implement cactus kev's poker hand evaluator

.gitignore

@@ -1,2 +1,3 @@
 node_modules
 config.json
+data/HandRanks.dat

package-lock.json

@@ -7,6 +7,9 @@
     "": {
       "name": "schmirc",
       "version": "1.0.0",
+      "cpu": [
+        "x64"
+      ],
       "license": "ISC",
       "dependencies": {
         "@xpressit/winning-poker-hand-rank": "^0.1.6",

package.json

@@ -2,9 +2,13 @@
   "name": "schmirc",
   "version": "1.0.0",
   "description": "",
-  "main": "index.js",
+  "main": "index.mjs",
+  "cpu": [
+    "x64"
+  ],
   "scripts": {
-    "start": "node ./src/index.mjs"
+    "start": "node ./src/index.mjs",
+    "build": "cd ./data && ./generate_table"
   },
   "author": "Flummi",
   "license": "ISC",

src/inc/handranker.mjs

@@ -1,6 +1,44 @@
-export default new class handranker {
-  constructor() {
-    return this;
-  };
+import fs from 'node:fs';
 
+export default new class handranker {
+  #ranks;
+
+  constructor() {
+    this.#ranks = fs.readFileSync('./data/HandRanks.dat');
+
+    this.handtypes = [
+      "InvalidHand", "HighCard", "Pair",
+      "TwoPairs", "ThreeOfAKind", "Straight",
+      "Flush", "FullHouse", "FourOfAKind",
+      "StraightFlush"
+    ];
+
+    this.cards = [''];
+    for(const cv of [..."23456789TJQKA"])
+      for(const cs of [..."CDHS"])
+        this.cards.push(cv + cs);
+  };
+  evalHand(cards) {
+    if(!this.#ranks)
+      throw new Error("HandRanks.dat not loaded, run 'npm run build' first!");
+
+    if(![7,6,5,3].includes(cards.length))
+      throw new Error("Hand must be 3, 5, 6, or 7 cards");
+
+    cards = cards.map(c => this.cards.indexOf(c));
+
+    let p = 53;
+    for(let i = 0; i < cards.length; i++)
+      p = this.#ranks.readUInt32LE((p + cards[i]) * 4);
+
+    if(cards.length == 5 || cards.length == 6)
+      p = this.#ranks.readUInt32LE(p * 4);
+
+    return {
+      handType: p >> 12,
+      handRank: p & 0x00000fff,
+      value: p,
+      handName: this.handtypes[p >> 12]
+    };
+  };
 };