package moe.nea.modernjava.launch.relaunch;

import moe.nea.modernjava.launch.util.PropertyNames;
import moe.nea.modernjava.launch.util.TextIoUtils;
import moe.nea.modernjava.launch.util.WellKnownBlackboard;
import net.minecraftforge.fml.common.launcher.FMLTweaker;
import net.minecraftforge.fml.nea.moe.modernjava.IAMFML;
import org.apache.commons.io.IOUtils;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.management.ManagementFactory;
import java.nio.file.Files;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

public class FCPRelauncher {

    /**
     * @return the original arguments, as passed to the main method.
     */
    public static List<String> getOriginalArguments() {
        List<String> originalArgs = new ArrayList<>();

        // Provided by FML
        // This is highly processed so there might be some arguments that become lost, but almost everything should be in here.
        // Namely non -- arguments get lost. I don't know any of these arguments that the vanilla launcher uses, so it should be fine?
        // Also, some tweakers are missing. But we can fix this.
        Map<String, String> launchArgs = WellKnownBlackboard.launchArgs();
        if ("UnknownFMLProfile".equals(launchArgs.get("--version"))) {
            launchArgs.remove("--version");
        }
        for (Map.Entry<String, String> argument : launchArgs.entrySet()) {
            originalArgs.add(argument.getKey());
            originalArgs.add(argument.getValue());
        }


        originalArgs.add("--tweakClass");
        originalArgs.add(FMLTweaker.class.getName());
        System.out.println("Reconstructed original minecraft arguments: " + originalArgs);
        return originalArgs;
    }

    public static File findJavaLauncher() {
        return new File("/home/nea/.sdkman/candidates/java/16.0.2-tem/bin/java");
    }

    public static File findAgentJar() {
        try {
            File file = File.createTempFile("mjr-agent", ".jar");
            try (InputStream is = FCPRelauncher.class.getResourceAsStream("/agent/agent.jar");
                 OutputStream os = Files.newOutputStream(file.toPath())) {
                assert is != null;
                IOUtils.copy(is, os);
            }
            return file;
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    public static void relaunch() {

        List<String> originalArgs = getOriginalArguments();

        File modernJavaPath = findJavaLauncher();
        System.out.println("Located modern minecraft at: " + modernJavaPath);

        File agentFile = findAgentJar();
        System.out.println("Located agent jar at: " + agentFile);


        ProcessBuilder processBuilder = new ProcessBuilder();
        processBuilder.inheritIO();
        processBuilder.directory(null);


        List<String> moduleOpens = new ArrayList<>();
        moduleOpens.add("java.base/java.util=ALL-UNNAMED");
        moduleOpens.add("java.base/jdk.internal.loader=ALL-UNNAMED");
        moduleOpens.add("java.base/java.lang.reflect=ALL-UNNAMED");


        List<String> fullCommandLine = new ArrayList<>();
        fullCommandLine.add(modernJavaPath.getAbsolutePath());
        fullCommandLine.addAll(ManagementFactory.getRuntimeMXBean().getInputArguments());
        fullCommandLine.add("-D" + PropertyNames.HAS_RELAUNCHED + "=true");
        fullCommandLine.add("-D" + PropertyNames.RELAUNCH_CLASSPATH + "=" + agentFile.getAbsolutePath() + File.pathSeparator + ManagementFactory.getRuntimeMXBean().getClassPath());
        fullCommandLine.add("--illegal-access=permit");
        for (String open : moduleOpens) {
            fullCommandLine.add("--add-opens");
            fullCommandLine.add(open);
        }
        if (System.getProperty(PropertyNames.DEBUG_PORT) != null)
            fullCommandLine.add("-agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=*:" + System.getProperty(PropertyNames.DEBUG_PORT));
        fullCommandLine.add("-javaagent:" + agentFile.getAbsolutePath());
        fullCommandLine.add("--add-modules=ALL-MODULE-PATH,ALL-SYSTEM,ALL-DEFAULT,java.sql");
        fullCommandLine.add("-Xbootclasspath/a:" + agentFile.getAbsolutePath());
        fullCommandLine.add("moe.nea.modernjava.agent.RelaunchEntryPoint");
        fullCommandLine.addAll(originalArgs);

        System.out.println("Full relaunch commandline: " + fullCommandLine);


        processBuilder.command(fullCommandLine);
        int exitCode;
        try {
            try {
                Process process = processBuilder.start();
                exitCode = process.waitFor();
            } finally {
                TextIoUtils.flushStdIO();
            }
        } catch (IOException | InterruptedException e) {
            throw new RuntimeException("Failed to relaunch with old java version", e);
        }


        System.out.println("Exiting outer relaunch layer");
        IAMFML.shutdown(exitCode);
    }

}