#include <SDL.h>
#include <SDL_mixer.h>
#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"
#include "font.h"
#include "gif.c"
#include <stdio.h>

struct Mouse {
	int x, y;
	bool buttons[3];
};

typedef bool(*LoopFun)(void);

SDL_Window* sdlWindow = NULL;
SDL_Renderer* sdlRenderer = NULL;
SDL_Texture* sdlFontTexture = NULL;
SDL_Texture* sdlTilesTexture = NULL;
SDL_Event sdlEvent;
bool anyKey = false;
LoopFun loop;
Mouse mouse;
int error = 0;

int tile_width = 16;
int tile_height = 16;
int map_width = 240;
int map_height = 240;
int screen_width = 256;
int screen_height = 192;
int zoom = 2;
char tiles_filename[100] = { 0 };
char map_filename[100] = { 0 };
int tilemap_width = 0;
int tilemap_height = 0;

int map_x = 0;
int map_y = 0;

int StrToInt(const char* str) {
	int val = 0;
	int size = strlen(str);
	for (int i = 0; i < size; i++) {
		if (str[i] < 48 || str[i] > 57) return 0;
		val = val * 10 + (str[i] - 48);
	}
	return val;
}

void LoadConfig() {
	FILE* f = fopen("config.ini", "r");
	if (!f) { error = 1; return; }
	char key[50];
	char val[255];
	while (!feof(f)) {
		fscanf(f, "%s = %s", key, val);
		if (strcmp(key, "tile_width") == 0) { tile_width = StrToInt(val); }
		else if (strcmp(key, "tile_height") == 0) { tile_height = StrToInt(val); }
		else if (strcmp(key, "map_width") == 0) { map_width = StrToInt(val); }
		else if (strcmp(key, "map_height") == 0) { map_height = StrToInt(val); }
		else if (strcmp(key, "screen_width") == 0) { screen_width = StrToInt(val); }
		else if (strcmp(key, "screen_height") == 0) { screen_height = StrToInt(val); }
		else if (strcmp(key, "zoom") == 0) { zoom = StrToInt(val); }
		else if (strcmp(key, "tiles") == 0) { strcpy(tiles_filename, val); }
		else if (strcmp(key, "map") == 0) { strcpy(map_filename, val); }
	}
	fclose(f);
}

void Init() {
	LoadConfig();
	SDL_Init(SDL_INIT_EVERYTHING);
	sdlWindow = SDL_CreateWindow("Mappy v0.1", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, screen_width*zoom, screen_height*zoom, SDL_WINDOW_SHOWN);
	sdlRenderer = SDL_CreateRenderer(sdlWindow, -1, SDL_RENDERER_PRESENTVSYNC);
	//SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "linear");
	SDL_RenderSetLogicalSize(sdlRenderer, screen_width, screen_height);

	unsigned short w, h;
	unsigned char* buffer = LoadGif(font, &w, &h);

	sdlFontTexture = SDL_CreateTexture(sdlRenderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STATIC, w, h);
	Uint32* pixels = (Uint32*)malloc(w*h*sizeof(Uint32));
	for (int i = 0; i < w*h; i++) { pixels[i] = buffer[i] == 0 ? 0x00000000 : 0xffffffff; }
	SDL_UpdateTexture(sdlFontTexture, NULL, pixels, w * sizeof(Uint32));
	SDL_SetTextureBlendMode(sdlFontTexture, SDL_BLENDMODE_BLEND);
	free(buffer);
	free(pixels);

	int c;
	FILE* f = fopen(tiles_filename, "rb");
	if (!f) {
		error = 2;
	} else {
		buffer = stbi_load_from_file(f, &tilemap_width, &tilemap_height, &c, 4);
		sdlTilesTexture = SDL_CreateTexture(sdlRenderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STATIC, tilemap_width, tilemap_height);
		SDL_UpdateTexture(sdlTilesTexture, NULL, buffer, tilemap_width * sizeof(Uint32));
		SDL_SetTextureBlendMode(sdlTilesTexture, SDL_BLENDMODE_BLEND);
		stbi_image_free(buffer);
	}

	//SDL_Surface* bmp = SDL_LoadBMP("assets.bmp");
	//texture = SDL_CreateTextureFromSurface(renderer, bmp);
	//SDL_FreeSurface(bmp);
}

void Quit() {
	SDL_DestroyTexture(sdlFontTexture);
	SDL_DestroyRenderer(sdlRenderer);
	SDL_DestroyWindow(sdlWindow);
	SDL_Quit();
}

void Flip() { SDL_RenderPresent(sdlRenderer); }
void Clear() { SDL_SetRenderDrawColor(sdlRenderer, 0, 0, 0, 255); SDL_RenderClear(sdlRenderer); }

void Draw(SDL_Texture* texture, int x, int y, int sx, int sy, int w, int h) {
	SDL_Rect src, dst;
	src.x = sx; src.y = sy;
	dst.x = x; dst.y = y;
	src.w = dst.w = w;
	src.h = dst.h = h;
	SDL_RenderCopy(sdlRenderer, texture, &src, &dst);
}

void FillRect(int x, int y, int w, int h, Uint8 r, Uint8 g, Uint8 b, Uint8 a = 255) {
	SDL_Rect src;
	src.x = x; src.y = y; src.w = w; src.h = h;
	SDL_SetRenderDrawColor(sdlRenderer, r, g, b, a);
	SDL_RenderFillRect(sdlRenderer, &src);
}

void Print(int x, int y, const char* text) {
	int str_size = strlen(text);
	for (int i = 0; i < str_size; i++) {
		char chr = text[i] - 32;
		Draw(sdlFontTexture, x + (i * 6), y, (chr & 0x0f) * 6, (chr >> 4) * 6, 6, 6);
	}
}

bool Button(int x, int y, char* text) {
	bool inside = (mouse.x >= x) && (mouse.y >= y) && (mouse.x < x + 51) && (mouse.y < y + 8);
	if (inside) {
		FillRect(x, y, 51, 9, 128, 64, 64, 255);
	} else {
		FillRect(x, y, 51, 9, 255, 64, 64, 255);
	}
	Print(x+2, y+2, text);
	return inside && mouse.buttons[0];
}

bool Update() {
	anyKey = false;
	while (SDL_PollEvent(&sdlEvent)) {
		if (sdlEvent.type == SDL_QUIT) {return true; break; }
		else if (sdlEvent.type == SDL_KEYDOWN) { 
			anyKey = true;
			if (sdlEvent.key.keysym.scancode == SDL_SCANCODE_ESCAPE) { return true; }
		}
	}
	Uint32 buttons = SDL_GetMouseState(&mouse.x, &mouse.y);
	mouse.x /= zoom;
	mouse.y /= zoom;
	mouse.buttons[0] = (buttons & 1) == 1;
	mouse.buttons[1] = (buttons & 2) == 2;
	mouse.buttons[2] = (buttons & 4) == 4;
	return false;
}

void PrintFatalError(const char* errorMsg) {
	int size = strlen(errorMsg);
	Print((screen_width - (size*6)) / 2, (screen_height - 6) / 2, errorMsg);
}
void ShowError() {
	switch (error) {
		case 1: PrintFatalError("No s'ha trobat l'arxiu config.ini"); break;
		case 2: PrintFatalError("No s'ha trobat arxiu de tiles"); break;
	}
}

int main(int argc, char* argv[]) {
	Init();

	while (!Update()) {
		Clear();

		if (error == 0) {
			int x = 0, y = 0;
			if (tilemap_width <= screen_width) {
				x = (screen_width - tilemap_width) / 2;
			} else {
				const int max_offset = tilemap_width - screen_width;
				const float mouse_ratio = float(mouse.x) / float(screen_width);
				x = -(mouse_ratio * max_offset);
			}
			if (tilemap_height <= screen_height) {
				y = (screen_height - tilemap_height) / 2;
			}
			else {
				const int max_offset = tilemap_height - screen_height;
				const float mouse_ratio = float(mouse.y) / float(screen_height);
				y = -(mouse_ratio * max_offset);
			}
			Draw(sdlTilesTexture, x, y, 0, 0, tilemap_width, tilemap_height);
			/*char num[5];
			sprintf(num, "%d", mouse.x);
			Print(100, 100, num);
			sprintf(num, ",%d", mouse.y);
			Print(118, 100, num);

			if (Button(2, 2, "New")) {
			strcpy(state, "New pressed");
			}
			if (Button(2, 12, "Open")) {
			strcpy(state, "open pressed");
			}
			if (Button(2, 22, "Save")) {
			strcpy(state, "save pressed");
			}
			if (Button(2, 32, "Save As")) {
			strcpy(state, "Save As pressed");
			}

			FillRect(0, 183, 256, 9, 128, 128, 128, 255);
			Print(2, 185, state);*/
		} else {
			ShowError();
		}
		Flip();
	}

	Quit();
	return 0;
}