package com.earth2me.essentials.anticheat.checks;

import com.earth2me.essentials.anticheat.NoCheatPlayer;
import com.earth2me.essentials.anticheat.data.PreciseLocation;
import java.util.HashSet;
import java.util.Set;
import net.minecraft.server.Block;
import org.bukkit.Location;
import org.bukkit.Material;
import org.bukkit.World;
import org.bukkit.inventory.ItemStack;
import org.bukkit.util.Vector;


/**
 * Some stuff that's used by different checks or just too complex to keep in other places
 *
 */
public class CheckUtil
{
	/**
	 * Check if a player looks at a target of a specific size, with a specific precision value (roughly)
	 */
	public static double directionCheck(final NoCheatPlayer player, final double targetX, final double targetY, final double targetZ, final double targetWidth, final double targetHeight, final double precision)
	{

		// Eye location of the player
		final Location eyes = player.getPlayer().getEyeLocation();

		final double factor = Math.sqrt(Math.pow(eyes.getX() - targetX, 2) + Math.pow(eyes.getY() - targetY, 2) + Math.pow(eyes.getZ() - targetZ, 2));

		// View direction of the player
		final Vector direction = eyes.getDirection();

		final double x = targetX - eyes.getX();
		final double y = targetY - eyes.getY();
		final double z = targetZ - eyes.getZ();

		final double xPrediction = factor * direction.getX();
		final double yPrediction = factor * direction.getY();
		final double zPrediction = factor * direction.getZ();

		double off = 0.0D;

		off += Math.max(Math.abs(x - xPrediction) - (targetWidth / 2 + precision), 0.0D);
		off += Math.max(Math.abs(z - zPrediction) - (targetWidth / 2 + precision), 0.0D);
		off += Math.max(Math.abs(y - yPrediction) - (targetHeight / 2 + precision), 0.0D);

		if (off > 1)
		{
			off = Math.sqrt(off);
		}

		return off;
	}

	/**
	 * Check if a player is close enough to a target, based on his eye location
	 *
	 * @param player
	 * @param targetX
	 * @param targetY
	 * @param targetZ
	 * @param limit
	 * @return
	 */
	public static final double reachCheck(final NoCheatPlayer player, final double targetX, final double targetY, final double targetZ, final double limit)
	{

		final Location eyes = player.getPlayer().getEyeLocation();

		final double distance = Math.sqrt(Math.pow(eyes.getX() - targetX, 2) + Math.pow(eyes.getY() - targetY, 2) + Math.pow(eyes.getZ() - targetZ, 2));

		return Math.max(distance - limit, 0.0D);
	}
	private final static double magic = 0.45D;
	private final static double magic2 = 0.55D;
	private static final int NONSOLID = 1;                      // 0x00000001
	private static final int SOLID = 2;                      // 0x00000010
	// All liquids are "nonsolid" too
	private static final int LIQUID = 4 | NONSOLID;           // 0x00000101
	// All ladders are "nonsolid" and "solid" too
	private static final int LADDER = 8 | NONSOLID | SOLID;   // 0x00001011
	// All fences are solid - fences are treated specially due
	// to being 1.5 blocks high
	private static final int FENCE = 16 | SOLID | NONSOLID;  // 0x00010011
	private static final int INGROUND = 128;
	private static final int ONGROUND = 256;
	// Until I can think of a better way to determine if a block is solid or
	// not, this is what I'll do
	private static final int types[];
	private static final Set<Material> foods = new HashSet<Material>();

	static
	{
		types = new int[256];

		// Find and define properties of all other blocks
		for (int i = 0; i < types.length; i++)
		{

			// Everything unknown is considered nonsolid and solid
			types[i] = NONSOLID | SOLID;

			if (Block.byId[i] != null)
			{
				if (Block.byId[i].material.isSolid())
				{
					// STONE, CAKE, LEAFS, ...
					types[i] = SOLID;
				}
				else if (Block.byId[i].material.isLiquid())
				{
					// WATER, LAVA, ...
					types[i] = LIQUID;
				}
				else
				{
					// AIR, SAPLINGS, ...
					types[i] = NONSOLID;
				}
			}
		}

		// Some exceptions where the above method fails

		// du'h
		types[Material.AIR.getId()] = NONSOLID;

		// Webs slow down a players fall extremely, so it makes
		// sense to treat them as optionally solid
		types[Material.WEB.getId()] = SOLID | NONSOLID;

		// Obvious
		types[Material.LADDER.getId()] = LADDER;
		types[Material.WATER_LILY.getId()] = LADDER;
		types[Material.VINE.getId()] = LADDER;

		types[Material.FENCE.getId()] = FENCE;
		types[Material.FENCE_GATE.getId()] = FENCE;
		types[Material.NETHER_FENCE.getId()] = FENCE;

		// These are sometimes solid, sometimes not
		types[Material.IRON_FENCE.getId()] = SOLID | NONSOLID;
		types[Material.THIN_GLASS.getId()] = SOLID | NONSOLID;

		// Signs are NOT solid, despite the game claiming they are
		types[Material.WALL_SIGN.getId()] = NONSOLID;
		types[Material.SIGN_POST.getId()] = NONSOLID;

		// (trap)doors can be solid or not
		types[Material.WOODEN_DOOR.getId()] = SOLID | NONSOLID;
		types[Material.IRON_DOOR_BLOCK.getId()] = SOLID | NONSOLID;
		types[Material.TRAP_DOOR.getId()] = SOLID | NONSOLID;

		// repeaters are technically half blocks
		types[Material.DIODE_BLOCK_OFF.getId()] = SOLID | NONSOLID;
		types[Material.DIODE_BLOCK_ON.getId()] = SOLID | NONSOLID;

		// pressure plates are so slim, you can consider them
		// nonsolid too
		types[Material.STONE_PLATE.getId()] = SOLID | NONSOLID;
		types[Material.WOOD_PLATE.getId()] = SOLID | NONSOLID;

		// We need to know what is considered food for the instanteat check
		foods.add(Material.APPLE);
		foods.add(Material.BREAD);
		foods.add(Material.COOKED_BEEF);
		foods.add(Material.COOKED_CHICKEN);
		foods.add(Material.COOKED_FISH);
		foods.add(Material.COOKIE);
		foods.add(Material.GOLDEN_APPLE);
		foods.add(Material.GRILLED_PORK);
		foods.add(Material.MELON);
		foods.add(Material.MUSHROOM_SOUP);
		foods.add(Material.PORK);
		foods.add(Material.RAW_BEEF);
		foods.add(Material.RAW_CHICKEN);
		foods.add(Material.RAW_FISH);
		foods.add(Material.ROTTEN_FLESH);
		foods.add(Material.SPIDER_EYE);
	}

	/**
	 * Ask NoCheat what it thinks about a certain location. Is it a place where a player can safely stand, should it be
	 * considered as being inside a liquid etc.
	 *
	 * @param world The world the coordinates belong to
	 * @param location The precise location in the world
	 *
	 * @return
	 */
	public static final int evaluateLocation(final World world, final PreciseLocation location)
	{

		final int lowerX = lowerBorder(location.x);
		final int upperX = upperBorder(location.x);
		final int Y = (int)location.y;
		final int lowerZ = lowerBorder(location.z);
		final int upperZ = upperBorder(location.z);

		// Check the four borders of the players hitbox for something he could
		// be standing on, and combine the results
		int result = 0;

		result |= evaluateSimpleLocation(world, lowerX, Y, lowerZ);
		result |= evaluateSimpleLocation(world, upperX, Y, lowerZ);
		result |= evaluateSimpleLocation(world, upperX, Y, upperZ);
		result |= evaluateSimpleLocation(world, lowerX, Y, upperZ);

		if (!isInGround(result))
		{
			// Original location: X, Z (allow standing in walls this time)
			if (isSolid(types[world.getBlockTypeIdAt(Location.locToBlock(location.x), Location.locToBlock(location.y), Location.locToBlock(location.z))]))
			{
				result |= INGROUND;
			}
		}

		return result;
	}

	/**
	 * Evaluate a location by only looking at a specific "column" of the map to find out if that "column" would allow a
	 * player to stand, swim etc. there
	 *
	 * @param world
	 * @param x
	 * @param y
	 * @param z
	 * @return Returns INGROUND, ONGROUND, LIQUID, combination of the three or 0
	 */
	private static final int evaluateSimpleLocation(final World world, final int x, final int y, final int z)
	{

		// First we need to know about the block itself, the block
		// below it and the block above it
		final int top = types[world.getBlockTypeIdAt(x, y + 1, z)];
		final int base = types[world.getBlockTypeIdAt(x, y, z)];
		final int below = types[world.getBlockTypeIdAt(x, y - 1, z)];

		int type = 0;
		// Special case: Standing on a fence
		// Behave as if there is a block on top of the fence
		if ((below == FENCE) && base != FENCE && isNonSolid(top))
		{
			type = INGROUND;
		}
		// Special case: Fence
		// Being a bit above a fence
		else if (below != FENCE && isNonSolid(base) && types[world.getBlockTypeIdAt(x, y - 2, z)] == FENCE)
		{
			type = ONGROUND;
		}
		else if (isNonSolid(top))
		{
			// Simplest (and most likely) case:
			// Below the player is a solid block
			if (isSolid(below) && isNonSolid(base))
			{
				type = ONGROUND;
			}
			// Next (likely) case:
			// There is a ladder
			else if (isLadder(base) || isLadder(top))
			{
				type = ONGROUND;
			}
			// Next (likely) case:
			// At least the block the player stands
			// in is solid
			else if (isSolid(base))
			{
				type = INGROUND;
			}
		}

		// (In every case, check for water)
		if (isLiquid(base) || isLiquid(top))
		{
			type |= LIQUID | INGROUND;
		}

		return type;
	}

	public static final boolean isSolid(final int value)
	{
		return (value & SOLID) == SOLID;
	}

	public static final boolean isLiquid(final int value)
	{
		return (value & LIQUID) == LIQUID;
	}

	private static final boolean isNonSolid(final int value)
	{
		return ((value & NONSOLID) == NONSOLID);
	}

	private static final boolean isLadder(final int value)
	{
		return ((value & LADDER) == LADDER);
	}

	public static final boolean isOnGround(final int fromType)
	{
		return (fromType & ONGROUND) == ONGROUND;
	}

	public static final boolean isInGround(final int fromType)
	{
		return (fromType & INGROUND) == INGROUND;
	}

	/**
	 * Personal Rounding function to determine if a player is still touching a block or not
	 *
	 * @param d1
	 * @return
	 */
	private static final int lowerBorder(final double d1)
	{

		final double floor = Math.floor(d1);

		if (floor + magic <= d1)
		{
			return (int)(floor);
		}
		else
		{
			return (int)(floor - 1);
		}
	}

	/**
	 * Personal Rounding function to determine if a player is still touching a block or not
	 *
	 * @param d1
	 * @return
	 */
	private static final int upperBorder(final double d1)
	{

		final double floor = Math.floor(d1);

		if (floor + magic2 < d1)
		{
			return (int)(floor + 1);
		}
		else
		{
			return (int)floor;
		}
	}

	public static int getType(final int typeId)
	{
		return types[typeId];
	}

	public static boolean isFood(ItemStack item)
	{
		if (item == null)
		{
			return false;
		}
		return foods.contains(item.getType());
	}
}