package net.minecraft.world.level.block;

import com.google.common.collect.Lists;
import java.util.List;
import net.minecraft.core.BlockPos;
import net.minecraft.core.Direction;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.block.state.properties.RailShape;
import org.jetbrains.annotations.Nullable;

public class RailState {
	private final Level level;
	private final BlockPos pos;
	private final BaseRailBlock block;
	private BlockState state;
	private final boolean isStraight;
	private final List<BlockPos> connections = Lists.<BlockPos>newArrayList();

	public RailState(Level level, BlockPos pos, BlockState state) {
		this.level = level;
		this.pos = pos;
		this.state = state;
		this.block = (BaseRailBlock)state.getBlock();
		RailShape railShape = state.getValue(this.block.getShapeProperty());
		this.isStraight = this.block.isStraight();
		this.updateConnections(railShape);
	}

	public List<BlockPos> getConnections() {
		return this.connections;
	}

	private void updateConnections(RailShape shape) {
		this.connections.clear();
		switch (shape) {
			case NORTH_SOUTH:
				this.connections.add(this.pos.north());
				this.connections.add(this.pos.south());
				break;
			case EAST_WEST:
				this.connections.add(this.pos.west());
				this.connections.add(this.pos.east());
				break;
			case ASCENDING_EAST:
				this.connections.add(this.pos.west());
				this.connections.add(this.pos.east().above());
				break;
			case ASCENDING_WEST:
				this.connections.add(this.pos.west().above());
				this.connections.add(this.pos.east());
				break;
			case ASCENDING_NORTH:
				this.connections.add(this.pos.north().above());
				this.connections.add(this.pos.south());
				break;
			case ASCENDING_SOUTH:
				this.connections.add(this.pos.north());
				this.connections.add(this.pos.south().above());
				break;
			case SOUTH_EAST:
				this.connections.add(this.pos.east());
				this.connections.add(this.pos.south());
				break;
			case SOUTH_WEST:
				this.connections.add(this.pos.west());
				this.connections.add(this.pos.south());
				break;
			case NORTH_WEST:
				this.connections.add(this.pos.west());
				this.connections.add(this.pos.north());
				break;
			case NORTH_EAST:
				this.connections.add(this.pos.east());
				this.connections.add(this.pos.north());
		}
	}

	private void removeSoftConnections() {
		for (int i = 0; i < this.connections.size(); i++) {
			RailState railState = this.getRail((BlockPos)this.connections.get(i));
			if (railState != null && railState.connectsTo(this)) {
				this.connections.set(i, railState.pos);
			} else {
				this.connections.remove(i--);
			}
		}
	}

	private boolean hasRail(BlockPos pos) {
		return BaseRailBlock.isRail(this.level, pos) || BaseRailBlock.isRail(this.level, pos.above()) || BaseRailBlock.isRail(this.level, pos.below());
	}

	@Nullable
	private RailState getRail(BlockPos pos) {
		BlockState blockState = this.level.getBlockState(pos);
		if (BaseRailBlock.isRail(blockState)) {
			return new RailState(this.level, pos, blockState);
		} else {
			BlockPos blockPos = pos.above();
			blockState = this.level.getBlockState(blockPos);
			if (BaseRailBlock.isRail(blockState)) {
				return new RailState(this.level, blockPos, blockState);
			} else {
				blockPos = pos.below();
				blockState = this.level.getBlockState(blockPos);
				return BaseRailBlock.isRail(blockState) ? new RailState(this.level, blockPos, blockState) : null;
			}
		}
	}

	private boolean connectsTo(RailState state) {
		return this.hasConnection(state.pos);
	}

	private boolean hasConnection(BlockPos pos) {
		for (int i = 0; i < this.connections.size(); i++) {
			BlockPos blockPos = (BlockPos)this.connections.get(i);
			if (blockPos.getX() == pos.getX() && blockPos.getZ() == pos.getZ()) {
				return true;
			}
		}

		return false;
	}

	protected int countPotentialConnections() {
		int i = 0;

		for (Direction direction : Direction.Plane.HORIZONTAL) {
			if (this.hasRail(this.pos.relative(direction))) {
				i++;
			}
		}

		return i;
	}

	private boolean canConnectTo(RailState state) {
		return this.connectsTo(state) || this.connections.size() != 2;
	}

	private void connectTo(RailState state) {
		this.connections.add(state.pos);
		BlockPos blockPos = this.pos.north();
		BlockPos blockPos2 = this.pos.south();
		BlockPos blockPos3 = this.pos.west();
		BlockPos blockPos4 = this.pos.east();
		boolean bl = this.hasConnection(blockPos);
		boolean bl2 = this.hasConnection(blockPos2);
		boolean bl3 = this.hasConnection(blockPos3);
		boolean bl4 = this.hasConnection(blockPos4);
		RailShape railShape = null;
		if (bl || bl2) {
			railShape = RailShape.NORTH_SOUTH;
		}

		if (bl3 || bl4) {
			railShape = RailShape.EAST_WEST;
		}

		if (!this.isStraight) {
			if (bl2 && bl4 && !bl && !bl3) {
				railShape = RailShape.SOUTH_EAST;
			}

			if (bl2 && bl3 && !bl && !bl4) {
				railShape = RailShape.SOUTH_WEST;
			}

			if (bl && bl3 && !bl2 && !bl4) {
				railShape = RailShape.NORTH_WEST;
			}

			if (bl && bl4 && !bl2 && !bl3) {
				railShape = RailShape.NORTH_EAST;
			}
		}

		if (railShape == RailShape.NORTH_SOUTH) {
			if (BaseRailBlock.isRail(this.level, blockPos.above())) {
				railShape = RailShape.ASCENDING_NORTH;
			}

			if (BaseRailBlock.isRail(this.level, blockPos2.above())) {
				railShape = RailShape.ASCENDING_SOUTH;
			}
		}

		if (railShape == RailShape.EAST_WEST) {
			if (BaseRailBlock.isRail(this.level, blockPos4.above())) {
				railShape = RailShape.ASCENDING_EAST;
			}

			if (BaseRailBlock.isRail(this.level, blockPos3.above())) {
				railShape = RailShape.ASCENDING_WEST;
			}
		}

		if (railShape == null) {
			railShape = RailShape.NORTH_SOUTH;
		}

		this.state = this.state.setValue(this.block.getShapeProperty(), railShape);
		this.level.setBlock(this.pos, this.state, 3);
	}

	private boolean hasNeighborRail(BlockPos pos) {
		RailState railState = this.getRail(pos);
		if (railState == null) {
			return false;
		} else {
			railState.removeSoftConnections();
			return railState.canConnectTo(this);
		}
	}

	public RailState place(boolean powered, boolean alwaysPlace, RailShape shape) {
		BlockPos blockPos = this.pos.north();
		BlockPos blockPos2 = this.pos.south();
		BlockPos blockPos3 = this.pos.west();
		BlockPos blockPos4 = this.pos.east();
		boolean bl = this.hasNeighborRail(blockPos);
		boolean bl2 = this.hasNeighborRail(blockPos2);
		boolean bl3 = this.hasNeighborRail(blockPos3);
		boolean bl4 = this.hasNeighborRail(blockPos4);
		RailShape railShape = null;
		boolean bl5 = bl || bl2;
		boolean bl6 = bl3 || bl4;
		if (bl5 && !bl6) {
			railShape = RailShape.NORTH_SOUTH;
		}

		if (bl6 && !bl5) {
			railShape = RailShape.EAST_WEST;
		}

		boolean bl7 = bl2 && bl4;
		boolean bl8 = bl2 && bl3;
		boolean bl9 = bl && bl4;
		boolean bl10 = bl && bl3;
		if (!this.isStraight) {
			if (bl7 && !bl && !bl3) {
				railShape = RailShape.SOUTH_EAST;
			}

			if (bl8 && !bl && !bl4) {
				railShape = RailShape.SOUTH_WEST;
			}

			if (bl10 && !bl2 && !bl4) {
				railShape = RailShape.NORTH_WEST;
			}

			if (bl9 && !bl2 && !bl3) {
				railShape = RailShape.NORTH_EAST;
			}
		}

		if (railShape == null) {
			if (bl5 && bl6) {
				railShape = shape;
			} else if (bl5) {
				railShape = RailShape.NORTH_SOUTH;
			} else if (bl6) {
				railShape = RailShape.EAST_WEST;
			}

			if (!this.isStraight) {
				if (powered) {
					if (bl7) {
						railShape = RailShape.SOUTH_EAST;
					}

					if (bl8) {
						railShape = RailShape.SOUTH_WEST;
					}

					if (bl9) {
						railShape = RailShape.NORTH_EAST;
					}

					if (bl10) {
						railShape = RailShape.NORTH_WEST;
					}
				} else {
					if (bl10) {
						railShape = RailShape.NORTH_WEST;
					}

					if (bl9) {
						railShape = RailShape.NORTH_EAST;
					}

					if (bl8) {
						railShape = RailShape.SOUTH_WEST;
					}

					if (bl7) {
						railShape = RailShape.SOUTH_EAST;
					}
				}
			}
		}

		if (railShape == RailShape.NORTH_SOUTH) {
			if (BaseRailBlock.isRail(this.level, blockPos.above())) {
				railShape = RailShape.ASCENDING_NORTH;
			}

			if (BaseRailBlock.isRail(this.level, blockPos2.above())) {
				railShape = RailShape.ASCENDING_SOUTH;
			}
		}

		if (railShape == RailShape.EAST_WEST) {
			if (BaseRailBlock.isRail(this.level, blockPos4.above())) {
				railShape = RailShape.ASCENDING_EAST;
			}

			if (BaseRailBlock.isRail(this.level, blockPos3.above())) {
				railShape = RailShape.ASCENDING_WEST;
			}
		}

		if (railShape == null) {
			railShape = shape;
		}

		this.updateConnections(railShape);
		this.state = this.state.setValue(this.block.getShapeProperty(), railShape);
		if (alwaysPlace || this.level.getBlockState(this.pos) != this.state) {
			this.level.setBlock(this.pos, this.state, 3);

			for (int i = 0; i < this.connections.size(); i++) {
				RailState railState = this.getRail((BlockPos)this.connections.get(i));
				if (railState != null) {
					railState.removeSoftConnections();
					if (railState.canConnectTo(this)) {
						railState.connectTo(this);
					}
				}
			}
		}

		return this;
	}

	public BlockState getState() {
		return this.state;
	}
}