<?php

/*
 *
 *  ____            _        _   __  __ _                  __  __ ____
 * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
 * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
 * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
 * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
 *
 * 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.
 *
 * @author PocketMine Team
 * @link http://www.pocketmine.net/
 *
 *
 */

declare(strict_types=1);

namespace pocketmine\block;

use pocketmine\block\utils\SupportType;
use pocketmine\data\runtime\RuntimeDataDescriber;
use pocketmine\event\block\BlockSpreadEvent;
use pocketmine\item\Fertilizer;
use pocketmine\item\Item;
use pocketmine\math\AxisAlignedBB;
use pocketmine\math\Facing;
use pocketmine\math\Vector3;
use pocketmine\player\Player;
use pocketmine\world\BlockTransaction;
use pocketmine\world\World;
use function array_key_first;
use function count;
use function shuffle;

class GlowLichen extends Transparent{

	/** @var int[] */
	protected array $faces = [];

	protected function describeBlockOnlyState(RuntimeDataDescriber $w) : void{
		$w->facingFlags($this->faces);
	}

	/** @return int[] */
	public function getFaces() : array{ return $this->faces; }

	public function hasFace(int $face) : bool{
		return isset($this->faces[$face]);
	}

	/**
	 * @param int[] $faces
	 * @return $this
	 */
	public function setFaces(array $faces) : self{
		$uniqueFaces = [];
		foreach($faces as $face){
			Facing::validate($face);
			$uniqueFaces[$face] = $face;
		}
		$this->faces = $uniqueFaces;
		return $this;
	}

	/** @return $this */
	public function setFace(int $face, bool $value) : self{
		Facing::validate($face);
		if($value){
			$this->faces[$face] = $face;
		}else{
			unset($this->faces[$face]);
		}
		return $this;
	}

	public function getLightLevel() : int{
		return 7;
	}

	public function isSolid() : bool{
		return false;
	}

	/**
	 * @return AxisAlignedBB[]
	 */
	protected function recalculateCollisionBoxes() : array{
		return [];
	}

	public function getSupportType(int $facing) : SupportType{
		return SupportType::NONE();
	}

	public function canBeReplaced() : bool{
		return true;
	}

	public function place(BlockTransaction $tx, Item $item, Block $blockReplace, Block $blockClicked, int $face, Vector3 $clickVector, ?Player $player = null) : bool{
		$this->faces = $blockReplace instanceof GlowLichen ? $blockReplace->faces : [];
		$availableFaces = $this->getAvailableFaces();

		if(count($availableFaces) === 0){
			return false;
		}

		$opposite = Facing::opposite($face);
		$placedFace = isset($availableFaces[$opposite]) ? $opposite : array_key_first($availableFaces);
		$this->faces[$placedFace] = $placedFace;

		return parent::place($tx, $item, $blockReplace, $blockClicked, $face, $clickVector, $player);
	}

	public function onNearbyBlockChange() : void{
		$changed = false;

		foreach($this->faces as $face){
			if(!$this->getAdjacentSupportType($face)->equals(SupportType::FULL())){
				unset($this->faces[$face]);
				$changed = true;
			}
		}

		if($changed){
			$world = $this->position->getWorld();
			if(count($this->faces) === 0){
				$world->useBreakOn($this->position);
			}else{
				$world->setBlock($this->position, $this);
			}
		}
	}

	private function getSpreadBlock(Block $replace, int $spreadFace) : ?Block{
		if($replace instanceof self && $replace->hasSameTypeId($this)){
			if($replace->hasFace($spreadFace)){
				return null;
			}
			$result = $replace;
		}elseif($replace->getTypeId() === BlockTypeIds::AIR){
			$result = VanillaBlocks::GLOW_LICHEN();
		}else{
			//TODO: if this is a water block, generate a waterlogged block
			return null;
		}
		return $result->setFace($spreadFace, true);
	}

	private function spread(World $world, Vector3 $replacePos, int $spreadFace) : bool{
		$supportBlock = $world->getBlock($replacePos->getSide($spreadFace));
		$supportFace = Facing::opposite($spreadFace);

		if(!$supportBlock->getSupportType($supportFace)->equals(SupportType::FULL())){
			return false;
		}

		$replacedBlock = $supportBlock->getSide($supportFace);
		$replacementBlock = $this->getSpreadBlock($replacedBlock, Facing::opposite($supportFace));
		if($replacementBlock === null){
			return false;
		}

		$ev = new BlockSpreadEvent($replacedBlock, $this, $replacementBlock);
		$ev->call();
		if(!$ev->isCancelled()){
			$world->setBlock($replacedBlock->getPosition(), $ev->getNewState());
			return true;
		}

		return false;
	}

	/**
	 * @phpstan-return \Generator<int, int, void, void>
	 */
	private static function getShuffledSpreadFaces(int $sourceFace) : \Generator{
		$skipAxis = Facing::axis($sourceFace);

		$faces = Facing::ALL;
		shuffle($faces);
		foreach($faces as $spreadFace){
			if(Facing::axis($spreadFace) !== $skipAxis){
				yield $spreadFace;
			}
		}
	}

	private function spreadAroundSupport(int $sourceFace) : bool{
		$world = $this->position->getWorld();

		$supportPos = $this->position->getSide($sourceFace);
		foreach(self::getShuffledSpreadFaces($sourceFace) as $spreadFace){
			$replacePos = $supportPos->getSide($spreadFace);
			if($this->spread($world, $replacePos, Facing::opposite($spreadFace))){
				return true;
			}
		}

		return false;
	}

	private function spreadAdjacentToSupport(int $sourceFace) : bool{
		$world = $this->position->getWorld();

		foreach(self::getShuffledSpreadFaces($sourceFace) as $spreadFace){
			$replacePos = $this->position->getSide($spreadFace);
			if($this->spread($world, $replacePos, $sourceFace)){
				return true;
			}
		}
		return false;
	}

	private function spreadWithinSelf(int $sourceFace) : bool{
		foreach(self::getShuffledSpreadFaces($sourceFace) as $spreadFace){
			if(!$this->hasFace($spreadFace) && $this->spread($this->position->getWorld(), $this->position, $spreadFace)){
				return true;
			}
		}

		return false;
	}

	public function onInteract(Item $item, int $face, Vector3 $clickVector, ?Player $player = null, array &$returnedItems = []) : bool{
		if($item instanceof Fertilizer && count($this->faces) > 0){
			$shuffledFaces = $this->faces;
			shuffle($shuffledFaces);

			$spreadMethods = [
				$this->spreadAroundSupport(...),
				$this->spreadAdjacentToSupport(...),
				$this->spreadWithinSelf(...),
			];
			shuffle($spreadMethods);

			foreach($shuffledFaces as $sourceFace){
				foreach($spreadMethods as $spreadMethod){
					if($spreadMethod($sourceFace)){
						$item->pop();
						break 2;
					}
				}
			}

			return true;
		}
		return false;
	}

	public function getDrops(Item $item) : array{
		if(($item->getBlockToolType() & BlockToolType::SHEARS) !== 0){
			return $this->getDropsForCompatibleTool($item);
		}

		return [];
	}

	public function getFlameEncouragement() : int{
		return 15;
	}

	public function getFlammability() : int{
		return 100;
	}

	/**
	 * @return array<int, int> $faces
	 */
	private function getAvailableFaces() : array{
		$faces = [];
		foreach(Facing::ALL as $face){
			if(!$this->hasFace($face) && $this->getAdjacentSupportType($face)->equals(SupportType::FULL())){
				$faces[$face] = $face;
			}
		}
		return $faces;
	}
}