feat: replay archived games, gamestate hash verification (#195)

create endpoint to load archived game. when joining game client first
checks if the game is active, if not it requests the game archive from
the server. the archive is sent to LocalServer to replay the game
locally. Every 10 ticks a hash is stored on the archive, and during
replay the LocalServer verifies this hash.

src/server/GameServer.ts

@@ -14,7 +14,7 @@ import {
   ServerTurnMessageSchema,
   Turn,
 } from "../core/Schemas";
-import { CreateGameRecord } from "../core/Util";
+import { createGameRecord } from "../core/Util";
 import { ServerConfig } from "../core/configuration/Config";
 import { GameType } from "../core/game/Game";
 import { archive } from "./Archive";
@@ -161,7 +161,7 @@ export class GameServer {
             client.lastPing = Date.now();
           }
           if (clientMsg.type == "hash") {
-            client.hashes.set(clientMsg.tick, clientMsg.hash);
+            client.hashes.set(clientMsg.turnNumber, clientMsg.hash);
           }
           if (clientMsg.type == "winner") {
             this.winner = clientMsg.winner;
@@ -238,7 +238,12 @@ export class GameServer {
         ),
       );
     } catch (error) {
-      throw new Error(`error sending start message for game ${this.id}`);
+      throw new Error(
+        `error sending start message for game ${this.id}, ${error}`.substring(
+          0,
+          250,
+        ),
+      );
     }
   }
 
@@ -251,7 +256,7 @@ export class GameServer {
     this.turns.push(pastTurn);
     this.intents = [];
 
-    this.maybeSendDesync();
+    this.handleSynchronization();
 
     let msg = "";
     try {
@@ -262,7 +267,12 @@ export class GameServer {
         }),
       );
     } catch (error) {
-      console.log(`error sending message for game ${this.id}`);
+      console.log(
+        `error sending message for game ${this.id}, error ${error}`.substring(
+          0,
+          250,
+        ),
+      );
       return;
     }
 
@@ -294,7 +304,7 @@ export class GameServer {
           persistentID: client.persistentID,
         }));
         archive(
-          CreateGameRecord(
+          createGameRecord(
             this.id,
             this.gameConfig,
             playerRecords,
@@ -405,8 +415,8 @@ export class GameServer {
     return this.gameConfig.gameType == GameType.Public;
   }
 
-  private maybeSendDesync() {
-    if (this.activeClients.length <= 1) {
+  private handleSynchronization() {
+    if (this.activeClients.length < 1) {
       return;
     }
     if (this.turns.length % 10 == 0 && this.turns.length != 0) {
@@ -415,7 +425,12 @@ export class GameServer {
       let { mostCommonHash, outOfSyncClients } =
         this.findOutOfSyncClients(lastHashTurn);
 
+      if (outOfSyncClients.length == 0) {
+        this.turns[lastHashTurn].hash = mostCommonHash;
+      }
+
       if (
+        outOfSyncClients.length > 0 &&
         outOfSyncClients.length >= Math.floor(this.activeClients.length / 2)
       ) {
         // If half clients out of sync assume all are out of sync.
@@ -430,8 +445,6 @@ export class GameServer {
           this.outOfSyncClients.add(oos.clientID);
         }
       }
-      return;
-      // TODO: renable this once desync issue fixed
 
       const serverDesync = ServerDesyncSchema.safeParse({
         type: "desync",
@@ -465,6 +478,7 @@ export class GameServer {
     for (const client of this.activeClients) {
       if (client.hashes.has(turnNumber)) {
         const clientHash = client.hashes.get(turnNumber)!;
+        console.log(`clientHash: ${clientHash}`);
         counts.set(clientHash, (counts.get(clientHash) || 0) + 1);
       }
     }