#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#define LEN_X 60
#define LEN_Y 20
#define PRINT_N 0
#define CELL_CHAR "*"
#define R_FACT 10
#define SLEEP 300

int generation;
int m[LEN_X][LEN_Y];

void clear() { printf("\e[1;1H\e[2J"); }

void put_world() {
  clear();
  printf("A GAME OF LIFE: #%i\n", generation);
  putchar('+');
  for (int sep = 0; sep < LEN_X; sep++) putchar('-');
  printf("+\n");
  for (int y = 0; y < LEN_Y; y++) {
    putchar('|');
    for (int x = 0; x < LEN_X; x++)
      if (m[x][y] > 0)
        if(PRINT_N) printf("%i", m[x][y]);
        else printf("%s", CELL_CHAR);
      else
        putchar(' ');
    printf("|\n");
  }
  putchar('+');
  for (int sep = 0; sep < LEN_X; sep++) putchar('-');
  printf("+\n");
  usleep(10000 * SLEEP);
}

void next_gen() {
  int m_ngen[LEN_X][LEN_Y];
  for (int x = 0; x < LEN_X; x++) {
    for (int y = 0; y < LEN_Y; y++) {
      int n = 0;
      if (y > 0 && m[x][y - 1] > 0) n++; // n
      if (x < LEN_X && y > 0 && m[x + 1][y - 1] > 0) n++; // ne
      if (x < LEN_X && m[x + 1][y] > 0) n++; // e
      if (x > 0 && y < LEN_Y && m[x - 1][y + 1] > 0) n++; // se
      if (y < LEN_Y && m[x][y + 1] > 0) n++; // s
      if (y < LEN_Y && x < LEN_X && m[x + 1][y + 1] > 0) n++; // sw
      if (x > 0 && m[x - 1][y] > 0) n++; // w
      if (x > 0 && y > 0 && m[x - 1][y - 1] > 0) n++; // nw

      if (m[x][y] > 0) 
        m_ngen[x][y] = (n < 2 || n > 3) ? 0 : n;
      else
        m_ngen[x][y] = (n == 3) ? n : 0;
    }
  }
  memcpy(m, m_ngen, sizeof(m_ngen));
}

void randomize(int fact) {
  srand(time(NULL));
  for (int x = 0; x <= LEN_X; x++) {
    for (int y = 0; y <= LEN_Y; y++) {
      int r = rand() % fact;
      m[x][y] = (r == 1) ? 1 : 0;
    }
  }
}

void init_world() {
  clear();

  randomize(R_FACT);

  /* int maxgens = 2000; */
  generation = 1;
  /* while (generation <= maxgens) { */
  while (1) {
    put_world();
    next_gen();
    generation++;
  }
}

int main() {
  init_world();
  return 0;
}