Add auto-updating support for Steam Workshop mods

src/main/java/com/osiris/autoplug/client/configs/ModsConfig.java

@@ -44,6 +44,7 @@ public ModsConfig() throws IOException, DuplicateKeyException, YamlReaderExcepti
                         "If there are mods that weren't found by the search-algorithm, you can add an id (spigot or bukkit) and a custom link (optional & must be a static link to the latest mod jar).\n" +
                         "modrinth-id: Is the 'Project-ID' and can be found on the mods modrinth site inside of the 'About' box, under 'Technical Information' at the bottom left.\n" +
                         "curseforge-id: Is also called 'Project-ID' and can be found on the mods curseforge site inside of the 'About' box at the right.\n" +
+                        "steam-workshop-id: The Steam Workshop item id read from the mods metadata. Requires server-updater.software to be a numeric Steam app-id.\n" +
                         "ignore-content-type: If true, does not check if the downloaded file is of type jar or zip, and downloads it anyway.\n" +
                         "force-latest: If true, does not search for updates compatible with this Minecraft version and simply picks the latest release.\n" +
                         "force-update: If true, downloads the update every time even if its already on the latest version.\n" +

src/main/java/com/osiris/autoplug/client/configs/UpdaterConfig.java

@@ -223,7 +223,9 @@ public UpdaterConfig() throws IOException, DuplicateKeyException, YamlReaderExce
                 "Updates your mods and the results are sent to AutoPlug-Web. You can configure this in the web-config.",
                 "Note that there is a web-cool-down (that cannot be changed) of a few hours, to prevent spamming of results to AutoPlug-Web.");
         mods_updater_profile = put(name, "mods-updater", "profile").setDefValues("AUTOMATIC");
-        mods_updater_path = put(name, "mods-updater", "path").setDefValues("./mods");
+        mods_updater_path = put(name, "mods-updater", "path").setDefValues("./mods").setComments(
+                "Path to your mods folder.",
+                "Steam Workshop mods with supported metadata (meta.cpp) can be updated through SteamCMD when server-updater.software is set to a numeric Steam app-id.");
         mods_updater_version = put(name, "mods-updater", "version").setComments("The Minecraft version to check and download mods for.",
                 "If left empty, taken from server-updater.version above, if also empty, taken from general.yml, if also empty, taken from server jar.");
         mods_updater_async = put(name, "mods-updater", "async").setDefValues("true").setComments(

src/main/java/com/osiris/autoplug/client/tasks/updater/mods/ModDownloadTask.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2024 Osiris-Team.
+ * All rights reserved.
+ *
+ * This software is copyrighted work, licensed under the terms
+ * of the MIT-License. Consult the "LICENSE" file for details.
+ */
+
+package com.osiris.autoplug.client.tasks.updater.mods;
+
+import com.osiris.autoplug.client.tasks.updater.search.SearchResult;
+
+interface ModDownloadTask {
+    void start();
+
+    boolean isAlive();
+
+    String getPlName();
+
+    SearchResult getSearchResult();
+
+    boolean isDownloadSuccessful();
+
+    boolean isInstallSuccessful();
+}

src/main/java/com/osiris/autoplug/client/tasks/updater/mods/SteamWorkshopMod.java

@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2024 Osiris-Team.
+ * All rights reserved.
+ *
+ * This software is copyrighted work, licensed under the terms
+ * of the MIT-License. Consult the "LICENSE" file for details.
+ */
+
+package com.osiris.autoplug.client.tasks.updater.mods;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.List;
+
+/**
+ * A Steam Workshop mod living in its own directory inside the mods folder.
+ * It is identified by the {@code publishedid} inside its {@code meta.cpp} file.
+ * The mod's version is the {@code timestamp} from that file (when present) or
+ * the {@code time_updated} value returned by the Steam Web API after the first
+ * update check. Note that the version is intentionally left empty when the
+ * meta.cpp provides no timestamp, so the first update check always runs.
+ */
+public class SteamWorkshopMod extends MinecraftMod {
+    private final File directory;
+    private String publishedId;
+    private final String timestamp;
+
+    public SteamWorkshopMod(File directory, String name, String publishedId) {
+        this(directory, name, publishedId, null);
+    }
+
+    public SteamWorkshopMod(File directory, String name, String publishedId, String timestamp) {
+        super(directory.getAbsolutePath(), name, timestamp, "Steam Workshop", null, null, null);
+        this.directory = directory;
+        this.publishedId = publishedId;
+        this.timestamp = timestamp;
+    }
+
+    public File getDirectory() {
+        return directory;
+    }
+
+    public String getPublishedId() {
+        return publishedId;
+    }
+
+    public void setPublishedId(String publishedId) {
+        this.publishedId = publishedId;
+    }
+
+    public String getTimestamp() {
+        return timestamp;
+    }
+
+    @NotNull
+    public static List<SteamWorkshopMod> findIn(File dir) throws IOException {
+        if (!dir.exists()) throw new FileNotFoundException("Directory does not exist: " + dir);
+        List<SteamWorkshopMod> mods = new ArrayList<>();
+        File[] files = dir.listFiles();
+        if (files == null) return mods;
+        Arrays.sort(files, Comparator.comparing(File::getName));
+        for (File file : files) {
+            if (!file.isDirectory()) continue;
+            File metaFile = new File(file, "meta.cpp");
+            if (metaFile.exists())
+                mods.add(readFromMeta(file, metaFile));
+        }
+        return mods;
+    }
+
+    static SteamWorkshopMod readFromMeta(File modDir, File metaFile) throws IOException {
+        String name = modDir.getName();
+        String publishedId = null;
+        String timestamp = null;
+        for (String line : Files.readAllLines(metaFile.toPath(), StandardCharsets.UTF_8)) {
+            String trimmedLine = line.trim();
+            if (trimmedLine.isEmpty() || trimmedLine.startsWith("//")) continue;
+
+            int equalsIndex = trimmedLine.indexOf('=');
+            if (equalsIndex < 0) continue;
+
+            String key = trimmedLine.substring(0, equalsIndex).trim();
+            String value = trimmedLine.substring(equalsIndex + 1).trim();
+            int semicolonIndex = value.indexOf(';');
+            if (semicolonIndex < 0) continue;
+            value = value.substring(0, semicolonIndex).trim();
+            if (value.startsWith("\"") && value.endsWith("\"") && value.length() >= 2)
+                value = value.substring(1, value.length() - 1);
+
+            if (key.equals("name")) name = value;
+            if (key.equals("publishedid")) publishedId = value;
+            if (key.equals("timestamp")) timestamp = value;
+        }
+
+        if (publishedId == null || !publishedId.matches("\\d+"))
+            throw new IOException("Failed to read publishedid from " + metaFile);
+
+        return new SteamWorkshopMod(modDir, name, publishedId, timestamp);
+    }
+}

src/main/java/com/osiris/autoplug/client/tasks/updater/mods/SteamWorkshopUpdateFinder.java

@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2024 Osiris-Team.
+ * All rights reserved.
+ *
+ * This software is copyrighted work, licensed under the terms
+ * of the MIT-License. Consult the "LICENSE" file for details.
+ */
+
+package com.osiris.autoplug.client.tasks.updater.mods;
+
+import com.osiris.autoplug.client.configs.UpdaterConfig;
+import com.osiris.autoplug.client.tasks.updater.search.SearchResult;
+import com.osiris.autoplug.client.utils.SteamCMD;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Finds updates for Steam Workshop mods via the Steam Web API, similar to how
+ * {@link com.osiris.autoplug.client.tasks.updater.plugins.ResourceFinder}
+ * finds updates for regular mods. Only reports an update when the Workshop
+ * item was actually updated after the currently cached version, so mods are
+ * not re-downloaded on every run.
+ */
+public class SteamWorkshopUpdateFinder {
+    private final UpdaterConfig updaterConfig;
+    private final SteamCMD steamCMD;
+
+    public SteamWorkshopUpdateFinder(UpdaterConfig updaterConfig, SteamCMD steamCMD) {
+        this.updaterConfig = updaterConfig;
+        this.steamCMD = steamCMD;
+    }
+
+    public SearchResult find(@NotNull SteamWorkshopMod mod) {
+        SearchResult result = new SearchResult(null, SearchResult.Type.UP_TO_DATE, mod.getVersion(), null, "steam-workshop", null, null, false);
+        result.mod = mod;
+        String workshopAppId = getWorkshopAppId();
+        if (workshopAppId == null) {
+            result.type = SearchResult.Type.API_ERROR;
+            result.setException(new Exception("Steam Workshop mod '" + mod.getName() + "' was found, but server-updater.software is not a numeric Steam app-id."));
+            return result;
+        }
+
+        try {
+            SteamCMD.SteamWorkshopItemDetails details = steamCMD.getWorkshopItemDetails(mod.getPublishedId());
+            result.latestVersion = details.getTimeUpdated();
+            result.downloadUrl = details.getFileUrl();
+            if (hasUpdate(mod, details.getTimeUpdated()))
+                result.type = SearchResult.Type.UPDATE_AVAILABLE;
+        } catch (Exception e) {
+            result.type = SearchResult.Type.API_ERROR;
+            result.setException(e);
+        }
+        return result;
+    }
+
+    /**
+     * Returns the Steam app-id configured in server-updater.software,
+     * or null when it is not a numeric Steam app-id (e.g. "paper").
+     */
+    public String getWorkshopAppId() {
+        String workshopAppId = updaterConfig.server_software.asString();
+        if (workshopAppId == null || !workshopAppId.matches("\\d+"))
+            return null;
+        return workshopAppId;
+    }
+
+    /**
+     * Compares the cached version with the time_updated value of the Workshop item.
+     * A missing cached version means the mod was never update-checked before.
+     */
+    boolean hasUpdate(SteamWorkshopMod mod, String latestTimeUpdated) {
+        if (latestTimeUpdated == null || latestTimeUpdated.isEmpty())
+            return false;
+        String currentVersion = mod.getVersion();
+        if (currentVersion == null || currentVersion.isEmpty())
+            return true;
+        if (latestTimeUpdated.equals(currentVersion))
+            return false;
+        try {
+            return Long.parseLong(latestTimeUpdated) > Long.parseLong(currentVersion);
+        } catch (NumberFormatException e) {
+            // Versions are not numerically comparable (e.g. a meta.cpp FILETIME
+            // timestamp vs the unix time_updated from Steam). Assume an update.
+            return true;
+        }
+    }
+}

src/main/java/com/osiris/autoplug/client/tasks/updater/mods/TaskModDownload.java

@@ -25,7 +25,7 @@
 import java.io.FileOutputStream;
 
 
-public class TaskModDownload extends BThread {
+public class TaskModDownload extends BThread implements ModDownloadTask {
     private final String plName;
     private final String plLatestVersion;
     private final String url;
@@ -207,6 +207,10 @@ public File getDownloadDest() {
         return dest;
     }
 
+    public SearchResult getSearchResult() {
+        return searchResult;
+    }
+
     public boolean isDownloadSuccessful() {
         return isDownloadSuccessful;
     }