Added fetchCommand utility

Implemented fetchCommand method to map command input to
available commands. Includes distance threshhold

commands.js

@@ -31,4 +31,43 @@ function getEditDistance(sourceString, targetString) {
     return matrix[targetString.length][sourceString.length];
 }
 
-//console.log(getEditDistance("saturday", "sunday")); //sollte 3 ergeben
+function fetchCommand(input, commands, threshhold){
+    let candidates = {};
+    let bestDistance = null;
+    for(let key in commands){
+        let distance = getEditDistance(input, key);
+        console.log("new it. key: "+key+" dist:"+distance);
+        if(distance >= threshhold) continue;
+        if(bestDistance === distance){ //another candidate
+            candidates[candidates.length] = key;
+            console.log("other candidate");
+        }
+        else if(bestDistance > distance || bestDistance === null){ //new best candidate
+            candidates = [key];
+            bestDistance = distance;
+            console.log("new best candidate");
+        }
+    }
+    return candidates;
+}
+
+/* //Test code
+const commands = {};
+commands['homeserver'] = {};
+commands['homeserver']['register'] = {};
+commands['homeserver']['register'].regex = /([a-zA-Z0-9])/;
+commands['homeserver']['register'].usage = '<user localpart>';
+commands['homeserver']['register'].exec = (args) => {
+    //args is a <user input args string>.match with .regex
+};
+
+commands['imninja'] = {};
+commands['imninja']['register'] = {};
+commands['imninja']['register'].regex = /([a-zA-Z0-9])/;
+commands['imninja']['register'].usage = '<user localpart>';
+commands['imninja']['register'].exec = (args) => {
+    //args is a <user input args string>.match with .regex
+};
+console.log(fetchCommand("inminja", commands)); // -> imninja
+console.log(fetchCommand("34C21", commands, 4)); // -> {}*/
+//console.log(getEditDistance("saturday", "sunday")); //should be 3