// Processes.cpp

//#include <cipres_config.h>

#if defined(_WIN32) || defined(_WIN64)

#define WIN32_LEAN_AND_MEAN

#include <windows.h>


#define TIMEOUT_PERIOD  1000

#elif defined(linux) || defined(__linux) || (defined(__APPLE__) && defined(__MACH__))

#include <sys/types.h>
#include <unistd.h>
#include <signal.h>
#include <cerrno>


#define INITIAL_TIMEOUT  50000
#define TIMEOUT_LIMIT    5

#endif

#include "ErrorHandling.hpp"
#include "cipres-jni.h"


using namespace CipresJNI;


#if defined(_WIN32) || defined(_WIN64)

// SendWindowClose
static BOOL CALLBACK SendWindowClose(HWND handle, LPARAM param)
{
	unsigned long pid;

	::GetWindowThreadProcessId(handle, &pid);

	if(pid == static_cast<long>(param))
		::PostMessage(handle, WM_CLOSE, NULL, NULL);

	return TRUE;
}

#elif defined(linux) || defined(__linux) || (defined(__APPLE__) && defined(__MACH__))

// ProcessExists
static bool ProcessExists(int pid) throw()
{
  int result = ::kill(pid, 0);

	return result == 0 || errno == EPERM;
}

#endif


// Java_org_cipres_jni_Processes_getProcessID
jint JNICALL Java_org_cipres_jni_Processes_getProcessID(JNIEnv *env, jclass obj)
{
#if defined(_WIN32) || defined(_WIN64)

	return ::GetCurrentProcessId();

#elif defined(linux) || defined(__linux) || (defined(__APPLE__) && defined(__MACH__))

	return ::getpid();

#endif
}

// Java_org_cipres_jni_Processes_processExists
jboolean JNICALL Java_org_cipres_jni_Processes_processExists(JNIEnv *env, jclass, jint pid)
{
#if defined(_WIN32) || defined(_WIN64)

	if(pid == 0)
		return true;

	HANDLE process = ::OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, pid);

	if(process != NULL) {
		::CloseHandle(process);

		return true;
	}
	else if(::GetLastError() == ERROR_ACCESS_DENIED)
		return true;
	else
		return false;

#elif defined(linux) || defined(__linux) || (defined(__APPLE__) && defined(__MACH__))

	return ProcessExists(pid);

#endif
}

// Java_org_cipres_jni_Processes_killProcess
void JNICALL Java_org_cipres_jni_Processes_killProcess(JNIEnv *env, jclass obj, jint pid, jboolean force)
{
#if defined(_WIN32) || defined(_WIN64)

	HANDLE process;

	if((process = ::OpenProcess(PROCESS_TERMINATE | SYNCHRONIZE, FALSE, pid)) == NULL) {
		long error_code = ::GetLastError();

		if(error_code != ERROR_ACCESS_DENIED) {
			ThrowSystemError(env, error_code);

			return;
		}
	}

	::EnumWindows(SendWindowClose, pid);

	if(!force) {
		::CloseHandle(process);

		return;
	}

	if(::WaitForSingleObject(process, TIMEOUT_PERIOD) != WAIT_OBJECT_0)
		::TerminateProcess(process, -1);

	::CloseHandle(process);

#elif defined(linux) || defined(__linux) || (defined(__APPLE__) && defined(__MACH__))

	if(::kill(pid, SIGTERM) != 0) {
		int error_code = errno;

		if(error_code == ESRCH)
			ThrowError(env, JAVA_CLASS_ILLEGAL_ARG, "No such process");
		else
			ThrowSystemError(env, error_code);

		return;
	}

	if(!force)
		return;

	unsigned int wait_period = INITIAL_TIMEOUT;

	for(int i = 0 ; i < TIMEOUT_LIMIT ; i++) {
		::usleep(wait_period);

		if(!ProcessExists(pid))
			return;

		wait_period *= 2;
	}

	::kill(pid, SIGKILL);

#endif
}