/*
 * 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.tile.crafting;

import java.util.Collections;
import java.util.EnumSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Optional;

import javax.annotation.Nonnull;

import net.minecraft.block.BlockState;
import net.minecraft.item.ItemStack;
import net.minecraft.nbt.CompoundNBT;
import net.minecraft.tileentity.TileEntity;
import net.minecraft.tileentity.TileEntityType;
import net.minecraft.util.Direction;
import net.minecraft.util.math.BlockPos;
import net.minecraft.world.IBlockReader;
import net.minecraftforge.client.model.data.IModelData;
import net.minecraftforge.common.util.Constants;

import appeng.api.config.Actionable;
import appeng.api.implementations.IPowerChannelState;
import appeng.api.networking.GridFlags;
import appeng.api.networking.IGridHost;
import appeng.api.networking.events.MENetworkChannelsChanged;
import appeng.api.networking.events.MENetworkEventSubscribe;
import appeng.api.networking.events.MENetworkPowerStatusChange;
import appeng.api.storage.IMEInventory;
import appeng.api.storage.channels.IItemStorageChannel;
import appeng.api.storage.data.IAEItemStack;
import appeng.api.util.AEPartLocation;
import appeng.api.util.WorldCoord;
import appeng.block.crafting.AbstractCraftingUnitBlock;
import appeng.block.crafting.AbstractCraftingUnitBlock.CraftingUnitType;
import appeng.core.Api;
import appeng.me.cluster.IAECluster;
import appeng.me.cluster.IAEMultiBlock;
import appeng.me.cluster.implementations.CraftingCPUCalculator;
import appeng.me.cluster.implementations.CraftingCPUCluster;
import appeng.me.helpers.AENetworkProxy;
import appeng.me.helpers.AENetworkProxyMultiblock;
import appeng.tile.grid.AENetworkTileEntity;
import appeng.util.Platform;

public class CraftingTileEntity extends AENetworkTileEntity implements IAEMultiBlock, IPowerChannelState {

    private final CraftingCPUCalculator calc = new CraftingCPUCalculator(this);
    private CompoundNBT previousState = null;
    private boolean isCoreBlock = false;
    private CraftingCPUCluster cluster;

    public CraftingTileEntity(TileEntityType<?> tileEntityTypeIn) {
        super(tileEntityTypeIn);
        this.getProxy().setFlags(GridFlags.MULTIBLOCK, GridFlags.REQUIRE_CHANNEL);
        this.getProxy().setValidSides(EnumSet.noneOf(Direction.class));
    }

    @Override
    protected AENetworkProxy createProxy() {
        return new AENetworkProxyMultiblock(this, "proxy", this.getItemFromTile(this), true);
    }

    @Override
    protected ItemStack getItemFromTile(final Object obj) {
        Optional<ItemStack> is;

        if (((CraftingTileEntity) obj).isAccelerator()) {
            is = Api.instance().definitions().blocks().craftingAccelerator().maybeStack(1);
        } else {
            is = Api.instance().definitions().blocks().craftingUnit().maybeStack(1);
        }

        return is.orElseGet(() -> super.getItemFromTile(obj));
    }

    @Override
    public boolean canBeRotated() {
        return true;// return BlockCraftingUnit.checkType( world.getBlockMetadata( xCoord, yCoord,
                    // zCoord ),
        // BlockCraftingUnit.BASE_MONITOR );
    }

    @Override
    public void setName(final String name) {
        super.setName(name);
        if (this.cluster != null) {
            this.cluster.updateName();
        }
    }

    public boolean isAccelerator() {
        if (this.world == null) {
            return false;
        }

        final AbstractCraftingUnitBlock unit = (AbstractCraftingUnitBlock) this.world.getBlockState(this.pos)
                .getBlock();
        return unit.type == CraftingUnitType.ACCELERATOR;
    }

    @Override
    public void onReady() {
        super.onReady();
        this.getProxy().setVisualRepresentation(this.getItemFromTile(this));
        this.calc.calculateMultiblock(world, getLocation());
    }

    public void updateMultiBlock(BlockPos changedPos) {
        this.calc.updateMultiblockAfterNeighborUpdate(this.world, this.getLocation(), changedPos);
    }

    public void updateStatus(final CraftingCPUCluster c) {
        if (this.cluster != null && this.cluster != c) {
            this.cluster.breakCluster();
        }

        this.cluster = c;
        this.updateMeta(true);
    }

    public void updateMeta(final boolean updateFormed) {
        if (this.world == null || this.notLoaded() || this.isRemoved()) {
            return;
        }

        final boolean formed = this.isFormed();
        boolean power = false;

        if (this.getProxy().isReady()) {
            power = this.getProxy().isActive();
        }

        final BlockState current = this.world.getBlockState(this.pos);

        // The tile might try to update while being destroyed
        if (current.getBlock() instanceof AbstractCraftingUnitBlock) {
            final BlockState newState = current.with(AbstractCraftingUnitBlock.POWERED, power)
                    .with(AbstractCraftingUnitBlock.FORMED, formed);

            if (current != newState) {
                // Not using flag 2 here (only send to clients, prevent block update) will cause
                // infinite loops
                // In case there is an inconsistency in the crafting clusters.
                this.world.setBlockState(this.pos, newState, Constants.BlockFlags.BLOCK_UPDATE);
            }
        }

        if (updateFormed) {
            if (formed) {
                this.getProxy().setValidSides(EnumSet.allOf(Direction.class));
            } else {
                this.getProxy().setValidSides(EnumSet.noneOf(Direction.class));
            }
        }
    }

    public boolean isFormed() {
        if (isRemote()) {
            return this.world.getBlockState(this.pos).get(AbstractCraftingUnitBlock.FORMED);
        }
        return this.cluster != null;
    }

    @Override
    public CompoundNBT write(final CompoundNBT data) {
        super.write(data);
        data.putBoolean("core", this.isCoreBlock());
        if (this.isCoreBlock() && this.cluster != null) {
            this.cluster.writeToNBT(data);
        }
        return data;
    }

    @Override
    public void read(final CompoundNBT data) {
        super.read(data);
        this.setCoreBlock(data.getBoolean("core"));
        if (this.isCoreBlock()) {
            if (this.cluster != null) {
                this.cluster.readFromNBT(data);
            } else {
                this.setPreviousState(data.copy());
            }
        }
    }

    @Override
    public void disconnect(final boolean update) {
        if (this.cluster != null) {
            this.cluster.destroy();
            if (update) {
                this.updateMeta(true);
            }
        }
    }

    @Override
    public IAECluster getCluster() {
        return this.cluster;
    }

    @Override
    public boolean isValid() {
        return true;
    }

    @MENetworkEventSubscribe
    public void onPowerStateChange(final MENetworkChannelsChanged ev) {
        this.updateMeta(false);
    }

    @MENetworkEventSubscribe
    public void onPowerStateChange(final MENetworkPowerStatusChange ev) {
        this.updateMeta(false);
    }

    public boolean isStatus() {
        return false;
    }

    public boolean isStorage() {
        return false;
    }

    public int getStorageBytes() {
        return 0;
    }

    public void breakCluster() {
        // Since breaking the cluster will most likely also update the TE's state,
        // it's essential that we're not working with outdated block-state information,
        // since this particular TE's block might already have been removed (state=air)
        updateContainingBlockInfo();

        if (this.cluster != null) {
            this.cluster.cancel();
            final IMEInventory<IAEItemStack> inv = this.cluster.getInventory();

            final LinkedList<WorldCoord> places = new LinkedList<>();

            final Iterator<IGridHost> i = this.cluster.getTiles();
            while (i.hasNext()) {
                final IGridHost h = i.next();
                if (h == this) {
                    places.add(new WorldCoord(this));
                } else {
                    final TileEntity te = (TileEntity) h;

                    for (final AEPartLocation d : AEPartLocation.SIDE_LOCATIONS) {
                        final WorldCoord wc = new WorldCoord(te);
                        wc.add(d, 1);
                        if (this.world.isAirBlock(wc.getPos())) {
                            places.add(wc);
                        }
                    }
                }
            }

            Collections.shuffle(places);

            if (places.isEmpty()) {
                throw new IllegalStateException(
                        this.cluster + " does not contain any kind of blocks, which were destroyed.");
            }

            for (IAEItemStack ais : inv.getAvailableItems(
                    Api.instance().storage().getStorageChannel(IItemStorageChannel.class).createList())) {
                ais = ais.copy();
                ais.setStackSize(ais.getDefinition().getMaxStackSize());
                while (true) {
                    final IAEItemStack g = inv.extractItems(ais.copy(), Actionable.MODULATE,
                            this.cluster.getActionSource());
                    if (g == null) {
                        break;
                    }

                    final WorldCoord wc = places.poll();
                    places.add(wc);

                    Platform.spawnDrops(this.world, wc.getPos(), Collections.singletonList(g.createItemStack()));
                }
            }

            this.cluster.destroy();
        }
    }

    @Override
    public boolean isPowered() {
        if (isRemote()) {
            return this.world.getBlockState(this.pos).get(AbstractCraftingUnitBlock.POWERED);
        }
        return this.getProxy().isActive();
    }

    @Override
    public boolean isActive() {
        if (Platform.isServer()) {
            return this.getProxy().isActive();
        }
        return this.isPowered() && this.isFormed();
    }

    public boolean isCoreBlock() {
        return this.isCoreBlock;
    }

    public void setCoreBlock(final boolean isCoreBlock) {
        this.isCoreBlock = isCoreBlock;
    }

    public CompoundNBT getPreviousState() {
        return this.previousState;
    }

    public void setPreviousState(final CompoundNBT previousState) {
        this.previousState = previousState;
    }

    @Nonnull
    @Override
    public IModelData getModelData() {
        return new CraftingCubeModelData(getUp(), getForward(), getConnections());
    }

    protected EnumSet<Direction> getConnections() {
        if (world == null) {
            return EnumSet.noneOf(Direction.class);
        }

        EnumSet<Direction> connections = EnumSet.noneOf(Direction.class);

        for (Direction facing : Direction.values()) {
            if (this.isConnected(world, pos, facing)) {
                connections.add(facing);
            }
        }

        return connections;
    }

    private boolean isConnected(IBlockReader world, BlockPos pos, Direction side) {
        BlockPos adjacentPos = pos.offset(side);
        return world.getBlockState(adjacentPos).getBlock() instanceof AbstractCraftingUnitBlock;
    }

    /**
     * When the block state changes (i.e. becoming formed or unformed), we need to
     * update the model data since it contains connections to neighboring tiles.
     */
    @Override
    public void updateContainingBlockInfo() {
        super.updateContainingBlockInfo();
        requestModelDataUpdate();
    }

}