Avoid trying to download things offline (#87)

src/main/java/net/fabricmc/loom/providers/MinecraftAssetsProvider.java

@@ -33,23 +33,22 @@ import net.fabricmc.loom.util.MinecraftVersionInfo;
 import net.fabricmc.loom.util.assets.AssetIndex;
 import net.fabricmc.loom.util.assets.AssetObject;
 import net.fabricmc.loom.util.progress.ProgressLogger;
+
+import org.gradle.api.GradleException;
 import org.gradle.api.Project;
 
 import java.io.File;
 import java.io.FileReader;
 import java.io.IOException;
-import java.lang.ref.SoftReference;
 import java.net.URL;
-import java.util.Collection;
-import java.util.Date;
-import java.util.HashSet;
 import java.util.Map;
 
 public class MinecraftAssetsProvider {
 	public static void provide(MinecraftProvider minecraftProvider, Project project) throws IOException {
 		LoomGradleExtension extension = project.getExtensions().getByType(LoomGradleExtension.class);
-		MinecraftVersionInfo versionInfo = minecraftProvider.versionInfo;
+		boolean offline = project.getGradle().getStartParameter().isOffline();
 
+		MinecraftVersionInfo versionInfo = minecraftProvider.versionInfo;
 		MinecraftVersionInfo.AssetIndex assetIndex = versionInfo.assetIndex;
 
 		// get existing cache files
@@ -61,8 +60,18 @@ public class MinecraftAssetsProvider {
 		File assetsInfo = new File(assets, "indexes" + File.separator + assetIndex.getFabricId(minecraftProvider.minecraftVersion) + ".json");
 		if (!assetsInfo.exists() || !Checksum.equals(assetsInfo, assetIndex.sha1)) {
 			project.getLogger().lifecycle(":downloading asset index");
+			if (offline) {
+				if (assetsInfo.exists()) {
+					//We know it's outdated but can't do anything about it, oh well
+					project.getLogger().warn("Asset index outdated");
+				} else {
+					//We don't know what assets we need, just that we don't have any
+					throw new GradleException("Asset index not found at " + assetsInfo.getAbsolutePath());
+				}
+			} else {
 				DownloadUtil.downloadIfChanged(new URL(assetIndex.url), assetsInfo, project.getLogger());
 			}
+		}
 
 		ProgressLogger progressLogger = ProgressLogger.getProgressFactory(project, MinecraftAssetsProvider.class.getName());
 		progressLogger.start("Downloading assets...", "assets");
@@ -81,9 +90,17 @@ public class MinecraftAssetsProvider {
 			File file = new File(assets, filename);
 
 			if (!file.exists() || !Checksum.equals(file, sha1)) {
+				if (offline) {
+					if (file.exists()) {
+						project.getLogger().warn("Outdated asset " + entry.getKey());
+					} else {
+						throw new GradleException("Asset " + entry.getKey() + " not found at " + file.getAbsolutePath());
+					}
+				} else {
 					project.getLogger().debug(":downloading asset " + entry.getKey());
 					DownloadUtil.downloadIfChanged(new URL(Constants.RESOURCES_BASE + sha1.substring(0, 2) + "/" + sha1), file, project.getLogger(), true);
 				}
+			}
 			String assetName = entry.getKey();
 			int end = assetName.lastIndexOf("/") + 1;
 			if (end > 0) {

src/main/java/net/fabricmc/loom/providers/MinecraftJarProvider.java

@@ -1,72 +0,0 @@
-/*
- * This file is part of fabric-loom, licensed under the MIT License (MIT).
- *
- * Copyright (c) 2016, 2017, 2018 FabricMC
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.fabricmc.loom.providers;
-
-import net.fabricmc.loom.LoomGradleExtension;
-import net.fabricmc.loom.util.MapJarsTiny;
-import net.fabricmc.stitch.merge.JarMerger;
-import org.gradle.api.Project;
-
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.util.Collection;
-
-public class MinecraftJarProvider {
-	public File MINECRAFT_MERGED_JAR;
-
-	MinecraftProvider minecraftProvider;
-
-	public MinecraftJarProvider(Project project, MinecraftProvider minecraftProvider) throws IOException {
-		this.minecraftProvider = minecraftProvider;
-		initFiles(project, minecraftProvider);
-		process(project, minecraftProvider);
-	}
-
-	private void process(Project project, MinecraftProvider minecraftProvider) throws IOException {
-		if (!MINECRAFT_MERGED_JAR.exists()) {
-			mergeJars(project);
-		}
-	}
-
-	public void mergeJars(Project project) throws IOException {
-		project.getLogger().lifecycle(":merging jars");
-		try (JarMerger jarMerger = new JarMerger(minecraftProvider.MINECRAFT_CLIENT_JAR, minecraftProvider.MINECRAFT_SERVER_JAR, minecraftProvider.MINECRAFT_MERGED_JAR)) {
-			jarMerger.enableSyntheticParamsOffset();
-			jarMerger.merge();
-		}
-	}
-
-	private void initFiles(Project project, MinecraftProvider minecraftProvider) {
-		LoomGradleExtension extension = project.getExtensions().getByType(LoomGradleExtension.class);
-		MINECRAFT_MERGED_JAR = new File(extension.getUserCache(), "minecraft-" + minecraftProvider.minecraftVersion + "-merged.jar");
-	}
-
-	public File getMergedJar() {
-		return MINECRAFT_MERGED_JAR;
-	}
-
-}

src/main/java/net/fabricmc/loom/providers/MinecraftMappedProvider.java

@@ -46,7 +46,7 @@ public class MinecraftMappedProvider extends DependencyProvider {
             throw new RuntimeException("mappings file not found");
         }
 
-        if (!extension.getMinecraftProvider().jarProvider.getMergedJar().exists()) {
+        if (!extension.getMinecraftProvider().getMergedJar().exists()) {
             throw new RuntimeException("input merged jar not found");
         }
 
@@ -57,7 +57,7 @@ public class MinecraftMappedProvider extends DependencyProvider {
             if (getIntermediaryJar().exists()) {
                 getIntermediaryJar().delete();
             }
-            new MapJarsTiny().mapJars(minecraftProvider.jarProvider, this, project);
+            new MapJarsTiny().mapJars(minecraftProvider, this, project);
         }
 
         if (!MINECRAFT_MAPPED_JAR.exists()) {

src/main/java/net/fabricmc/loom/providers/MinecraftProvider.java

@@ -29,7 +29,9 @@ import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.util.*;
+import net.fabricmc.stitch.merge.JarMerger;
 
+import org.gradle.api.GradleException;
 import org.gradle.api.Project;
 import org.gradle.api.logging.Logger;
 
@@ -47,7 +49,6 @@ public class MinecraftProvider extends DependencyProvider {
 
 	public MinecraftVersionInfo versionInfo;
 	public MinecraftLibraryProvider libraryProvider;
-	public MinecraftJarProvider jarProvider;
 
 	File MINECRAFT_JSON;
 	File MINECRAFT_CLIENT_JAR;
@@ -59,10 +60,11 @@ public class MinecraftProvider extends DependencyProvider {
 	@Override
 	public void provide(DependencyInfo dependency, Project project, LoomGradleExtension extension, Consumer<Runnable> postPopulationScheduler) throws Exception {
 		minecraftVersion = dependency.getDependency().getVersion();
+		boolean offline = project.getGradle().getStartParameter().isOffline();
 
 		initFiles(project);
 
-		downloadMcJson(project);
+		downloadMcJson(project, offline);
 		try (FileReader reader = new FileReader(MINECRAFT_JSON)) {
 			versionInfo = gson.fromJson(reader, MinecraftVersionInfo.class);
 		}
@@ -70,11 +72,25 @@ public class MinecraftProvider extends DependencyProvider {
 		// Add Loom as an annotation processor
         addDependency(project.files(this.getClass().getProtectionDomain().getCodeSource().getLocation()), project, "compileOnly");
 
+        if (offline) {
+        	if (MINECRAFT_CLIENT_JAR.exists() && MINECRAFT_SERVER_JAR.exists()) {
+        		project.getLogger().debug("Found client and server jars, presuming up-to-date");
+        	} else if (MINECRAFT_MERGED_JAR.exists()) {
+        		//Strictly we don't need the split jars if the merged one exists, let's try go on
+        		project.getLogger().warn("Missing game jar but merged jar present, things might end badly");
+        	} else {
+        		throw new GradleException("Missing jar(s); Client: " + MINECRAFT_CLIENT_JAR.exists() + ", Server: " + MINECRAFT_SERVER_JAR.exists());
+        	}
+        } else {
         	downloadJars(project.getLogger());
+        }
 
 		libraryProvider = new MinecraftLibraryProvider();
 		libraryProvider.provide(this, project);
-		jarProvider = new MinecraftJarProvider(project, this);
+
+		if (!MINECRAFT_MERGED_JAR.exists()) {
+			mergeJars(project.getLogger());
+		}
 	}
 
 	private void initFiles(Project project) {
@@ -86,19 +102,40 @@ public class MinecraftProvider extends DependencyProvider {
 
 	}
 
-	private void downloadMcJson(Project project) throws IOException {
+	private void downloadMcJson(Project project, boolean offline) throws IOException {
 		LoomGradleExtension extension = project.getExtensions().getByType(LoomGradleExtension.class);
 		File manifests = new File(extension.getUserCache(), "version_manifest.json");
 
+		if (offline) {
+			if (manifests.exists()) {
+				//If there is the manifests already we'll presume that's good enough
+				project.getLogger().debug("Found version manifests, presuming up-to-date");
+			} else {
+				//If we don't have the manifests then there's nothing more we can do
+				throw new GradleException("Version manifests not found at " + manifests.getAbsolutePath());
+			}
+		} else {
 			project.getLogger().debug("Downloading version manifests");
 			DownloadUtil.downloadIfChanged(new URL("https://launchermeta.mojang.com/mc/game/version_manifest.json"), manifests, project.getLogger());
+		}
+
 		String versionManifest = Files.asCharSource(manifests, StandardCharsets.UTF_8).read();
 		ManifestVersion mcManifest = new GsonBuilder().create().fromJson(versionManifest, ManifestVersion.class);
 
 		Optional<ManifestVersion.Versions> optionalVersion = mcManifest.versions.stream().filter(versions -> versions.id.equalsIgnoreCase(minecraftVersion)).findFirst();
 		if (optionalVersion.isPresent()) {
+			if (offline) {
+				if (MINECRAFT_JSON.exists()) {
+					//If there is the manifest already we'll presume that's good enough
+					project.getLogger().debug("Found Minecraft {} manifest, presuming up-to-date", minecraftVersion);
+				} else {
+					//If we don't have the manifests then there's nothing more we can do
+					throw new GradleException("Minecraft " + minecraftVersion + " manifest not found at " + MINECRAFT_JSON.getAbsolutePath());
+				}
+			} else {
 				project.getLogger().debug("Downloading Minecraft {} manifest", minecraftVersion);
 				DownloadUtil.downloadIfChanged(new URL(optionalVersion.get().url), MINECRAFT_JSON, project.getLogger());
+			}
 		} else {
 			throw new RuntimeException("Failed to find minecraft version: " + minecraftVersion);
 		}
@@ -117,6 +154,18 @@ public class MinecraftProvider extends DependencyProvider {
 		}
 	}
 
+	private void mergeJars(Logger logger) throws IOException {
+		logger.lifecycle(":merging jars");
+		try (JarMerger jarMerger = new JarMerger(MINECRAFT_CLIENT_JAR, MINECRAFT_SERVER_JAR, MINECRAFT_MERGED_JAR)) {
+			jarMerger.enableSyntheticParamsOffset();
+			jarMerger.merge();
+		}
+	}
+
+	public File getMergedJar() {
+		return MINECRAFT_MERGED_JAR;
+	}
+
 	@Override
 	public String getTargetConfig() {
 		return Constants.MINECRAFT;

src/main/java/net/fabricmc/loom/task/CleanLoomBinaries.java

@@ -33,7 +33,7 @@ public class CleanLoomBinaries extends DefaultLoomTask {
     public void run() {
         Project project = this.getProject();
         LoomGradleExtension extension = project.getExtensions().getByType(LoomGradleExtension.class);
-        extension.getMinecraftProvider().jarProvider.getMergedJar().delete();
+        extension.getMinecraftProvider().getMergedJar().delete();
         extension.getMinecraftMappedProvider().getIntermediaryJar().delete();
         extension.getMinecraftMappedProvider().getMappedJar().delete();
     }

src/main/java/net/fabricmc/loom/util/MapJarsTiny.java

@@ -26,8 +26,8 @@ package net.fabricmc.loom.util;
 
 
 import net.fabricmc.loom.LoomGradleExtension;
-import net.fabricmc.loom.providers.MinecraftJarProvider;
 import net.fabricmc.loom.providers.MinecraftMappedProvider;
+import net.fabricmc.loom.providers.MinecraftProvider;
 import net.fabricmc.loom.providers.MappingsProvider;
 import net.fabricmc.tinyremapper.OutputConsumerPath;
 import net.fabricmc.tinyremapper.TinyRemapper;
@@ -41,7 +41,7 @@ import java.util.Arrays;
 
 public class MapJarsTiny {
 
-	public void mapJars(MinecraftJarProvider jarProvider, MinecraftMappedProvider mapProvider, Project project) throws IOException {
+	public void mapJars(MinecraftProvider jarProvider, MinecraftMappedProvider mapProvider, Project project) throws IOException {
 		String fromM = "official";
 
 		LoomGradleExtension extension = project.getExtensions().getByType(LoomGradleExtension.class);