#include "debug.h"
#include <SDL.h>
#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"
#include "parser.h"

typedef unsigned char byte;
typedef unsigned short word;

static SDL_Window*		debug_window = nullptr;
static SDL_Renderer*	debug_renderer = nullptr;
static SDL_Texture*		debug_texture = nullptr;
static SDL_Rect			src, dst;
static Uint8			ink[4];
static Uint8			paper[4];
static unsigned char*	debug_mem = nullptr;

static unsigned short* rX;
static unsigned char* rY;
static unsigned char* rZ;
static unsigned short* pc;

static char*			program = nullptr;
static word*			lines = nullptr;

static void debug_set_ink(const unsigned char r, const unsigned char g, const unsigned char b) {
	ink[0] = r; ink[1] = g; ink[2] = b; ink[3] = 255;
	SDL_SetRenderDrawColor(debug_renderer, ink[0], ink[1], ink[2], ink[3]);
	SDL_SetTextureColorMod(debug_texture, ink[0], ink[1], ink[2]);
}

static void debug_set_paper(const unsigned char r, const unsigned char g, const unsigned char b) {
	paper[0] = r; paper[1] = g; paper[2] = b; paper[3] = 255;
}

static void debug_draw_char(int x, int y, int c) {
	src.x = (c & 0xf) << 3; src.y = (c >> 4) << 3;
	dst.x = x << 3; dst.y = y << 3;
	src.w = src.h = dst.w = dst.h = 8;
	SDL_RenderCopy(debug_renderer, debug_texture, &src, &dst);
}

static void debug_print(int x, int y, const char* text) {
	while (*text != 0) {
		debug_draw_char(x, y, *text);
		x++;
		text++;
	}
}

static void debug_print_ex(int x, int y, const unsigned char* text, int len) {
	while (len != 0) {
		debug_draw_char(x, y, *text);
		x++; text++; len--;
	}
}

static void debug_draw_outset(int x, int y, int w, int h) {
	x = (x << 3) - 1; y = (y << 3) - 1; w = (w << 3) + 2; h = (h << 3) + 2;
	SDL_SetRenderDrawColor(debug_renderer, 255, 255, 255, 255);
	SDL_RenderDrawLine(debug_renderer, x, y, x, y + h);
	SDL_RenderDrawLine(debug_renderer, x, y, x + w, y);
	SDL_SetRenderDrawColor(debug_renderer, 0, 0, 0, 255);
	SDL_RenderDrawLine(debug_renderer, x + w, y, x + w, y + h);
	SDL_RenderDrawLine(debug_renderer, x, y + h, x + w, y + h);
	SDL_SetRenderDrawColor(debug_renderer, ink[0], ink[1], ink[2], ink[3]);
}

static void debug_draw_inset(int x, int y, int w, int h) {
	x = (x << 3) - 1; y = (y << 3) - 1; w = (w << 3) + 1; h = (h << 3) + 1;
	SDL_SetRenderDrawColor(debug_renderer, 0, 0, 0, 255);
	SDL_RenderDrawLine(debug_renderer, x, y, x, y + h);
	SDL_RenderDrawLine(debug_renderer, x, y, x + w, y);
	SDL_SetRenderDrawColor(debug_renderer, 255, 255, 255, 255);
	SDL_RenderDrawLine(debug_renderer, x + w, y, x + w, y + h);
	SDL_RenderDrawLine(debug_renderer, x, y + h, x + w, y + h);
	SDL_SetRenderDrawColor(debug_renderer, ink[0], ink[1], ink[2], ink[3]);
}

static void debug_draw_rect(int x, int y, int w, int h) {
	dst.x = (x << 3) - 1; dst.y = (y << 3) - 1; dst.w = (w << 3) + 2; dst.h = (h << 3) + 2;
	SDL_RenderDrawRect(debug_renderer, &dst);
}

static void debug_fill_rect(int x, int y, int w, int h) {
	dst.x = x << 3; dst.y = y << 3; dst.w = w << 3; dst.h = h << 3;
	SDL_RenderFillRect(debug_renderer, &dst);
}

static void debug_clear() {
	SDL_SetRenderDrawColor(debug_renderer, paper[0], paper[1], paper[2], paper[3]);
	SDL_RenderClear(debug_renderer);
	SDL_SetRenderDrawColor(debug_renderer, ink[0], ink[1], ink[2], ink[3]);
}

static void debug_draw_space(int x, int y, int w, int h, const char* title) {
	debug_set_ink(64, 64, 64);
	debug_fill_rect(x, y, w, h);
	debug_draw_inset(x, y, w, h);
	debug_set_ink(0, 0, 0);
	debug_print(x, y-1, title);
}

static void debug_print_memory(word offset) {
	debug_draw_space(1, 39, 37, 20, "MEMORY:");
	debug_set_ink(255, 255, 255);
	char cadena[255];
	for (int i = 0; i < 20; i++) {
		sprintf(cadena, "%.4X %.2X %.2X %.2X %.2X %.2X %.2X %.2X %.2X", offset, debug_mem[offset], debug_mem[offset + 1], debug_mem[offset + 2], debug_mem[offset + 3], debug_mem[offset + 4], debug_mem[offset + 5], debug_mem[offset + 6], debug_mem[offset + 7]);
		debug_print(1, 39+i, cadena); debug_print_ex(30, 39+i, &debug_mem[offset], 8);
		offset += 8;
	}
}

static void debug_print_datastack(byte offset) {
	debug_draw_space(72, 2, 3, 20, "DS:");
	char cadena[10];
	for (int i = 0; i < 20; i++) {
		sprintf(cadena, "%.2X", debug_mem[0x8801 + i + offset]);
		if (debug_mem[0x8800] == 1 + i + offset) debug_set_ink(255, 0, 0); else debug_set_ink(255, 255, 255);
		debug_print(72, 2 + i, cadena); debug_print_ex(74, 2 + i, &debug_mem[0x8801 + i + offset], 1);
	}
}

static void debug_print_callstack(byte offset) {
	debug_draw_space(76, 2, 3, 20, "CS:");
	char cadena[10];
	for (int i = 0; i < 20; i++) {
		sprintf(cadena, "%.2X", debug_mem[0x8901 + i + offset]);
		if (debug_mem[0x8900] == 1 + i + offset) debug_set_ink(255, 0, 0); else debug_set_ink(255, 255, 255);
		debug_print(76, 2 + i, cadena); debug_print_ex(78, 2 + i, &debug_mem[0x8901 + i + offset], 1);
	}
}

static void debug_print_basic(byte offset) {
	debug_draw_space(1, 2, 70, 35, "CODE:");
	debug_set_ink(255, 255, 255);
	int line = offset;
	int row = 0;
	char* prog = program;
	if (lines[*pc] == line) { debug_set_ink(128, 128, 0); debug_fill_rect(1, 2 + line, 70, 1); debug_set_ink(255, 255, 0); }
	else debug_set_ink(255, 255, 255);
	while (line < 35 && *prog != 0) {
		if (*prog == '\t') {
			row += 4;
		} else if (*prog == '\n') {
			row = 0; line++;
			if (lines[*pc] == line) { debug_set_ink(128, 128, 0); debug_fill_rect(1, 2 + line, 70, 1); debug_set_ink(255, 255, 0); }
			else debug_set_ink(255, 255, 255);
		} else if (*prog == 13) {
			// row++;
		} else {
			if (row < 70) debug_draw_char(1 + row, 2 + line, *prog);
			row++;
		}
		prog++;
	}
}

static void debug_print_registers() {
	debug_draw_space(72, 23, 6, 1, "rX:");
	debug_draw_space(72, 25, 3, 1, "rY:");
	debug_draw_space(72, 27, 3, 1, "rZ:");
	debug_set_ink(255, 255, 255);
	char cadena[10];
	sprintf(cadena, "%.4X", *rX);
	debug_print(72, 23, cadena); debug_print_ex(76, 23, &debug_mem[0xFFFA], 2);
	sprintf(cadena, "%.2X", *rY);
	debug_print(72, 25, cadena); debug_print_ex(74, 25, &debug_mem[0xFFFC], 1);
	sprintf(cadena, "%.2X", *rZ);
	debug_print(72, 27, cadena); debug_print_ex(74, 27, &debug_mem[0xFFFD], 1);
}

void debug_init(unsigned char* mem) {
	debug_mem = mem;
	lines = parser_get_lines();

	rX = (unsigned short*)&debug_mem[0xFFFA];
	rY = &debug_mem[0xFFFC];
	rZ = &debug_mem[0xFFFD];
	pc = (unsigned short*)&debug_mem[0xFFFE];

	debug_window = SDL_CreateWindow("Definitely PaCo Debugger", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, SDL_WINDOW_SHOWN);
	debug_renderer = SDL_CreateRenderer(debug_window, -1, SDL_RENDERER_PRESENTVSYNC);
	//SDL_RenderSetLogicalSize(debug_renderer, 152, 120);
	SDL_SetRenderDrawColor(debug_renderer, 128, 128, 128, 255);

	FILE* f = fopen("font.png", "rb");
	int x = 128, y = 128, c;
	Uint8* buffer = stbi_load_from_file(f, &x, &y, &c, 4);
	debug_texture = SDL_CreateTexture(debug_renderer, SDL_PIXELFORMAT_ABGR8888, SDL_TEXTUREACCESS_STATIC, 128, 128);
	SDL_UpdateTexture(debug_texture, NULL, buffer, 128 * sizeof(Uint32));
	SDL_SetTextureBlendMode(debug_texture, SDL_BLENDMODE_BLEND);
	stbi_image_free(buffer);
	fclose(f);

	f = fopen("test.bas", "rb");
	fseek(f, 0, SEEK_END);
	long fsize = ftell(f);
	fseek(f, 0, SEEK_SET);  //same as rewind(f);
	program = (char*)malloc(fsize + 1);
	fread(program, fsize, 1, f);
	fclose(f);
	program[fsize] = 0;

	debug_update();
}

void debug_update() {
	debug_set_paper(128, 128, 128);
	debug_clear();

	debug_set_ink(64, 64, 64);
	debug_fill_rect(39, 39, 40, 20);
	debug_draw_inset(39, 39, 40, 20);

	debug_set_ink(0, 0, 0);
	debug_print(39, 38, "DISASSEMBLY:");

	debug_print_memory(0);
	debug_print_datastack(0);
	debug_print_callstack(0);
	debug_print_registers();
	debug_print_basic(0);

	SDL_RenderPresent(debug_renderer);
}