/*
 * WorldEdit, a Minecraft world manipulation toolkit
 * Copyright (C) sk89q <http://www.sk89q.com>
 * Copyright (C) WorldEdit team and contributors
 *
 * This program 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.
 *
 * This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
 */

package com.sk89q.worldedit.command;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.sk89q.worldedit.command.util.Logging.LogMode.ALL;
import static com.sk89q.worldedit.command.util.Logging.LogMode.ORIENTATION_REGION;
import static com.sk89q.worldedit.command.util.Logging.LogMode.REGION;
import static com.sk89q.worldedit.regions.Regions.asFlatRegion;
import static com.sk89q.worldedit.regions.Regions.maximumBlockY;
import static com.sk89q.worldedit.regions.Regions.minimumBlockY;

import com.sk89q.minecraft.util.commands.Command;
import com.sk89q.minecraft.util.commands.CommandPermissions;
import com.sk89q.worldedit.EditSession;
import com.sk89q.worldedit.LocalSession;
import com.sk89q.worldedit.WorldEdit;
import com.sk89q.worldedit.WorldEditException;
import com.sk89q.worldedit.command.util.Logging;
import com.sk89q.worldedit.entity.Player;
import com.sk89q.worldedit.function.GroundFunction;
import com.sk89q.worldedit.function.generator.FloraGenerator;
import com.sk89q.worldedit.function.mask.ExistingBlockMask;
import com.sk89q.worldedit.function.mask.Mask;
import com.sk89q.worldedit.function.mask.NoiseFilter2D;
import com.sk89q.worldedit.function.operation.Operations;
import com.sk89q.worldedit.function.pattern.Pattern;
import com.sk89q.worldedit.function.visitor.LayerVisitor;
import com.sk89q.worldedit.internal.annotation.Direction;
import com.sk89q.worldedit.internal.annotation.Selection;
import com.sk89q.worldedit.internal.expression.ExpressionException;
import com.sk89q.worldedit.math.BlockVector3;
import com.sk89q.worldedit.math.Vector3;
import com.sk89q.worldedit.math.convolution.GaussianKernel;
import com.sk89q.worldedit.math.convolution.HeightMap;
import com.sk89q.worldedit.math.convolution.HeightMapFilter;
import com.sk89q.worldedit.math.noise.RandomNoise;
import com.sk89q.worldedit.regions.ConvexPolyhedralRegion;
import com.sk89q.worldedit.regions.CuboidRegion;
import com.sk89q.worldedit.regions.Region;
import com.sk89q.worldedit.regions.RegionOperationException;
import com.sk89q.worldedit.util.TreeGenerator.TreeType;
import com.sk89q.worldedit.util.command.binding.Range;
import com.sk89q.worldedit.util.command.binding.Switch;
import com.sk89q.worldedit.util.command.binding.Text;
import com.sk89q.worldedit.util.command.parametric.Optional;

import java.util.ArrayList;
import java.util.List;

/**
 * Commands that operate on regions.
 */
public class RegionCommands {

    private final WorldEdit worldEdit;

    /**
     * Create a new instance.
     *
     * @param worldEdit reference to WorldEdit
     */
    public RegionCommands(WorldEdit worldEdit) {
        checkNotNull(worldEdit);
        this.worldEdit = worldEdit;
    }

    @Command(
            aliases = { "/line" },
            usage = "<pattern> [thickness]",
            desc = "Draws a line segment between cuboid selection corners",
            help =
                "Draws a line segment between cuboid selection corners.\n" +
                "Can only be used with cuboid selections.\n" +
                "Flags:\n" +
                "  -h generates only a shell",
            flags = "h",
            min = 1,
            max = 2
    )
    @CommandPermissions("worldedit.region.line")
    @Logging(REGION)
    public void line(Player player, EditSession editSession,
                     @Selection Region region,
                     Pattern pattern,
                     @Optional("0") @Range(min = 0) int thickness,
                     @Switch('h') boolean shell) throws WorldEditException {

        if (!(region instanceof CuboidRegion)) {
            player.printError("//line only works with cuboid selections");
            return;
        }

        CuboidRegion cuboidregion = (CuboidRegion) region;
        BlockVector3 pos1 = cuboidregion.getPos1();
        BlockVector3 pos2 = cuboidregion.getPos2();
        int blocksChanged = editSession.drawLine(pattern, pos1, pos2, thickness, !shell);

        player.print(blocksChanged + " block(s) have been changed.");
    }

    @Command(
            aliases = { "/curve" },
            usage = "<pattern> [thickness]",
            desc = "Draws a spline through selected points",
            help =
                "Draws a spline through selected points.\n" +
                "Can only be used with convex polyhedral selections.\n" +
                "Flags:\n" +
                "  -h generates only a shell",
            flags = "h",
            min = 1,
            max = 2
    )
    @CommandPermissions("worldedit.region.curve")
    @Logging(REGION)
    public void curve(Player player, EditSession editSession,
                      @Selection Region region,
                      Pattern pattern,
                      @Optional("0") @Range(min = 0) int thickness,
                      @Switch('h') boolean shell) throws WorldEditException {
        if (!(region instanceof ConvexPolyhedralRegion)) {
            player.printError("//curve only works with convex polyhedral selections");
            return;
        }

        ConvexPolyhedralRegion cpregion = (ConvexPolyhedralRegion) region;
        List<BlockVector3> vectors = new ArrayList<>(cpregion.getVertices());

        int blocksChanged = editSession.drawSpline(pattern, vectors, 0, 0, 0, 10, thickness, !shell);

        player.print(blocksChanged + " block(s) have been changed.");
    }

    @Command(
        aliases = { "/replace", "/re", "/rep" },
        usage = "[from-block] <to-block>",
        desc = "Replace all blocks in the selection with another",
        flags = "f",
        min = 1,
        max = 2
    )
    @CommandPermissions("worldedit.region.replace")
    @Logging(REGION)
    public void replace(Player player, EditSession editSession, @Selection Region region, @Optional Mask from, Pattern to) throws WorldEditException {
        if (from == null) {
            from = new ExistingBlockMask(editSession);
        }
        int affected = editSession.replaceBlocks(region, from, to);
        player.print(affected + " block(s) have been replaced.");
    }

    @Command(
        aliases = { "/overlay" },
        usage = "<pattern>",
        desc = "Set a block on top of blocks in the region",
        min = 1,
        max = 1
    )
    @CommandPermissions("worldedit.region.overlay")
    @Logging(REGION)
    public void overlay(Player player, EditSession editSession, @Selection Region region, Pattern pattern) throws WorldEditException {
        int affected = editSession.overlayCuboidBlocks(region, pattern);
        player.print(affected + " block(s) have been overlaid.");
    }

    @Command(
        aliases = { "/center", "/middle" },
        usage = "<pattern>",
        desc = "Set the center block(s)",
        min = 1,
        max = 1
    )
    @Logging(REGION)
    @CommandPermissions("worldedit.region.center")
    public void center(Player player, EditSession editSession, @Selection Region region, Pattern pattern) throws WorldEditException {
        int affected = editSession.center(region, pattern);
        player.print("Center set ("+ affected + " blocks changed)");
    }

    @Command(
        aliases = { "/naturalize" },
        usage = "",
        desc = "3 layers of dirt on top then rock below",
        min = 0,
        max = 0
    )
    @CommandPermissions("worldedit.region.naturalize")
    @Logging(REGION)
    public void naturalize(Player player, EditSession editSession, @Selection Region region) throws WorldEditException {
        int affected = editSession.naturalizeCuboidBlocks(region);
        player.print(affected + " block(s) have been made to look more natural.");
    }

    @Command(
        aliases = { "/walls" },
        usage = "<pattern>",
        desc = "Build the four sides of the selection",
        min = 1,
        max = 1
    )
    @CommandPermissions("worldedit.region.walls")
    @Logging(REGION)
    public void walls(Player player, EditSession editSession, @Selection Region region, Pattern pattern) throws WorldEditException {
        int affected = editSession.makeWalls(region, pattern);
        player.print(affected + " block(s) have been changed.");
    }

    @Command(
        aliases = { "/faces", "/outline" },
        usage = "<pattern>",
        desc = "Build the walls, ceiling, and floor of a selection",
        min = 1,
        max = 1
    )
    @CommandPermissions("worldedit.region.faces")
    @Logging(REGION)
    public void faces(Player player, EditSession editSession, @Selection Region region, Pattern pattern) throws WorldEditException {
        int affected = editSession.makeCuboidFaces(region, pattern);
        player.print(affected + " block(s) have been changed.");
    }

    @Command(
        aliases = { "/smooth" },
        usage = "[iterations] [filter]",
        desc = "Smooth the elevation in the selection",
        help =
            "Smooths the elevation in the selection.\n" +
            "Optionally, restricts the height map to a set of blocks specified with mask syntax.\n" +
            "For example, '//smooth 1 grass_block,dirt,stone' would only smooth natural surface terrain.",
        min = 0,
        max = 2
    )
    @CommandPermissions("worldedit.region.smooth")
    @Logging(REGION)
    public void smooth(Player player, EditSession editSession, @Selection Region region, @Optional("1") int iterations, @Optional Mask mask) throws WorldEditException {
        HeightMap heightMap = new HeightMap(editSession, region, mask);
        HeightMapFilter filter = new HeightMapFilter(new GaussianKernel(5, 1.0));
        int affected = heightMap.applyFilter(filter, iterations);
        player.print("Terrain's height map smoothed. " + affected + " block(s) changed.");

    }

    @Command(
        aliases = { "/move" },
        usage = "[count] [direction] [leave-id]",
        flags = "sa",
        desc = "Move the contents of the selection",
        help =
            "Moves the contents of the selection.\n" +
            "The -s flag shifts the selection to the target location.\n" +
            "The -a flag skips air blocks.\n" +
            "Optionally fills the old location with <leave-id>.",
        min = 0,
        max = 3
    )
    @CommandPermissions("worldedit.region.move")
    @Logging(ORIENTATION_REGION)
    public void move(Player player, EditSession editSession, LocalSession session,
                     @Selection Region region,
                     @Optional("1") @Range(min = 1) int count,
                     @Optional(Direction.AIM) @Direction(includeDiagonals = true) BlockVector3 direction,
                     @Optional("air") Pattern replace,
                     @Switch('s') boolean moveSelection,
                     @Switch('a') boolean ignoreAirBlocks) throws WorldEditException {

        int affected = editSession.moveRegion(region, direction, count, !ignoreAirBlocks, replace);

        if (moveSelection) {
            try {
                region.shift(direction.multiply(count));

                session.getRegionSelector(player.getWorld()).learnChanges();
                session.getRegionSelector(player.getWorld()).explainRegionAdjust(player, session);
            } catch (RegionOperationException e) {
                player.printError(e.getMessage());
            }
        }

        player.print(affected + " blocks moved.");
    }

    @Command(
        aliases = { "/stack" },
        usage = "[count] [direction]",
        flags = "sa",
        desc = "Repeat the contents of the selection",
        help =
            "Repeats the contents of the selection.\n" +
            "Flags:\n" +
            "  -s shifts the selection to the last stacked copy\n" +
            "  -a skips air blocks",
        min = 0,
        max = 2
    )
    @CommandPermissions("worldedit.region.stack")
    @Logging(ORIENTATION_REGION)
    public void stack(Player player, EditSession editSession, LocalSession session,
                      @Selection Region region,
                      @Optional("1") @Range(min = 1) int count,
                      @Optional(Direction.AIM) @Direction(includeDiagonals = true) BlockVector3 direction,
                      @Switch('s') boolean moveSelection,
                      @Switch('a') boolean ignoreAirBlocks) throws WorldEditException {
        int affected = editSession.stackCuboidRegion(region, direction, count, !ignoreAirBlocks);

        if (moveSelection) {
            try {
                final BlockVector3 size = region.getMaximumPoint().subtract(region.getMinimumPoint());

                final BlockVector3 shiftVector = direction.toVector3().multiply(count * (Math.abs(direction.dot(size)) + 1)).toBlockPoint();
                region.shift(shiftVector);

                session.getRegionSelector(player.getWorld()).learnChanges();
                session.getRegionSelector(player.getWorld()).explainRegionAdjust(player, session);
            } catch (RegionOperationException e) {
                player.printError(e.getMessage());
            }
        }

        player.print(affected + " blocks changed. Undo with //undo");
    }

    @Command(
        aliases = { "/regen" },
        usage = "",
        desc = "Regenerates the contents of the selection",
        help =
            "Regenerates the contents of the current selection.\n" +
            "This command might affect things outside the selection,\n" +
            "if they are within the same chunk.",
        min = 0,
        max = 0
    )
    @CommandPermissions("worldedit.regen")
    @Logging(REGION)
    public void regenerateChunk(Player player, LocalSession session, EditSession editSession, @Selection Region region) throws WorldEditException {
        Mask mask = session.getMask();
        try {
            session.setMask((Mask) null);
            player.getWorld().regenerate(region, editSession);
        } finally {
            session.setMask(mask);
        }
        player.print("Region regenerated.");
    }

    @Command(
            aliases = { "/deform" },
            usage = "<expression>",
            desc = "Deforms a selected region with an expression",
            help =
                "Deforms a selected region with an expression\n" +
                "The expression is executed for each block and is expected\n" +
                "to modify the variables x, y and z to point to a new block\n" +
                "to fetch. See also tinyurl.com/wesyntax.",
            flags = "ro",
            min = 1,
            max = -1
    )
    @CommandPermissions("worldedit.region.deform")
    @Logging(ALL)
    public void deform(Player player, LocalSession session, EditSession editSession,
                       @Selection Region region,
                       @Text String expression,
                       @Switch('r') boolean useRawCoords,
                       @Switch('o') boolean offset) throws WorldEditException {
        final Vector3 zero;
        Vector3 unit;

        if (useRawCoords) {
            zero = Vector3.ZERO;
            unit = Vector3.ONE;
        } else if (offset) {
            zero = session.getPlacementPosition(player).toVector3();
            unit = Vector3.ONE;
        } else {
            final Vector3 min = region.getMinimumPoint().toVector3();
            final Vector3 max = region.getMaximumPoint().toVector3();

            zero = max.add(min).divide(2);
            unit = max.subtract(zero);

            if (unit.getX() == 0) unit = unit.withX(1.0);
            if (unit.getY() == 0) unit = unit.withY(1.0);
            if (unit.getZ() == 0) unit = unit.withZ(1.0);
        }

        try {
            final int affected = editSession.deformRegion(region, zero, unit, expression, session.getTimeout());
            player.findFreePosition();
            player.print(affected + " block(s) have been deformed.");
        } catch (ExpressionException e) {
            player.printError(e.getMessage());
        }
    }

    @Command(
        aliases = { "/hollow" },
        usage = "[<thickness>[ <pattern>]]",
        desc = "Hollows out the object contained in this selection",
        help =
            "Hollows out the object contained in this selection.\n" +
            "Optionally fills the hollowed out part with the given block.\n" +
            "Thickness is measured in manhattan distance.",
        min = 0,
        max = 2
    )
    @CommandPermissions("worldedit.region.hollow")
    @Logging(REGION)
    public void hollow(Player player, EditSession editSession,
                       @Selection Region region,
                       @Optional("0") @Range(min = 0) int thickness,
                       @Optional("air") Pattern pattern) throws WorldEditException {

        int affected = editSession.hollowOutRegion(region, thickness, pattern);
        player.print(affected + " block(s) have been changed.");
    }

    @Command(
            aliases = { "/forest" },
            usage = "[type] [density]",
            desc = "Make a forest within the region",
            min = 0,
            max = 2
    )
    @CommandPermissions("worldedit.region.forest")
    @Logging(REGION)
    public void forest(Player player, EditSession editSession, @Selection Region region, @Optional("tree") TreeType type,
                       @Optional("5") @Range(min = 0, max = 100) double density) throws WorldEditException {
        int affected = editSession.makeForest(region, density / 100, type);
        player.print(affected + " trees created.");
    }

    @Command(
            aliases = { "/flora" },
            usage = "[density]",
            desc = "Make flora within the region",
            min = 0,
            max = 1
    )
    @CommandPermissions("worldedit.region.flora")
    @Logging(REGION)
    public void flora(Player player, EditSession editSession, @Selection Region region, @Optional("10") @Range(min = 0, max = 100) double density) throws WorldEditException {
        density = density / 100;
        FloraGenerator generator = new FloraGenerator(editSession);
        GroundFunction ground = new GroundFunction(new ExistingBlockMask(editSession), generator);
        LayerVisitor visitor = new LayerVisitor(asFlatRegion(region), minimumBlockY(region), maximumBlockY(region), ground);
        visitor.setMask(new NoiseFilter2D(new RandomNoise(), density));
        Operations.completeLegacy(visitor);

        player.print(ground.getAffected() + " flora created.");
    }

}