/**
* 向上找到最近的指定组件
* @param {*} context 当前上下文
* @param {*} componentName 组件的名称
* @returns
*/
export const findComponentUpward = function(context, componentName) {
  let parent = context.$parent;
  let name = parent.$options.name;

  while (parent && (!name || [componentName].indexOf(name) < 0)) {
      parent = parent.$parent;
      if (parent) name = parent.$options.name;
  }
  return parent;
}

/**
* 向上找到所有的指定组件
* @param {*} context 当前上下文
* @param {*} componentName 组件的名称
* @returns
*/
export const findComponentsUpward = function (context, componentName) {
  let parents = [];
  const parent = context.$parent;

  if (parent) {
      if (parent.$options.name === componentName) parents.push(parent);
      return parents.concat(findComponentsUpward(parent, componentName));
  } else {
      return [];
  }
}

/**
* 向下找到最近的指定组件
* @param {*} context 当前上下文
* @param {*} componentName 组件的名称
* @returns
*/
export const findComponentDownward = function (context, componentName) {
  const childrens = context.$children;
  let children = null;

  if (childrens.length) {
      for (const child of childrens) {
          const name = child.$options.name;

          if (name === componentName) {
              children = child;
              break;
          } else {
              children = findComponentDownward(child, componentName);
              if (children) break;
          }
      }
  }
  return children;
}

/**
* 向下找到所有指定的组件
* @param {*} context 当前上下文
* @param {*} componentName 组件的名称
* @returns
*/
export const findComponentsDownward = function (context, componentName) {
  return context.$children.reduce((components, child) => {
      if (child.$options.name === componentName) components.push(child);
      const foundChilds = findComponentsDownward(child, componentName);
      return components.concat(foundChilds);
  }, []);
}

/**
* 找到指定组件的兄弟组件
* @param {*} context 当前上下文
* @param {*} componentName 组件的名称
* @param {*} exceptMe 是否排除自己
* @returns
*/
export const findBrothersComponents = function (context, componentName, exceptMe = true) {
  let res = context.$parent.$children.filter((item) => {
      return item.$options.name === componentName;
  });
  let index = res.findIndex((item) => item._uid === context._uid);
  if (exceptMe) res.splice(index, 1);
  return res;
}

export default {
  findComponentUpward,
  findComponentsUpward,
  findComponentDownward,
  findComponentsDownward,
  findBrothersComponents
}