import process from 'process';

/**
 * State machine for request
 *
 * @example
 *
 * let former = this.state.rs;
 * this.setState({
 *   rs: former.trans(true),
 * })
 */
export class RequestState {
  loading: boolean;
  success: boolean;
  constructor() {
    this.loading = true;
    this.success = false;
  }

  trans(success: boolean): RequestState {
    if (this.loading) {
      this.loading = false;
      this.success = success;
    } else {
      console.error('calling trans on not loading state');
    }
    return this;
  }
}

/**
 * Get URL of backend
 * @param path Relative path to base url, begins with `/`
 * @returns Full url
 *
 * @example
 *
 * ``` tsx
 * import { getUrl } from '@/service';
 * import { Component, ReactNode } from 'react';
 * import Taro from '@tarojs/taro';
 *
 * class Index extends Component {
 *   state = {
 *     testData: {},
 *   }
 *   componentDidMount(): void {
 *    Taro.request({
 *      url: getUrl('/testdata'),
 *      method: 'GET',
 *    }).then(res => {
 *      console.log(res.data);
 *      this.setState({ testData: res.data.data });
 *    });
 *  }
 *  render() { ... }
 * }
 * ```
 */
export function getUrl(path: string): string {
  const baseUrl = process.env.TARO_APP_API;
  // console.log('bu:', baseUrl);
  if (baseUrl) {
    return baseUrl + path;
  } else {
    console.log('env TARO_APP_API is undefined');
    return '';
  }
}