export const findNewNode = (oldTreeData, newTreeData) => {
  let res;
  for (let i = 0; i < oldTreeData.length; i++) {
    const oldNode = oldTreeData[i];
    const newNode = newTreeData[i];
    if (oldNode.children && newNode.children && oldNode.children.length === newNode.children.length) res = findNewNode(oldNode.children, newNode.children)
    else if (!oldNode.children && newNode.children) res = newNode.children[0];
    else if (oldNode.children && newNode.children && oldNode.children.length !== newNode.children.length) res = newNode.children[newNode.children.length - 1]
    //console.log(res)
    return res
  }
}

export const deleteNode = (tree, title) => {
  return tree.reduce((newTree, node) => {
    if (node.title === title) {
      return newTree;
    }
    else if (node.title !== title && node.children && node.children.length) {
      return newTree.concat({
        ...node,
        children: deleteNode(node.children, title)
      })
    }
    else return newTree.concat(node)
  }, [])
}

export const addNode = (tree, parentTitle, newNode) => {
  return tree.reduce((newTree, node) => {
    if (node.title === parentTitle) {
      if (node.children) node.children.push(newNode)
      else node.children = [newNode]
      return newTree.concat(node)
    }
    else if (node.children) {
      return newTree.concat({
        ...node,
        children: addNode(node.children, parentTitle, newNode)
      })
    } else return newTree.concat(node)
  }, [])
}

export const getParent = (tree, node) => {
  const {id} = node;
  for (let i = 0; i < tree.length; i++) {
    if (tree[i].children && tree[i].children.find(child => child.id === id)) return tree[i];
    else if (tree[i].children) return getParent(tree[i].children, node)
  }
}