EpicHeads/main/java/com/songoda/epicheads/cache/PatchFile.java

package com.songoda.epicheads.cache;

import com.songoda.epicheads.EpicHeads;

import java.io.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

public class PatchFile implements Mod {

	private final String name;
	private final List<HeadPatch> patches = new ArrayList<>();

	public PatchFile(String name) {
		this(name, Collections.emptyList());
	}

	public PatchFile(String name, List<HeadPatch> patches) {
		this.name = name;
		this.patches.addAll(patches);
	}

	@Override
	public String getName() {
		return name;
	}

	@Override
	public Mod.ModType getType() {
		return ModType.PATCH;
	}

	public int getPatchCount() {
		return patches.size();
	}

	public void addPatch(HeadPatch patch) {
		patches.add(patch);
	}

	@Override
	public void applyMod(CacheFile cache) {
		for (HeadPatch patch : patches) {
			patch.applyPatch(cache);
		}
	}

	@Override
	public String toString() {
		return getType() + " {name: \"" + name + "\", patchCount: " + getPatchCount() + "}";
	}

	public void write(File file) throws IOException {
		if (file.isDirectory())
			throw new IOException("File " + file + " is a directory");

		if (!file.exists() && !file.createNewFile())
			throw new IOException("Unable to create file " + file);

		try (FileOutputStream stream = new FileOutputStream(file)) {
			writeCompressed(stream);
		}
	}

	public void writeCompressed(OutputStream os) throws IOException {
		try (GZIPOutputStream zos = new GZIPOutputStream(os); ObjectOutputStream stream = new ObjectOutputStream(zos)) {

			write(stream);

			stream.flush();
		}
	}

	@Override
	public void write(ObjectOutputStream stream) throws IOException {
		stream.writeInt(2);
		stream.writeUTF(name);

		stream.writeInt(patches.size());
		for (HeadPatch patch : patches) {
			patch.write(stream);
		}
	}

	public static PatchFile read(File file) throws IOException {
		if (file.isDirectory())
			throw new IOException("File " + file + " is a directory");

		if (!file.exists())
			throw new IOException("File " + file + " does not exist");

		try (FileInputStream stream = new FileInputStream(file)) {
			return readCompressed(stream);
		}
	}

	public static PatchFile readResource(String resource) throws IOException {
		try (InputStream stream = EpicHeads.getInstance().getResource(resource)) {
			return readCompressed(stream);
		}
	}

	public static PatchFile readCompressed(InputStream is) throws IOException {
		try (GZIPInputStream zis = new GZIPInputStream(is); ObjectInputStream stream = new ObjectInputStream(zis)) {

			return read(stream);
		}
	}

	public static PatchFile read(ObjectInputStream stream) throws IOException {
		int version = stream.readInt();

		String name = stream.readUTF();

		int patchCount = stream.readInt();
		List<HeadPatch> patches = new ArrayList<>(patchCount);
		for (int index = 0; index < patchCount; ++index) {
			patches.add(HeadPatch.read(version, stream));
		}

		return new PatchFile(name, patches);
	}

}