Inceptum/wrapper/src/main/java/io/gitlab/jfronny/inceptum/util/MetaHolder.java

package io.gitlab.jfronny.inceptum.util;

import com.google.gson.GsonBuilder;
import io.gitlab.jfronny.inceptum.gson.ComparableVersionAdapter;
import io.gitlab.jfronny.inceptum.model.ComparableVersion;
import io.gitlab.jfronny.inceptum.model.inceptum.InceptumVersion;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URISyntaxException;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Path;

public class MetaHolder {
    public static final InceptumVersion VERSION;
    public static final Path BASE_PATH;

    static {
        try (InputStream is = MetaHolder.class.getClassLoader().getResourceAsStream("version.json");
             InputStreamReader isr = new InputStreamReader(is)) {
            VERSION = new GsonBuilder()
                    .registerTypeAdapter(ComparableVersion.class, new ComparableVersionAdapter())
                    .create()
                    .fromJson(isr, InceptumVersion.class);
            if (System.getProperty("inceptum.base") == null) {
                Path runDir = getRunDir();
                BASE_PATH = VERSION.isRelease && !Files.exists(runDir)
                        ? getConfigPath().resolve("Inceptum")
                        : runDir;
            }
            else {
                BASE_PATH = Path.of(System.getProperty("inceptum.base"));
            }
        } catch (IOException e) {
            throw new RuntimeException("Could not get version info", e);
        }
    }

    private static Path getConfigPath() {
        return switch (OSCheck.OS) {
            case WINDOWS -> Path.of(System.getenv("APPDATA"));
            case MAC_OS -> Path.of(System.getProperty("user.home")).resolve("Library").resolve("Application Support");
            case LINUX -> {
                String s = System.getenv().get("XDG_CONFIG_HOME");
                if (s == null)
                    yield Path.of(System.getProperty("user.home")).resolve(".config");
                else
                    yield Path.of(s);
            }
        };
    }

    private static Path getRunDir() {
        Path simpleRunDir = Path.of(".").resolve("run");
        if (Files.exists(simpleRunDir)) return simpleRunDir;
        URL url = MetaHolder.class.getProtectionDomain().getCodeSource().getLocation();
        String p = url.getPath();
        if (p.endsWith(".jar") && !p.endsWith("/build/libs/wrapper-" + VERSION.version + ".jar")) {
            try {
                return new File(url.toURI()).toPath().getParent().resolve("run");
            } catch (URISyntaxException e) {
                e.printStackTrace();
                return simpleRunDir;
            }
        } else {
            System.out.println("Not running in a jar, using ./run");
            return simpleRunDir;
        }
    }
}