83 lines
2.5 KiB
Java
83 lines
2.5 KiB
Java
package wtf.beatrice.hidekobot.util;
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import org.random.util.RandomOrgRandom;
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import wtf.beatrice.hidekobot.Cache;
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import wtf.beatrice.hidekobot.datasources.ConfigurationEntry;
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import java.security.SecureRandom;
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import java.util.Random;
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public class RandomUtil
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{
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private RandomUtil() {
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throw new IllegalStateException("Utility class");
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}
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// the Random instance that we should always use when looking for an RNG based thing.
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// the seed is updated periodically, if the random.org integration is enabled.
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private static Random randomInstance = new SecureRandom();
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/**
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* Returns a random integer picked in a range.
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*
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* @param min the minimum value (inclusive)
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* @param max the maximum value (inclusive)
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* @return a random number in range [min; max]
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*/
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public static int getRandomNumber(int min, int max)
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{
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if(min == max) return min; // dumbass
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if(min > max) // swap em
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{
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min = min - max;
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max = min + max;
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min = max - min;
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}
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// find our range of randomness (eg. 5 -> 8 = 4), add +1 since we want to be inclusive at both sides
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int difference = (max - min) + 1;
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// find a number between 0 and our range (eg. 5 -> 8 = 0 -> 3)
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int randomTemp = getRandom().nextInt(difference);
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// add the minimum value, so we are sure to be in the original range (0->5, 1->6, 2->7, 3->8)
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return randomTemp + min;
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}
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public static Random getRandom() {
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return randomInstance;
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}
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public static void initRandomOrg()
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{
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/* we use the random.org instance to generate 160 random bytes.
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then, we're feeding those 160 bytes as a seed for a SecureRandom.
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this is preferred to calling the RandomOrgRandom directly every time,
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because it has to query the api and (1) takes a long time, especially with big
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dice rolls, and (2) you'd run in the limits extremely quickly if the bot
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was run publicly for everyone to use.
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*/
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String apiKey = Cache.getRandomOrgApiKey();
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RandomOrgRandom randomOrg = new RandomOrgRandom(apiKey);
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byte[] randomBytes = new byte[160];
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randomOrg.nextBytes(randomBytes);
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randomInstance = new SecureRandom(randomBytes);
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}
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public static boolean isRandomOrgKeyValid()
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{
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String apiKey = Cache.getRandomOrgApiKey();
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return apiKey != null &&
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!apiKey.isEmpty() &&
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!apiKey.equals(ConfigurationEntry.RANDOM_ORG_API_KEY.getDefaultValue());
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}
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}
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