Image Repo Loader

1 files changed, 144 insertions, 0 deletions

diff --git a/src/main/java/de/hysky/skyblocker/config/ImageRepoLoader.java b/src/main/java/de/hysky/skyblocker/config/ImageRepoLoader.java
new file mode 100644
index 00000000..0591cd96
--- /dev/null
+++ b/src/main/java/de/hysky/skyblocker/config/ImageRepoLoader.java
@@ -0,0 +1,144 @@
+package de.hysky.skyblocker.config;
+
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
+import java.util.concurrent.CompletableFuture;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
+
+import org.slf4j.Logger;
+
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
+import com.mojang.logging.LogUtils;
+import com.mojang.serialization.Codec;
+import com.mojang.serialization.JsonOps;
+import com.mojang.serialization.codecs.RecordCodecBuilder;
+
+import de.hysky.skyblocker.SkyblockerMod;
+import de.hysky.skyblocker.utils.FileUtils;
+import de.hysky.skyblocker.utils.Http;
+
+public class ImageRepoLoader {
+	private static final Logger LOGGER = LogUtils.getLogger();
+	static final Path REPO_DIRECTORY = SkyblockerMod.CONFIG_DIR.resolve("image-repo");
+	private static final String BRANCH_INFO = "https://api.github.com/repos/SkyblockerMod/Skyblocker-Assets/branches/images";
+	private static final String REPO_DOWNLOAD = "https://github.com/SkyblockerMod/Skyblocker-Assets/archive/refs/heads/images.zip";
+	private static final String PLACEHOLDER_HASH = "None!";
+
+	public static void init() {
+		update(0);
+	}
+
+	/**
+	 * Attempts to update/load the image repository, if any errors are encountered it will try 3 times.
+	 */
+	private static void update(int retries) {
+		CompletableFuture.runAsync(() -> {
+			if (retries < 3) {
+				try {
+					long start = System.currentTimeMillis();
+					//Retrieve the saved commit hash
+					String savedCommitHash = checkSavedCommitData();
+
+					//Fetch the latest commit data
+					JsonObject response = JsonParser.parseString(Http.sendGetRequest(BRANCH_INFO)).getAsJsonObject();
+					String latestCommitHash = response.getAsJsonObject("commit").get("sha").getAsString();
+
+					//Download the repository if there was a new commit
+					if (!savedCommitHash.equals(latestCommitHash)) {
+						InputStream in = Http.downloadContent(REPO_DOWNLOAD);
+
+						//Delete all directories to clear potentially now unused/old files
+						//TODO change this to only delete periodically?
+						deleteDirectories();
+
+						try (ZipInputStream zis = new ZipInputStream(in)) {
+							ZipEntry entry;
+
+							while ((entry = zis.getNextEntry()) != null) {
+								Path outputFile = REPO_DIRECTORY.resolve(entry.getName());
+
+								if (entry.isDirectory()) {
+									Files.createDirectories(outputFile);
+								} else {
+									Files.createDirectories(outputFile.getParent());
+									Files.copy(zis, outputFile, StandardCopyOption.REPLACE_EXISTING);
+								}
+							}
+						}
+
+						writeCommitData(latestCommitHash);
+
+						long end = System.currentTimeMillis();
+						LOGGER.info("[Skyblocker] Successfully updated the Image Respository in {} ms! {} → {}", end - start, savedCommitHash, latestCommitHash);
+					} else {
+						LOGGER.info("[Skyblocker] The Image Respository is up to date!");
+					}
+				} catch (Exception e) {
+					LOGGER.error("[Skyblocker] Error while downloading image repo on attempt {}!", retries, e);
+					update(retries + 1);
+				}
+			}
+		});
+	}
+
+	/**
+	 * @return The stored hash or the {@link #PLACEHOLDER_HASH}.
+	 */
+	private static String checkSavedCommitData() throws IOException {
+		Path file = REPO_DIRECTORY.resolve("image_repo.json");
+
+		if (Files.exists(file)) {
+			try (BufferedReader reader = Files.newBufferedReader(file)) {
+				CommitData commitData = CommitData.CODEC.parse(JsonOps.INSTANCE, JsonParser.parseReader(reader)).result().orElseThrow();
+
+				return commitData.commit();
+			}
+		}
+
+		return PLACEHOLDER_HASH;
+	}
+
+	/**
+	 * Writes the {@code newHash} into a file to be used to check for repo updates.
+	 * 
+	 * @implNote Checking whether the directory exists or not isn't needed as this is called after all files are written successfully.
+	 */
+	private static void writeCommitData(String newHash) throws IOException {
+		Path file = REPO_DIRECTORY.resolve("image_repo.json");
+		CommitData commitData = new CommitData(newHash, System.currentTimeMillis());
+
+		try (BufferedWriter writer = Files.newBufferedWriter(file)) {
+			SkyblockerMod.GSON.toJson(CommitData.CODEC.encodeStart(JsonOps.INSTANCE, commitData).result().orElseThrow(), writer);
+		}
+	}
+
+	/**
+	 * Deletes all directories (not files) inside of the {@link #REPO_DIRECTORY}
+	 * @throws IOException 
+	 */
+	private static void deleteDirectories() throws IOException {
+		Files.list(REPO_DIRECTORY)
+				.filter(Files::isDirectory)
+				.forEach(dir -> {
+					try {
+						FileUtils.recursiveDelete(dir);
+					} catch (Exception e) {
+						LOGGER.error("[Skyblocker] Encountered an exception while deleting a directory! Path: {}", dir.toAbsolutePath(), e);
+					}
+				});
+	}
+
+	record CommitData(String commit, long lastUpdated) {
+		static final Codec<CommitData> CODEC = RecordCodecBuilder.create(instance -> instance.group(
+				Codec.STRING.fieldOf("commit").forGetter(CommitData::commit),
+				Codec.LONG.fieldOf("lastUpdated").forGetter(CommitData::lastUpdated))
+				.apply(instance, CommitData::new));		
+	}
+}