From ba64c020496159d3c66068ccd5de72672463fb33 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Beatrice=20Dellac=C3=A0?= <hello@beatrice.wtf>
Date: Tue, 20 Dec 2022 22:15:52 +0100
Subject: [PATCH] Increase randomness by updating the random's seed every
 minute

---
 src/main/java/wtf/beatrice/hidekobot/Cache.java     | 13 +++++++++++++
 src/main/java/wtf/beatrice/hidekobot/HidekoBot.java |  3 +++
 .../hidekobot/runnables/RandomSeedTask.java         | 12 ++++++++++++
 .../wtf/beatrice/hidekobot/util/RandomUtil.java     |  7 +++----
 4 files changed, 31 insertions(+), 4 deletions(-)
 create mode 100644 src/main/java/wtf/beatrice/hidekobot/runnables/RandomSeedTask.java

diff --git a/src/main/java/wtf/beatrice/hidekobot/Cache.java b/src/main/java/wtf/beatrice/hidekobot/Cache.java
index e41476b..97016b0 100644
--- a/src/main/java/wtf/beatrice/hidekobot/Cache.java
+++ b/src/main/java/wtf/beatrice/hidekobot/Cache.java
@@ -14,6 +14,7 @@ import wtf.beatrice.hidekobot.util.Logger;
 import java.awt.*;
 import java.lang.reflect.Field;
 import java.time.LocalDateTime;
+import java.util.Random;
 
 public class Cache
 {
@@ -23,6 +24,10 @@ public class Cache
     private static final String botPrefix = "hideko";
     private static final Logger logger = new Logger(Cache.class);
 
+    // the Random instance that we should always use when looking for an RNG based thing.
+    // the seed is updated periodically.
+    private static final Random randomInstance = new Random();
+
     private static PropertiesSource propertiesSource = null;
     private static ConfigurationSource configurationSource = null;
     private static DatabaseSource databaseSource = null;
@@ -60,6 +65,14 @@ public class Cache
      */
     public static int[] getSupportedAvatarResolutions() { return supportedAvatarResolutions; }
 
+    public static Random getRandom() {
+        return randomInstance;
+    }
+
+    public static void setRandomSeed(long seed) {
+        randomInstance.setSeed(seed);
+    }
+
     /**
      * Checks if the bot has been started with the verbose argument.
      *
diff --git a/src/main/java/wtf/beatrice/hidekobot/HidekoBot.java b/src/main/java/wtf/beatrice/hidekobot/HidekoBot.java
index a4ad60d..527abed 100644
--- a/src/main/java/wtf/beatrice/hidekobot/HidekoBot.java
+++ b/src/main/java/wtf/beatrice/hidekobot/HidekoBot.java
@@ -18,6 +18,7 @@ import wtf.beatrice.hidekobot.listeners.SlashCommandCompletionListener;
 import wtf.beatrice.hidekobot.listeners.SlashCommandListener;
 import wtf.beatrice.hidekobot.runnables.ExpiredMessageTask;
 import wtf.beatrice.hidekobot.runnables.HeartBeatTask;
+import wtf.beatrice.hidekobot.runnables.RandomSeedTask;
 import wtf.beatrice.hidekobot.runnables.StatusUpdateTask;
 import wtf.beatrice.hidekobot.util.CommandUtil;
 import wtf.beatrice.hidekobot.util.Logger;
@@ -184,6 +185,8 @@ public class HidekoBot
         scheduler.scheduleAtFixedRate(heartBeatTask, 10, 30, TimeUnit.SECONDS); //every 30 seconds
         StatusUpdateTask statusUpdateTask = new StatusUpdateTask();
         scheduler.scheduleAtFixedRate(statusUpdateTask, 0, 60 * 5, TimeUnit.SECONDS); // every 5 minutes
+        RandomSeedTask randomSeedTask = new RandomSeedTask();
+        scheduler.scheduleAtFixedRate(randomSeedTask, 0, 60, TimeUnit.SECONDS); // every minute
 
         // register shutdown interrupt signal listener for proper shutdown.
         Signal.handle(new Signal("INT"), signal -> shutdown());
diff --git a/src/main/java/wtf/beatrice/hidekobot/runnables/RandomSeedTask.java b/src/main/java/wtf/beatrice/hidekobot/runnables/RandomSeedTask.java
new file mode 100644
index 0000000..f4623a0
--- /dev/null
+++ b/src/main/java/wtf/beatrice/hidekobot/runnables/RandomSeedTask.java
@@ -0,0 +1,12 @@
+package wtf.beatrice.hidekobot.runnables;
+
+import wtf.beatrice.hidekobot.Cache;
+
+public class RandomSeedTask implements Runnable
+{
+
+    @Override
+    public void run() {
+        Cache.setRandomSeed(System.currentTimeMillis());
+    }
+}
diff --git a/src/main/java/wtf/beatrice/hidekobot/util/RandomUtil.java b/src/main/java/wtf/beatrice/hidekobot/util/RandomUtil.java
index f9dec08..e3a8779 100644
--- a/src/main/java/wtf/beatrice/hidekobot/util/RandomUtil.java
+++ b/src/main/java/wtf/beatrice/hidekobot/util/RandomUtil.java
@@ -1,12 +1,11 @@
 package wtf.beatrice.hidekobot.util;
 
+import wtf.beatrice.hidekobot.Cache;
+
 import java.util.Random;
 
 public class RandomUtil
 {
-    private static final Random random = new Random();
-
-
     /**
      * Returns a random integer picked in a range.
      *
@@ -29,7 +28,7 @@ public class RandomUtil
         int difference = (max - min) + 1;
 
         // find a number between 0 and our range (eg. 5 -> 8 = 0 -> 3)
-        int randomTemp = random.nextInt(difference);
+        int randomTemp = Cache.getRandom().nextInt(difference);
 
         // add the minimum value, so we are sure to be in the original range (0->5, 1->6, 2->7, 3->8)
         return randomTemp + min;