'use strict';

var defaults = require('./defaults');
var utils = require('./utils');
var dispatchRequest = require('./core/dispatchRequest');
var InterceptorManager = require('./core/InterceptorManager');
var isAbsoluteURL = require('./helpers/isAbsoluteURL');
var combineURLs = require('./helpers/combineURLs');
var bind = require('./helpers/bind');
var transformData = require('./helpers/transformData');

function Axios(defaultConfig) {
  this.defaults = utils.merge({}, defaultConfig);
  this.interceptors = {
    request: new InterceptorManager(),
    response: new InterceptorManager()
  };
}

Axios.prototype.request = function request(config) {
  /*eslint no-param-reassign:0*/
  // Allow for axios('example/url'[, config]) a la fetch API
  if (typeof config === 'string') {
    config = utils.merge({
      url: arguments[0]
    }, arguments[1]);
  }

  config = utils.merge(defaults, this.defaults, { method: 'get' }, config);

  // Support baseURL config
  if (config.baseURL && !isAbsoluteURL(config.url)) {
    config.url = combineURLs(config.baseURL, config.url);
  }

  // Don't allow overriding defaults.withCredentials
  config.withCredentials = config.withCredentials || this.defaults.withCredentials;

  // Transform request data
  config.data = transformData(
    config.data,
    config.headers,
    config.transformRequest
  );

  // Flatten headers
  config.headers = utils.merge(
    config.headers.common || {},
    config.headers[config.method] || {},
    config.headers || {}
  );

  utils.forEach(
    ['delete', 'get', 'head', 'post', 'put', 'patch', 'common'],
    function cleanHeaderConfig(method) {
      delete config.headers[method];
    }
  );

  // Hook up interceptors middleware
  var chain = [dispatchRequest, undefined];
  var promise = Promise.resolve(config);

  this.interceptors.request.forEach(function unshiftRequestInterceptors(interceptor) {
    chain.unshift(interceptor.fulfilled, interceptor.rejected);
  });

  this.interceptors.response.forEach(function pushResponseInterceptors(interceptor) {
    chain.push(interceptor.fulfilled, interceptor.rejected);
  });

  while (chain.length) {
    promise = promise.then(chain.shift(), chain.shift());
  }

  return promise;
};

var defaultInstance = new Axios(defaults);
var axios = module.exports = bind(Axios.prototype.request, defaultInstance);

// Expose properties from defaultInstance
axios.defaults = defaultInstance.defaults;
axios.interceptors = defaultInstance.interceptors;

// Factory for creating new instances
axios.create = function create(defaultConfig) {
  return new Axios(defaultConfig);
};

// Expose all/spread
axios.all = function all(promises) {
  return Promise.all(promises);
};
axios.spread = require('./helpers/spread');

// Provide aliases for supported request methods
utils.forEach(['delete', 'get', 'head'], function forEachMethodNoData(method) {
  /*eslint func-names:0*/
  Axios.prototype[method] = function(url, config) {
    return this.request(utils.merge(config || {}, {
      method: method,
      url: url
    }));
  };
  axios[method] = bind(Axios.prototype[method], defaultInstance);
});

utils.forEach(['post', 'put', 'patch'], function forEachMethodWithData(method) {
  /*eslint func-names:0*/
  Axios.prototype[method] = function(url, data, config) {
    return this.request(utils.merge(config || {}, {
      method: method,
      url: url,
      data: data
    }));
  };
  axios[method] = bind(Axios.prototype[method], defaultInstance);
});
