#include <raylib.h>
#include <stdlib.h>
#include <stdio.h>
#include <time.h>

int width = 110;
int height = 90;
int cell_size = 6;
int FPS = 40;
char title[124];

int *current_state;
int *prev_state;
#define wrap(coord,max) ((coord) < 0 ? (max) + (coord) : (coord) % (max))
#define cell_at(x,y) (prev_state[wrap(y, height) * width + wrap(x, width)])

void on_create(void);
void keys(void);
void set_cells(char *pattern, int x, int y);

int main(int arvc, char *argv){
	on_create();
	InitWindow(width * cell_size, height * cell_size, "Game of Life");
	SetTargetFPS(FPS);
	while (!WindowShouldClose()){
		keys();
		for (int i = 0; i < height * width; i++)
			prev_state[i] = current_state[i];
		// update and draw
		BeginDrawing();
		ClearBackground(BLACK);
		for (int x = 0; x < width; x++){
		for (int y = 0; y < height; y++){
			int n_neighbours = cell_at(x - 1, y - 1) + cell_at(x, y - 1) + cell_at(x + 1, y - 1)
					 + cell_at(x - 1, y)     +		     cell_at(x + 1, y)
					 + cell_at(x - 1, y + 1) + cell_at(x, y + 1) + cell_at(x + 1, y + 1);
			if (cell_at(x,y) == 1)
				current_state[y * width + x] = n_neighbours == 2 || n_neighbours == 3;
			else
				current_state[y * width + x] = n_neighbours == 3;
			if (cell_at(x,y))
				DrawRectangle(x * cell_size, y * cell_size, cell_size, cell_size, WHITE);
		}
		}
		EndDrawing();
	}
	CloseWindow();
	return 0;
}

void keys(void){
	sprintf(title, "Game of Life [FPS: %d]", GetFPS());
	SetWindowTitle(title);
	if (IsKeyPressed(KEY_KP_ADD)){
		FPS += 5;
		if (FPS >= 300)
			FPS = 300;
		SetTargetFPS(FPS);

	}else if (IsKeyPressed(KEY_KP_SUBTRACT) || IsKeyPressed(KEY_SLASH)){
		FPS -= 5;
		if (FPS < 1)
			FPS = 1;
		SetTargetFPS(FPS);
	}
	if (IsKeyPressed(KEY_SPACE)){
		do {
			BeginDrawing();
			EndDrawing();
		}while (!IsKeyPressed(KEY_SPACE));
	}
}

void set_cells(char *pattern, int x, int y){
	for (int i = 0; x + i < width && *pattern; i++, pattern++)
		current_state[width * y + x + i] = *pattern == '#';
}

void on_create(void){
	current_state = calloc(height * width, sizeof(*current_state));
	prev_state = calloc(height * width, sizeof(*current_state));

	/* Pentomino
	set_cells("  ## ", 80,50);
	set_cells(" ##  ", 80,51);
	set_cells("  #  ", 80,52);

	set_cells("  ## ", 200,160);
	set_cells(" ##  ", 200,161);
	set_cells("  #  ", 200,162);

	set_cells("  ## ", 300,200);
	set_cells(" ##  ", 300,201);
	set_cells("  #  ", 300,202);

	set_cells("  ## ", 310,50);
	set_cells(" ##  ", 310,51);
	set_cells("  #  ", 310,52);*/

	/* Gosper Glider Gun
	set_cells("........................#............", 60, 45);
	set_cells("......................#.#............", 60, 46);
	set_cells("............##......##............##.", 60, 47);
	set_cells("...........#...#....##............##.", 60, 48);
	set_cells("##........#.....#...##...............", 60, 49);
	set_cells("##........#...#.##....#.#............", 60, 50);
	set_cells("..........#.....#.......#............", 60, 51);
	set_cells("...........#...#.....................", 60, 52);
	set_cells("............##.......................", 60, 53);*/

	// Infinite Growth
	// set_cells("########.#####...###......#######.#####", 150, 30);

	// Random
	srand(time(0));
	for (int i = 0; i < width * height; i++)
		current_state[i] = rand() % 100 >= 40;
}