commit ead39f6fd10f97944343be77bb6375b117da88f4
Author: EpicKnarvik97 <kristian.knarvik@knett.no>
Date:   Wed Jan 18 16:15:51 2023 +0100

    Initial commit

diff --git a/pom.xml b/pom.xml
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index 0000000..6011849
--- /dev/null
+++ b/pom.xml
@@ -0,0 +1,88 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>net.knarcraft</groupId>
+    <artifactId>KnarGUI</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <packaging>jar</packaging>
+
+    <name>KnarGUI</name>
+
+    <properties>
+        <java.version>16</java.version>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.8.1</version>
+                <configuration>
+                    <source>${java.version}</source>
+                    <target>${java.version}</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+                <version>3.2.4</version>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>shade</goal>
+                        </goals>
+                        <configuration>
+                            <createDependencyReducedPom>false</createDependencyReducedPom>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+    </build>
+
+    <repositories>
+        <repository>
+            <id>spigotmc-repo</id>
+            <url>https://hub.spigotmc.org/nexus/content/repositories/snapshots/</url>
+        </repository>
+        <repository>
+            <id>sonatype</id>
+            <url>https://oss.sonatype.org/content/groups/public/</url>
+        </repository>
+        <repository>
+            <id>knarcraft-repo</id>
+            <url>https://git.knarcraft.net/api/packages/EpicKnarvik97/maven</url>
+        </repository>
+    </repositories>
+    <distributionManagement>
+        <repository>
+            <id>knarcraft-repo</id>
+            <url>https://git.knarcraft.net/api/packages/EpicKnarvik97/maven</url>
+        </repository>
+        <snapshotRepository>
+            <id>knarcraft-repo</id>
+            <url>https://git.knarcraft.net/api/packages/EpicKnarvik97/maven</url>
+        </snapshotRepository>
+    </distributionManagement>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.spigotmc</groupId>
+            <artifactId>spigot-api</artifactId>
+            <version>1.19.3-R0.1-SNAPSHOT</version>
+            <scope>provided</scope>
+        </dependency>
+    </dependencies>
+</project>
diff --git a/src/net/knarcraft/knargui/AbstractGUI.java b/src/net/knarcraft/knargui/AbstractGUI.java
new file mode 100644
index 0000000..3fb8988
--- /dev/null
+++ b/src/net/knarcraft/knargui/AbstractGUI.java
@@ -0,0 +1,110 @@
+package net.knarcraft.knargui;
+
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+import org.bukkit.event.inventory.ClickType;
+import org.bukkit.event.inventory.InventoryType;
+import org.bukkit.inventory.Inventory;
+import org.bukkit.inventory.ItemStack;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+
+public abstract class AbstractGUI {
+
+    private final UUID uuid;
+    private final Inventory inventory;
+    private final Map<Integer, Map<ClickType, GUIAction>> actions;
+
+    /**
+     * Instantiates a new abstract GUI
+     *
+     * @param inventorySize <p>The size of the inventory (ignored if inventory type is set)</p>
+     * @param inventoryName <p>The name of the inventory</p>
+     * @param inventoryType <p>The type of inventory to use for the GUI, or null for a variable chest GUI</p>
+     */
+    public AbstractGUI(int inventorySize, String inventoryName, InventoryType inventoryType) {
+        this.uuid = UUID.randomUUID();
+        if (inventoryType == null) {
+            this.inventory = Bukkit.createInventory(null, inventorySize, inventoryName);
+        } else {
+            this.inventory = Bukkit.createInventory(null, inventoryType, inventoryName);
+        }
+        this.actions = new HashMap<>();
+        GUIRegistry.registerGUI(this);
+    }
+
+    /**
+     * Gets this inventory's unique id
+     *
+     * @return <p>This inventory's unique id</p>
+     */
+    public UUID getUuid() {
+        return this.uuid;
+    }
+
+    /**
+     * Gets the inventory used for this GUI
+     *
+     * @return <p>The inventory used for this GUI</p>
+     */
+    public Inventory getInventory() {
+        return this.inventory;
+    }
+
+    /**
+     * Sets the item in the given inventory slot
+     *
+     * @param inventorySlot <p>The inventory slot to set the item for</p>
+     * @param itemStack     <p>The item to display in the slot</p>
+     * @return <p>This GUI. Used for chaining commands</p>
+     */
+    public AbstractGUI setItem(int inventorySlot, ItemStack itemStack) {
+        this.inventory.setItem(inventorySlot, itemStack);
+        return this;
+    }
+
+    /**
+     * Sets the action for clicking the given item slot
+     *
+     * @param inventorySlot <p>The inventory slot to set the action for</p>
+     * @param clickType     <p>The type of click to set an action for</p>
+     * @param action        <p>The action triggered when a click occurs</p>
+     * @return <p>This GUI. Used for chaining commands</p>
+     */
+    public AbstractGUI setClickAction(int inventorySlot, ClickType clickType, GUIAction action) {
+        if (!this.actions.containsKey(inventorySlot)) {
+            this.actions.put(inventorySlot, new HashMap<>());
+        }
+        this.actions.get(inventorySlot).put(clickType, action);
+        return this;
+    }
+
+    /**
+     * Opens this inventory for the given player
+     *
+     * @param player <p>The player to open this inventory for</p>
+     */
+    public void openFor(Player player) {
+        player.openInventory(this.inventory);
+        GUIRegistry.registerOpenGUI(player, getUuid());
+    }
+
+    /**
+     * Gets the action to trigger for the given inventory slot, and the given click type
+     *
+     * @param inventorySlot <p>The inventory slot to get the action for</p>
+     * @param clickType     <p>The click type to get the action for</p>
+     * @return <p>The action to run, or null if not set</p>
+     */
+    public GUIAction getAction(int inventorySlot, ClickType clickType) {
+        Map<ClickType, GUIAction> storedActions = this.actions.get(inventorySlot);
+        if (storedActions == null) {
+            return null;
+        } else {
+            return storedActions.get(clickType);
+        }
+    }
+
+}
diff --git a/src/net/knarcraft/knargui/AnvilGUI.java b/src/net/knarcraft/knargui/AnvilGUI.java
new file mode 100644
index 0000000..1c111ed
--- /dev/null
+++ b/src/net/knarcraft/knargui/AnvilGUI.java
@@ -0,0 +1,52 @@
+package net.knarcraft.knargui;
+
+import org.bukkit.entity.Player;
+import org.bukkit.event.inventory.InventoryType;
+import org.bukkit.inventory.AnvilInventory;
+
+import java.util.function.BiConsumer;
+
+/**
+ * A user-interface using an anvil GUI
+ */
+public abstract class AnvilGUI extends AbstractGUI {
+
+    private BiConsumer<String, Player> action;
+
+    public AnvilGUI(String inventoryName) {
+        super(0, inventoryName, InventoryType.ANVIL);
+    }
+
+    /**
+     * Gets the text the user has written in the renaming field
+     *
+     * @return <p>The text in the renaming field</p>
+     */
+    public String getText() {
+        AnvilInventory anvilInventory = (AnvilInventory) this.getInventory();
+        return anvilInventory.getRenameText();
+    }
+
+    /**
+     * Sets an action to be run if this GUI is closed
+     *
+     * <p>The action will be passed the current value of the anvil text</p>
+     *
+     * @param action <p>The action to be run</p>
+     */
+    public void setCloseAction(BiConsumer<String, Player> action) {
+        this.action = action;
+    }
+
+    /**
+     * Runs the action this GUI should run when closing
+     *
+     * @param player <p>The player that closed this GUI</p>
+     */
+    public void runCloseAction(Player player) {
+        if (action != null) {
+            this.action.accept(getText(), player);
+        }
+    }
+
+}
diff --git a/src/net/knarcraft/knargui/GUIAction.java b/src/net/knarcraft/knargui/GUIAction.java
new file mode 100644
index 0000000..b0ef768
--- /dev/null
+++ b/src/net/knarcraft/knargui/GUIAction.java
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+package net.knarcraft.knargui;
+
+import org.bukkit.entity.Player;
+
+/**
+ * An action which can be triggered on GUI interaction
+ */
+public interface GUIAction {
+
+    /**
+     * Runs this action for the given player
+     *
+     * @param player <p>The player that triggered this action</p>
+     */
+    void run(Player player);
+
+}
diff --git a/src/net/knarcraft/knargui/GUIListener.java b/src/net/knarcraft/knargui/GUIListener.java
new file mode 100644
index 0000000..d05c604
--- /dev/null
+++ b/src/net/knarcraft/knargui/GUIListener.java
@@ -0,0 +1,52 @@
+package net.knarcraft.knargui;
+
+import org.bukkit.entity.HumanEntity;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.inventory.InventoryClickEvent;
+import org.bukkit.event.inventory.InventoryCloseEvent;
+import org.bukkit.event.player.PlayerQuitEvent;
+
+/**
+ * A listener for tracking GUI interaction
+ */
+public class GUIListener implements Listener {
+
+    @EventHandler
+    public void onInventoryClick(InventoryClickEvent event) {
+        HumanEntity clicker = event.getWhoClicked();
+        //We're not interested in NPCs
+        if (!(clicker instanceof Player player)) {
+            return;
+        }
+
+        AbstractGUI gui = GUIRegistry.getOpenGUI(player);
+
+        //Not our GUI
+        if (gui == null) {
+            return;
+        }
+
+        //Cancel the event to prevent the player from moving or taking items
+        event.setCancelled(true);
+        GUIAction action = gui.getAction(event.getSlot(), event.getClick());
+        if (action != null) {
+            action.run(player);
+        }
+    }
+
+    @EventHandler
+    public void onInventoryClose(InventoryCloseEvent event) {
+        if (!(event.getPlayer() instanceof Player player)) {
+            return;
+        }
+        GUIRegistry.closeGUI(player);
+    }
+
+    @EventHandler
+    public void onPlayerQuit(PlayerQuitEvent event) {
+        GUIRegistry.closeGUI(event.getPlayer());
+    }
+
+}
diff --git a/src/net/knarcraft/knargui/GUIRegistry.java b/src/net/knarcraft/knargui/GUIRegistry.java
new file mode 100644
index 0000000..0a6c738
--- /dev/null
+++ b/src/net/knarcraft/knargui/GUIRegistry.java
@@ -0,0 +1,86 @@
+package net.knarcraft.knargui;
+
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+
+/**
+ * A registry that keeps track of every GUI
+ */
+public class GUIRegistry {
+
+    private static final Map<UUID, AbstractGUI> registeredGUIs = new HashMap<>();
+    private static final Map<UUID, UUID> openGUIs = new HashMap<>();
+
+    /**
+     * Registers a GUI being opened
+     *
+     * @param player <p>The player the GUI is open for</p>
+     * @param guiId  <p>The unique identifier for the opened GUI</p>
+     */
+    public static void registerOpenGUI(Player player, UUID guiId) {
+        if (!registeredGUIs.containsKey(guiId)) {
+            throw new IllegalArgumentException("Tried to register GUI being opened for unknown GUI");
+        }
+        openGUIs.put(player.getUniqueId(), guiId);
+    }
+
+    /**
+     * Registers the given GUI as a tracked GUI
+     *
+     * @param newGUI <p>The GUI to register</p>
+     */
+    public static void registerGUI(AbstractGUI newGUI) {
+        registeredGUIs.put(newGUI.getUuid(), newGUI);
+    }
+
+    /**
+     * Gets the given player's currently open GUI
+     *
+     * @param player <p>The player to get the GUI for</p>
+     * @return <p>The player's open GUI, or null if no GUI is open</p>
+     */
+    public static AbstractGUI getOpenGUI(Player player) {
+        UUID guiId = openGUIs.get(player.getUniqueId());
+        if (guiId == null) {
+            return null;
+        }
+
+        return registeredGUIs.get(guiId);
+    }
+
+    /**
+     * Registers a GUI as being closed for the given player
+     *
+     * @param player <p>The player that closed a GUI</p>
+     */
+    public static void closeGUI(Player player) {
+        //Run the close action if an anvil GUI is used
+        AbstractGUI gui = getOpenGUI(player);
+        if (gui instanceof AnvilGUI anvilGUI) {
+            anvilGUI.runCloseAction(player);
+        }
+        //Un-register the player's open GUI
+        openGUIs.remove(player.getUniqueId());
+    }
+
+    /**
+     * Deletes the given GUI
+     *
+     * @param guiId <p>The id of the GUI to delete</p>
+     */
+    public static void deleteGUI(UUID guiId) {
+        for (Player player : Bukkit.getOnlinePlayers()) {
+            AbstractGUI gui = getOpenGUI(player);
+            //Close the deleted GUI for every player that has it open. The listener should take care of the rest.
+            if (gui != null && gui.getUuid().equals(guiId)) {
+                player.closeInventory();
+            }
+        }
+        registeredGUIs.remove(guiId);
+    }
+
+}
diff --git a/src/net/knarcraft/knargui/KnarGUI.java b/src/net/knarcraft/knargui/KnarGUI.java
new file mode 100644
index 0000000..9e66306
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+++ b/src/net/knarcraft/knargui/KnarGUI.java
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+package net.knarcraft.knargui;
+
+@SuppressWarnings("unused")
+public final class KnarGUI {
+
+    private KnarGUI() {
+
+    }
+
+}