Adds a custom configuration to retain comments

src/main/java/net/knarcraft/stargate/config/StargateConfig.java

@@ -361,7 +361,7 @@ public final class StargateConfig {
      */
     public void loadConfig() {
         Stargate.getInstance().reloadConfig();
-        FileConfiguration newConfig = Stargate.getInstance().getConfig();
+        FileConfiguration newConfig = Stargate.getInstance().getConfiguration();
 
         boolean isMigrating = false;
         if (newConfig.getString("lang") != null || newConfig.getString("economy.freeGatesGreen") != null ||

src/main/java/net/knarcraft/stargate/config/StargateYamlConfiguration.java

@@ -0,0 +1,155 @@
+package net.knarcraft.stargate.config;
+
+import org.bukkit.configuration.InvalidConfigurationException;
+import org.bukkit.configuration.file.FileConfiguration;
+import org.bukkit.configuration.file.YamlConfiguration;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A YAML configuration which keeps all comments
+ *
+ * @author Thorin
+ */
+public class StargateYamlConfiguration extends YamlConfiguration {
+
+    static public final String END_OF_COMMENT = "_endOfComment_";
+    static public final String START_OF_COMMENT = "comment_";
+
+    @Override
+    public @NotNull String saveToString() {
+        return this.convertYAMLMappingsToComments(super.saveToString());
+    }
+
+    @Override
+    public void loadFromString(@NotNull String contents) throws InvalidConfigurationException {
+        super.loadFromString(this.convertCommentsToYAMLMappings(contents));
+    }
+
+    /**
+     * Reads a file with comments, and recreates them into yaml mappings
+     *
+     * <p>A mapping follows this format: comment_{CommentNumber}: "The comment"
+     * This needs to be done as comments otherwise get removed using
+     * the {@link FileConfiguration#save(File)} method. The config
+     * needs to be saved if a config value has changed.</p>
+     */
+    private String convertCommentsToYAMLMappings(String configString) {
+        StringBuilder yamlBuilder = new StringBuilder();
+        List<String> currentComment = new ArrayList<>();
+        int commentId = 0;
+
+        for (String line : configString.split("\n")) {
+            if (line.trim().startsWith("#")) {
+                //Temporarily store the comment line
+                currentComment.add(line.trim().replaceFirst("#", ""));
+            } else {
+                //Write the full formatted comment to the StringBuilder
+                if (!currentComment.isEmpty()) {
+                    int indentation = getIndentation(line);
+                    generateCommentYAML(yamlBuilder, currentComment, commentId++, indentation);
+                    currentComment = new ArrayList<>();
+                }
+                //Add the non-comment line assuming it isn't empty
+                if (!line.trim().isEmpty()) {
+                    yamlBuilder.append(line).append("\n");
+                }
+            }
+        }
+        return yamlBuilder.toString();
+    }
+
+    /**
+     * Generates a YAML-compatible string for one comment block
+     *
+     * @param yamlBuilder  <p>The string builder to add the generated YAML to</p>
+     * @param commentLines <p>The lines of the comment to convert into YAML</p>
+     * @param commentId    <p>The unique id of the comment</p>
+     * @param indentation  <p>The indentation to add to every line</p>
+     */
+    private void generateCommentYAML(StringBuilder yamlBuilder, List<String> commentLines, int commentId, int indentation) {
+        String subIndentation = this.addIndentation(indentation + 2);
+        //Add the comment start marker
+        yamlBuilder.append(this.addIndentation(indentation)).append(START_OF_COMMENT).append(commentId).append(": |\n");
+        for (String commentLine : commentLines) {
+            //Add each comment line with the proper indentation
+            yamlBuilder.append(subIndentation).append(commentLine).append("\n");
+        }
+        //Add the comment end marker
+        yamlBuilder.append(subIndentation).append(subIndentation).append(END_OF_COMMENT).append("\n");
+    }
+
+    /**
+     * Converts the internal YAML mapping format to a readable config file
+     *
+     * <p>The internal YAML structure is converted to a string with the same format as a standard configuration file.
+     * The internal structure has comments in the format: START_OF_COMMENT + id + multi-line YAML string +
+     * END_OF_COMMENT.</p>
+     *
+     * @param yamlString <p>A string using the YAML format</p>
+     * @return <p>The corresponding comment string</p>
+     */
+    private String convertYAMLMappingsToComments(String yamlString) {
+        StringBuilder finalText = new StringBuilder();
+        boolean isReadingCommentBlock = false;
+        int commentIndentation = 0;
+        for (String line : yamlString.split("\n")) {
+            String possibleComment = line.trim();
+
+            if (isReadingCommentBlock && line.contains(END_OF_COMMENT)) {
+                //Skip the line signifying the end of a comment
+                isReadingCommentBlock = false;
+            } else if (possibleComment.startsWith(START_OF_COMMENT)) {
+                //Skip the comment start line, and start comment parsing
+                isReadingCommentBlock = true;
+                //Get the indentation to use for the comment block
+                commentIndentation = getIndentation(line);
+                //Add an empty line before every comment block
+                finalText.append("\n");
+            } else if (line.isEmpty() && !isReadingCommentBlock) {
+                //Output the empty line as-is, as it's not part of a comment
+                finalText.append("\n");
+            } else if (isReadingCommentBlock) {
+                //Output the comment with correct indentation
+                finalText.append(addIndentation(commentIndentation)).append("# ").append(possibleComment).append("\n");
+            } else {
+                //Output the configuration key
+                finalText.append(line).append("\n");
+            }
+        }
+        return finalText.toString().trim();
+    }
+
+    /**
+     * Gets a string containing the given indentation
+     *
+     * @param indentationSpaces <p>The number spaces to use for indentation</p>
+     * @return <p>A string containing the number of spaces specified</p>
+     */
+    private String addIndentation(int indentationSpaces) {
+        return " ".repeat(Math.max(0, indentationSpaces));
+    }
+
+
+    /**
+     * Gets the indentation (number of spaces) of the given line
+     *
+     * @param line <p>The line to get indentation of</p>
+     * @return <p>The number of spaces in the line's indentation</p>
+     */
+    private int getIndentation(String line) {
+        int spacesFound = 0;
+        for (char aCharacter : line.toCharArray()) {
+            if (aCharacter == ' ') {
+                spacesFound++;
+            } else {
+                break;
+            }
+        }
+        return spacesFound;
+    }
+
+}