#include "ios_system.h"
#include <wchar.h>
#include <iron_gpu.h>
#include <iron_system.h>
#include <iron_math.h>
#include <objc/runtime.h>
#include <mach/mach_time.h>
#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

#define MAX_TOUCH_COUNT 10

extern char mobile_title[1024];
static void *touches[MAX_TOUCH_COUNT];
static int backing_width;
static int backing_height;
static bool shift_down = false;
static bool visible;
static MyView *my_view;
static MyViewController *my_view_controller;
static bool keyboard_shown = false;
static char language[3];
static char sysid[512];
static const char *video_formats[] = {"mp4", NULL};
static void (*resize_callback)(int x, int y, void *data) = NULL;
static void *resize_callback_data = NULL;

void iron_internal_call_resize_callback(int width, int height) {
	if (resize_callback != NULL) {
		resize_callback(width, height, resize_callback_data);
	}
}

static int get_touch_index(void *touch) {
	for (int i = 0; i < MAX_TOUCH_COUNT; ++i) {
		if (touches[i] == touch) {
			return i;
		}
	}
	return -1;
}

static int add_touch(void *touch) {
	for (int i = 0; i < MAX_TOUCH_COUNT; ++i) {
		if (touches[i] == NULL) {
			touches[i] = touch;
			return i;
		}
	}
	return -1;
}

static int remove_touch(void *touch) {
	for (int i = 0; i < MAX_TOUCH_COUNT; ++i) {
		if (touches[i] == touch) {
			touches[i] = NULL;
			return i;
		}
	}
	return -1;
}

int iron_window_width() {
	return backing_width;
}

int iron_window_height() {
	return backing_height;
}

CAMetalLayer *get_metal_layer(void) {
	return [my_view metal_layer];
}

id get_metal_device(void) {
	return [my_view metal_device];
}

id get_metal_queue(void) {
	return [my_view metal_queue];
}

void iron_display_init(void) {}

iron_display_mode_t iron_display_current_mode(int display) {
	iron_display_mode_t dm;
	dm.width = iron_window_width();
	dm.height = iron_window_height();
	dm.frequency = (int)[[UIScreen mainScreen] maximumFramesPerSecond];
	dm.bits_per_pixel = 32;
	return dm;
}

int iron_count_displays(void) {
	return 1;
}

int iron_primary_display(void) {
	return 0;
}

void iron_internal_mouse_lock(void) {}
void iron_internal_mouse_unlock(void) {}

bool iron_mouse_can_lock(void) {
	return false;
}

void iron_mouse_show(void) {}
void iron_mouse_hide(void) {}
void iron_mouse_set_position(int x, int y) {}
void iron_mouse_get_position(int *x, int *y) {}
void iron_mouse_set_cursor(int cursor_index) {}

bool with_autoreleasepool(bool (*f)(void)) {
	@autoreleasepool {
		return f();
	}
}

const char *iron_get_resource_path(void) {
	return [[[NSBundle mainBundle] resourcePath] cStringUsingEncoding:1];
}

bool iron_internal_handle_messages(void) {
	SInt32 result;
	do {
		result = CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0, TRUE);
	} while (result == kCFRunLoopRunHandledSource);
	return true;
}

void iron_set_keep_screen_on(bool on) {}

void iron_keyboard_show(void) {
	keyboard_shown = true;
	[my_view show_keyboard];
}

void iron_keyboard_hide(void) {
	keyboard_shown = false;
	[my_view hide_keyboard];
}

bool iron_keyboard_active(void) {
	return keyboard_shown;
}

void iron_load_url(const char *url) {
	[[UIApplication sharedApplication] openURL:[NSURL URLWithString:[NSString stringWithUTF8String:url]]];
}

const char *iron_language(void) {
	NSString *nsstr = [[NSLocale preferredLanguages] objectAtIndex:0];
	const char *lang = [nsstr UTF8String];
	language[0] = lang[0];
	language[1] = lang[1];
	language[2] = 0;
	return language;
}

void iron_internal_shutdown(void) {}

void iron_init(iron_window_options_t *win) {
	gpu_init(win->depth_bits, true);
}

const char *iron_system_id(void) {
	const char *name = [[[UIDevice currentDevice] name] UTF8String];
	const char *vendorId = [[[[UIDevice currentDevice] identifierForVendor] UUIDString] UTF8String];
	strcpy(sysid, name);
	strcat(sysid, "-");
	strcat(sysid, vendorId);
	return sysid;
}

const char *iron_internal_save_path(void) {
	NSArray *paths = NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, YES);
	NSString *resolvedPath = [paths objectAtIndex:0];
	NSString *appName = [NSString stringWithUTF8String:iron_application_name()];
	resolvedPath = [resolvedPath stringByAppendingPathComponent:appName];
	NSFileManager *fileMgr = [[NSFileManager alloc] init];
	NSError *error;
	[fileMgr createDirectoryAtPath:resolvedPath withIntermediateDirectories:YES attributes:nil error:&error];
	resolvedPath = [resolvedPath stringByAppendingString:@"/"];
	return [resolvedPath cStringUsingEncoding:1];
}

const char **iron_video_formats(void) {
	return video_formats;
}

double iron_frequency(void) {
	mach_timebase_info_data_t info;
	mach_timebase_info(&info);
	return (double)info.denom / (double)info.numer / 1e-9;
}

uint64_t iron_timestamp(void) {
	uint64_t time = mach_absolute_time();
	return time;
}

int main(int argc, char *argv[]) {
	int res = 0;
	@autoreleasepool {
		[IronSceneDelegate description]; // otherwise removed by the linker
		res = UIApplicationMain(argc, argv, nil, nil);
	}
	return res;
}

int iron_window_x() {
	return 0;
}

int iron_window_y() {
	return 0;
}

void iron_window_resize(int width, int height) {}
void iron_window_move(int x, int y) {}
void iron_window_change_mode(iron_window_mode_t mode) {}
void iron_window_destroy() {}
void iron_window_show() {}
void iron_window_hide() {}
void iron_window_set_title(const char *title) {}
void iron_window_create(iron_window_options_t *win) {}

void iron_window_set_resize_callback(void (*callback)(int x, int y, void *data), void *data) {
	resize_callback = callback;
	resize_callback_data = data;
}

void iron_window_set_close_callback(bool (*callback)(void *), void *data) {}

iron_window_mode_t iron_window_get_mode() {
	return IRON_WINDOW_MODE_FULLSCREEN;
}

int iron_window_display() {
	return 0;
}

@implementation MyView

+ (Class)layerClass {
	return [CAMetalLayer class];
}

- (void)hoverGesture:(UIHoverGestureRecognizer *)recognizer {
	CGPoint point = [recognizer locationInView:self];
	float x = point.x * self.contentScaleFactor;
	float y = point.y * self.contentScaleFactor;
	iron_internal_pen_trigger_move(x, y, 0.0); // Pencil hover
}

- (id)initWithFrame:(CGRect)frame {
	self = [super initWithFrame:(CGRect)frame];
	self.contentScaleFactor = [UIScreen mainScreen].scale;
	backing_width = frame.size.width * self.contentScaleFactor;
	backing_height = frame.size.height * self.contentScaleFactor;

	for (int i = 0; i < MAX_TOUCH_COUNT; ++i) {
		touches[i] = NULL;
	}

	device = MTLCreateSystemDefaultDevice();
	queue = [device newCommandQueue];
	library = [device newDefaultLibrary];

	CAMetalLayer *layer = (CAMetalLayer *)self.layer;
	layer.device = device;
	layer.pixelFormat = MTLPixelFormatBGRA8Unorm;
	layer.framebufferOnly = YES;
	layer.opaque = YES;
	layer.backgroundColor = nil;

	[self addGestureRecognizer:[[UIHoverGestureRecognizer alloc] initWithTarget:self action:@selector(hoverGesture:)]];
	return self;
}

- (void)layoutSubviews {
	backing_width = self.frame.size.width * self.contentScaleFactor;
	backing_height = self.frame.size.height * self.contentScaleFactor;
	gpu_resize(backing_width, backing_height);
	iron_internal_call_resize_callback(backing_width, backing_height);
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
	for (UITouch *touch in touches) {
		int index = get_touch_index((__bridge void *)touch);
		if (index == -1) {
			index = add_touch((__bridge void *)touch);
		}
		if (index >= 0) {
			CGPoint point = [touch locationInView:self];
			float x = point.x * self.contentScaleFactor;
			float y = point.y * self.contentScaleFactor;
			if (index == 0) {
				iron_internal_mouse_trigger_press(event.buttonMask == UIEventButtonMaskSecondary ? 1 : 0, x, y);
			}
			iron_internal_surface_trigger_touch_start(index, x, y);
			if (touch.type == UITouchTypePencil) {
				iron_internal_pen_trigger_press(x, y, 0.0);
			}
		}
	}
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
	for (UITouch *touch in touches) {
		int index = get_touch_index((__bridge void *)touch);
		if (index >= 0) {
			CGPoint point = [touch locationInView:self];
			float x = point.x * self.contentScaleFactor;
			float y = point.y * self.contentScaleFactor;
			if (index == 0) {
				iron_internal_mouse_trigger_move(x, y);
			}
			iron_internal_surface_trigger_move(index, x, y);
		}
	}
}

- (void)touchesEstimatedPropertiesUpdated:(NSSet<UITouch *> *)touches {
	for (UITouch *touch in touches) {
		if (touch.type == UITouchTypePencil) {
			CGPoint point = [touch locationInView:self];
			float x = point.x * self.contentScaleFactor;
			float y = point.y * self.contentScaleFactor;
			iron_internal_pen_trigger_move(x, y, touch.force);
		}
	}
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
	for (UITouch *touch in touches) {
		int index = remove_touch((__bridge void *)touch);
		if (index >= 0) {
			CGPoint point = [touch locationInView:self];
			float x = point.x * self.contentScaleFactor;
			float y = point.y * self.contentScaleFactor;
			if (index == 0) {
				iron_internal_mouse_trigger_release(event.buttonMask == UIEventButtonMaskSecondary ? 1 : 0, x, y);
			}
			iron_internal_surface_trigger_touch_end(index, x, y);
			if (touch.type == UITouchTypePencil) {
				iron_internal_pen_trigger_release(x, y, 0.0);
			}
		}
	}
}

- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event {
	for (UITouch *touch in touches) {
		int index = remove_touch((__bridge void *)touch);
		if (index >= 0) {
			CGPoint point = [touch locationInView:self];
			float x = point.x * self.contentScaleFactor;
			float y = point.y * self.contentScaleFactor;
			if (index == 0) {
				iron_internal_mouse_trigger_release(event.buttonMask == UIEventButtonMaskSecondary ? 1 : 0, x, y);
			}
			iron_internal_surface_trigger_touch_end(index, x, y);
			if (touch.type == UITouchTypePencil) {
				iron_internal_pen_trigger_release(x, y, 0.0);
			}
		}
	}
}

- (void)show_keyboard {
	[self becomeFirstResponder];
}

- (void)hide_keyboard {
	[self resignFirstResponder];
}

- (BOOL)hasText {
	return YES;
}

- (void)insertText:(NSString *)text {
	if ([text length] == 1) {
		unichar ch = [text characterAtIndex:[text length] - 1];
		if (ch == 8212) {
			ch = '_';
		}
		if (ch == L'\n') {
			iron_internal_keyboard_trigger_key_down(IRON_KEY_RETURN);
			iron_internal_keyboard_trigger_key_up(IRON_KEY_RETURN);
			return;
		}
		if (ch == L'.') {
			iron_internal_keyboard_trigger_key_down(IRON_KEY_PERIOD);
			iron_internal_keyboard_trigger_key_up(IRON_KEY_PERIOD);
		}
		else if (ch == L'%') {
			iron_internal_keyboard_trigger_key_down(IRON_KEY_PERCENT);
			iron_internal_keyboard_trigger_key_up(IRON_KEY_PERCENT);
		}
		else if (ch == L'(') {
			iron_internal_keyboard_trigger_key_down(IRON_KEY_OPEN_PAREN);
			iron_internal_keyboard_trigger_key_up(IRON_KEY_OPEN_PAREN);
		}
		else if (ch == L'&') {
			iron_internal_keyboard_trigger_key_down(IRON_KEY_AMPERSAND);
			iron_internal_keyboard_trigger_key_up(IRON_KEY_AMPERSAND);
		}
		else if (ch == L'$') {
			iron_internal_keyboard_trigger_key_down(IRON_KEY_DOLLAR);
			iron_internal_keyboard_trigger_key_up(IRON_KEY_DOLLAR);
		}
		else if (ch == L'#') {
			iron_internal_keyboard_trigger_key_down(IRON_KEY_HASH);
			iron_internal_keyboard_trigger_key_up(IRON_KEY_HASH);
		}
		else if (ch >= L'a' && ch <= L'z') {
			if (shift_down) {
				iron_internal_keyboard_trigger_key_up(IRON_KEY_SHIFT);
				shift_down = false;
			}
			iron_internal_keyboard_trigger_key_down(ch + IRON_KEY_A - L'a');
			iron_internal_keyboard_trigger_key_up(ch + IRON_KEY_A - L'a');
		}
		else {
			if (!shift_down) {
				iron_internal_keyboard_trigger_key_down(IRON_KEY_SHIFT);
				shift_down = true;
			}
			iron_internal_keyboard_trigger_key_down(ch + IRON_KEY_A - L'A');
			iron_internal_keyboard_trigger_key_up(ch + IRON_KEY_A - L'A');
		}
		iron_internal_keyboard_trigger_key_press(ch);
	}
}

- (void)deleteBackward {
	iron_internal_keyboard_trigger_key_down(IRON_KEY_BACKSPACE);
	iron_internal_keyboard_trigger_key_up(IRON_KEY_BACKSPACE);
}

- (BOOL)canBecomeFirstResponder {
	return YES;
}

- (void)onKeyboardHide:(NSNotification *)notification {
	iron_keyboard_hide();
}

- (CAMetalLayer *)metal_layer {
	return (CAMetalLayer *)self.layer;
}

- (id<MTLDevice>)metal_device {
	return device;
}

- (id<MTLCommandQueue>)metal_queue {
	return queue;
}

@end

@implementation MyViewController

- (void)loadView {
	visible = true;
	self.view = my_view = [[MyView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
	[self.view addInteraction: [[UIDropInteraction alloc] initWithDelegate: self]];
	[self setNeedsUpdateOfScreenEdgesDeferringSystemGestures];
}

- (void)setVisible:(BOOL)value {
	visible = value;
}

void importFile(NSURL *url) {
	NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
	NSString *folderName = [NSString stringWithUTF8String:mobile_title];
	NSString *filePath = [[paths objectAtIndex:0] stringByAppendingPathComponent:folderName];
	if (![[NSFileManager defaultManager] fileExistsAtPath:filePath]) {
		[[NSFileManager defaultManager] createDirectoryAtPath:filePath withIntermediateDirectories:NO attributes:nil error:nil];
	}
	NSString *suggestedName = url.path.lastPathComponent;
	filePath = [filePath stringByAppendingPathComponent:suggestedName];
	CFURLRef cfurl = (__bridge CFURLRef)url;
	CFURLStartAccessingSecurityScopedResource(cfurl);
	[[NSFileManager defaultManager] copyItemAtPath:url.path toPath:filePath error:nil];
	CFURLStopAccessingSecurityScopedResource(cfurl);
	wchar_t *wpath = (wchar_t *)[filePath cStringUsingEncoding:NSUTF32LittleEndianStringEncoding];
	iron_internal_drop_files_callback(wpath);
}

- (void)documentPicker:(UIDocumentPickerViewController *)controller didPickDocumentAtURL:(NSURL *)url {
	// wchar_t *filePath = (wchar_t *)[url.path cStringUsingEncoding:NSUTF32LittleEndianStringEncoding];
	// CFURLRef cfurl = (__bridge CFURLRef)url;
	// CFURLStartAccessingSecurityScopedResource(cfurl);
	// iron_internal_drop_files_callback(filePath);
	// CFURLStopAccessingSecurityScopedResource(cfurl);
	importFile(url);
}

- (void)dropInteraction:(UIDropInteraction *)interaction performDrop:(id<UIDropSession>)session {
	CGPoint point = [session locationInView:self.view];
	float x = point.x * my_view.contentScaleFactor;
	float y = point.y * my_view.contentScaleFactor;
	iron_internal_mouse_trigger_move(x, y);
	iron_internal_surface_trigger_move(0, x, y);
	for (UIDragItem *item in session.items) {
		[item.itemProvider loadInPlaceFileRepresentationForTypeIdentifier:item.itemProvider.registeredTypeIdentifiers[0] completionHandler:^(NSURL * _Nullable url, BOOL isInPlace, NSError * _Nullable error) {
			importFile(url);
		}];
	}
}

- (UIDropProposal *)dropInteraction:(UIDropInteraction *)interaction sessionDidUpdate:(id<UIDropSession>)session {
	return [[UIDropProposal alloc] initWithDropOperation: UIDropOperationCopy];
}

- (UIRectEdge)preferredScreenEdgesDeferringSystemGestures {
    return UIRectEdgeAll;
}

@end

@implementation IronSceneDelegate

- (void)mainLoop {
	@autoreleasepool {
		kickstart(0, NULL);
	}
}

- (void)scene:(UIScene *)scene willConnectToSession:(UISceneSession *)session options:(UISceneConnectionOptions *)connectionOptions {
	#ifdef IRON_A2
	AVAudioSession *sessionInstance = [AVAudioSession sharedInstance];
	NSError *error;
	NSString *category = AVAudioSessionCategoryAmbient;
	[sessionInstance setCategory:category error:&error];
	#endif

	UIWindowScene *windowScene = (UIWindowScene *)scene;
    self.window = [[UIWindow alloc] initWithWindowScene:windowScene];
	self.window.frame = windowScene.coordinateSpace.bounds;
    [self.window setBackgroundColor:[UIColor blackColor]];

	my_view_controller = [[MyViewController alloc] init];
	my_view_controller.view.multipleTouchEnabled = YES;
	[self.window setRootViewController:my_view_controller];
	[self.window makeKeyAndVisible];
	[my_view_controller setVisible:YES];
	[self performSelectorOnMainThread:@selector(mainLoop) withObject:nil waitUntilDone:NO];
}

- (void)sceneDidDisconnect:(UIScene *)scene {
	iron_internal_shutdown_callback();
}

- (void)sceneDidBecomeActive:(UIScene *)scene {
    iron_internal_resume_callback();
}

- (void)sceneWillResignActive:(UIScene *)scene {
    iron_internal_pause_callback();
}

- (void)sceneWillEnterForeground:(UIScene *)scene {
    iron_internal_foreground_callback();
}

- (void)sceneDidEnterBackground:(UIScene *)scene {
    iron_internal_background_callback();
}

@end

#ifdef WITH_GAMEPAD

const char *iron_gamepad_vendor(int gamepad) {
	return "nobody";
}

const char *iron_gamepad_product_name(int gamepad) {
	return "none";
}

bool iron_gamepad_connected(int num) {
	return true;
}

void iron_gamepad_rumble(int gamepad, float left, float right) {}

#endif