lx01

module lx01.core

import lx01.io as IO
import lx01.reflect as Ref

class System {
	private Ref.JavaBridge bridge = Ref.JavaBridge.new()
	private GarbageCollector gc = GarbageCollector.new()

	private Thread[] hooks = Thread.new[]

	void exit (int status) {
		bridge.execute("java.lang.System", "exit", Object.new[status])
	}

	void runGarbageCollector () {
		gc.execute()
		hooks.forEach(t -> t.start)
	}

	boolean addShutdownHook (Thread thread) {
		return hooks.add(thread)
	}

	boolean removeShutdownHook (Thread thread) {
		return hooks.remove(thread)
	}

	long execute (string command, optional string[] settings, optional IO.File directory) throws IO.IOException {
		execute(command.split(" "), settings.isPresent() ? {settings} | {null}, directory.isPresent() ? {directory} | {null})
	}

	long execute (string[] command, optional string[] settings, optional IO.File directory) throws IO.IOException {
		string[] osettings = settings.isPresent() ? {settings} : {null}
		IO.File[] ofile = directory.isPresent() ? {directory} : {null}
		if (command == null or command.isEmpty()) throw NullValueException.new("No command supplied to execute")
		for (string s in command)
			if (s == null)
				throw NullValueException.new("Commands contain null values")
		for (string s in osettings)
			if (s == null)
				throw NullValueException.new("Settings contain null values")
		try {
			bridge.execute("java.lang.Runtime", "getRuntime").execute("exec", Object.new[command, osettings, ofile]).execute("pid").asLong()
		} catch Ref.BridgeInvocationException as bie {
			if (bie.getType() == "java.io.IOException")
				throw IO.IOException.new(bie.getMessage())
			if (bie.getType() == "java.lang.UnsupportedOperationException")
				throw NotSupportedException.new(bie.getMessage())
			if (bie.getType() == "java.lang.SecurityException")
				return -1
			throw Ref.JavaBridgeError.new()
		}
	}

	long getAvailableMemory () {
		try {
			bridge.execute("java.lang.Runtime", "getRuntime").execute("freeMemory").asLong()
		} catch Ref.BridgeInvocationException as bie {
			throw Ref.JavaBridgeError.new()
		}
	}

	long getActiveMemory () {
		try {
			getUsableMemory() - getAvailableMemory()
		} catch Ref.BridgeInvocationException as bie {
			throw Ref.JavaBridgeError.new()
		}
	}

	long getUsableMemory () {
		try {
			bridge.execute("java.lang.Runtime", "getRuntime").execute("maxMemory").asLong()
		} catch Ref.BridgeInvocationException as bie {
			throw Ref.JavaBridgeError.new()
		}
	}
}