/**
 * 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;

import java.util.Random;

import net.minecraft.block.Block;
import net.minecraft.init.Blocks;
import net.minecraft.world.World;

import cpw.mods.fml.common.eventhandler.Event.Result;
import cpw.mods.fml.common.eventhandler.SubscribeEvent;
import net.minecraftforge.event.terraingen.PopulateChunkEvent;
import net.minecraftforge.event.terraingen.TerrainGen;

import buildcraft.BuildCraftCore;

public class SpringPopulate {

	@SubscribeEvent
	public void populate(PopulateChunkEvent.Post event) {
		boolean doGen = TerrainGen.populate(event.chunkProvider, event.world, event.rand, event.chunkX, event.chunkZ, event.hasVillageGenerated, PopulateChunkEvent.Populate.EventType.CUSTOM);

		if (!doGen || !BlockSpring.EnumSpring.WATER.canGen) {
			event.setResult(Result.ALLOW);
			return;
		}

		// shift to world coordinates
		int worldX = event.chunkX << 4;
		int worldZ = event.chunkZ << 4;

		doPopulate(event.world, event.rand, worldX, worldZ);
	}

	private void doPopulate(World world, Random random, int x, int z) {
		int dimId = world.provider.dimensionId;
		// No water springs will generate in the Nether or End.
		if (dimId == -1 || dimId == 1) {
			return;
		}

		// A spring will be generated every 40th chunk.
		if (random.nextFloat() > 0.025f) {
			return;
		}

		int posX = x + random.nextInt(16);
		int posZ = z + random.nextInt(16);

		for (int i = 0; i < 5; i++) {
			Block candidate = world.getBlock(posX, i, posZ);

			if (candidate != Blocks.bedrock) {
				continue;
			}

			// Handle flat bedrock maps
			int y = i > 0 ? i : i - 1;

			world.setBlock(posX, y + 1, posZ, BuildCraftCore.springBlock);

			for (int j = y + 2; j < world.getHeight(); j++) {
				if (world.isAirBlock(posX, j, posZ)) {
					break;
				} else {
					world.setBlock(posX, j, posZ, Blocks.water);
				}
			}

			break;
		}
	}
}