1 files changed, 35 insertions, 15 deletions

diff --git a/packages/sortug/src/utils.ts b/packages/sortug/src/utils.ts
index 687b8db..43fac8a 100644
--- a/packages/sortug/src/utils.ts
+++ b/packages/sortug/src/utils.ts
@@ -1,25 +1,45 @@
+export function cycleNext(current: number, max: number) {
+  if (current + 1 === max) return 0;
+  else return current + 1;
+}
+export function cyclePrev(current: number, max: number) {
+  if (current === 0) return max;
+  else return current - 1;
+}
+
 export function randomFromArray<T>(a: Array<T>): T {
   const l = a.length;
-  const ind = Math.floor(Math.random() * l);
-  if (ind === l) return a[ind - 1];
-  else return a[ind];
+  if (l === 0) throw new Error("Empty array!");
+  const randomIdx = Math.floor(Math.random() * l);
+  const idx = randomIdx === l ? randomIdx - 1 : randomIdx;
+  const el = a[idx]!;
+  return el;
 }
-export function randomFromArrayAcc<T>(a: Array<T>, s?: Set<T>): T {
-  const st = s ? s : new Set(a);
-  const l = a.length;
-  const ind = Math.floor(Math.random() * l);
-  const res = ind === l ? a[ind - 1] : a[ind];
-  if (st.has(res)) return randomFromArrayAcc(a, st);
-  else {
-    st.add(res);
-    // TODO have to return this too?
-    return res;
-  }
+export function randomFromArrayMany<T>(
+  a: Array<T>,
+  count: number,
+  canRepeat = false,
+): Array<T> {
+  if (canRepeat) return [...new Array(count)].map((s) => randomFromArray(a));
+  else return randomFromArrayNoRepeat(a, count);
+}
+export function randomFromArrayNoRepeat<T>(
+  a: Array<T>,
+  count: number,
+  acc?: Set<T>,
+): T[] {
+  const all = new Set(a);
+  const st = acc ? acc : new Set<T>();
+  if (all.size === st.size || st.size === count) return [...st];
+  const el = randomFromArray(a);
+  if (!st.has(el)) st.add(el);
+  return randomFromArrayNoRepeat(a, count, st);
 }
+
 export function notRandomFromArray<T>(data: string, a: Array<T>): T {
   const l = a.length;
   const ind = hashTextToNumber(data, l - 1);
-  return a[ind];
+  return a[ind]!;
 }
 
 function hashTextToNumber(text: string, max: number): number {