#1026 Add more tags for forced commands (lazily replaced) (#214)

* #1026 Add more tags for forced commands (lazily replaced)
- Extract lazy replacement of tags to its own class
- Implement wrapper to replace a String property within an object
  - Use wrapper in command manager and add new tags

* Make argument type generic in lazy tags util

src/main/java/fr/xephi/authme/util/lazytags/DependentTag.java

@@ -1,16 +1,16 @@
 package fr.xephi.authme.util.lazytags;
 
-import org.bukkit.entity.Player;
-
 import java.util.function.Function;
 
 /**
- * Replaceable tag whose value depends on the player.
+ * Replaceable tag whose value depends on an argument.
+ *
+ * @param <A> the argument type
  */
-public class PlayerTag implements Tag {
+public class DependentTag<A> implements Tag<A> {
 
     private final String name;
-    private final Function<Player, String> replacementFunction;
+    private final Function<A, String> replacementFunction;
 
     /**
      * Constructor.
@@ -18,7 +18,7 @@ public class PlayerTag implements Tag {
      * @param name the tag (placeholder) that will be replaced
      * @param replacementFunction the function producing the replacement
      */
-    public PlayerTag(String name, Function<Player, String> replacementFunction) {
+    public DependentTag(String name, Function<A, String> replacementFunction) {
         this.name = name;
         this.replacementFunction = replacementFunction;
     }
@@ -29,7 +29,7 @@ public class PlayerTag implements Tag {
     }
 
     @Override
-    public String getValue(Player player) {
-        return replacementFunction.apply(player);
+    public String getValue(A argument) {
+        return replacementFunction.apply(argument);
     }
 }

src/main/java/fr/xephi/authme/util/lazytags/SimpleTag.java

@@ -1,13 +1,13 @@
 package fr.xephi.authme.util.lazytags;
 
-import org.bukkit.entity.Player;
-
 import java.util.function.Supplier;
 
 /**
- * Tag to be replaced that does not depend on the player.
+ * Tag to be replaced that does not depend on an argument.
+ *
+ * @param <A> type of the argument (not used in this implementation)
  */
-public class SimpleTag implements Tag {
+public class SimpleTag<A> implements Tag<A> {
 
     private final String name;
     private final Supplier<String> replacementFunction;
@@ -23,7 +23,7 @@ public class SimpleTag implements Tag {
     }
 
     @Override
-    public String getValue(Player player) {
+    public String getValue(A argument) {
         return replacementFunction.get();
     }
 }

src/main/java/fr/xephi/authme/util/lazytags/Tag.java

@@ -1,11 +1,11 @@
 package fr.xephi.authme.util.lazytags;
 
-import org.bukkit.entity.Player;
-
 /**
- * Represents a tag in a text to be replaced with a value (which may depend on the Player).
+ * Represents a tag in a text to be replaced with a value (which may depend on some argument).
+ *
+ * @param <A> argument type the replacement may depend on
  */
-public interface Tag {
+public interface Tag<A> {
 
     /**
      * @return the tag to replace
@@ -13,10 +13,10 @@ public interface Tag {
     String getName();
 
     /**
-     * Returns the value to replace the tag with for the given player.
+     * Returns the value to replace the tag with for the given argument.
      *
-     * @param player the player to evaluate the replacement for
+     * @param argument the argument to evaluate the replacement for
      * @return the replacement
      */
-    String getValue(Player player);
+    String getValue(A argument);
 }

src/main/java/fr/xephi/authme/util/lazytags/TagBuilder.java

@@ -1,7 +1,5 @@
 package fr.xephi.authme.util.lazytags;
 
-import org.bukkit.entity.Player;
-
 import java.util.function.Function;
 import java.util.function.Supplier;
 
@@ -13,11 +11,11 @@ public final class TagBuilder {
     private TagBuilder() {
     }
 
-    public static Tag createTag(String name, Function<Player, String> replacementFunction) {
-        return new PlayerTag(name, replacementFunction);
+    public static <A> Tag<A> createTag(String name, Function<A, String> replacementFunction) {
+        return new DependentTag<>(name, replacementFunction);
     }
 
-    public static Tag createTag(String name, Supplier<String> replacementFunction) {
-        return new SimpleTag(name, replacementFunction);
+    public static <A> Tag<A> createTag(String name, Supplier<String> replacementFunction) {
+        return new SimpleTag<>(name, replacementFunction);
     }
 }

src/main/java/fr/xephi/authme/util/lazytags/TagReplacer.java

@@ -0,0 +1,102 @@
+package fr.xephi.authme.util.lazytags;
+
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+/**
+ * Replaces tags lazily by first determining which tags are being used
+ * and only applying those replacements afterwards.
+ *
+ * @param <A> the argument type
+ */
+public class TagReplacer<A> {
+
+    private final List<Tag<A>> tags;
+    private final Collection<String> messages;
+
+    /**
+     * Private constructor. Use {@link #newReplacer(Collection, Collection)}.
+     *
+     * @param tags the tags that are being used in the messages
+     * @param messages the messages
+     */
+    private TagReplacer(List<Tag<A>> tags, Collection<String> messages) {
+        this.tags = tags;
+        this.messages = messages;
+    }
+
+    /**
+     * Creates a new instance of this class, which will provide the given
+     * messages adapted with the provided tags.
+     *
+     * @param allTags all available tags
+     * @param messages the messages to use
+     * @param <A> the argument type
+     * @return new tag replacer instance
+     */
+    public static <A> TagReplacer<A> newReplacer(Collection<Tag<A>> allTags, Collection<String> messages) {
+        List<Tag<A>> usedTags = determineUsedTags(allTags, messages);
+        return new TagReplacer<>(usedTags, messages);
+    }
+
+    /**
+     * Returns the messages with the tags applied for the given argument.
+     *
+     * @param argument the argument to get the messages for
+     * @return the adapted messages
+     */
+    public List<String> getAdaptedMessages(A argument) {
+        // Note ljacqu 20170121: Using a Map might seem more natural here but we avoid doing so for performance
+        // Although the performance gain here is probably minimal...
+        List<TagValue> tagValues = new LinkedList<>();
+        for (Tag<A> tag : tags) {
+            tagValues.add(new TagValue(tag.getName(), tag.getValue(argument)));
+        }
+
+        List<String> adaptedMessages = new LinkedList<>();
+        for (String line : messages) {
+            String adaptedLine = line;
+            for (TagValue tagValue : tagValues) {
+                adaptedLine = adaptedLine.replace(tagValue.tag, tagValue.value);
+            }
+            adaptedMessages.add(adaptedLine);
+        }
+        return adaptedMessages;
+    }
+
+    /**
+     * Determines which tags are used somewhere in the given list of messages.
+     *
+     * @param allTags all available tags
+     * @param messages the messages
+     * @param <A> argument type
+     * @return tags used at least once
+     */
+    private static <A> List<Tag<A>> determineUsedTags(Collection<Tag<A>> allTags, Collection<String> messages) {
+        return allTags.stream()
+            .filter(tag -> messages.stream().anyMatch(msg -> msg.contains(tag.getName())))
+            .collect(Collectors.toList());
+    }
+
+    /** (Tag, value) pair. */
+    private static final class TagValue {
+
+        /** The tag to replace. */
+        private final String tag;
+        /** The value to replace with. */
+        private final String value;
+
+        TagValue(String tag, String value) {
+            this.tag = tag;
+            this.value = value;
+        }
+
+        @Override
+        public String toString() {
+            return "TagValue[tag='" + tag + "', value='" + value + "']";
+        }
+    }
+
+}

src/main/java/fr/xephi/authme/util/lazytags/WrappedTagReplacer.java

@@ -0,0 +1,61 @@
+package fr.xephi.authme.util.lazytags;
+
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.function.BiFunction;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+/**
+ * Applies tags lazily to the String property of an item. This class wraps
+ * a {@link TagReplacer} with the extraction of the String property and
+ * the creation of new items with the adapted string property.
+ *
+ * @param <T> the item type
+ * @param <A> the argument type to evaluate the replacements
+ */
+public class WrappedTagReplacer<T, A> {
+
+    private final Collection<T> items;
+    private final BiFunction<T, String, ? extends T> itemCreator;
+    private final TagReplacer<A> tagReplacer;
+
+    /**
+     * Constructor.
+     *
+     * @param allTags all available tags
+     * @param items the items to apply the replacements on
+     * @param stringGetter getter of the String property to adapt on the items
+     * @param itemCreator a function of signature (T, String) -> T: the original item and the adapted String are passed
+     */
+    public WrappedTagReplacer(Collection<Tag<A>> allTags,
+                              Collection<T> items,
+                              Function<? super T, String> stringGetter,
+                              BiFunction<T, String, ? extends T> itemCreator) {
+        this.items = items;
+        this.itemCreator = itemCreator;
+
+        List<String> stringItems = items.stream().map(stringGetter).collect(Collectors.toList());
+        tagReplacer = TagReplacer.newReplacer(allTags, stringItems);
+    }
+
+    /**
+     * Creates adapted items for the given argument.
+     *
+     * @param argument the argument to adapt the items for
+     * @return the adapted items
+     */
+    public List<T> getAdaptedItems(A argument) {
+        List<String> adaptedStrings = tagReplacer.getAdaptedMessages(argument);
+        List<T> adaptedItems = new LinkedList<>();
+
+        Iterator<T> originalItemsIter = items.iterator();
+        Iterator<String> newStringsIter = adaptedStrings.iterator();
+        while (originalItemsIter.hasNext() && newStringsIter.hasNext()) {
+            adaptedItems.add(itemCreator.apply(originalItemsIter.next(), newStringsIter.next()));
+        }
+        return adaptedItems;
+    }
+}