From 1e313915ce9426fc76f0b4025b2217ead30a6d7f Mon Sep 17 00:00:00 2001
From: Alexander Polynomdivision <digitalmail555@googlemail.com>
Date: Fri, 14 Sep 2018 17:02:50 +0200
Subject: [PATCH] feat: Implement the Lev. Distance into the review

---
 src/config.ts        |  2 ++
 src/pages/review.tsx | 17 ++++++++++++-----
 2 files changed, 14 insertions(+), 5 deletions(-)
 create mode 100644 src/config.ts

diff --git a/src/config.ts b/src/config.ts
new file mode 100644
index 0000000..0170d89
--- /dev/null
+++ b/src/config.ts
@@ -0,0 +1,2 @@
+// Maximum distance from the answer to be still considered correct
+export const LEVENSHTEIN_MAX_DISTANCE = 2;
diff --git a/src/pages/review.tsx b/src/pages/review.tsx
index 633f745..ca49de1 100644
--- a/src/pages/review.tsx
+++ b/src/pages/review.tsx
@@ -13,6 +13,9 @@ import { Redirect } from "react-router-dom";
 
 import { IVocab, ReviewMode, VocabType } from "../models/vocab";
 
+import { levW } from "../algorithms/levenshtein";
+import { LEVENSHTEIN_MAX_DISTANCE } from "../config";
+
 interface IProps {
     levelId: number;
     vocabByLevel: (level: number) => IVocab[];
@@ -60,13 +63,14 @@ export default class ReviewPage extends React.Component<IProps, IState> {
         const current = this.currentVocab();
 
         // Check if the given answer is somewhere in the german words
-        const german = this.currentVocab().german.map((str) => str.toLowerCase());
-        const found = german.find((el) => el === this.state.input.toLowerCase());
+        const { input } = this.state;
+        const german = current.german.map((str) => str.toLowerCase());
+        const dists = german.map((ger) => levW(input.toLowerCase(), ger));
+        const minDist = Math.min(...dists);
 
         // Check if the user's answer was correct
-        // TODO: Levensthein-Distance?
-        if (found) {
-            // TODO: Show it's correct
+        if (minDist === 0) {
+            // TODO: Show it's correct?
             // Show the next vocab word
             if (this.state.current + 1 >= this.vocab.length) {
                 // TODO: Set some data that the summary screen will show
@@ -80,6 +84,9 @@ export default class ReviewPage extends React.Component<IProps, IState> {
                     input: "",
                 });
             }
+        } else if (minDist <= LEVENSHTEIN_MAX_DISTANCE) {
+            // TODO: Show a hint
+            console.log("Partially correct");
         } else {
             this.setState({
                 popoverOpen: true,