BlockStateReader.php

<?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\data\bedrock\block\convert;
 
use pocketmine\block\utils\BellAttachmentType;
use pocketmine\block\utils\SlabType;
use pocketmine\block\utils\WallConnectionType;
use pocketmine\data\bedrock\block\BlockLegacyMetadata;
use pocketmine\data\bedrock\block\BlockStateData;
use pocketmine\data\bedrock\block\BlockStateDeserializeException;
use pocketmine\data\bedrock\block\BlockStateNames;
use pocketmine\data\bedrock\block\BlockStateStringValues as StringValues;
use pocketmine\math\Axis;
use pocketmine\math\Facing;
use pocketmine\nbt\tag\ByteTag;
use pocketmine\nbt\tag\IntTag;
use pocketmine\nbt\tag\StringTag;
use pocketmine\nbt\tag\Tag;
use function array_keys;
use function count;
use function get_class;
use function implode;
 
final class BlockStateReader{
 
    private array $unusedStates;
 
    public function __construct(
        private BlockStateData $data
    ){
        $this->unusedStates = $this->data->getStates();
    }
 
    public function missingOrWrongTypeException(string $name, ?Tag $tag) : BlockStateDeserializeException{
        return new BlockStateDeserializeException("Property \"$name\" " . ($tag !== null ? "has unexpected type " . get_class($tag) : "is missing"));
    }
 
    public function badValueException(string $name, string $stringifiedValue, ?string $reason = null) : BlockStateDeserializeException{
        return new BlockStateDeserializeException(
            "Property \"$name\" has unexpected value \"$stringifiedValue\"" . (
            $reason !== null ? " ($reason)" : ""
        ));
    }
 
    public function readBool(string $name) : bool{
        unset($this->unusedStates[$name]);
        $tag = $this->data->getState($name);
        if($tag instanceof ByteTag){
            switch($tag->getValue()){
                case 0: return false;
                case 1: return true;
                default: throw $this->badValueException($name, (string) $tag->getValue());
            }
        }
        throw $this->missingOrWrongTypeException($name, $tag);
    }
 
    public function readInt(string $name) : int{
        unset($this->unusedStates[$name]);
        $tag = $this->data->getState($name);
        if($tag instanceof IntTag){
            return $tag->getValue();
        }
        throw $this->missingOrWrongTypeException($name, $tag);
    }
 
    public function readBoundedInt(string $name, int $min, int $max) : int{
        $result = $this->readInt($name);
        if($result < $min || $result > $max){
            throw $this->badValueException($name, (string) $result, "Must be inside the range $min ... $max");
        }
        return $result;
    }
 
    public function readString(string $name) : string{
        unset($this->unusedStates[$name]);
        //TODO: only allow a specific set of values (strings are primarily used for enums)
        $tag = $this->data->getState($name);
        if($tag instanceof StringTag){
            return $tag->getValue();
        }
        throw $this->missingOrWrongTypeException($name, $tag);
    }
 
    private function parseFacingValue(int $value, array $mapping) : int{
        $result = $mapping[$value] ?? null;
        if($result === null){
            throw new BlockStateDeserializeException("Unmapped facing value " . $value);
        }
        return $result;
    }
 
    public function readFacingDirection() : int{
        return $this->parseFacingValue($this->readInt(BlockStateNames::FACING_DIRECTION), [
            0 => Facing::DOWN,
            1 => Facing::UP,
            2 => Facing::NORTH,
            3 => Facing::SOUTH,
            4 => Facing::WEST,
            5 => Facing::EAST
        ]);
    }
 
    public function readBlockFace() : int{
        return match($raw = $this->readString(BlockStateNames::MC_BLOCK_FACE)){
            StringValues::MC_BLOCK_FACE_DOWN => Facing::DOWN,
            StringValues::MC_BLOCK_FACE_UP => Facing::UP,
            StringValues::MC_BLOCK_FACE_NORTH => Facing::NORTH,
            StringValues::MC_BLOCK_FACE_SOUTH => Facing::SOUTH,
            StringValues::MC_BLOCK_FACE_WEST => Facing::WEST,
            StringValues::MC_BLOCK_FACE_EAST => Facing::EAST,
            default => throw $this->badValueException(BlockStateNames::MC_BLOCK_FACE, $raw)
        };
    }
 
    public function readFacingFlags() : array{
        $result = [];
        $flags = $this->readBoundedInt(BlockStateNames::MULTI_FACE_DIRECTION_BITS, 0, 63);
        foreach([
            BlockLegacyMetadata::MULTI_FACE_DIRECTION_FLAG_DOWN => Facing::DOWN,
            BlockLegacyMetadata::MULTI_FACE_DIRECTION_FLAG_UP => Facing::UP,
            BlockLegacyMetadata::MULTI_FACE_DIRECTION_FLAG_NORTH => Facing::NORTH,
            BlockLegacyMetadata::MULTI_FACE_DIRECTION_FLAG_SOUTH => Facing::SOUTH,
            BlockLegacyMetadata::MULTI_FACE_DIRECTION_FLAG_WEST => Facing::WEST,
            BlockLegacyMetadata::MULTI_FACE_DIRECTION_FLAG_EAST => Facing::EAST
        ] as $flag => $facing){
            if(($flags & $flag) !== 0){
                $result[$facing] = $facing;
            }
        }
 
        return $result;
    }
 
    public function readEndRodFacingDirection() : int{
        $result = $this->readFacingDirection();
        return Facing::axis($result) !== Axis::Y ? Facing::opposite($result) : $result;
    }
 
    public function readHorizontalFacing() : int{
        return $this->parseFacingValue($this->readInt(BlockStateNames::FACING_DIRECTION), [
            0 => Facing::NORTH, //should be illegal, but 1.13 allows it
            1 => Facing::NORTH, //also should be illegal
            2 => Facing::NORTH,
            3 => Facing::SOUTH,
            4 => Facing::WEST,
            5 => Facing::EAST
        ]);
    }
 
    public function readWeirdoHorizontalFacing() : int{
        return $this->parseFacingValue($this->readInt(BlockStateNames::WEIRDO_DIRECTION), [
            0 => Facing::EAST,
            1 => Facing::WEST,
            2 => Facing::SOUTH,
            3 => Facing::NORTH
        ]);
    }
 
    public function readLegacyHorizontalFacing() : int{
        return $this->parseFacingValue($this->readInt(BlockStateNames::DIRECTION), [
            0 => Facing::SOUTH,
            1 => Facing::WEST,
            2 => Facing::NORTH,
            3 => Facing::EAST
        ]);
    }
 
    public function read5MinusHorizontalFacing() : int{
        return $this->parseFacingValue($this->readInt(BlockStateNames::DIRECTION), [
            0 => Facing::EAST,
            1 => Facing::WEST,
            2 => Facing::SOUTH,
            3 => Facing::NORTH
        ]);
    }
 
    public function readCardinalHorizontalFacing() : int{
        return match($raw = $this->readString(BlockStateNames::MC_CARDINAL_DIRECTION)){
            StringValues::MC_CARDINAL_DIRECTION_NORTH => Facing::NORTH,
            StringValues::MC_CARDINAL_DIRECTION_SOUTH => Facing::SOUTH,
            StringValues::MC_CARDINAL_DIRECTION_WEST => Facing::WEST,
            StringValues::MC_CARDINAL_DIRECTION_EAST => Facing::EAST,
            default => throw $this->badValueException(BlockStateNames::MC_CARDINAL_DIRECTION, $raw)
        };
    }
 
    public function readCoralFacing() : int{
        return $this->parseFacingValue($this->readInt(BlockStateNames::CORAL_DIRECTION), [
            0 => Facing::WEST,
            1 => Facing::EAST,
            2 => Facing::NORTH,
            3 => Facing::SOUTH
        ]);
    }
 
    public function readFacingWithoutDown() : int{
        $result = $this->readFacingDirection();
        if($result === Facing::DOWN){ //shouldn't be legal, but 1.13 allows it
            $result = Facing::UP;
        }
        return $result;
    }
 
    public function readFacingWithoutUp() : int{
        $result = $this->readFacingDirection();
        if($result === Facing::UP){
            $result = Facing::DOWN; //shouldn't be legal, but 1.13 allows it
        }
        return $result;
    }
 
    public function readPillarAxis() : int{
        $rawValue = $this->readString(BlockStateNames::PILLAR_AXIS);
        $value = [
            StringValues::PILLAR_AXIS_X => Axis::X,
            StringValues::PILLAR_AXIS_Y => Axis::Y,
            StringValues::PILLAR_AXIS_Z => Axis::Z
        ][$rawValue] ?? null;
        if($value === null){
            throw $this->badValueException(BlockStateNames::PILLAR_AXIS, $rawValue, "Invalid axis value");
        }
        return $value;
    }
 
    public function readSlabPosition() : SlabType{
        return match($rawValue = $this->readString(BlockStateNames::MC_VERTICAL_HALF)){
            StringValues::MC_VERTICAL_HALF_BOTTOM => SlabType::BOTTOM,
            StringValues::MC_VERTICAL_HALF_TOP => SlabType::TOP,
            default => throw $this->badValueException(BlockStateNames::MC_VERTICAL_HALF, $rawValue, "Invalid slab position"),
        };
    }
 
    public function readTorchFacing() : int{
        //TODO: horizontal directions are flipped (MCPE bug: https://bugs.mojang.com/browse/MCPE-152036)
        return match($rawValue = $this->readString(BlockStateNames::TORCH_FACING_DIRECTION)){
            StringValues::TORCH_FACING_DIRECTION_EAST => Facing::WEST,
            StringValues::TORCH_FACING_DIRECTION_NORTH => Facing::SOUTH,
            StringValues::TORCH_FACING_DIRECTION_SOUTH => Facing::NORTH,
            StringValues::TORCH_FACING_DIRECTION_TOP => Facing::UP,
            StringValues::TORCH_FACING_DIRECTION_UNKNOWN => Facing::UP, //should be illegal, but 1.13 allows it
            StringValues::TORCH_FACING_DIRECTION_WEST => Facing::EAST,
            default => throw $this->badValueException(BlockStateNames::TORCH_FACING_DIRECTION, $rawValue, "Invalid torch facing"),
        };
    }
 
    public function readBellAttachmentType() : BellAttachmentType{
        return match($type = $this->readString(BlockStateNames::ATTACHMENT)){
            StringValues::ATTACHMENT_HANGING => BellAttachmentType::CEILING,
            StringValues::ATTACHMENT_STANDING => BellAttachmentType::FLOOR,
            StringValues::ATTACHMENT_SIDE => BellAttachmentType::ONE_WALL,
            StringValues::ATTACHMENT_MULTIPLE => BellAttachmentType::TWO_WALLS,
            default => throw $this->badValueException(BlockStateNames::ATTACHMENT, $type),
        };
    }
 
    public function readWallConnectionType(string $name) : ?WallConnectionType{
        return match($type = $this->readString($name)){
            //TODO: this looks a bit confusing due to use of EAST, but the values are the same for all connections
            //we need to find a better way to auto-generate the constant names when they are reused
            //for now, using these constants is better than nothing since it still gives static analysability
            StringValues::WALL_CONNECTION_TYPE_EAST_NONE => null,
            StringValues::WALL_CONNECTION_TYPE_EAST_SHORT => WallConnectionType::SHORT,
            StringValues::WALL_CONNECTION_TYPE_EAST_TALL => WallConnectionType::TALL,
            default => throw $this->badValueException($name, $type),
        };
    }
 
    public function ignored(string $name) : void{
        if($this->data->getState($name) !== null){
            unset($this->unusedStates[$name]);
        }else{
            throw $this->missingOrWrongTypeException($name, null);
        }
    }
 
    public function todo(string $name) : void{
        $this->ignored($name);
    }
 
    public function checkUnreadProperties() : void{
        if(count($this->unusedStates) > 0){
            throw new BlockStateDeserializeException("Unread properties: " . implode(", ", array_keys($this->unusedStates)));
        }
    }
}