<?php
/**
 *   _____            _____      _       _            _____  ______ 
 *  / ____|          |  __ \    (_)     | |          |  __ \|  ____|
 * | |  __  ___ _ __ | |__) |_ _ _ _ __ | |_ ___ _ __| |__) | |__   
 * | | |_ |/ _ \ '_ \|  ___/ _` | | '_ \| __/ _ \ '__|  ___/|  __|  
 * | |__| |  __/ | | | |  | (_| | | | | | ||  __/ |  | |    | |____ 
 *  \_____|\___|_| |_|_|   \__,_|_|_| |_|\__\___|_|  |_|    |______|
 * Pocketmine Generator for Earth and heightmap based generation.
 *
 * Copyright (C) Ad5001 2017
 * 
 * @author Ad5001
 * @api 3.0.0
 * @copyright 2017 Ad5001
 * @license NTOSL - View LICENSE.md
 * @version 1.0.0
 * @package BetterGen (https://github.com/Ad5001/BetterGen)
 * @subpackage GenPainterPE
 *
 * Imported from BetterGen (https://github.com/Ad5001/BetterGen/blob/master/src/Ad5001/BetterGen/populator/CavePopulator.php)
 */

namespace Ad5001\GenPainterPE\populator;

use Ad5001\GenPainterPE\utils\BuildingUtils;
use pocketmine\block\Block;
use pocketmine\level\ChunkManager;
use pocketmine\level\Level;
use pocketmine\math\Vector3;
use pocketmine\utils\Random;

class CavePopulator extends AmountPopulator {
	/** @var ChunkManager */
	protected $level;
	const STOP = false;
	const CONTINUE = true;
	
	/**
	 * Populates the chunk
	 *
	 * @param ChunkManager $level
	 * @param int $chunkX
	 * @param int $chunkZ
	 * @param Random $random
	 * @return void
	 */
	public function populate(ChunkManager $level, $chunkX, $chunkZ, Random $random) {
		$this->level = $level;
		$amount = $this->getAmount($random);
		for($i = 0; $i < $amount; $i++) {
			$x = $random->nextRange($chunkX << 4, ($chunkX << 4) + 15);
			$z = $random->nextRange($chunkZ << 4, ($chunkZ << 4) + 15);
			$y = $random->nextRange(10, $this->getHighestWorkableBlock($x, $z));
			// echo "Generating cave at $x, $y, $z." . PHP_EOL;
			$this->generateCave($x, $y, $z, $random);
		}
		// echo "Finished Populating chunk $chunkX, $chunkZ !" . PHP_EOL;
		// Filling water & lava sources randomly
		for($i = 0; $i < $random->nextBoundedInt(5) + 3; $i ++) {
			$x = $random->nextRange($chunkX << 4, ($chunkX << 4) + 15);
			$z = $random->nextRange($chunkZ << 4, ($chunkZ << 4) + 15);
			$y = $random->nextRange(10, $this->getHighestWorkableBlock($x, $z));
			if ($level->getBlockIdAt($x, $y, $z) == Block::STONE && ($level->getBlockIdAt($x + 1, $y, $z) == Block::AIR || $level->getBlockIdAt($x - 1, $y, $z) == Block::AIR || $level->getBlockIdAt($x, $y, $z + 1) == Block::AIR || $level->getBlockIdAt($x, $y, $z - 1) == Block::AIR) && $level->getBlockIdAt($x, $y - 1, $z) !== Block::AIR && $level->getBlockIdAt($x, $y + 1, $z) !== Block::AIR) {
				if ($y < 40 && $random->nextBoolean ()) {
					$level->setBlockIdAt($x, $y, $z, Block::LAVA);
				} else {
					$level->setBlockIdAt($x, $y, $z, Block::WATER);
				}
			}
		}
	}
	
	/**
	 * Gets the top block (y) on an x and z axes
	 * @param int $x
	 * @param int $z
	 */
	protected function getHighestWorkableBlock($x, $z) {
		for($y = Level::Y_MAX - 1; $y > 0; -- $y) {
			$b = $this->level->getBlockIdAt($x, $y, $z);
			if ($b === Block::DIRT or $b === Block::GRASS or $b === Block::PODZOL or $b === Block::SAND or $b === Block::SNOW_BLOCK or $b === Block::SANDSTONE) {
				break;
			} elseif ($b !== 0 and $b !== Block::SNOW_LAYER and $b !== Block::WATER) {
				return - 1;
			}
		}
		
		return ++$y;
	}
	
	/**
	 * Generates a cave
	 *
	 * @param int $x
	 * @param int $y
	 * @param int $z
	 * @param Random $random
	 * @return void
	 */
	public function generateCave($x, $y, $z, Random $random) {
		$generatedBranches = $random->nextBoundedInt(10) + 1;
		foreach($gen = $this->generateBranch($x, $y, $z, 5, 3, 5, $random) as $v3) {
			$generatedBranches --;
			if ($generatedBranches <= 0) {
				$gen->send(self::STOP);
			} else {
				$gen->send(self::CONTINUE);
			}
		}
	}

	/**
	 * Generates a cave branch
	 *
	 * @param int $x
	 * @param int $y
	 * @param int $z
	 * @param int $length
	 * @param int $height
	 * @param int $depth
	 * @param Random $random
	 * @yield Vector3
	 * @return void
	 */
	public function generateBranch($x, $y, $z, $length, $height, $depth, Random $random) {
		if (! (yield new Vector3($x, $y, $z))) {
			for($i = 0; $i <= 4; $i ++) {
				BuildingUtils::buildRandom($this->level, new Vector3($x, $y, $z), new Vector3($length - $i, $height - $i, $depth - $i), $random, Block::get(Block::AIR));
				$x += round(($random->nextBoundedInt(round(30 * ($length / 10)) + 1) / 10 - 2));
				$yP = $random->nextRange(-14, 14);
				if ($yP > 12) {
					$y ++;
				} elseif ($yP < - 12) {
					$y --;
				}
				$z += round(($random->nextBoundedInt(round(30 * ($depth / 10)) + 1) / 10 - 1));
				return;
			}
		}
		$repeat = $random->nextBoundedInt(25) + 15;
		while($repeat-- > 0) {
			BuildingUtils::buildRandom($this->level, new Vector3($x, $y, $z), new Vector3($length, $height, $depth), $random, Block::get(Block::AIR));
			$x += round(($random->nextBoundedInt(round(30 * ($length / 10)) + 1) / 10 - 2));
			$yP = $random->nextRange(- 14, 14);
			if ($yP > 12) {
				$y ++;
			} elseif ($yP < - 12) {
				$y --;
			}
			$z += round(($random->nextBoundedInt(round(30 * ($depth / 10)) + 1) / 10 - 1));
			$height += $random->nextBoundedInt(3) - 1;
			$length += $random->nextBoundedInt(3) - 1;
			$depth += $random->nextBoundedInt(3) - 1;
			if ($height < 3)
				$height = 3;
			if ($length < 3)
				$length = 3;
			if ($height < 3)
				$height = 3;
			if ($height < 7)
				$height = 7;
			if ($length < 7)
				$length = 7;
			if ($height < 7)
				$height = 7;
			if ($random->nextBoundedInt(10) == 0) {
				foreach($generator = $this->generateBranch($x, $y, $z, $length, $height, $depth, $random) as $gen) {
					if (! (yield $gen))
						$generator->send(self::STOP);
				}
			}
		}
		return;
	}
}