VillagerTradeLimiter/src/com/pretzel/dev/villagertradelimiter/listeners/InventoryListener.java

package com.pretzel.dev.villagertradelimiter.listeners;

import com.pretzel.dev.villagertradelimiter.VillagerTradeLimiter;
import com.pretzel.dev.villagertradelimiter.data.Cooldown;
import com.pretzel.dev.villagertradelimiter.data.PlayerData;
import com.pretzel.dev.villagertradelimiter.settings.Settings;
import com.pretzel.dev.villagertradelimiter.wrappers.VillagerWrapper;
import org.bukkit.Bukkit;
import org.bukkit.Material;
import org.bukkit.configuration.ConfigurationSection;
import org.bukkit.entity.Player;
import org.bukkit.entity.Villager;
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.inventory.InventoryType;
import org.bukkit.inventory.ItemStack;
import org.bukkit.inventory.MerchantRecipe;

import java.time.Instant;
import java.util.Date;

public class InventoryListener implements Listener {

    private final VillagerTradeLimiter instance;
    private final Settings settings;

    /**
     * @param instance The instance of VillagerTradeLimiter.java
     * @param settings The settings instance
     */
    public InventoryListener(final VillagerTradeLimiter instance, final Settings settings) {
        this.instance = instance;
        this.settings = settings;
    }

    /** Handles when a player clicks in an inventory window */
    @EventHandler
    public void onPlayerClickInventory(final InventoryClickEvent event) {
        if(event.getInventory().getType() != InventoryType.CHEST) return;
        if(event.getInventory().getSize() != 9) return;
        if(!(event.getWhoClicked() instanceof Player)) return;
        if(settings.shouldSkipNPC(event.getWhoClicked())) return; //Skips NPCs
        ItemStack barrier = event.getInventory().getItem(8);
        if(barrier == null || !barrier.isSimilar(instance.getBarrier())) return;

        //If the inventory matches the invsee inventory, cancel click events
        event.setCancelled(true);
        if(event.getCurrentItem() != null && event.getCurrentItem().isSimilar(instance.getBarrier())) {
            Bukkit.getScheduler().runTaskLater(instance, () -> event.getWhoClicked().closeInventory(), 0L);
        }
    }

    /** Handles when a player stops trading with a villager */
    @EventHandler
    public void onPlayerStopTrading(final InventoryCloseEvent event) {
        //Don't do anything unless the player is actually finished trading with a villager
        if(event.getInventory().getType() != InventoryType.MERCHANT) return;
        if(!(event.getPlayer() instanceof Player)) return;
        if(!(event.getInventory().getHolder() instanceof Villager)) return;
        final Player player = (Player)event.getPlayer();
        final Villager villager = (Villager)event.getInventory().getHolder();
        if(settings.shouldSkipNPC(player) || settings.shouldSkipNPC(villager)) return; //Skips NPCs

        //Reset the villager's NBT data when a player is finished trading
        final PlayerData playerData = instance.getPlayerData().get(player.getUniqueId());
        if(playerData == null) return;

        final VillagerWrapper villagerWrapper = playerData.getTradingVillager();
        if(villagerWrapper == null) return;
        playerData.setTradingVillager(null);
        villagerWrapper.reset();
    }

    /** Handles when a player successfully trades with a villager */
    @EventHandler
    public void onPlayerMakeTrade(final InventoryClickEvent event) {
        if(event.getInventory().getType() != InventoryType.MERCHANT) return;
        if(!(event.getInventory().getHolder() instanceof Villager)) return;
        if(!(event.getWhoClicked() instanceof Player)) return;
        if(event.getRawSlot() != 2) return;
        final Player player = (Player)event.getWhoClicked();
        final Villager villager = (Villager)event.getInventory().getHolder();
        if(settings.shouldSkipNPC(player) || settings.shouldSkipNPC(villager)) return; //Skips NPCs

        //Get the items involved in the trade
        final ItemStack result = event.getCurrentItem();
        ItemStack ingredient1 = event.getInventory().getItem(0);
        ItemStack ingredient2 = event.getInventory().getItem(1);
        if(result == null || result.getType() == Material.AIR) return;
        if(ingredient1 == null) ingredient1 = new ItemStack(Material.AIR, 1);
        if(ingredient2 == null) ingredient2 = new ItemStack(Material.AIR, 1);

        //Check if there is a cooldown set for the trade
        final ConfigurationSection overrides = instance.getCfg().getConfigurationSection("Overrides");
        if(overrides == null) return;

        final String type = settings.getType(result, ingredient1, ingredient2);
        String cooldownStr = instance.getCfg().getString("Cooldown", "0");
        cooldownStr = overrides.getString(type+".Cooldown", cooldownStr);
        String restockStr = instance.getCfg().getString("Restock", "0");
        restockStr = overrides.getString(type+".Restock", restockStr);

        if(cooldownStr.equals("0") && restockStr.equals("0")) return;

        //Get the selected recipe by the items in the slots
        final MerchantRecipe selectedRecipe = getSelectedRecipe(villager, ingredient1, ingredient2, result);
        if(selectedRecipe == null) {
            event.setCancelled(true);
            return;
        }

        //Add a cooldown to the trade if the player has reached the max uses
        final PlayerData playerData = instance.getPlayerData().get(player.getUniqueId());
        final PlayerData villagerData = instance.getPlayerData().get(villager.getUniqueId());
        if(playerData == null || playerData.getTradingVillager() == null) return;
        Bukkit.getScheduler().runTaskLater(instance, () -> {
            int uses = selectedRecipe.getUses();
            final String time = Cooldown.formatTime(Date.from(Instant.now()));
            if(uses >= selectedRecipe.getMaxUses()) {
                if(!playerData.getTradingCooldowns().containsKey(type)) {
                    playerData.getTradingCooldowns().put(type, time);
                }
                if(villagerData != null && !villagerData.getTradingCooldowns().containsKey(type)) {
                    villagerData.getTradingCooldowns().put(type, time);
                }
            }
        }, 1);
    }

    /**
     * @param villager The villager to get the recipe from
     * @param ingredient1 The item in the first ingredient slot of the trade interface
     * @param ingredient2 The item in the second ingredient slot of the trade interface
     * @param result The item in the result slot of the trade interface
     * @return The villager's recipe that matches the items in the slots
     */
    private MerchantRecipe getSelectedRecipe(final Villager villager, final ItemStack ingredient1, final ItemStack ingredient2, final ItemStack result) {
        for(MerchantRecipe recipe : villager.getRecipes()) {
            final ItemStack item1 = recipe.getIngredients().get(0);
            final ItemStack item2 = recipe.getIngredients().get(1);
            if(!recipe.getResult().isSimilar(result)) continue;
            if((item1.isSimilar(ingredient1) && item2.isSimilar(ingredient2)) || (item1.isSimilar(ingredient2) && item2.isSimilar(ingredient1)))
                return recipe;
        }
        return null;
    }
}