remove consequtive identical hints #142

client/src/components/hints.tsx

@@ -1,6 +1,7 @@
 import { GameHint } from "./infoview/rpc_api";
 import * as React from 'react';
 import Markdown from './markdown';
+import { ProofStep } from "./infoview/context";
 
 export function Hint({hint, step, selected, toggleSelection, lastLevel} : {hint: GameHint, step: number, selected: number, toggleSelection: any, lastLevel?: boolean}) {
   return <div className={`message information step-${step}` + (step == selected ? ' selected' : '') + (lastLevel ? ' recent' : '')} onClick={toggleSelection}>
@@ -43,3 +44,23 @@ export function DeletedHints({hints} : {hints: GameHint[]}) {
     {hiddenHints.map((hint, i) => <DeletedHint key={`deleted-hidden-hint-${i}`} hint={hint}/>)}
   </>
 }
+
+/** Filter hints to not show consequtive identical hints twice.
+ *
+ * This function takes a `ProofStep[]` and extracts the hints in form of an
+ * element of type `GameHint[][]` where it removes hints that are identical to hints
+ * appearing in the previous step.
+ *
+ * This effectively means we prevent consequtive identical hints from being shown.
+ */
+export function filterHints(proof: ProofStep[]): GameHint[][] {
+  return proof.map((step, i) => {
+    if (i == 0){
+      return step.hints
+    } else {
+      // TODO: Writing all fields explicitely is somewhat fragile to changes, is there a
+      // good way to shallow-compare objects?
+      return step.hints.filter((hint) => proof[i-1].hints.find((x) => (x.text == hint.text && x.hidden == hint.hidden)) === undefined)
+    }
+  })
+}