/*
 * This file is part of Applied Energistics 2.
 * Copyright (c) 2013 - 2014, AlgorithmX2, All rights reserved.
 *
 * Applied Energistics 2 is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Applied Energistics 2 is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Applied Energistics 2.  If not, see <http://www.gnu.org/licenses/lgpl>.
 */

package appeng.me.storage;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map.Entry;

import appeng.api.networking.security.IActionSource;
import appeng.api.networking.storage.IBaseMonitor;
import appeng.api.storage.IMEInventory;
import appeng.api.storage.IMEMonitor;
import appeng.api.storage.IMEMonitorHandlerReceiver;
import appeng.api.storage.IStorageChannel;
import appeng.api.storage.data.IAEStack;
import appeng.api.storage.data.IItemList;
import appeng.util.Platform;
import appeng.util.inv.ItemListIgnoreCrafting;

public class MEMonitorPassThrough<T extends IAEStack<T>> extends MEPassThrough<T>
        implements IMEMonitor<T>, IMEMonitorHandlerReceiver<T> {

    private final HashMap<IMEMonitorHandlerReceiver<T>, Object> listeners = new HashMap<>();
    private IActionSource changeSource;
    private IMEMonitor<T> monitor;

    public MEMonitorPassThrough(final IMEInventory<T> i, final IStorageChannel channel) {
        super(i, channel);
        if (i instanceof IMEMonitor) {
            this.monitor = (IMEMonitor<T>) i;
        }
    }

    @Override
    public void setInternal(final IMEInventory<T> i) {
        if (this.monitor != null) {
            this.monitor.removeListener(this);
        }

        this.monitor = null;
        final IItemList<T> before = this.getInternal() == null ? this.getWrappedChannel().createList()
                : this.getInternal()
                        .getAvailableItems(new ItemListIgnoreCrafting(this.getWrappedChannel().createList()));

        super.setInternal(i);
        if (i instanceof IMEMonitor) {
            this.monitor = (IMEMonitor<T>) i;
        }

        final IItemList<T> after = this.getInternal() == null ? this.getWrappedChannel().createList()
                : this.getInternal()
                        .getAvailableItems(new ItemListIgnoreCrafting(this.getWrappedChannel().createList()));

        if (this.monitor != null) {
            this.monitor.addListener(this, this.monitor);
        }

        Platform.postListChanges(before, after, this, this.getChangeSource());
    }

    @Override
    public IItemList<T> getAvailableItems(final IItemList out) {
        super.getAvailableItems(new ItemListIgnoreCrafting(out));
        return out;
    }

    @Override
    public void addListener(final IMEMonitorHandlerReceiver<T> l, final Object verificationToken) {
        this.listeners.put(l, verificationToken);
    }

    @Override
    public void removeListener(final IMEMonitorHandlerReceiver<T> l) {
        this.listeners.remove(l);
    }

    @Override
    public IItemList<T> getStorageList() {
        if (this.monitor == null) {
            final IItemList<T> out = this.getWrappedChannel().createList();
            this.getInternal().getAvailableItems(new ItemListIgnoreCrafting(out));
            return out;
        }
        return this.monitor.getStorageList();
    }

    @Override
    public boolean isValid(final Object verificationToken) {
        return verificationToken == this.monitor;
    }

    @Override
    public void postChange(final IBaseMonitor<T> monitor, final Iterable<T> change, final IActionSource source) {
        final Iterator<Entry<IMEMonitorHandlerReceiver<T>, Object>> i = this.listeners.entrySet().iterator();
        while (i.hasNext()) {
            final Entry<IMEMonitorHandlerReceiver<T>, Object> e = i.next();
            final IMEMonitorHandlerReceiver<T> receiver = e.getKey();
            if (receiver.isValid(e.getValue())) {
                receiver.postChange(this, change, source);
            } else {
                i.remove();
            }
        }
    }

    @Override
    public void onListUpdate() {
        final Iterator<Entry<IMEMonitorHandlerReceiver<T>, Object>> i = this.listeners.entrySet().iterator();
        while (i.hasNext()) {
            final Entry<IMEMonitorHandlerReceiver<T>, Object> e = i.next();
            final IMEMonitorHandlerReceiver<T> receiver = e.getKey();
            if (receiver.isValid(e.getValue())) {
                receiver.onListUpdate();
            } else {
                i.remove();
            }
        }
    }

    private IActionSource getChangeSource() {
        return this.changeSource;
    }

    public void setChangeSource(final IActionSource changeSource) {
        this.changeSource = changeSource;
    }
}
