export default function move(list: List, source: string, destination: string): List {
  const fileIDs: Array<string> = [];
  const folderIDs: Array<string> = [];

  // file
  for (let i = 0; i < list.length; i++) {
    list[i].files.forEach((file) => fileIDs.push(file.id));
  }
  // folder
  list.forEach((folder) => folderIDs.push(folder.id));

  function checkValueInArray(arr: Array<string>, key: string) {
    return arr.find((a) => a === key);
  }

  const checkSourceIsFile = checkValueInArray(fileIDs, source);
  const checkSourceIsFolder = checkValueInArray(folderIDs, source);

  if (checkSourceIsFile === undefined) {
    if (checkSourceIsFolder !== undefined) {
      throw new Error('You cannot move a folder');
    } else {
      throw new Error('This ID does not even exist, dude');
    }
  }

  const checkDestinationIsFolder = checkValueInArray(folderIDs, destination);
  const checkDestinationIsFile = checkValueInArray(fileIDs, destination);

  if (checkDestinationIsFolder === undefined) {
    if (checkDestinationIsFile !== undefined) {
      throw new Error('You cannot specify a file as the destination');
    } else {
      throw new Error('This ID does not even exist, dude');
    }
  }

  function getFolderIdOfSource(list: List, source: string): number {
    for (let i = 0; i < list.length; i++) {
      if (list[i].files.find((item) => item.id === source)) {
        return i;
      }
    }
    return -1;
  }

  const sourceFolderID = getFolderIdOfSource(list, source);

  const folderObject = list[sourceFolderID];
  let mutateObject = list[sourceFolderID];

  mutateObject = {
    ...folderObject,
    files: folderObject.files.filter((i) => i.id !== source),
  };

  list[sourceFolderID] = mutateObject;

  function folderIdOfDestionation(list: List, destination: string): number {
    for (let i = 0; i < list.length; i++) {
      if (list[i].id == destination) {
        return i;
      }
    }
    return -1;
  }
  const destinationFolderID = folderIdOfDestionation(list, destination);

  const fileToMove = folderObject.files.find((item) => item.id === source)!;

  list[destinationFolderID].files.push(fileToMove);

  return list;
}