/* libUIOHook: Cross-platfrom userland keyboard and mouse hooking.
 * Copyright (C) 2006-2017 Alexander Barker.  All Rights Received.
 * https://github.com/kwhat/libuiohook/
 *
 * libUIOHook is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * libUIOHook is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <inttypes.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <uiohook.h>

#ifdef _WIN32
#include <windows.h>
#else
#if defined(__APPLE__) && defined(__MACH__)
#include <CoreFoundation/CoreFoundation.h>
#endif

#include <pthread.h>
#endif

// Native thread errors.
#define UIOHOOK_ERROR_THREAD_CREATE				0x10

// Thread and mutex variables.
#ifdef _WIN32
static HANDLE hook_thread;

static HANDLE hook_running_mutex;
static HANDLE hook_control_mutex;
static HANDLE hook_control_cond;
#else
static pthread_t hook_thread;

static pthread_mutex_t hook_running_mutex;
static pthread_mutex_t hook_control_mutex;
static pthread_cond_t hook_control_cond;
#endif


bool logger_proc(unsigned int level, const char *format, ...) {
	bool status = false;
	
	va_list args;
	switch (level) {
		#ifdef USE_DEBUG
		case LOG_LEVEL_DEBUG:
		case LOG_LEVEL_INFO:
			va_start(args, format);
			status = vfprintf(stdout, format, args) >= 0;
			va_end(args);
			break;
		#endif

		case LOG_LEVEL_WARN:
		case LOG_LEVEL_ERROR:
			va_start(args, format);
			status = vfprintf(stderr, format, args) >= 0;
			va_end(args);
			break;
	}
	
	return status;
}

// NOTE: The following callback executes on the same thread that hook_run() is called 
// from.  This is important because hook_run() attaches to the operating systems
// event dispatcher and may delay event delivery to the target application.
// Furthermore, some operating systems may choose to disable your hook if it 
// takes to long to process.  If you need to do any extended processing, please 
// do so by copying the event to your own queued dispatch thread.
void dispatch_proc(uiohook_event * const event) {
	char buffer[256] = { 0 };
	size_t length = snprintf(buffer, sizeof(buffer), 
			"id=%i,when=%" PRIu64 ",mask=0x%X", 
			event->type, event->time, event->mask);
	
	switch (event->type) {
		case EVENT_HOOK_ENABLED:
			// Lock the running mutex so we know if the hook is enabled.
			#ifdef _WIN32
			WaitForSingleObject(hook_running_mutex, INFINITE);
			#else
			pthread_mutex_lock(&hook_running_mutex);
			#endif
			
			
			#ifdef _WIN32
			// Signal the control event.
			SetEvent(hook_control_cond);
			#else
			// Unlock the control mutex so hook_enable() can continue.
			pthread_cond_signal(&hook_control_cond);
			pthread_mutex_unlock(&hook_control_mutex);
			#endif
			break;
			
		case EVENT_HOOK_DISABLED:
			// Lock the control mutex until we exit.
			#ifdef _WIN32
			WaitForSingleObject(hook_control_mutex, INFINITE);
			#else
			pthread_mutex_lock(&hook_control_mutex);
			#endif
			
			// Unlock the running mutex so we know if the hook is disabled.
			#ifdef _WIN32
			ReleaseMutex(hook_running_mutex);
			ResetEvent(hook_control_cond);
			#else
			#if defined(__APPLE__) && defined(__MACH__)
			// Stop the main runloop so that this program ends.
			CFRunLoopStop(CFRunLoopGetMain());
			#endif
			
			pthread_mutex_unlock(&hook_running_mutex);
			#endif
			break;
		
		case EVENT_KEY_PRESSED:
			// If the escape key is pressed, naturally terminate the program.
			if (event->data.keyboard.keycode == VC_ESCAPE) {
				int status = hook_stop();
				switch (status) {
					// System level errors.
					case UIOHOOK_ERROR_OUT_OF_MEMORY:
						logger_proc(LOG_LEVEL_ERROR, "Failed to allocate memory. (%#X)", status);
						break;
			
					case UIOHOOK_ERROR_X_RECORD_GET_CONTEXT:
						// NOTE This is the only platform specific error that occurs on hook_stop().
						logger_proc(LOG_LEVEL_ERROR, "Failed to get XRecord context. (%#X)", status);
						break;

					// Default error.
					case UIOHOOK_FAILURE:
					default:
						logger_proc(LOG_LEVEL_ERROR, "An unknown hook error occurred. (%#X)", status);
						break;
				}
			}
		case EVENT_KEY_RELEASED:
			snprintf(buffer + length, sizeof(buffer) - length, 
				",keycode=%u,rawcode=0x%X",
				event->data.keyboard.keycode, event->data.keyboard.rawcode);
			break;

		case EVENT_KEY_TYPED:
			snprintf(buffer + length, sizeof(buffer) - length, 
				",keychar=%lc,rawcode=%u",
				(wint_t) event->data.keyboard.keychar,
				event->data.keyboard.rawcode);
			break;

		case EVENT_MOUSE_PRESSED:
		case EVENT_MOUSE_RELEASED:
		case EVENT_MOUSE_CLICKED:
		case EVENT_MOUSE_MOVED:
		case EVENT_MOUSE_DRAGGED:
			snprintf(buffer + length, sizeof(buffer) - length, 
				",x=%i,y=%i,button=%i,clicks=%i",
				event->data.mouse.x, event->data.mouse.y,
				event->data.mouse.button, event->data.mouse.clicks);
			break;

		case EVENT_MOUSE_WHEEL:
			snprintf(buffer + length, sizeof(buffer) - length, 
				",type=%i,amount=%i,rotation=%i",
				event->data.wheel.type, event->data.wheel.amount,
				event->data.wheel.rotation);
			break;

		default:
			break;
	}

	fprintf(stdout, "%s\n",	 buffer);
}

#ifdef _WIN32
DWORD WINAPI hook_thread_proc(LPVOID arg) {
#else
void *hook_thread_proc(void *arg) {
#endif
	// Set the hook status.
	int status = hook_run();
	if (status != UIOHOOK_SUCCESS) {
		#ifdef _WIN32
		*(DWORD *) arg = status;
		#else
		*(int *) arg = status;
		#endif
	}
	
	// Make sure we signal that we have passed any exception throwing code for
	// the waiting hook_enable().
	#ifdef _WIN32
	SetEvent(hook_control_cond);
	
	return status;
	#else
	// Make sure we signal that we have passed any exception throwing code for
	// the waiting hook_enable().
	pthread_cond_signal(&hook_control_cond);
	pthread_mutex_unlock(&hook_control_mutex);
	
	return arg;
	#endif
}

int hook_enable() {
	// Lock the thread control mutex.  This will be unlocked when the
	// thread has finished starting, or when it has fully stopped.
	#ifdef _WIN32
	WaitForSingleObject(hook_control_mutex, INFINITE);
	#else
	pthread_mutex_lock(&hook_control_mutex);
	#endif
	
	// Set the initial status.
	int status = UIOHOOK_FAILURE;
	
	#ifndef _WIN32
	// Create the thread attribute.
	pthread_attr_t hook_thread_attr;
	pthread_attr_init(&hook_thread_attr);

	// Get the policy and priority for the thread attr.
	int policy;
	pthread_attr_getschedpolicy(&hook_thread_attr, &policy);
	int priority = sched_get_priority_max(policy);
	#endif
	
	#if defined(_WIN32)
	DWORD hook_thread_id;
	DWORD *hook_thread_status = malloc(sizeof(DWORD));
	hook_thread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE) hook_thread_proc, hook_thread_status, 0, &hook_thread_id);
	if (hook_thread != INVALID_HANDLE_VALUE) {
	#else
	int *hook_thread_status = malloc(sizeof(int));
	if (pthread_create(&hook_thread, &hook_thread_attr, hook_thread_proc, hook_thread_status) == 0) {
	#endif
		#if defined(_WIN32)
		// Attempt to set the thread priority to time critical.
		if (SetThreadPriority(hook_thread, THREAD_PRIORITY_TIME_CRITICAL) == 0) {
			logger_proc(LOG_LEVEL_WARN, "%s [%u]: Could not set thread priority %li for thread %#p! (%#lX)\n",
					__FUNCTION__, __LINE__, (long) THREAD_PRIORITY_TIME_CRITICAL,
					hook_thread	, (unsigned long) GetLastError());
		}
		#elif (defined(__APPLE__) && defined(__MACH__)) || _POSIX_C_SOURCE >= 200112L
		// Some POSIX revisions do not support pthread_setschedprio so we will 
		// use pthread_setschedparam instead.
		struct sched_param param = { .sched_priority = priority };
		if (pthread_setschedparam(hook_thread, SCHED_OTHER, &param) != 0) {
			logger_proc(LOG_LEVEL_WARN,	"%s [%u]: Could not set thread priority %i for thread 0x%lX!\n",
					__FUNCTION__, __LINE__, priority, (unsigned long) hook_thread);
		}
		#else
		// Raise the thread priority using glibc pthread_setschedprio.
		if (pthread_setschedprio(hook_thread, priority) != 0) {
			logger_proc(LOG_LEVEL_WARN,	"%s [%u]: Could not set thread priority %i for thread 0x%lX!\n",
					__FUNCTION__, __LINE__, priority, (unsigned long) hook_thread);
		}
		#endif
		
		
		// Wait for the thread to indicate that it has passed the 
		// initialization portion by blocking until either a EVENT_HOOK_ENABLED 
		// event is received or the thread terminates.
		// NOTE This unlocks the hook_control_mutex while we wait.
		#ifdef _WIN32
		WaitForSingleObject(hook_control_cond, INFINITE);
		#else
		pthread_cond_wait(&hook_control_cond, &hook_control_mutex);
		#endif

		#ifdef _WIN32
		if (WaitForSingleObject(hook_running_mutex, 0) != WAIT_TIMEOUT) {
		#else
		if (pthread_mutex_trylock(&hook_running_mutex) == 0) {
		#endif
			// Lock Successful; The hook is not running but the hook_control_cond 
			// was signaled!  This indicates that there was a startup problem!
			
			// Get the status back from the thread.
			#ifdef _WIN32
			WaitForSingleObject(hook_thread,  INFINITE);
			GetExitCodeThread(hook_thread, hook_thread_status);
			#else
			pthread_join(hook_thread, (void **) &hook_thread_status);
			status = *hook_thread_status;
			#endif
		}
		else {
			// Lock Failure; The hook is currently running and wait was signaled
			// indicating that we have passed all possible start checks.  We can 
			// always assume a successful startup at this point.
			status = UIOHOOK_SUCCESS;
		}
		
		free(hook_thread_status);
	
		logger_proc(LOG_LEVEL_DEBUG,	"%s [%u]: Thread Result: (%#X).\n",
				__FUNCTION__, __LINE__, status);
	}
	else {
		status = UIOHOOK_ERROR_THREAD_CREATE;
	}
	
	// Make sure the control mutex is unlocked.
	#ifdef _WIN32
	ReleaseMutex(hook_control_mutex);
	#else
	pthread_mutex_unlock(&hook_control_mutex);
	#endif
	
	return status;
}


int main() {
	// Lock the thread control mutex.  This will be unlocked when the
	// thread has finished starting, or when it has fully stopped.
	#ifdef _WIN32
	// Create event handles for the thread hook.
	hook_running_mutex = CreateMutex(NULL, FALSE, TEXT("hook_running_mutex"));
	hook_control_mutex = CreateMutex(NULL, FALSE, TEXT("hook_control_mutex"));
	hook_control_cond = CreateEvent(NULL, TRUE, FALSE, TEXT("hook_control_cond"));
	#else
	pthread_mutex_init(&hook_running_mutex, NULL);
	pthread_mutex_init(&hook_control_mutex, NULL);
	pthread_cond_init(&hook_control_cond, NULL);
	#endif
	
	// Set the logger callback for library output.
	hook_set_logger_proc(&logger_proc);
	
	// Set the event callback for uiohook events.
	hook_set_dispatch_proc(&dispatch_proc);

	// Start the hook and block.
	// NOTE If EVENT_HOOK_ENABLED was delivered, the status will always succeed.
	int status = hook_enable();
	switch (status) {
		case UIOHOOK_SUCCESS:
			// We no longer block, so we need to explicitly wait for the thread to die.
			#ifdef _WIN32
			WaitForSingleObject(hook_thread,  INFINITE);
			#else
			#if defined(__APPLE__) && defined(__MACH__)
			// NOTE Darwin requires that you start your own runloop from main.
			CFRunLoopRun();
			#endif
			
			pthread_join(hook_thread, NULL);
			#endif
			break;

		// System level errors.
		case UIOHOOK_ERROR_OUT_OF_MEMORY:
			logger_proc(LOG_LEVEL_ERROR, "Failed to allocate memory. (%#X)\n", status);
			break;


		// X11 specific errors.
		case UIOHOOK_ERROR_X_OPEN_DISPLAY:
			logger_proc(LOG_LEVEL_ERROR, "Failed to open X11 display. (%#X)\n", status);
			break;

		case UIOHOOK_ERROR_X_RECORD_NOT_FOUND:
			logger_proc(LOG_LEVEL_ERROR, "Unable to locate XRecord extension. (%#X)\n", status);
			break;

		case UIOHOOK_ERROR_X_RECORD_ALLOC_RANGE:
			logger_proc(LOG_LEVEL_ERROR, "Unable to allocate XRecord range. (%#X)\n", status);
			break;

		case UIOHOOK_ERROR_X_RECORD_CREATE_CONTEXT:
			logger_proc(LOG_LEVEL_ERROR, "Unable to allocate XRecord context. (%#X)\n", status);
			break;

		case UIOHOOK_ERROR_X_RECORD_ENABLE_CONTEXT:
			logger_proc(LOG_LEVEL_ERROR, "Failed to enable XRecord context. (%#X)\n", status);
			break;


		// Windows specific errors.
		case UIOHOOK_ERROR_SET_WINDOWS_HOOK_EX:
			logger_proc(LOG_LEVEL_ERROR, "Failed to register low level windows hook. (%#X)\n", status);
			break;


		// Darwin specific errors.
		case UIOHOOK_ERROR_AXAPI_DISABLED:
			logger_proc(LOG_LEVEL_ERROR, "Failed to enable access for assistive devices. (%#X)\n", status);
			break;

		case UIOHOOK_ERROR_CREATE_EVENT_PORT:
			logger_proc(LOG_LEVEL_ERROR, "Failed to create apple event port. (%#X)\n", status);
			break;

		case UIOHOOK_ERROR_CREATE_RUN_LOOP_SOURCE:
			logger_proc(LOG_LEVEL_ERROR, "Failed to create apple run loop source. (%#X)\n", status);
			break;

		case UIOHOOK_ERROR_GET_RUNLOOP:
			logger_proc(LOG_LEVEL_ERROR, "Failed to acquire apple run loop. (%#X)\n", status);
			break;

		case UIOHOOK_ERROR_CREATE_OBSERVER:
			logger_proc(LOG_LEVEL_ERROR, "Failed to create apple run loop observer. (%#X)\n", status);
			break;

		// Default error.
		case UIOHOOK_FAILURE:
		default:
			logger_proc(LOG_LEVEL_ERROR, "An unknown hook error occurred. (%#X)\n", status);
			break;
	}
	
	#ifdef _WIN32
	// Create event handles for the thread hook.
	CloseHandle(hook_thread);
	CloseHandle(hook_running_mutex);
	CloseHandle(hook_control_mutex);
	CloseHandle(hook_control_cond);
	#else
	pthread_mutex_destroy(&hook_running_mutex);
	pthread_mutex_destroy(&hook_control_mutex);
	pthread_cond_destroy(&hook_control_cond); 
	#endif

	return status;
}