Adds code for migrating old configuration values

src/main/java/net/knarcraft/blacksmith/BlacksmithPlugin.java

@@ -22,6 +22,8 @@ import net.knarcraft.knarlib.formatting.StringFormatter;
 import net.knarcraft.knarlib.formatting.TranslatableMessage;
 import net.knarcraft.knarlib.formatting.TranslatableTimeUnit;
 import net.knarcraft.knarlib.formatting.Translator;
+import net.knarcraft.knarlib.property.ColorConversion;
+import net.knarcraft.knarlib.util.FileHelper;
 import net.knarcraft.knarlib.util.UpdateChecker;
 import org.bukkit.command.CommandExecutor;
 import org.bukkit.command.PluginCommand;
@@ -35,6 +37,9 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Map;
 import java.util.logging.Level;
 
 /**
@@ -142,8 +147,12 @@ public class BlacksmithPlugin extends JavaPlugin {
 
         //Copy default config to disk
         FileConfiguration fileConfiguration = this.getConfig();
-        fileConfiguration.options().copyDefaults(true);
         this.saveDefaultConfig();
+        if (fileConfiguration.getString("defaults.dropItem") != null) {
+            migrateConfig(fileConfiguration);
+            this.saveConfig();
+        }
+        fileConfiguration.options().copyDefaults(true);
         this.reloadConfig();
         this.saveConfig();
 
@@ -253,4 +262,48 @@ public class BlacksmithPlugin extends JavaPlugin {
         }
     }
 
+    /**
+     * Changes all configuration values from the old name to the new name
+     *
+     * @param fileConfiguration <p>The config to read from and write to</p>
+     */
+    private void migrateConfig(FileConfiguration fileConfiguration) {
+        //Save the old config just in case something goes wrong
+        try {
+            fileConfiguration.save(getDataFolder() + "/config.yml.old");
+        } catch (IOException e) {
+            e.printStackTrace();
+            return;
+        }
+
+        //Read all available config migrations
+        Map<String, String> migrationFields = null;
+        try {
+            InputStream inputStream = FileHelper.getInputStreamForInternalFile("/config-migrations.txt");
+            if (inputStream != null) {
+                migrationFields = FileHelper.readKeyValuePairs(FileHelper.getBufferedReaderFromInputStream(inputStream),
+                        "=", ColorConversion.NORMAL);
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+            return;
+        }
+
+        if (migrationFields == null) {
+            return;
+        }
+
+        //Replace old config names with the new ones
+        for (String key : migrationFields.keySet()) {
+            if (fileConfiguration.contains(key)) {
+                String newPath = migrationFields.get(key);
+                Object oldValue = fileConfiguration.get(key);
+                if (!newPath.trim().isEmpty()) {
+                    fileConfiguration.set(newPath, oldValue);
+                }
+                fileConfiguration.set(key, null);
+            }
+        }
+    }
+
 }