Start reimplementation of simplex pattern (#520)

* Start reimplementation of simplex pattern

* Fix suggestions

* Allow nested weighted patterns

* Add documentation and improve error handling

* Remove unnecessary code and obsolete TODOs

worldedit-core/src/main/java/com/sk89q/util/StringUtil.java

@@ -20,6 +20,7 @@
 package com.sk89q.util;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 import java.util.Locale;
@@ -331,4 +332,37 @@ public final class StringUtil {
 
         return parsableBlocks;
     }
+
+    /**
+     * Splits a string respecting enclosing quotes.
+     *
+     * @param input the input to split.
+     * @param delimiter the delimiter to split on.
+     * @param open the opening quote character.
+     * @param close the closing quote character.
+     * @return a list of split strings.
+     */
+    public static List<String> split(String input, char delimiter, char open, char close) {
+        if (input.indexOf(open) == -1 && input.indexOf(close) == -1) {
+            return Arrays.asList(input.split(String.valueOf(delimiter)));
+        }
+        int level = 0;
+        int begin = 0;
+        List<String> split = new ArrayList<>();
+        for (int i = 0; i < input.length(); i++) {
+            char c = input.charAt(i);
+            if (c == delimiter && level == 0) {
+                split.add(input.substring(begin, i));
+                begin = i + 1;
+            } else if (c == open) {
+                level++;
+            } else if (c == close) {
+                level--;
+            }
+        }
+        if (begin < input.length()) {
+            split.add(input.substring(begin));
+        }
+        return split;
+    }
 }

worldedit-core/src/main/java/com/sk89q/worldedit/extension/factory/BlockFactory.java

@@ -58,8 +58,8 @@ public class BlockFactory extends AbstractFactory<BaseBlock> {
      */
     public Set<BaseBlock> parseFromListInput(String input, ParserContext context) throws InputParseException {
         Set<BaseBlock> blocks = new HashSet<>();
-        String[] splits = input.split(",");
-        for (String token : StringUtil.parseListInQuotes(splits, ',', '[', ']', true)) {
+        // String[] splits = input.split(",");
+        for (String token : StringUtil.split(input, ',', '[', ']')) {
             blocks.add(parseFromInput(token, context));
         }
         return blocks;

worldedit-core/src/main/java/com/sk89q/worldedit/extension/factory/PatternFactory.java

@@ -24,6 +24,7 @@ import com.sk89q.worldedit.extension.factory.parser.pattern.BlockCategoryPattern
 import com.sk89q.worldedit.extension.factory.parser.pattern.ClipboardPatternParser;
 import com.sk89q.worldedit.extension.factory.parser.pattern.RandomPatternParser;
 import com.sk89q.worldedit.extension.factory.parser.pattern.RandomStatePatternParser;
+import com.sk89q.worldedit.extension.factory.parser.pattern.SimplexPatternParser;
 import com.sk89q.worldedit.extension.factory.parser.pattern.SingleBlockPatternParser;
 import com.sk89q.worldedit.extension.factory.parser.pattern.TypeOrStateApplyingPatternParser;
 import com.sk89q.worldedit.function.pattern.Pattern;
@@ -54,6 +55,9 @@ public final class PatternFactory extends AbstractFactory<Pattern> {
         register(new TypeOrStateApplyingPatternParser(worldEdit));
         register(new RandomStatePatternParser(worldEdit));
         register(new BlockCategoryPatternParser(worldEdit));
+
+        // FAWE
+        register(new SimplexPatternParser(worldEdit));
     }
 
 }

worldedit-core/src/main/java/com/sk89q/worldedit/extension/factory/parser/RichParser.java

@@ -0,0 +1,118 @@
+package com.sk89q.worldedit.extension.factory.parser;
+
+import com.sk89q.util.StringUtil;
+import com.sk89q.worldedit.WorldEdit;
+import com.sk89q.worldedit.extension.input.InputParseException;
+import com.sk89q.worldedit.extension.input.ParserContext;
+import com.sk89q.worldedit.internal.registry.InputParser;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.StringJoiner;
+import java.util.stream.Stream;
+
+/**
+ * A rich parser allows parsing of patterns and masks with extra arguments,
+ * e.g. #simplex[scale][pattern].
+ *
+ * @param <E> the parse result.
+ */
+public abstract class RichParser<E> extends InputParser<E> {
+    private final String prefix;
+    private final String required;
+
+    /**
+     * Create a new rich parser with a defined prefix for the result, e.g. {@code #simplex}.
+     *
+     * @param worldEdit the worldedit instance.
+     * @param prefix    the prefix of this parser result.
+     */
+    protected RichParser(WorldEdit worldEdit, String prefix) {
+        super(worldEdit);
+        this.prefix = prefix;
+        this.required = prefix + "[";
+    }
+
+    @Override
+    public Stream<String> getSuggestions(String input) {
+        // we don't even want to start suggesting if it's not meant to be this parser result
+        if (input.length() > this.required.length() && !input.startsWith(this.required)) {
+            return Stream.empty();
+        }
+        // suggest until the first [ as long as it isn't fully typed
+        if (input.length() < this.required.length()) {
+            return Stream.of(this.required).filter(s -> s.startsWith(input));
+        }
+        // we know that it is at least "<required>"
+        String[] strings = extractArguments(input.substring(this.prefix.length()), false);
+        StringJoiner joiner = new StringJoiner(",");
+        for (int i = 0; i < strings.length - 1; i++) {
+            joiner.add("[" + strings[i] + "]");
+        }
+        String previous = this.prefix + joiner;
+        return getSuggestions(strings[strings.length - 1], strings.length - 1).map(s -> previous + "[" + s + "]");
+    }
+
+    @Override
+    public E parseFromInput(String input, ParserContext context) throws InputParseException {
+        if (!input.startsWith(this.prefix)) return null;
+        if (input.length() < this.prefix.length()) return null;
+        String[] arguments = extractArguments(input.substring(prefix.length()), true);
+        return parseFromInput(arguments, context);
+    }
+
+    /**
+     * Returns a stream of suggestions for the argument at the given index.
+     *
+     * @param argumentInput the already provided input for the argument at the given index.
+     * @param index         the index of the argument to get suggestions for.
+     * @return a stream of suggestions matching the given input for the argument at the given index.
+     */
+    protected abstract Stream<String> getSuggestions(String argumentInput, int index);
+
+    /**
+     * Parses the already split arguments.
+     *
+     * @param arguments the array of arguments that were split (can be empty).
+     * @param context   the context of this parsing process.
+     * @return the resulting parsed type.
+     * @throws InputParseException if the input couldn't be parsed correctly.
+     */
+    protected abstract E parseFromInput(@NotNull String[] arguments, ParserContext context) throws InputParseException;
+
+    /**
+     * Extracts arguments enclosed by {@code []} into an array.
+     * Example: {@code [Hello][World]} results in a list containing {@code Hello} and {@code World}.
+     *
+     * @param input          the input to extract arguments from.
+     * @param requireClosing whether or not the extraction requires valid bracketing.
+     * @return an array of extracted arguments.
+     * @throws InputParseException if {@code requireClosing == true} and the count of [ != the count of ]
+     */
+    protected String[] extractArguments(String input, boolean requireClosing) throws InputParseException {
+        int open = 0; // the "level"
+        int openIndex = 0;
+        int i = 0;
+        List<String> arguments = new ArrayList<>();
+        for (; i < input.length(); i++) {
+            if (input.charAt(i) == '[') {
+                if (open++ == 0) {
+                    openIndex = i;
+                }
+            }
+            if (input.charAt(i) == ']') {
+                if (--open == 0) {
+                    arguments.add(input.substring(openIndex + 1, i));
+                }
+            }
+        }
+        if (!requireClosing && open > 0) {
+            arguments.add(input.substring(openIndex + 1));
+        }
+        if (requireClosing && open != 0) {
+            throw new InputParseException("Invalid bracketing, are you missing a '[' or ']'?");
+        }
+        return arguments.toArray(new String[0]);
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/extension/factory/parser/pattern/RandomPatternParser.java

@@ -38,8 +38,9 @@ public class RandomPatternParser extends InputParser<Pattern> {
 
     @Override
     public Stream<String> getSuggestions(String input) {
-        String[] splits = input.split(",", -1);
-        List<String> patterns = StringUtil.parseListInQuotes(splits, ',', '[', ']', true);
+        List<String> patterns = StringUtil.split(input, ',', '[', ']');
+        /*String[] splits = input.split(",", -1);
+        List<String> patterns = StringUtil.parseListInQuotes(splits, ',', '[', ']', true);*/
         if (patterns.size() == 1) {
             return Stream.empty();
         }
@@ -63,8 +64,9 @@ public class RandomPatternParser extends InputParser<Pattern> {
     public Pattern parseFromInput(String input, ParserContext context) throws InputParseException {
         RandomPattern randomPattern = new RandomPattern();
 
-        String[] splits = input.split(",", -1);
-        List<String> patterns = StringUtil.parseListInQuotes(splits, ',', '[', ']', true);
+        List<String> patterns = StringUtil.split(input, ',', '[', ']');
+        /*String[] splits = input.split(",", -1);
+        List<String> patterns = StringUtil.parseListInQuotes(splits, ',', '[', ']', true);*/
         if (patterns.size() == 1) {
             return null; // let a 'single'-pattern parser handle it
         }
@@ -74,7 +76,7 @@ public class RandomPatternParser extends InputParser<Pattern> {
 
             // Parse special percentage syntax
             if (token.matches("[0-9]+(\\.[0-9]*)?%.*")) {
-                String[] p = token.split("%");
+                String[] p = token.split("%", 2);
 
                 if (p.length < 2) {
                     throw new InputParseException("Missing the type after the % symbol for '" + input + "'");

worldedit-core/src/main/java/com/sk89q/worldedit/extension/factory/parser/pattern/SimplexPatternParser.java

@@ -0,0 +1,75 @@
+package com.sk89q.worldedit.extension.factory.parser.pattern;
+
+import com.boydti.fawe.object.random.SimplexRandom;
+import com.sk89q.worldedit.WorldEdit;
+import com.sk89q.worldedit.extension.factory.parser.RichParser;
+import com.sk89q.worldedit.extension.input.InputParseException;
+import com.sk89q.worldedit.extension.input.ParserContext;
+import com.sk89q.worldedit.function.pattern.Pattern;
+import com.sk89q.worldedit.function.pattern.RandomPattern;
+import com.sk89q.worldedit.world.block.BlockStateHolder;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.stream.Stream;
+
+public class SimplexPatternParser extends RichParser<Pattern> {
+    private static final String SIMPLEX_PREFIX = "#simplex";
+
+    public SimplexPatternParser(WorldEdit worldEdit) {
+        super(worldEdit, SIMPLEX_PREFIX);
+    }
+
+    @Override
+    protected Stream<String> getSuggestions(String argumentInput, int index) {
+        if (index == 0) {
+            if (argumentInput.isEmpty()) {
+                return Stream.of("1", "2", "3", "4", "5", "6", "7", "8", "9");
+            }
+            // if already a valid number, suggest more digits
+            if (isDouble(argumentInput)) {
+                Stream<String> numbers = Stream.of("", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9");
+                if (argumentInput.indexOf('.') == -1) {
+                    numbers = Stream.concat(numbers, Stream.of("."));
+                }
+                return numbers.map(s -> argumentInput + s);
+            }
+            // no valid input anymore
+            return Stream.empty();
+        }
+        if (index == 1) {
+            return worldEdit.getPatternFactory().getSuggestions(argumentInput).stream();
+        }
+        return Stream.empty();
+    }
+
+    @Override
+    protected Pattern parseFromInput(@NotNull String[] arguments, ParserContext context) {
+        if (arguments.length != 2) {
+            throw new InputParseException("Simplex requires a scale and a pattern, e.g. #simplex[5][dirt,stone]");
+        }
+        double scale = Double.parseDouble(arguments[0]);
+        scale = 1d / Math.max(1, scale);
+        Pattern inner = worldEdit.getPatternFactory().parseFromInput(arguments[1], context);
+        if (inner instanceof RandomPattern) {
+            return new RandomPattern(new SimplexRandom(scale), (RandomPattern) inner);
+        } else if (inner instanceof BlockStateHolder) {
+            return inner; // single blocks won't have any impact on how simplex behaves
+        } else {
+            throw new InputParseException("Pattern " + inner.getClass().getSimpleName() + " cannot be used with #simplex");
+        }
+    }
+
+    private static boolean isDouble(String input) {
+        boolean point = false;
+        for (char c : input.toCharArray()) {
+            if (!Character.isDigit(c)) {
+                if (c == '.' && !point) {
+                    point = true;
+                } else {
+                    return false;
+                }
+            }
+        }
+        return true;
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/function/pattern/RandomPattern.java

@@ -52,6 +52,19 @@ public class RandomPattern extends AbstractPattern {
         this.random = random;
     }
 
+    /**
+     * Create a random pattern from an existing one but with a different random.
+     *
+     * @param random the new random to use.
+     * @param parent the existing random pattern.
+     */
+    public RandomPattern(SimpleRandom random, RandomPattern parent) {
+        this.random = random;
+        this.weights = parent.weights;
+        this.collection = RandomCollection.of(weights, random);
+        this.patterns = parent.patterns;
+    }
+
     /**
      * Add a pattern to the weight list of patterns.
      *