DynRes/src/main/java/io/gitlab/jfronny/dynres/mixin/ServerPropertiesHandlerMixin.java

package io.gitlab.jfronny.dynres.mixin;

import io.gitlab.jfronny.dynres.Cfg;
import io.gitlab.jfronny.dynres.DynRes;
import io.gitlab.jfronny.libjf.web.api.WebServer;
import io.gitlab.jfronny.libjf.web.impl.util.WebPaths;
import net.minecraft.server.dedicated.ServerPropertiesHandler;
import org.spongepowered.asm.mixin.Final;
import org.spongepowered.asm.mixin.Mixin;
import org.spongepowered.asm.mixin.Mutable;
import org.spongepowered.asm.mixin.Shadow;
import org.spongepowered.asm.mixin.injection.At;
import org.spongepowered.asm.mixin.injection.Inject;
import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;

import java.io.IOException;
import java.nio.file.Files;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

@Mixin(ServerPropertiesHandler.class)
public class ServerPropertiesHandlerMixin {
    @Mutable @Final @Shadow public String resourcePackHash;
    @Mutable @Final @Shadow public String resourcePackSha1;
    @Mutable @Final @Shadow public String resourcePack;

    @Inject(at = @At("RETURN"), method = "<init>(Ljava/util/Properties;)V")
    public void init(CallbackInfo info) {
        if (DynRes.packFile != null) {
            resourcePack = WebPaths.concat(WebServer.getInstance().getServerRoot(), "resources.zip");
            DynRes.LOGGER.info("Pack link: " + resourcePack);
            resourcePackSha1 = "";
            if (Cfg.hashResources) {
                try {
                    StringBuilder result = new StringBuilder();
                    for (byte b : MessageDigest.getInstance("SHA-1").digest(Files.readAllBytes(DynRes.packFile))) {
                        result.append(Integer.toString((b & 0xff) + 0x100, 16).substring(1));
                    }
                    resourcePackSha1 = result.toString();
                    DynRes.LOGGER.info("Set hash to " + resourcePackSha1);
                } catch (IOException | NoSuchAlgorithmException e) {
                    DynRes.LOGGER.error("Failed to get hash, continuing with empty", e);
                }
            }
            resourcePackHash = resourcePackSha1;
        }
    }
}