#include <furi.h>
#include <furi_hal.h>

#include <gui/gui.h>
#include <input/input.h>
#include <dialogs/dialogs.h>
#include <storage/storage.h>

#define TAG "schip"
#define FONT_SIZE 180
#define MEM_SIZE 0x1000
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define REGISTERS_COUNT 16
#define STACK_SIZE 16
#define KEYPAD_WIDTH 4
#define KEYPAD_HEIGHT 4
#define BUTTONS_COUNT 16
#define ROM_START 0x200
#define FILES_PATH "/ext/schip"
#define FILE_EXTENSION ".ch8"
#define RPL_COUNT 8

const uint8_t font[FONT_SIZE] = {
	0xF0, 0x90, 0x90, 0x90, 0xF0, // 0
	0x20, 0x60, 0x20, 0x20, 0x70, // 1
	0xF0, 0x10, 0xF0, 0x80, 0xF0, // 2
	0xF0, 0x10, 0xF0, 0x10, 0xF0, // 3
	0x90, 0x90, 0xF0, 0x10, 0x10, // 4
	0xF0, 0x80, 0xF0, 0x10, 0xF0, // 5
	0xF0, 0x80, 0xF0, 0x90, 0xF0, // 6
	0xF0, 0x10, 0x20, 0x40, 0x40, // 7
	0xF0, 0x90, 0xF0, 0x90, 0xF0, // 8
	0xF0, 0x90, 0xF0, 0x10, 0xF0, // 9
	0xF0, 0x90, 0xF0, 0x90, 0x90, // A
	0xE0, 0x90, 0xE0, 0x90, 0xE0, // B
	0xF0, 0x80, 0x80, 0x80, 0xF0, // C
	0xE0, 0x90, 0x90, 0x90, 0xE0, // D
	0xF0, 0x80, 0xF0, 0x80, 0xF0, // E
	0xF0, 0x80, 0xF0, 0x80, 0x80, // F
	0x3C, 0x7E, 0xE7, 0xC3, 0xC3, 0xC3, 0xC3, 0xE7, 0x7E, 0x3C, // 0h
        0x18, 0x38, 0x58, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x3C, // 1h
        0x3E, 0x7F, 0xC3, 0x06, 0x0C, 0x18, 0x30, 0x60, 0xFF, 0xFF, // 2h
        0x3C, 0x7E, 0xC3, 0x03, 0x0E, 0x0E, 0x03, 0xC3, 0x7E, 0x3C, // 3h
        0x06, 0x0E, 0x1E, 0x36, 0x66, 0xC6, 0xFF, 0xFF, 0x06, 0x06, // 4h
        0xFF, 0xFF, 0xC0, 0xC0, 0xFC, 0xFE, 0x03, 0xC3, 0x7E, 0x3C, // 5h
        0x3E, 0x7C, 0xC0, 0xC0, 0xFC, 0xFE, 0xC3, 0xC3, 0x7E, 0x3C, // 6h
        0xFF, 0xFF, 0x03, 0x06, 0x0C, 0x18, 0x30, 0x60, 0x60, 0x60, // 7h
        0x3C, 0x7E, 0xC3, 0xC3, 0x7E, 0x7E, 0xC3, 0xC3, 0x7E, 0x3C, // 8h
        0x3C, 0x7E, 0xC3, 0xC3, 0x7F, 0x3F, 0x03, 0x03, 0x3E, 0x7C  // 9h
};
uint8_t memory[MEM_SIZE];
bool screen[SCREEN_WIDTH][SCREEN_HEIGHT];
bool hires = false;
uint8_t registers[REGISTERS_COUNT];
uint16_t I = 0;
uint16_t PC = ROM_START;
uint8_t time_delay = 0;
uint8_t time_sound = 0;
uint16_t stack[STACK_SIZE];
uint8_t stack_pointer;
uint8_t rpl[RPL_COUNT];

bool keyboard_open = false;
uint8_t keyboard_x = 0;
uint8_t keyboard_y = 0;

bool buttons[BUTTONS_COUNT];
uint8_t keypad[BUTTONS_COUNT] = {
	1,  2,  3,  12,
	4,  5,  6,  13,
	7,  8,  9,  14,
	10, 0,  11, 15
};

bool run = true;

FuriString* file_path;

static void app_draw_callback(Canvas* canvas, void* ctx) {
	UNUSED(ctx);

	canvas_clear(canvas);
	canvas_set_font(canvas, FontSecondary);
	if(keyboard_open) {
		for(uint8_t x = 0; x < KEYPAD_WIDTH; x++)
			for(uint8_t y = 0; y < KEYPAD_HEIGHT; y++)
				canvas_draw_frame(canvas, 32 + x * 16, y * 16, 16, 16);
		canvas_draw_frame(canvas, 33 + keyboard_x * 16, 1 + keyboard_y * 16, 14, 14);
		
		canvas_draw_str(canvas, 38 + 16 * 0, 12 + 16 * 0, "1");
		canvas_draw_str(canvas, 38 + 16 * 1, 12 + 16 * 0, "2");
		canvas_draw_str(canvas, 38 + 16 * 2, 12 + 16 * 0, "3");
		canvas_draw_str(canvas, 38 + 16 * 3, 12 + 16 * 0, "C");
		canvas_draw_str(canvas, 38 + 16 * 0, 12 + 16 * 1, "4");
		canvas_draw_str(canvas, 38 + 16 * 1, 12 + 16 * 1, "5");
		canvas_draw_str(canvas, 38 + 16 * 2, 12 + 16 * 1, "6");
		canvas_draw_str(canvas, 38 + 16 * 3, 12 + 16 * 1, "D");
		canvas_draw_str(canvas, 38 + 16 * 0, 12 + 16 * 2, "7");
		canvas_draw_str(canvas, 38 + 16 * 1, 12 + 16 * 2, "8");
		canvas_draw_str(canvas, 38 + 16 * 2, 12 + 16 * 2, "9");
		canvas_draw_str(canvas, 38 + 16 * 3, 12 + 16 * 2, "E");
		canvas_draw_str(canvas, 38 + 16 * 0, 12 + 16 * 3, "A");
		canvas_draw_str(canvas, 38 + 16 * 1, 12 + 16 * 3, "0");
		canvas_draw_str(canvas, 38 + 16 * 2, 12 + 16 * 3, "B");
		canvas_draw_str(canvas, 38 + 16 * 3, 12 + 16 * 3, "F");
	} else {
		for(uint8_t x = 0; x < SCREEN_WIDTH; x++)
			for(uint8_t y = 0; y < SCREEN_HEIGHT; y++)
				if(screen[x][y]) canvas_draw_dot(canvas, x, y);
	}
}

static void app_input_callback(InputEvent* input_event, void* ctx) {
	furi_assert(ctx);

	FuriMessageQueue* event_queue = ctx;
	furi_message_queue_put(event_queue, input_event, FuriWaitForever);
}

static bool nthbit(uint8_t n, uint8_t k) {
	return (n & ( 1 << k )) >> k == 1;
}

static bool toggle_pixel(uint8_t x, uint8_t y) {
	bool collision = false;
	if(hires) {
		collision = screen[x][y];
		screen[x][y] = !screen[x][y];
	} else {
		collision = screen[x * 2][y * 2];
		screen[x * 2][y * 2] = !screen[x * 2][y * 2];
		screen[x * 2 + 1][y * 2] = !screen[x * 2 + 1][y * 2];
		screen[x * 2][y * 2 + 1] = !screen[x * 2][y * 2 + 1];
		screen[x * 2 + 1][y * 2 + 1] = !screen[x * 2 + 1][y * 2 + 1];
	}
	return collision;
}

// TODO fix this:
/*
: draw-title
	draw-x := 16
	draw-y := 16
	dir := 32
	i := sprite-title
	loop
		sprite draw-x draw-y 0
		i += dir
		draw-y += 16
		if draw-y > TITLE_HEIGHT then draw-x += 16
		if draw-y > TITLE_HEIGHT then draw-y := 16
		if draw-x != TITLE_WIDTH then
	again
	dir := key
;
*/

FuriTimer* timer;
static void tick(void* context) {
	UNUSED(context);
	if(!run) return;
	furi_check(PC < MEM_SIZE - 1);
	uint8_t d1 = memory[PC] / 16;
	uint8_t d2 = memory[PC] % 16;
	uint8_t d3 = memory[PC + 1] / 16;
	uint8_t d4 = memory[PC + 1] % 16;
	uint16_t d5 = d2 * 256 + d3 * 16 + d4; // I
	uint16_t d6 = d1 * 4096 + d2 * 256 + d3 * 16 + d4; // Whole instruction
	// FURI_LOG_T(TAG, "Executing instruction %x at address %x", d6, PC);
	uint8_t d7 = d3 * 16 + d4; // Byte
	bool next = true;
	
	if(d1 == 0x0 && d2 == 0x0 && d3 == 0xc) {
		// TODO: scroll down d4 px
	} else if(d6 == 0x00e0) {
		for(uint8_t x = 0; x < SCREEN_WIDTH; x++)
			for(uint8_t y = 0; y < SCREEN_HEIGHT; y++)
				screen[x][y] = false;
	} else if(d6 == 0x00ee) {
		PC = stack[stack_pointer--];
	} else if(d6 == 0x00fb) {
		// TODO: scroll right 4 px
	} else if(d6 == 0x00fc) {
		// TODO: scroll left 4 px
	} else if(d6 == 0x00fd) {
		run = false;
	} else if(d6 == 0x00fe) {
		hires = false;
	} else if(d6 == 0x00ff) {
		hires = true;
	} else if(d1 == 0x0 || d1 == 0x1) {
		PC = d5;
		next = false;
	} else if(d1 == 0x2) {
		stack[++stack_pointer] = PC;
		PC = d5;
		next = false;
	} else if(d1 == 0x3) {
		if(registers[d2] == d7) PC += 2;
	} else if(d1 == 0x4) {
		if(registers[d2] != d7) PC += 2;
	} else if(d1 == 0x5) {
		if(registers[d2] == registers[d3]) PC += 2;
	} else if(d1 == 0x6) {
		registers[d2] = d7;
	} else if(d1 == 0x7) {
		registers[d2] += d7;
	} else if(d1 == 0x8 && d4 == 0x0) {
		registers[d2] = registers[d3];
	} else if(d1 == 0x8 && d4 == 0x1) {
		registers[d2] |= registers[d3];
	} else if(d1 == 0x8 && d4 == 0x2) {
		registers[d2] &= registers[d3];
	} else if(d1 == 0x8 && d4 == 0x3) {
		registers[d2] ^= registers[d3];
	} else if(d1 == 0x8 && d4 == 0x4) {
		uint16_t v = registers[d2] + registers[d3];
		registers[0xf] = v > 0xff;
		registers[d2] = v % 0x100;
	} else if(d1 == 0x8 && d4 == 0x5) {
		registers[0xf] = registers[d2] > registers[d3];
		registers[d2] -= registers[d3];
	} else if(d1 == 0x8 && d4 == 0x6) {
		registers[0xf] = registers[d2] % 2 == 1;
		registers[d2] >>= 1;
	} else if(d1 == 0x8 && d4 == 0x7) {
		registers[0xf] = registers[d3] > registers[d2];
		registers[d2] = registers[d3] - registers[d2];
	} else if(d1 == 0x8 && d4 == 0xe) {
		registers[0xf] = registers[d2] / 128 == 1;
		registers[d2] <<= 1;
	} else if(d1 == 0x9) {
		if(registers[d2] != registers[d3]) PC += 2;
	} else if(d1 == 0xa) {
		I = d5;
	} else if(d1 == 0xb) {
		PC = d5 + registers[0x0];
		next = false;
	} else if(d1 == 0xc) {
		registers[d2] = (rand() % 0x100) & d7;
	} else if(d1 == 0xd) {
		bool collision = false;
		if(d4 == 0) for(uint8_t i = 0; i < 16; i++) {
			for(uint8_t j = 0; j < 8; j++)
				if(nthbit(memory[I + i * 2], 7 - j)) collision |= toggle_pixel(registers[d2] + j, registers[d3] + i);
			for(uint8_t j = 0; j < 8; j++)
				if(nthbit(memory[I + i * 2 + 1], 7 - j)) collision |= toggle_pixel(registers[d2] + 8 + j, registers[d3] + i);
		} else for(uint8_t i = 0; i < d4; i++) {
			for(uint8_t j = 0; j < 8; j++)
				if(nthbit(memory[I + i], 7 - j)) collision |= toggle_pixel(registers[d2] + j, registers[d3] + i);
		}
		registers[0xf] = collision;
	} else if(d1 == 0xe && d7 == 0x9e) {
		if(buttons[registers[d2]]) PC += 2;
	} else if(d1 == 0xe && d7 == 0xa1) {
		if(!buttons[registers[d2]]) PC += 2;
	} else if(d1 == 0xf && d7 == 0x07) {
		registers[d2] = time_delay;
	} else if(d1 == 0xf && d7 == 0x0a) {
		next = false;
		for(uint8_t i = 0; i < BUTTONS_COUNT; i++)
			if(buttons[i]) {
				next = true;
				registers[d2] = i;
				break;
			}
	} else if(d1 == 0xf && d7 == 0x15) {
		time_delay = registers[d2];
	} else if(d1 == 0xf && d7 == 0x18) {
		time_sound = registers[d2];
	} else if(d1 == 0xf && d7 == 0x1e) {
		I += registers[d2];
	} else if(d1 == 0xf && d7 == 0x29) {
		I = 5 * registers[d2];
	} else if(d1 == 0xf && d7 == 0x30) {
		I = 10 * (registers[d2] - 0x10) + 80;
	} else if(d1 == 0xf && d7 == 0x33) {
		memory[I] = registers[d2] / 100;
		memory[I + 1] = (registers[d2] / 10) % 10;
		memory[I + 2] = registers[d2] % 10;
	} else if(d1 == 0xf && d7 == 0x55) {
		for(uint8_t i = 0; i <= d2; i++)
			memory[I + i] = registers[i];
	} else if(d1 == 0xf && d7 == 0x65) {
		for(uint8_t i = 0; i <= d2; i++)
			registers[i] = memory[I + i];
	} else if(d1 == 0xf && d7 == 0x75) {
		for(uint8_t i = 0; i <= d2; i++)
			rpl[I + i] = registers[i];
	} else if(d1 == 0xf && d7 == 0x85) {
		for(uint8_t i = 0; i <= d2; i++)
			registers[i] = rpl[I + i];
	} 
	
	if(next) PC += 2;
}

FuriTimer* timer_delay;
static void tick_delay(void* context) {
	UNUSED(context);
	if(time_delay > 0) time_delay--;
}

FuriTimer* timer_sound;
//TODO: fix sound
/*bool speaker_on = false;
static void tick_sound(void* context) {
	UNUSED(context);
	if(time_sound > 0) time_sound--;
	if(time_sound > 0 && !speaker_on) {
		furi_hal_speaker_start(800, 1.f);
		speaker_on = true;
	} else if(time_sound == 0 && speaker_on) {
		furi_hal_speaker_stop();
		speaker_on = false;
	}
}*/
static void tick_sound(void* context) {
	UNUSED(context);
	if(time_sound > 0) time_sound--;
	if(time_sound > 0)
		furi_hal_vibro_on(true);
	else
		furi_hal_vibro_on(false);
}

int32_t schip_main(void* p) {
	for(int i = 0; i < FONT_SIZE; i++)
		memory[i] = font[i];

	UNUSED(p);
	FuriMessageQueue* event_queue = furi_message_queue_alloc(8, sizeof(InputEvent));

	// Configure view port
	ViewPort* view_port = view_port_alloc();
	view_port_draw_callback_set(view_port, app_draw_callback, view_port);
	view_port_input_callback_set(view_port, app_input_callback, event_queue);

	// Register view port in GUI
	Gui* gui = furi_record_open(RECORD_GUI);
	gui_add_view_port(gui, view_port, GuiLayerFullscreen);

	InputEvent event;
	
	// void* speaker = (void*)furi_hal_speaker_acquire(1000);
	
	Storage* storage = furi_record_open(RECORD_STORAGE);
	storage_simply_mkdir(storage, FILES_PATH);
	
	file_path = furi_string_alloc_set_str(FILES_PATH);
	DialogsFileBrowserOptions browser_options;
	dialog_file_browser_set_basic_options(&browser_options, FILE_EXTENSION, NULL);
	browser_options.base_path = FILES_PATH;
	DialogsApp* dialogs = furi_record_open(RECORD_DIALOGS);
	bool running = dialog_file_browser_show(dialogs, file_path, file_path, &browser_options);
	furi_record_close(RECORD_DIALOGS);
	
	if(running) {
		File* file = storage_file_alloc(storage);
		furi_check(storage_file_open(file, furi_string_get_cstr(file_path), FSAM_READ, FSOM_OPEN_EXISTING));
		uint8_t read_byte;
		uint16_t read_size;
		uint16_t p = ROM_START;
		do {
			read_size = storage_file_read(file, &read_byte, 1);
			memory[p] = read_byte;
			p++;
			
		} while(read_size > 0);
		storage_file_close(file);
		storage_file_free(file);
	}
	
	furi_record_close(RECORD_STORAGE);
	
	// We have to round up to 17 here
	
	timer = furi_timer_alloc(tick, FuriTimerTypePeriodic, NULL);
	furi_timer_start(timer, 1);
	
	timer_delay = furi_timer_alloc(tick_delay, FuriTimerTypePeriodic, NULL);
	furi_timer_start(timer_delay, 17);
	
	timer_sound = furi_timer_alloc(tick_sound, FuriTimerTypePeriodic, NULL);
	furi_timer_start(timer_sound, 17);

	while(running) {
		if(furi_message_queue_get(event_queue, &event, 100) == FuriStatusOk) {
			if(event.type == InputTypeLong && event.key == InputKeyBack) running = false;
			if(event.type == InputTypePress && event.key == InputKeyBack) keyboard_open = !keyboard_open;
			if(keyboard_open) {
				if(event.type == InputTypePress && event.key == InputKeyLeft) keyboard_x--;
				if(event.type == InputTypePress && event.key == InputKeyDown) keyboard_y++;
				if(event.type == InputTypePress && event.key == InputKeyRight) keyboard_x++;
				if(event.type == InputTypePress && event.key == InputKeyUp) keyboard_y--;
				
				keyboard_x %= KEYPAD_WIDTH;
				keyboard_y %= KEYPAD_HEIGHT;
				
				if(event.type == InputTypePress && event.key == InputKeyOk) buttons[keypad[keyboard_y * 4 + keyboard_x]] = true;
				if(event.type == InputTypeRelease && event.key == InputKeyOk) buttons[keypad[keyboard_y * 4 + keyboard_x]] = false;
			} else {
				if(event.type == InputTypePress && event.key == InputKeyUp) buttons[5] = true;
				if(event.type == InputTypeRelease && event.key == InputKeyUp) buttons[5] = false;
				if(event.type == InputTypePress && event.key == InputKeyLeft) buttons[7] = true;
				if(event.type == InputTypeRelease && event.key == InputKeyLeft) buttons[7] = false;
				if(event.type == InputTypePress && event.key == InputKeyDown) buttons[8] = true;
				if(event.type == InputTypeRelease && event.key == InputKeyDown) buttons[8] = false;
				if(event.type == InputTypePress && event.key == InputKeyRight) buttons[9] = true;
				if(event.type == InputTypeRelease && event.key == InputKeyRight) buttons[9] = false;
				if(event.type == InputTypePress && event.key == InputKeyOk) buttons[6] = true;
				if(event.type == InputTypeRelease && event.key == InputKeyOk) buttons[6] = false;
			}
		}
		view_port_update(view_port);
	}

	furi_timer_stop(timer);
	furi_timer_free(timer);
	
	furi_timer_stop(timer_delay);
	furi_timer_free(timer_delay);
	
	furi_timer_stop(timer_sound);
	furi_timer_free(timer_sound);
	
	// furi_hal_speaker_release(speaker);
	
	view_port_enabled_set(view_port, false);
	gui_remove_view_port(gui, view_port);
	view_port_free(view_port);
	furi_message_queue_free(event_queue);

	furi_record_close(RECORD_GUI);

	return 0;
}