Show download exceptions properly in CLI

src/main/kotlin/link/infra/packwiz/installer/DownloadTask.kt

@@ -152,6 +152,9 @@ internal class DownloadTask private constructor(val metadata: IndexFile.File, de
 			}
 		}
 
+		// TODO: if already exists and has correct hash, ignore?
+		// TODO: add .disabled support?
+
 		try {
 			val hash: Hash
 			val fileHashFormat: String
@@ -176,7 +179,14 @@ internal class DownloadTask private constructor(val metadata: IndexFile.File, de
 			}
 
 			if (fileSource.hashIsEqual(hash)) {
+				// isDirectory follows symlinks, but createDirectories doesn't
+				try {
 					Files.createDirectories(destPath.parent)
+				} catch (e: FileAlreadyExistsException) {
+					if (!Files.isDirectory(destPath.parent)) {
+						throw e
+					}
+				}
 				Files.copy(data.inputStream(), destPath, StandardCopyOption.REPLACE_EXISTING)
 				data.clear()
 			} else {

src/main/kotlin/link/infra/packwiz/installer/UpdateManager.kt

@@ -255,8 +255,7 @@ class UpdateManager internal constructor(private val opts: Options, val ui: IUse
 			return
 		}
 		if (!indexFileSource.hashIsEqual(indexHash)) {
-			// TODO: throw exception
+			ui.handleExceptionAndExit(RuntimeException("Your index hash is invalid! Please run packwiz refresh on the pack again"))
-			println("I was meant to put an error message here but I'll do that later")
 			return
 		}
 		if (stateHandler.cancelButton) {

src/main/kotlin/link/infra/packwiz/installer/ui/CLIHandler.kt

@@ -3,6 +3,7 @@ package link.infra.packwiz.installer.ui
 import link.infra.packwiz.installer.ui.IUserInterface.ExceptionListResult
 import java.util.concurrent.CompletableFuture
 import java.util.concurrent.Future
+import kotlin.system.exitProcess
 
 class CLIHandler : IUserInterface {
 	override fun handleException(e: Exception) {
@@ -40,8 +41,11 @@ class CLIHandler : IUserInterface {
 	}
 
 	override fun showExceptions(exceptions: List<ExceptionDetails>, numTotal: Int, allowsIgnore: Boolean): Future<ExceptionListResult> {
-		val future = CompletableFuture<ExceptionListResult>()
+		println("Failed to download modpack, the following errors were encountered:")
-		future.complete(ExceptionListResult.CANCEL)
+		for (ex in exceptions) {
-		return future
+			println(ex.name + ": ")
+			ex.exception.printStackTrace()
+		}
+		exitProcess(1)
 	}
 }

src/main/kotlin/link/infra/packwiz/installer/ui/InstallWindow.kt

@@ -180,11 +180,18 @@ class InstallWindow : IUserInterface {
 	override fun showOptions(options: List<IOptionDetails>): Future<Boolean> {
 		val future = CompletableFuture<Boolean>()
 		EventQueue.invokeLater {
+			if (options.isEmpty()) {
+				JOptionPane.showMessageDialog(null,
+					"This modpack has no optional mods!",
+					"Optional mods", JOptionPane.INFORMATION_MESSAGE)
+				future.complete(false)
+			} else {
 				OptionsSelectWindow(options, future, frmPackwizlauncher).apply {
 					defaultCloseOperation = JDialog.DISPOSE_ON_CLOSE
 					isVisible = true
 				}
 			}
+		}
 		return future
 	}
 
@@ -201,7 +208,7 @@ class InstallWindow : IUserInterface {
 
 	override fun disableOptionsButton() {
 		btnOptions.apply {
-			text = "Optional mods..."
+			text = "No optional mods"
 			isEnabled = false
 		}
 	}