import config from '../config';
import * as Errors from './Errors';

class Api {
  constructor() {
  }

  baseUrl() { return config.baseApiUrl; }

  url(path) {
    return this.baseUrl() + path;
  }

  checkStatus(response) {
    if (response.status >= 200 && response.status < 300) {
      return response;
    } else if (response.status === 404) {
      throw new Errors.ApiNotFoundError(response.statusText, response);
    } else {
      throw new Errors.ApiServerError(response.statusText || "Unknown Server Error", response);
    }
  }

  parseJSON(response) {
    return response.json();
  }

  performRequest(url, method, params = {}) {
    const hasBody = Object.keys(params || {}).length !== 0;

    const headers = new Headers();
    headers.append('Accept', 'application/json');

    const opts = {
      headers,
      method: method,
      credentials: "same-origin"
    };

    if (hasBody) {
      headers.append('Content-Type', 'application/json');
      opts.body = JSON.stringify(params);
    }

    return fetch(url, opts).then(this.checkStatus).then(this.parseJSON);
  }

  get(url, params = {}) {

    const queryParams = [];

    for (let key in params) {
      const val = params[key];
      if (Array.isArray(val)) {
        for (let x of val) {
          queryParams.push(encodeURIComponent(key) + "[]=" + (x === null ? '' : encodeURIComponent(x)));
        }
      } else {
        queryParams.push(encodeURIComponent(key) + "=" + (val === null ? '' : encodeURIComponent(val)));
      }
    }

    if (queryParams.length) {
      url = url + "?" + queryParams.join("&");
    }

    return this.performRequest(url, "GET");
  }

  post(url, params = {}) {
    return this.performRequest(url, "POST", params);
  }

  getRecipeList(page, per, sortColumn, sortDirection, name, tags) {
    const params = {
      page: page || null,
      per: per || null,
      sort_column: sortColumn || null,
      sort_direction: sortDirection || null,
      name: name || null,
      tags: tags || null
    };

    return this.get("/recipes", params);
  }

  postLogin(username, password) {
    const params = {
      username: username,
      password: password
    };

    return this.post("/login", params);
  }

  getCurrentUser() {
    return this.get("/user")
  }
}

const api = new Api();

export default api;