package jalview.bin;

import java.io.File;
import java.lang.management.ManagementFactory;
import java.lang.management.OperatingSystemMXBean;
import java.util.ArrayList;

public class Launcher
{

  private final static String startClass = "jalview.bin.Jalview";

  private final static int maxHeapSizePerCent = 95;

  private final static String dockIconPath = "JalviewLogo_Huge.png";

  public static void main(String[] args)
  {
    final String javaBin = System.getProperty("java.home") + File.separator
            + "bin" + File.separator + "java";

    ArrayList<String> command = new ArrayList<>();
    command.add(javaBin);

    boolean isAMac = System.getProperty("os.name").indexOf("Mac") > -1;

    for (String jvmArg : ManagementFactory.getRuntimeMXBean()
            .getInputArguments())
    {
      command.add(jvmArg);
    }
    command.add("-cp");
    command.add(ManagementFactory.getRuntimeMXBean().getClassPath());
    ArrayList<String> arguments = new ArrayList<>();
    for (String arg : args)
    {
      arguments.add(arg);
    }

    // add memory setting if not specified
    boolean memSet = false;
    boolean dockIcon = false;
    ARG: for (int i = 0; i < command.size(); i++)
    {
      String arg = command.get(i);
      if (arg.startsWith("-Xmx"))
      {
        memSet = true;
      }
      else if (arg.startsWith("-Xdock:icon"))
      {
        dockIcon = true;
      }
    }

    if (!memSet)
    {
      long maxMemLong = -1;
      long physicalMem = getPhysicalMemory();
      if (physicalMem > 0)
      {
        maxMemLong = physicalMem * maxHeapSizePerCent / 100;
      }
      if (maxMemLong > 0)
      {
        command.add("-Xmx" + Long.toString(maxMemLong));
      }
    }

    if (!dockIcon && isAMac)
    {
      command.add("-Xdock:icon=" + dockIconPath);
      // -Xdock:name=... doesn't actually work :(
      // Leaving it in in case it gets fixed
      command.add("-Xdock:name=" + "Jalview");
    }

    command.add(startClass);
    command.addAll(arguments);

    final ProcessBuilder builder = new ProcessBuilder(command);

    System.out.println("COMMAND: " + String.join(" ", builder.command()));

    try
    {
      builder.inheritIO();
      Process process = builder.start();
      process.waitFor();
    } catch (Exception e)
    {
      e.printStackTrace();
    }
    // System.exit(0);

  }

  public static long getPhysicalMemory()
  {
    final OperatingSystemMXBean o = ManagementFactory
            .getOperatingSystemMXBean();

    try
    {
      if (o instanceof com.sun.management.OperatingSystemMXBean)
      {
        final com.sun.management.OperatingSystemMXBean osb = (com.sun.management.OperatingSystemMXBean) o;
        return osb.getTotalPhysicalMemorySize();
      }
    } catch (NoClassDefFoundError e)
    {
      // com.sun.management.OperatingSystemMXBean doesn't exist in this JVM
      System.out.println("No com.sun.management.OperatingSystemMXBean");
    }

    // We didn't get a com.sun.management.OperatingSystemMXBean.
    return -1;
  }

}