<?php

/*
 * CavePopulator from BetterGen
 * Copyright (C) Ad5001 2017
 * Licensed under the BoxOfDevs Public General LICENSE which can be found in the file LICENSE in the root directory
 * @author ad5001
 */
namespace Ad5001\BetterGen\populator;

use pocketmine\utils\Random;
use pocketmine\block\Block;
use pocketmine\level\ChunkManager;
use pocketmine\math\Vector3;
use Ad5001\BetterGen\utils\BuildingUtils;
use Ad5001\BetterGen\populator\AmountPopulator;

class CavePopulator extends AmountPopulator {
	protected $level;
	const STOP = false;
	const CONTINUE = true;
	
	/*
	 * Populate the chunk
	 * @param $level pocketmine\level\ChunkManager
	 * @param $chunkX int
	 * @param $chunkZ int
	 * @param $random pocketmine\utils\Random
	 */
	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 ( 10 ) + 15; $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 $x int
	 * @param $z int
	 */
	protected function getHighestWorkableBlock($x, $z) {
		for($y = 127; $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 $x int
	 * @param $y int
	 * @param $z int
	 * @param $random pocketmine\utils\Random
	 * @return void
	 */
	public function generateCave($x, $y, $z, Random $random) {
		$generatedBranches = $random->nextBoundedInt ( 10 ) + 1;
		// echo "Num of branch left => " . $generatedBranches . PHP_EOL;
		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 $x int
	 * @param $y int
	 * @param $z int
	 * @param $length int
	 * @param $height int
	 * @param $depth int
	 * @param $random pocketmine\utils\Random
	 * @yield int
	 * @return void
	 */
	public function generateBranch($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 ) {
			// echo "Y => $y; H => $height; L => $length; D => $depth; R => $repeat" . PHP_EOL;
			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;
	}
}