Core/src/main/java/eu/univento/core/api/items/ClickInventory.java

package eu.univento.core.api.items;

import eu.univento.core.api.items.events.NamedCloseEvent;
import eu.univento.core.api.items.events.PageCloseEvent;
import eu.univento.core.api.player.CustomPlayer;
import org.bukkit.Bukkit;
import org.bukkit.Material;
import org.bukkit.event.inventory.InventoryClickEvent;
import org.bukkit.event.inventory.InventoryDragEvent;
import org.bukkit.inventory.Inventory;
import org.bukkit.inventory.ItemStack;
import org.bukkit.metadata.FixedMetadataValue;
import org.bukkit.plugin.java.JavaPlugin;

import java.lang.reflect.Array;
import java.util.HashMap;

/**
 * @author joethei
 * @version 0.1
 */
public abstract class ClickInventory<E>{

    protected static JavaPlugin plugin;
    protected Inventory currentInventory;
    protected boolean inventoryInUse;
    private boolean modifiable;
    private CustomPlayer player;
    private boolean playerInventoryUsed;
    private ItemStack[] previousContents;
    private String inventoryName;
    private HashMap<Object, Object> savedData;

    protected void saveContents() {
        this.previousContents = this.getPlayer().getInventory().getContents().clone();
    }

    public Object getData(final Object key) {
        return this.savedData.get(key);
    }

    public ClickInventory setData(final Object key, final Object obj) {
        if (obj == null) {
            this.savedData.remove(key);
        }
        else {
            this.savedData.put(key, obj);
        }
        return this;
    }

    public ClickInventory(String inventoryName, final CustomPlayer player) {
        this.savedData = new HashMap<>();
        this.player = player;
        if (inventoryName == null) {
            inventoryName = this.getClass().getSimpleName();
        }
        this.inventoryName = inventoryName;
    }

    public String getName() {
        return this.inventoryName;
    }

    public ClickInventory setPlayerInventory() {
        if (!this.isInUse()) {
            this.playerInventoryUsed = true;
        }
        return this;
    }

    public void closeInventory() {
        this.closeInventory(true);
    }

    protected void onInventoryDrag(final InventoryDragEvent event) {
        if (!this.isModifiable()) {
            event.getRawSlots().stream().filter(this::checkInMenu).forEachOrdered(slot -> event.setCancelled(true));
        }
    }

    protected boolean checkInMenu(int rawSlot) {
        if (this.isPlayerInventory()) {
            if (this.getPlayer().getOpenInventory().getTopInventory().getHolder() != this.getPlayer()) {
                rawSlot -= this.getPlayer().getOpenInventory().getTopInventory().getSize();
            }
            return rawSlot >= 0 && rawSlot < this.currentInventory.getSize();
        }
        return rawSlot < this.currentInventory.getSize();
    }

    public boolean isPlayerInventory() {
        return this.playerInventoryUsed;
    }

    protected abstract void onInventoryClick(final InventoryClickEvent e);

    private void closeInventory(final boolean forceClose, final boolean restoreInventory) {
        InventoryManager.removeInventory(this);
        this.inventoryInUse = false;
        if (this.getPlayer().hasMetadata(this.getClass().getSimpleName())) {
            final E[] invs = (E[])this.getPlayer().getMetadata(this.getClass().getSimpleName()).get(0).value();
            if (invs[isPlayerInventory() ? 1 : 0] == this)
                invs[isPlayerInventory() ? 1 : 0] = null;
        }
        if (this instanceof NamedInventory) {
            Bukkit.getPluginManager().callEvent(new NamedCloseEvent((NamedInventory) this));
        }
        if (this instanceof PageInventory) {
            Bukkit.getPluginManager().callEvent(new PageCloseEvent((PageInventory) this));
        }
        if (forceClose && (!this.isPlayerInventory() || this.getPlayer().getOpenInventory().getTopInventory().equals(this.currentInventory))) {
            this.getPlayer().closeInventory();
        }
        if (this.isPlayerInventory() && restoreInventory) {
            this.getPlayer().getInventory().clear();
            this.getPlayer().getInventory().setContents(this.previousContents);
            Bukkit.getScheduler().scheduleSyncDelayedTask(ClickInventory.plugin, () -> ClickInventory.this.getPlayer().updateInventory());
        }
    }

    public void closeInventory(final boolean forceClose) {
        this.closeInventory(forceClose, true);
    }

    public ItemStack getItem(int slot) {
        if (this.isPlayerInventory()) {
            slot += 9;
            if (slot >= 36) {
                slot -= 36;
            }
        }
        if (this.currentInventory != null && this.currentInventory.getSize() > slot) {
            return this.currentInventory.getItem(slot);
        }
        return null;
    }

    protected void setItems(final ItemStack[] items) {
        if (this.isPlayerInventory()) {
            for (int i = 0; i < items.length; ++i) {
                this.setItem(i, items[i]);
            }
        }
        else {
            this.currentInventory.setContents(items);
        }
    }

    protected void setItem(int slot, final ItemStack item) {
        if (this.isPlayerInventory()) {
            slot += 9;
            if (slot >= 36) {
                slot -= 36;
            }
        }
        this.currentInventory.setItem(slot, item);
    }

    public CustomPlayer getPlayer() {
        return this.player;
    }

    public boolean isInUse() {
        return this.inventoryInUse;
    }

    public boolean isModifiable() {
        return this.modifiable;
    }

    protected void openInventory() {
        final boolean isSwitchingInventory = this.isInUse();
        ItemStack heldItem = null;
        final ClickInventory[] invs = new ClickInventory[2];
        for (final String inv : new String[] { "PageInventory", "NamedInventory", "AnvilInventory" }) {
            if (this.getPlayer().hasMetadata(inv)) {
                final E[] invss = (E[])(this.getPlayer().hasMetadata(inv) ? this.getPlayer().getMetadata(inv).get(0).value() : null);
                if (invss != null) {
                    for (int i = 0; i < 2; ++i) {
                        if (invss[i] != null) {
                            invs[i] = (ClickInventory)invss[i];
                        }
                    }
                }
            }
        }
        if (!this.isPlayerInventory()) {
            this.inventoryInUse = false;
            boolean previous = false;
            if (invs[1] != null) {
                previous = invs[1].inventoryInUse;
                invs[1].inventoryInUse = false;
            }
            if (isSwitchingInventory) {
                heldItem = this.getPlayer().getItemOnCursor();
                this.getPlayer().setItemOnCursor(new ItemStack(Material.AIR));
            }
            if (invs[1] != null) {
                invs[1].inventoryInUse = previous;
            }
        }
        else {
            this.getPlayer().updateInventory();
            if (!isSwitchingInventory && this.getPlayer().getOpenInventory().getTopInventory().getHolder() == this.getPlayer()) {
                this.getPlayer().openInventory(Bukkit.createInventory(null, 0, this.getTitle()));
            }
        }
        if (!isSwitchingInventory) {
            InventoryManager.addInventory(this);
            final int slot = this.isPlayerInventory() ? 1 : 0;
            if (invs[slot] != null) {
                if (invs[slot].inventoryInUse) {
                    invs[slot].closeInventory(false, false);
                }
                if (this.isPlayerInventory()) {
                    this.previousContents = invs[1].previousContents;
                }
            }
            final E[] inv2 = (E[])(this.getPlayer().hasMetadata(this.getClass().getSimpleName()) ? this.getPlayer().getMetadata(this.getClass().getSimpleName()).get(0).value() : ((Object[]) Array.newInstance(this.getClass(), 2)));
            inv2[slot] = (E)this;
            this.getPlayer().setMetadata(this.getClass().getSimpleName(), new FixedMetadataValue(ClickInventory.plugin, inv2));
        }
        else if (heldItem != null && heldItem.getType() != Material.AIR) {
            this.getPlayer().setItemOnCursor(heldItem);
            this.getPlayer().updateInventory();
        }
        this.inventoryInUse = true;
    }

    public abstract String getTitle();

    public void setModifiable(final boolean modifiable) {
        this.modifiable = modifiable;
    }

    public abstract void setTitle(final String p0);
}