/**
 * Copyright (c) 2011-2015, SpaceToad and the BuildCraft Team
 * http://www.mod-buildcraft.com
 * <p/>
 * BuildCraft is distributed under the terms of the Minecraft Mod Public
 * License 1.0, or MMPL. Please check the contents of the license located in
 * http://www.mod-buildcraft.com/MMPL-1.0.txt
 */
package buildcraft.core.statements;

import java.util.Locale;

import net.minecraft.client.renderer.texture.IIconRegister;
import net.minecraft.inventory.IInventory;
import net.minecraft.item.ItemStack;
import net.minecraft.tileentity.TileEntity;

import net.minecraftforge.common.util.ForgeDirection;

import buildcraft.api.core.IInvSlot;
import buildcraft.api.statements.IStatementContainer;
import buildcraft.api.statements.IStatementParameter;
import buildcraft.api.statements.ITriggerExternal;
import buildcraft.api.statements.StatementParameterItemStack;
import buildcraft.core.ItemList;
import buildcraft.core.lib.inventory.InventoryIterator;
import buildcraft.core.lib.inventory.StackHelper;
import buildcraft.core.lib.utils.StringUtils;

public class TriggerInventory extends BCStatement implements ITriggerExternal {

	public enum State {

		Empty, Contains, Space, Full
	}

	public State state;

	public TriggerInventory(State state) {
		super("buildcraft:inventory." + state.name().toLowerCase(Locale.ENGLISH), "buildcraft.inventory." + state.name().toLowerCase(Locale.ENGLISH));

		this.state = state;
	}

	@Override
	public int maxParameters() {
		return state == State.Contains || state == State.Space ? 1 : 0;
	}

	@Override
	public String getDescription() {
		return StringUtils.localize("gate.trigger.inventory." + state.name().toLowerCase(Locale.ENGLISH));
	}

	@Override
	public boolean isTriggerActive(TileEntity tile, ForgeDirection side, IStatementContainer container, IStatementParameter[] parameters) {
		ItemStack searchedStack = null;

		if (parameters != null && parameters.length >= 1 && parameters[0] != null) {
			searchedStack = parameters[0].getItemStack();
		}

		if (tile instanceof IInventory) {
			boolean hasSlots = false;
			boolean foundItems = false;
			boolean foundSpace = false;

			for (IInvSlot slot : InventoryIterator.getIterable((IInventory) tile, side.getOpposite())) {
				hasSlots = true;
				ItemStack stack = slot.getStackInSlot();

				foundItems |= stack != null
						&& (searchedStack == null || StackHelper.canStacksOrListsMerge(stack, searchedStack));

				foundSpace |= (stack == null
						|| (StackHelper.canStacksOrListsMerge(stack, searchedStack) && stack.stackSize < stack
						.getMaxStackSize()))
						&& (searchedStack == null || searchedStack.getItem() instanceof ItemList || slot
						.canPutStackInSlot(searchedStack));
				// On the test above, we deactivate item list as inventories
				// typically don't check for lists possibility. This is a
				// heuristic which is more desirable than expensive computation
				// of list components or possibility of extension
			}

			if (!hasSlots) {
				return false;
			}

			switch (state) {
				case Empty:
					return !foundItems;
				case Contains:
					return foundItems;
				case Space:
					return foundSpace;
				default:
					return !foundSpace;
			}
		}

		return false;
	}


	@Override
	public void registerIcons(IIconRegister register) {
		icon = register.registerIcon("buildcraftcore:triggers/trigger_inventory_" + state.name().toLowerCase());
	}

	@Override
	public IStatementParameter createParameter(int index) {
		return new StatementParameterItemStack();
	}
}