Add and sort

addAndSort.js

/* 
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Given two arrays:

Array 1 - A distinct set of ice cream flavors

Array 2 - A set of ice cream flavors (may contain duplicates)

Please write a function that returns the values of Array 2 sorted by the order of Array 1.


```jsx
Array 1 - ['vanilla', 'mint', 'chocolate']

Array 2 - [ 'mint', 'vanilla', 'mint', 'chocolate',  'mint', 'chocolate']

Return Value -  ['vanilla', 'mint', 'mint', 'mint', 'chocolate', 'chocolate']
```



 */


const arr1 = ['vanilla', 'mint', 'chocolate'];
const arr2 = ['chocolate', 'chocolate', 'chocolate', 'mint', 'mint', 'mint'];


//['vanilla', 'mint', 'mint', 'mint', 'chocolate'];

let sortedFlavors = (distinctFlavors, dupFlavors) => dupFlavors.reduce((sortedFlavors, flavor, index, originalArray) => {

    // if current flavor is not current in the sortedFlavors array
    if (sortedFlavors.indexOf(flavor) < 0) {
        const isThereAflavorAlreadyInArrayAtIndexOfCurrentFlavor = !!sortedFlavors[distinctFlavors.indexOf(flavor)];
        if (isThereAflavorAlreadyInArrayAtIndexOfCurrentFlavor) {
            const idx = sortedFlavors.lastIndexOf(distinctFlavors.indexOf(flavor));
            if (idx === 0) {
                sortedFlavors.push(flavor);
            } else {
                const indexOfPreviousFlavor = sortedFlavors.lastIndexOf(distinctFlavors[distinctFlavors.indexOf(flavor) - 1]);
                sortedFlavors.splice(indexOfPreviousFlavor + 1, 0, flavor);
            }
        } else {
            const indexOfFlavor = distinctFlavors.indexOf(flavor);
            sortedFlavors[indexOfFlavor] = flavor;      
        }

    } else {
      // current flavor is already in the array once so we just need to add this new instance next to that one
      const idx = sortedFlavors.lastIndexOf(flavor);
      sortedFlavors.splice(idx, 0, flavor);
    }

    if (index === originalArray.length - 1) {
        // this should remove possible empty indexes if, for example, mint or chocolate is not in dupFlavors
        const stringWithEmptyRemoved = sortedFlavors.join('-').replace('--', '-');

        // this accounts for a beginning '-' if, for example, vanilla is not in dupFlavors
        if (stringWithEmptyRemoved[0] === '-') {
          return stringWithEmptyRemoved.slice(1).split('-')
        }

        // turn back into an array
        return stringWithEmptyRemoved.split('-');
    }

    return sortedFlavors

}, []);


console.log(sortedFlavors(arr1, arr2));