#include <glib.h>
#include <gtk/gtk.h>
#include <gdk/gdk.h>

#include "private.h"

#include "world.h"


static GtkWidget *window;

static int started;
static int stopped;
static unsigned long long frameCount;
static gint64 startTime;
static gint64 currentTime;
static guint timerInterval;

static Callback initCallback;
static Callback drawCallback;

static int width;
static int height;
static double frameRate = 30;

static int cameraEnabled;
static double cameraX;
static double cameraY;
static double cameraZoom = 1;

static HeliArray keysPressed;
static HeliArray keysPressedInFrame;
static HeliArray keysReleasedInFrame;
static HeliArray buttonsPressed;
static HeliArray buttonsPressedInFrame;
static HeliArray buttonsReleasedInFrame;

static int mouseMovedInFrame;
static double _mouseX;
static double _mouseY;

static char* buttonNames[] = {
	"left",
	"middle",
	"right" };
static int buttonsCount = (int)(sizeof(buttonNames)/sizeof(*buttonNames));



void playSound(const char *path, int loop) {
	#warning "TODO: playSound: not implemented yet"
}

void stopSound(const char *path) {
	#warning "TODO: stopSound: not implemented yet"
}

int keyDown(const char *code)
	{ return heliStringmapGet(&keysPressed, code) != NULL; }
int keyWentDown(const char *code)
	{ return heliStringmapGet(&keysPressedInFrame, code) != NULL; }
int keyWentUp(const char *code)
	{ return heliStringmapGet(&keysReleasedInFrame, code) != NULL; }

int mouseDidMove()
	{ return mouseMovedInFrame; }
int mouseDown(const char *code)
	{ return heliStringmapGet(&buttonsPressed, code) != NULL; }
int mouseWentDown(const char *code)
	{ return heliStringmapGet(&buttonsPressedInFrame, code) != NULL; }
int mouseWentUp(const char *code)
	{ return heliStringmapGet(&buttonsReleasedInFrame, code) != NULL; }
double mouseX()
	{ return _mouseX; }
double mouseY()
	{ return _mouseY; }

int mousePressedOver(Sprite sprite)
	{ return buttonsPressed.count && mouseIsOver(sprite); }

int worldGetWidth()
	{ return width; }
void worldSetWidth(int w) {
	width = w;
	if (started) gtk_widget_set_size_request(window, width, height);
}

int worldGetHeight()
	{ return height; }
void worldSetHeight(int h) {
	height = h;
	if (started) gtk_widget_set_size_request(window, width, height);
}

double worldGetFrameRate()
	{ return frameRate; }
void worldSetFrameRate(double frameRate) {
	if (!(frameRate > 1)) frameRate = 1;
	if (!(frameRate < 100)) frameRate = 100;
}

int worldGetFrameCount()
	{ return (int)frameCount; }
double worldGetSeconds()
	{ return started ? (currentTime - startTime)*1e-6 : 0.0; }

void worldSetInit(Callback init)
	{ initCallback = init; }
void worldSetDraw(Callback draw)
	{ drawCallback = draw; }
void worldStop()
	{ if (started) stopped = TRUE; }


void cameraOn()
	{ cameraEnabled = TRUE; }
void cameraOff()
	{ cameraEnabled = FALSE; }
int cameraIsActive()
	{ return cameraEnabled; }

double cameraMouseX()
	{ return _mouseX/cameraZoom + cameraX; }
double cameraMouseY()
	{ return _mouseY/cameraZoom + cameraY; }

double cameraGetX()
	{ return cameraX; }
void cameraSetX(double x)
	{ cameraX = x; }

double cameraGetY()
	{ return cameraY; }
void cameraSetY(double y)
	{ cameraY = y; }

double cameraGetZoom()
	{ return cameraZoom; }
void cameraSetZoom(double x)
	{ cameraZoom = x > 1e-6 ? x : 1e-6; }


static gboolean timeout(gpointer data G_GNUC_UNUSED) {
	gtk_widget_queue_draw(window);
	if (stopped) {
		gtk_window_close(GTK_WINDOW(window));
		return FALSE;
	}
	guint interval = (guint)round(1000/frameRate);
	if (interval != timerInterval) {
		timerInterval = interval;
		g_timeout_add(timerInterval, timeout, NULL);
		return FALSE;
	}
	return TRUE;
}

static gboolean draw(GtkWidget *widget G_GNUC_UNUSED, cairo_t *cr, gpointer data G_GNUC_UNUSED) {
	guint64 newTime = g_get_monotonic_time();
	heliCairo = cr;

	if (!frameCount) {
		startTime = currentTime = newTime;
		if (initCallback) initCallback();
		heliDrawingPrepareFrame();
		if (drawCallback) drawCallback();
		heliArrayClear(&keysPressedInFrame);
		heliArrayClear(&keysReleasedInFrame);
		heliArrayClear(&buttonsPressedInFrame);
		heliArrayClear(&buttonsReleasedInFrame);
		++frameCount;
	} else {
		double dt = 1/frameRate;
		guint64 timeStep = (guint64)round(dt*1e6);
		while(currentTime < newTime) {
			currentTime += timeStep;
			++frameCount;
			heliSpriteUpdate(dt);
			heliDrawingPrepareFrame();
			if (drawCallback) drawCallback();
			heliArrayClear(&keysPressedInFrame);
			heliArrayClear(&keysReleasedInFrame);
			heliArrayClear(&buttonsPressedInFrame);
			heliArrayClear(&buttonsReleasedInFrame);
		}
	}

	heliCairo = NULL;
	return TRUE;
}

static gboolean handleEvent(GtkWidget *widget G_GNUC_UNUSED, GdkEvent *event, gpointer data G_GNUC_UNUSED) {
	gchar *keyname;
	int button;
	
	switch(event->type) {
	case GDK_KEY_PRESS:
		keyname = heliStringCopy( gdk_keyval_name(event->key.keyval) );
		heliLowercase(keyname);
		heliStringmapAdd(&keysPressed, keyname, NULL, NULL);
		heliStringmapAdd(&keysPressedInFrame, keyname, NULL, NULL);
		free(keyname);
		return TRUE;
	case GDK_KEY_RELEASE:
		keyname = heliStringCopy( gdk_keyval_name(event->key.keyval) );
		heliLowercase(keyname);
		heliStringmapRemove(&keysPressed, keyname);
		heliStringmapAdd(&keysReleasedInFrame, keyname, NULL, NULL);
		free(keyname);
		return TRUE;
	case GDK_BUTTON_PRESS:
		button = event->button.button;
		if (button >= 0 && button < buttonsCount) {
			heliStringmapAdd(&buttonsPressed, buttonNames[button], NULL, NULL);
			heliStringmapAdd(&buttonsPressedInFrame, buttonNames[button], NULL, NULL);
		}
		_mouseX = event->button.x;
		_mouseY = event->button.y;
		return TRUE;
	case GDK_BUTTON_RELEASE:
		button = event->button.button;
		if (button >= 0 && button < buttonsCount) {
			heliStringmapRemove(&buttonsPressed, buttonNames[button]);
			heliStringmapAdd(&buttonsReleasedInFrame, buttonNames[button], NULL, NULL);
		}
		_mouseX = event->button.x;
		_mouseY = event->button.y;
		return TRUE;
	case GDK_MOTION_NOTIFY:
		_mouseX = event->motion.x;
		_mouseY = event->motion.y;
		return TRUE;
	default:
		break;
	}
	return FALSE;
}

static void activate(GtkApplication* app, gpointer data G_GNUC_UNUSED) {
	window = gtk_application_window_new(app);
	g_signal_connect(window, "draw", G_CALLBACK(draw), NULL);
	g_signal_connect(window, "event", G_CALLBACK(handleEvent), NULL);
	gtk_widget_add_events( window,
						   GDK_POINTER_MOTION_MASK
						 | GDK_BUTTON_PRESS_MASK
						 | GDK_BUTTON_RELEASE_MASK
						 | GDK_KEY_PRESS_MASK
						 | GDK_KEY_RELEASE_MASK );
	gtk_widget_set_size_request(window, width, height);
	gtk_widget_show(window);
	timerInterval = (guint)round(1000/frameRate);
	g_timeout_add(timerInterval, timeout, NULL);
	if (initCallback) initCallback();
}

void worldRun() {
	if (started) return;
	started = TRUE;
	stopped = FALSE;

	frameCount = 0;
	srand(time(NULL));

	GtkApplication *application = gtk_application_new(NULL, 0);
	g_signal_connect(application, "activate", G_CALLBACK(activate), NULL);
	g_application_run(G_APPLICATION(application), 0, NULL);
	g_object_unref(application);
	
	heliSpriteFinish();
	heliDrawingFinish();
	heliAnimationFinish();

	heliArrayDestroy(&keysPressed);
	heliArrayDestroy(&keysPressed);
	heliArrayDestroy(&keysPressedInFrame);
	heliArrayDestroy(&keysReleasedInFrame);
	heliArrayDestroy(&buttonsPressed);
	heliArrayDestroy(&buttonsPressedInFrame);
	heliArrayDestroy(&buttonsReleasedInFrame);
	
	started = FALSE;
}