessions/new?return_to=' +
        encodeURIComponent(window.location.pathname + window.location.search + window.location.hash);
    return {};
  } else if (response.status >= 200 && response.status < 300) {
    return response;
  } else {
    const error = new Error(response.status);
    error.response = response;
    throw error;
  }
}

/**
 * Parse response as JSON
 * @param response
 * @returns {object}
 */
export function parseJSON (response) {
  return response.json();
}

/**
 * Shortcut to do a GET request and return response json
 * @param url
 * @param data
 */
export function getJSON (url, data) {
  return request(url)
      .setData(data)
      .submit()
      .then(checkStatus)
      .then(parseJSON);
}

/**
 * Shortcut to do a POST request and return response json
 * @param url
 * @param data
 */
export function postJSON (url, data) {
  return request(url)
      .setMethod('POST')
      .setData(data)
      .submit()
      .then(checkStatus)
      .then(parseJSON);
}

/**
 * Shortcut to do a POST request
 * @param url
 * @param data
 */
export function post (url, data) {
  return request(url)
      .setMethod('POST')
      .setData(data)
      .submit()
      .then(checkStatus);
}

/**
 * Shortcut to do a POST request and return response json
 * @param url
 * @param data
 */
export function requestDelete (url, data) {
  return request(url)
      .setMethod('DELETE')
      .setData(data)
      .submit()
      .then(checkStatus);
}

/**
 * Delay promise for testing purposes
 * @param response
 * @returns {Promise}
 */
export function delay (response) {
  return new Promise(resolve => setTimeout(() => resolve(response), 1200));
}