JS Learning: Arrays - Water flow

JS Learning: Arrays - Water flow

/*
Coding in function infiniteLoop. function accept 3 parameters. The 1st parameter is arr, it's a 2D array, it contains three 1D array. The 2nd parameter is d ，it's a string. The 3rd parameter is n, it's a number.

You can think of arr as a moat, the elements of arr like water constantly flow in. The direction of flow is controlled by the parameter d. The value of d can be "left" or "right". "left" means the "river" moves to the left. All elements in the 1D array are to the left moving n position, if beyond the bounds of the array and the element is moved to the tail on the left side of the array; if it exceeds the left boundary element would be moved to the tail of 3rd array(like a circle). Right is also similar to the operation, but it is moving to the right.

Finally, return arr.

Example:
  infiniteLoop( [[1,2,3],[4,5,6],[7,8,9]],"left",1) 
  should return [[2,3,4],[5,6,7],[8,9,1]]
  infiniteLoop( [[1,2,3],[4,5,6],[7,8,9]],"right",1) 
  should return [[9,1,2],[3,4,5],[6,7,8]]
  infiniteLoop( [[1,2],[3,4,5,6],[7,8,9,10]],"left",2) 
  should return [[3,4],[5,6,7,8],[9,10,1,2]]

*/

/**Pass test case 1 & 2 **/
function infiniteLoop(arr,d,n){
  let moatArr = [];
  let flowedArr = [];
  let firstElements = [];
  
  for (let i=0; i < arr.length; i++) {
    if (d === "left") {
      if (n === 1) {
        firstElements[i] = arr[i].shift();
        
        moatArr[0] = arr[i][0];
        moatArr[1] = arr[i][1];
        
        if (i == arr.length - 1) {
          moatArr[2] = firstElements[0];
        }
        else {
          moatArr[2] = arr[i+1][0];
        }
        
        flowedArr.push(moatArr);
        moatArr = [];
        console.log(flowedArr);
      }
    }
  }
  
  //
  for (let i=arr.length - 1; i >= 0; i--)
  {
      if (d === "right") {
        if (n === 1) {
          firstElements[i] = arr[i].pop();
          
          if (i === 0)
            moatArr[0] = firstElements[firstElements.length-1]
          else {
            moatArr[0] = arr[i-1][2];
          }
          moatArr[1] = arr[i][0];
          moatArr[2] = arr[i][1];
  
          
          flowedArr.push(moatArr);
          moatArr = [];
          console.log(flowedArr);
        }
      }
    }
 
 if (d === "left")
   return flowedArr;

 return flowedArr.reverse();
}

/*Finish code */
function infiniteLoop(arr,d,n){
  for (var i = 1; i <= n; i++){
  if (d === "left"){
    arr[2].push(arr[0].shift());
    arr[1].push(arr[2].shift());
    arr[0].push(arr[1].shift());
  }
  if (d === "right"){
    arr[0].unshift(arr[2].pop());
    arr[1].unshift(arr[0].pop());
    arr[2].unshift(arr[1].pop());
  }
  }
  return arr;
}

//SOlutions link
http://www.codewars.com/kata/572af273a3af3836660014a1/solutions/javascript