From 1951f742d95d823f23169a61ee3cc7d918885df0 Mon Sep 17 00:00:00 2001
From: Andres Almiray <aalmiray@gmail.com>
Date: Tue, 2 Feb 2021 22:49:10 +0100
Subject: [PATCH] Issue #81. Handle implicit layers config file

---
 .../layrry/launcher/LayrryLauncher.java       | 29 +++++++++++++++++++
 .../layrry/launcher/internal/Args.java        |  2 +-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/layrry-launcher/src/main/java/org/moditect/layrry/launcher/LayrryLauncher.java b/layrry-launcher/src/main/java/org/moditect/layrry/launcher/LayrryLauncher.java
index d1d4172c..872031b9 100644
--- a/layrry-launcher/src/main/java/org/moditect/layrry/launcher/LayrryLauncher.java
+++ b/layrry-launcher/src/main/java/org/moditect/layrry/launcher/LayrryLauncher.java
@@ -79,6 +79,17 @@ public static void launch(String... args) throws Exception {
         URL propertiesFileUrl = toUrl(propertiesFile);
 
         String layersConfig = arguments.getLayersConfig();
+        if (null == layersConfig || layersConfig.isEmpty()) {
+            layersConfig = resolveLayersConfigFile(basedir);
+        }
+        if (null == layersConfig) {
+            jCommander.getConsole()
+                .println("Missing --layers-config parameter or local file named layers" + getSupportedConfigFormats());
+            jCommander.getConsole().println("");
+            printUsage(jCommander);
+            return;
+        }
+
         URL layersConfigUrl = toUrl(layersConfig);
 
         if (null != layersConfigUrl) {
@@ -139,4 +150,22 @@ private static Set<String> getSupportedConfigFormats() {
 
         return extensions;
     }
+
+    private static String resolveLayersConfigFile(File basedir) {
+        if (basedir == null) {
+            basedir = new File(System.getProperty("user.dir"));
+        }
+
+        ServiceLoader<LayersConfigParser> parsers = ServiceLoader.load(LayersConfigParser.class,
+            LayrryLauncher.class.getClassLoader());
+
+        for (LayersConfigParser parser : parsers) {
+            File layersConfigFile = new File(basedir, "layers."+parser.getPreferredFileExtension());
+            if(layersConfigFile.exists()) {
+                return layersConfigFile.getAbsolutePath();
+            }
+        }
+
+        return null;
+    }
 }
diff --git a/layrry-launcher/src/main/java/org/moditect/layrry/launcher/internal/Args.java b/layrry-launcher/src/main/java/org/moditect/layrry/launcher/internal/Args.java
index a35a1d3d..bf305825 100644
--- a/layrry-launcher/src/main/java/org/moditect/layrry/launcher/internal/Args.java
+++ b/layrry-launcher/src/main/java/org/moditect/layrry/launcher/internal/Args.java
@@ -26,7 +26,7 @@ public class Args {
     @Parameter(description = "[arguments]")
     private List<String> mainArgs = new ArrayList<>();
 
-    @Parameter(names = "--layers-config", required = true, description = "Layers configuration file. May be a local file or remote URL.")
+    @Parameter(names = "--layers-config", description = "Layers configuration file. May be a local file or remote URL.")
     private String layersConfig;
 
     @Parameter(names = "--properties", description = "Additional configuration properties. May be a local file or remote URL. Must use the Java properties format.")