// url是否带有host
const hasHost = (url) => {
  return url.indexOf('https') >- 1 || url.indexOf('http') >- 1;
}

// 解析查询字符串 decodeURIComponent
const parseQuery = (query) => {
  const queryArr = query ? query.split('&') : [];
  let params = {};
  for (var i = 0, n = queryArr.length; i < n; i++) {
    let arr = queryArr[i].split('=');
    if(arr.length>0){
      let key = decodeURIComponent(arr.shift());
      let value = decodeURIComponent(arr.join('=')); // 参数如果带=，在这里加上去
      params[key] = value;
    }
  }
  return params;
}

// 解析路径
// 将类似/a/b/1 解析成 {path:/a/b, params:{id:1}}
const parsePath = (path:string, pattern?:string) =>{
  const keyArr = pattern ? pattern.split('/') : [];
  const valueArr = path.split('/');
  let pathObj:any = { path, params:{}};
  let pathArr = [];
  for (var i = 0, n = keyArr.length; i < n; i++) {
    var key = keyArr[i];
    var value = valueArr[i];
    if(key.indexOf(':') == -1){
      if(key == value){
        pathArr.push(key);
      }else{
        break;
      }
    }else{
      var nKey = key.replace(':','');
      pathObj.path = pathArr.join('/');
      if(value) pathObj.params = {[nKey]:value}
    }
  }
  return pathObj;
}

const patternToPath = (pattern) => {
  return pattern.split('/:')[0];
}

// 将类似/a/b/1?x=1&y=2 解析成 {path:/a/b, params:{id:1,x:1,y:2}}
const parseUrl = (url:string,pattern?:string) => {
  const arr = url ? url.split('?') : [];
  let path = arr[0];
  let params = parseQuery(arr[1]) || {};
  let pathObj = parsePath(path, pattern);
  pathObj.params = Object.assign({}, pathObj.params, params);
  return pathObj
}

/**
 * 拼接query值
 * @param params 参数
 * @param isAdd 是否追加
 * @returns {string}
 */
const stringifyQuery = (params, isAdd) => {
  let query = '';
  for (let key of Object.keys(params)) {
    let value = params[key];
    if(value || value == 0) {
      key = encodeURIComponent(key);
      value = encodeURIComponent(value);
      query += ('&' + key + '=' + value);
    }
  }
  return isAdd ? query : query.replace(/&/,'?');
}

// 将类似/a/b {x:1}, /a/b/1 {y:2}这样的配置拼接为url
// encodeURIComponent
const stringifyUrl = (url, params, pattern?) => {
  const urlObj = parseUrl(url,pattern); // 剔除参数，只留纯路径
  let path = urlObj.path;
  params = Object.assign({}, params, urlObj.params);
  if(pattern && pattern.indexOf('/:') > -1){
    const match = pattern.match(/\/:(.*)/);
    if(match){
      const key = match[1];
      const value = params[key];
      // 如果params有匹配的参数，则路径添加这个参数，并且从params中删除
      if(value || value == 0) {
        delete params[key];
        path = pattern.replace(':' + key, value);// 匹配到/:然后进行替换
      }
    }
  }
  const query = stringifyQuery(params, false);
  return path + query;
}

export {
  patternToPath,
  parsePath,
  parseUrl,
  stringifyUrl,
  hasHost
}