#include "aoc.h"
#include <functional>
#include <string.h>

namespace aoc2022 {

static int X = 1;
static int cycles = 1;

static int get_number(const char *p) {
  int sign = *p == '-' ? -1 : 1;
  if (sign == -1) p++;
  int d{0};
  while(*p >= '0' && *p <= '9') {
    d = d * 10 + *p - '0';
    p++;
  }
  return sign * d;
}

struct CP {
  int d{0};
  bool done = false;

  CP(int x): d(x) {}
};

void point(int d, CP cp[], int* total) {
  // printf("cycle %d X %d\n", d, X);
  for (int i = 0; i < 6; i++) {
    if (!cp[i].done && cp[i].d == d) {
      *total += X * d;
      // printf("%d: %d = %d\n", d, X, X * d);
      cp[i].done = true;
      break;
    }
  }
}

// static void print(char p[]) {
//   for(int i = 0; i < 240; i++) {
//     printf("%c", p[i]);
//     if ((i+1) % 40 == 0) {
//       printf("\n");
//     }
//   }
// }

static void draw(int i, char crt[], char c) {
  crt[i - 1] = c; 
}

static void reset(char crt[]) {
  for (int i = 0; i < 240; i++) {
     * (crt + i) = '.';
  }
}

static void set(char crt[], int x) {
  reset(crt);
  crt[x] = '#';
  crt[x+1] = '#';
  crt[x+2] = '#';
}

std::pair<int, int> day10(line_view file) 
{ 

  char screen[240] = {0};
  char sprite[240] = {0};
  reset(screen);
  set(sprite, X);

  struct {
    const char *cmd;
    std::function<void(const char*, CP [], int*, char [])> f;
  } cmds[] = {
    {"addx", [&sprite](const char* p, CP cp[], int* total, char crt[]){
      auto d = get_number(p);
      point(cycles, cp, total);
      draw(cycles, crt, sprite[cycles % 40]);
      cycles += 1; 
      point(cycles, cp, total);
      draw(cycles, crt, sprite[cycles % 40]);
      cycles += 1; 
      X += d;
      set(sprite, X);
    }},
    {"noop", [&sprite](const char* p, CP cp[], int* total, char crt[]){
      // printf("noop\n");
      point(cycles, cp, total);
      draw(cycles, crt, sprite[cycles % 40]);
      cycles += 1;
    }},
  };

  CP cp[] = {20, 60, 100, 140, 180, 220};
  int total{0};
  per_line(file, [&cmds, &cp, &total, &screen](line_view lv) {
     for(auto &c: cmds)  {
        if (strncmp(c.cmd, lv.line, 4) == 0) {
            c.f(lv.line+5, cp, &total, screen);
            break;
        }
     }
     return true;
  });

  // print(screen);
  return {total, 0};
}

} // namespace aoc2022