Ginger3D/src/main/java/com/github/halotroop/litecraft/save/LitecraftSave.java

package com.github.halotroop.litecraft.save;

import java.io.*;
import java.util.Random;

import com.github.halotroop.litecraft.world.*;
import com.github.halotroop.litecraft.world.gen.*;

import tk.valoeghese.sod.*;

public final class LitecraftSave
{
	public LitecraftSave(String name, boolean mustCreateNew)
	{
		StringBuilder sb = new StringBuilder(SAVE_DIR).append(name);
		File saveDir = new File(sb.toString());

		if (mustCreateNew)
		{
			while (saveDir.exists())
			{
				sb.append('_'); // append "_" to the save name until we get a unique save, if we must create a new save
				saveDir = new File(sb.toString());
			}
		}

		this.file = saveDir;
		this.file.mkdirs();
	}

	private final File file;

	public boolean saveChunk(Chunk chunk)
	{
		StringBuilder fileLocBuilder = new StringBuilder(this.file.getPath())
				.append('/').append(chunk.dimension)
				.append('/').append(chunk.chunkX)
				.append('/').append(chunk.chunkZ);
		File chunkDir = new File(fileLocBuilder.toString());
		chunkDir.mkdirs(); // create directory for file if it does not exist

		// format: <save dir>/<dim>/<chunkX>/<chunkZ>/<chunkY>.sod
		File chunkFile = new File(fileLocBuilder.append('/').append(chunk.chunkY).append(".sod").toString());

		try
		{
			chunkFile.createNewFile();

			BinaryData data = new BinaryData(); // create new empty binary data
			chunk.write(data); // write the chunk info to the binary data
			return data.write(chunkFile); // write the data to the file, return whether an io exception occurred
		}
		catch (IOException e)
		{
			e.printStackTrace();
			return false; // io exception = chunk writing failed at some point
		}
	}

	public Chunk readChunk(int chunkX, int chunkY, int chunkZ, int dimension)
	{
		// format: <save dir>/<dim>/<chunkX>/<chunkZ>/<chunkY>.sod
		File chunkFile = new File(new StringBuilder(this.file.getPath())
				.append('/').append(dimension)
				.append('/').append(chunkX)
				.append('/').append(chunkZ)
				.append('/').append(chunkY).append(".sod").toString());

		if (chunkFile.isFile())
		{
			BinaryData data = BinaryData.read(chunkFile);

			Chunk result = new Chunk(chunkX, chunkY, chunkZ, dimension); // create chunk
			result.read(data); // load the chunk data we have just read into the chunk
			return result;
		}
		else return null;
	}

	public World getWorldOrCreate(Dimension<?> dim)
	{
		File worldFile = new File(this.file.getPath() + "/global_data.sod");

		if (worldFile.isFile()) // load world
		{
			BinaryData data = BinaryData.read(worldFile); // read data from the world file
			DataSection properties = data.get("properties"); // get the properties data section from the data that we have just read
			long seed = 0; // default seed if we cannot read it is 0

			try // try read the seed from the file
			{
				seed = properties.readLong(0); // seed is at index 0
			}
			catch (Throwable e)
			{
				e.printStackTrace();
			}

			World world = new World(seed, 10, dim, this); // create new world with seed read from file or 0, if it could not be read
			world.spawnPlayer(); // spawn player in world
			return world;
		}
		else // create world
		{
			long seed = new Random().nextLong();

			try
			{
				worldFile.createNewFile(); // create world file
				BinaryData data = new BinaryData(); // create empty binary data
				DataSection properties = new DataSection(); // create empty data section for properties
				properties.writeLong(seed); // write seed at index 0
				data.put("properties", properties); // add properties section
				data.write(worldFile); // write to file
			}
			catch (IOException e)
			{
				// If this fails the world seed will not be consistent across saves
				e.printStackTrace();
			}

			World world = new World(seed, 2, dim, this); // create new world with generated seed
			world.spawnPlayer(); // spawn player in world
			return world;
		}
	}

	private static final String SAVE_DIR = "./saves/";
}