Initial work on reputation nft

forum-network/src/classes/reputation-token.js

@@ -0,0 +1,28 @@
+import { ERC721 } from './erc721.js';
+import { CryptoUtil } from './crypto.js';
+
+export class ReputationToken extends ERC721 {
+  constructor() {
+    super('Reputation', 'REP');
+    this.histories = new Map(); // token id --> {increment, context (i.e. validation pool id)}
+    this.values = new Map(); // token id --> current value
+  }
+
+  mint(to, value, context) {
+    const tokenId = CryptoUtil.randomUUID();
+    super.mint(to, tokenId);
+    this.values.set(tokenId, value);
+    this.histories.set(tokenId, [{ increment: value, context }]);
+  }
+
+  incrementValue(tokenId, increment, context) {
+    const value = this.values.get(tokenId);
+    const newValue = value + increment;
+    const history = this.histories.get(tokenId);
+    if (newValue < 0) {
+      throw new Error('Token value can not become negative');
+    }
+    this.values.set(tokenId, newValue);
+    history.push({ increment, context });
+  }
+}