Remove obsolete biome profile files

Also used to rename unedited "Minetest Game.mt" files to "Minetest Game v.4.mt"

src/main/java/amidst/AmidstSettings.java

@@ -41,6 +41,7 @@ public class AmidstSettings {
 
 	public final Setting<String> lastProfile;
 	public final Setting<String> lastBiomeProfile;
+	public final Setting<Long>   lastBiomeProfilePurge;
 	public final Setting<String> worldType;
 
 	/**
@@ -78,6 +79,7 @@ public class AmidstSettings {
 	
 		lastProfile                = Settings.createString(   preferences, "profile",              "");
 		lastBiomeProfile           = Settings.createString(   preferences, "biomeProfile",         "");
+		lastBiomeProfilePurge      = Settings.createLong(     preferences, "biomePurgeDate",       0);		
 		worldType                  = Settings.createString(   preferences, "worldType",            WorldType.PROMPT_EACH_TIME);
 		biomeProfileSelection = new BiomeProfileSelection(BiomeProfileImpl.getDefaultProfiles().iterator().next());
 		// @formatter:on

src/main/java/amidst/gui/main/menu/BiomeProfileMenuFactory.java

@@ -164,7 +164,7 @@ public class BiomeProfileMenuFactory implements BiomeProfileUpdateListener {
 
 	private void initParentMenu() {
 		parentMenu.removeAll();
-		biomeProfileDirectory.saveDefaultProfilesIfNecessary();
+		biomeProfileDirectory.saveDefaultProfilesIfNecessary(settings);
 		BiomeProfileVisitorImpl visitor = new BiomeProfileVisitorImpl(parentMenu, actions, settings);
 		biomeProfileDirectory.visitProfiles(visitor);
 		parentMenu.addSeparator();

src/main/java/amidst/minetest/world/mapgen/DefaultBiomes.java

@@ -1,7 +1,13 @@
 package amidst.minetest.world.mapgen;
 
+import java.time.LocalDate;
+import java.time.Month;
+import java.util.AbstractMap;
+import java.util.ArrayList;
 import java.util.LinkedHashMap;
+import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 
 import amidst.mojangapi.world.biome.BiomeColor;
 
@@ -10,11 +16,39 @@ public class DefaultBiomes {
 	private static Map<String, MinetestBiome[]> biomeLists = null;
 
 	public static final String BIOMEPROFILENAME_V6            = "v6";
-	public static final String BIOMEPROFILENAME_MINETEST_GAME = "Minetest Game";
+	public static final String BIOMEPROFILENAME_MINETEST_GAME = "Minetest Game v.4";
 	
 	public static final short FLOATLAND_SHADOW_LIMIT    = 1024;
 	public static final short FLOATLAND_LEVEL           = 1280;
 	
+	/**
+	 * List of biome profile files that were created by older versions of Admist
+	 * and can now be deleted.
+	 * @see getObsoleteBiomeProfilesDate()
+	 */
+	public static List<Entry<String, String>> getObsoleteBiomeProfiles() {
+		
+		List<Entry<String, String>> result = new ArrayList<Entry<String, String>>();
+		
+		result.add(new AbstractMap.SimpleEntry<String, String>("Minetest Game",    "c0f90f045b4111bab064f669958196fd73bad894"));
+		
+		result.add(new AbstractMap.SimpleEntry<String, String>("Minetest default", "b9535c9299fd0ee92067c8c6b38a46c43d22be71")); // v1.1
+		result.add(new AbstractMap.SimpleEntry<String, String>("V6 biomes",        "2c74eaf3c805c9f05797bfed906b70dd18772587")); // v1.1
+		result.add(new AbstractMap.SimpleEntry<String, String>("VoxelGarden",      "8ab488cbbe5c3cbfc1aa3bae8c717104e98e00ca")); // v1.1
+
+		return result;
+	}
+	
+	/**
+	 * Returns the date of the data provided by getObsoleteBiomeProfiles().
+	 * If the returned date is younger than the last time obsolete biomes were removed, then
+	 * no further checks are necessary. 
+	 * @see getObsoleteBiomeProfiles()
+	 */
+	public static LocalDate getObsoleteBiomeProfilesDate() {
+		return LocalDate.of(2018, Month.OCTOBER, 20);
+	}
+	
 	/**
 	 * The first item in the list will be considered the definitive biome list
 	 */

src/main/java/amidst/minetest/world/oracle/BiomeDataOracleV7.java

@@ -147,7 +147,7 @@ public class BiomeDataOracleV7 extends MinetestBiomeDataOracle {
 
 		if (lastHeight != Short.MIN_VALUE) {
 			// Perhaps the height hasn't changed and we can save some tests with this information: We can check if
-			// height is the same with only two tests (and only 1 will be needed if lastHeight was sea level).
+			// height is the same with only two tests (and only 1 will be needed if lastHeight was highestGround).
 			int lastAirHeight = lastHeight + 1;
 			
 			float density_gradient = -((float)(lastAirHeight - mount_zero_level) / mnt_h_n);

src/main/java/amidst/settings/Settings.java

@@ -28,6 +28,13 @@ public enum Settings {
 				value -> preferences.putBoolean(key, value));
 	}
 
+	public static Setting<Long> createLong(Preferences preferences, String key, long defaultValue) {
+		return new SettingBase<>(
+				defaultValue,
+				value -> preferences.getLong(key, value),
+				value -> preferences.putLong(key, value));
+	}
+	
 	public static Setting<Dimension> createDimension(Preferences preferences, String key, Dimension defaultValue) {
 		return new SettingBase<>(
 				defaultValue,

src/main/java/amidst/settings/biomeprofile/BiomeAuthority.java

@@ -104,8 +104,8 @@ public class BiomeAuthority implements BiomeProfileUpdateListener {
 		);
 		
 		// Makes sure the default biomeprofiles for this game engine are added to the biomes 
-		// directory so the user can edit them. 
-		biomeProfileDirectory.saveDefaultProfilesIfNecessary();
+		// directory so the user can edit them.
+		biomeProfileDirectory.saveDefaultProfilesIfNecessary(settings);
 
 		// Makes sure biomeProfileSelection is set to a profile that's suitable for the
 		// current game engine.

src/main/java/amidst/settings/biomeprofile/BiomeProfileDirectory.java

@@ -1,15 +1,20 @@
 package amidst.settings.biomeprofile;
 
 import java.io.File;
+import java.io.FileInputStream;
 import java.io.FilenameFilter;
 import java.io.IOException;
-import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.security.MessageDigest;
+import java.time.LocalDate;
 import java.util.Collection;
+import java.util.Map.Entry;
 
+import amidst.AmidstSettings;
 import amidst.AmidstVersion;
 import amidst.documentation.Immutable;
 import amidst.logging.AmidstLogger;
+import amidst.minetest.world.mapgen.DefaultBiomes;
 import amidst.parsing.FormatException;
 import amidst.parsing.json.JsonReader;
 import amidst.util.OperatingSystemDetector;
@@ -139,11 +144,14 @@ public class BiomeProfileDirectory {
 		this.biomeProfileImpl = biome_profile_impl;
 	}
 	
-	public void saveDefaultProfilesIfNecessary() {
+	public void saveDefaultProfilesIfNecessary(AmidstSettings settings) {
 		if (!isValid()) {
 			AmidstLogger.info("Unable to find biome profile directory.");
 		} else {
 			AmidstLogger.info("Found biome profile directory.");
+			
+			removeObsoleteBiomeProfileFiles(settings);
+			
 			for(BiomeProfile profile : createDefaultProfiles()) {						
 				File profileFile = new File(root, profile.getName() + "." + profileFileExtension);
 				
@@ -158,6 +166,73 @@ public class BiomeProfileDirectory {
 		}
 	}
 
+	/**
+	 * Delete any old biome profile files that are out of date, or have had their name changed.
+	 * This only deletes known files, to prevent removal of anything user-created or user-edited. 
+	 */
+	private void removeObsoleteBiomeProfileFiles(AmidstSettings settings) {
+		
+		long obsoleteLastRemoved_epochDay = settings.lastBiomeProfilePurge.get();
+		
+		if ((obsoleteLastRemoved_epochDay == 0) || (LocalDate.now().toEpochDay() < obsoleteLastRemoved_epochDay)) {
+			// The data we have about obsolete biome profiles is more recent than the 
+			// last time we removed obsolete biome profiles, so do so again.
+			try {
+				MessageDigest shaDigest = MessageDigest.getInstance("SHA-1");
+				
+				// Realistically it's only the Minetest biome profiles that will need older files removed 
+				for(Entry<String, String> entry : DefaultBiomes.getObsoleteBiomeProfiles()) {
+					
+					File obsoleteFile = new File(root, entry.getKey() + "." + profileFileExtension);
+					if (obsoleteFile.isFile()) {
+						// check the file content matches the obsolete content, i.e. hasn't been edited by the user
+						if (entry.getValue().equals(getFileChecksum(shaDigest, obsoleteFile))) {
+							AmidstLogger.info("Removing obsolete biome profile \"" + obsoleteFile.getName() + "\"");
+							obsoleteFile.delete();
+						}
+					}
+				}
+				// Save the date the cleanup was performed
+				settings.lastBiomeProfilePurge.set(LocalDate.now().toEpochDay());
+			} catch(Exception ex) {
+				// cleaning up obsolete files is not critical
+				AmidstLogger.error("Exception removing old biome profiles: " + ex.getMessage());
+			}
+		}
+	}
+	
+	private static String getFileChecksum(MessageDigest digest, File file) throws IOException
+	{
+	    //Get file input stream for reading the file content
+	    FileInputStream fis = new FileInputStream(file);
+	     
+	    //Create byte array to read data in chunks
+	    byte[] byteArray = new byte[1024];
+	    int bytesCount = 0;
+	      
+	    //Read file data and update in message digest
+	    while ((bytesCount = fis.read(byteArray)) != -1) {
+	        digest.update(byteArray, 0, bytesCount);
+	    };
+	     
+	    //close the stream; We don't need it now.
+	    fis.close();
+	     
+	    //Get the hash's bytes
+	    byte[] bytes = digest.digest();
+	     
+	    //This bytes[] has bytes in decimal format;
+	    //Convert it to hexadecimal format
+	    StringBuilder sb = new StringBuilder();
+	    for(int i=0; i< bytes.length ;i++)
+	    {
+	        sb.append(Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1));
+	    }
+	     
+	    //return complete hash
+	    return sb.toString();
+	}	
+	
 	public void visitProfiles(BiomeProfileVisitor visitor) {
 		visitProfiles(root, visitor);
 	}