#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>

#include "../../lib/aoc.h"

typedef struct Ratio {
  long long num;
  long long denom;
} Ratio;

typedef struct Line {
  Ratio slope;
  Ratio offset;
} Line;

Ratio ratio_subtract(Ratio r1, Ratio r2) {
  Ratio r3;
  r3.num= r1.num * r2.denom - r2.num * r1.denom;
  r3.denom= r1.denom* r2.denom;
  return r3;
}

Ratio ratio_divide(Ratio r1, Ratio r2) {
  Ratio r3;
  r3.num = r1.num * r2.denom;
  r3.denom = r1.denom * r2.num;
  return r3;
}

bool proper(Ratio r) {
  return r.num % r.denom == 0;
}

Ratio intersect_x(Line l1, Line l2) {
  Ratio left_side = ratio_subtract(l1.slope, l2.slope);
  Ratio right_side = ratio_subtract(l2.offset, l1.offset);
  Ratio divided = ratio_divide(right_side, left_side);
  printf("left: %lld/%lld, right: %lld/%lld, divided: %lld/%lld\n", left_side.num, left_side.denom, right_side.num, right_side.denom, divided.num, divided.denom);
  return divided;
}

long long li_cost(int ax, int ay, int bx, int by, long long px, long long py) {
  printf("prize at %lld, %lld\n", px, py);
  Line b_line;
  b_line.slope.num = by;
  b_line.slope.denom = bx;
  b_line.offset.num = 0;
  b_line.offset.denom = 1;

  Line a_line;
  a_line.slope.num = ay;
  a_line.slope.denom = ax;
  a_line.offset.num = -1 * ((px * ay) - (py * ax));
  a_line.offset.denom = ax;
  
  Ratio r = intersect_x(b_line, a_line);

  if (!proper(r)) {
    printf("bzzt\n");
    return 0;
  }

  long long b_x_movement = (r.num / r.denom);
  if (b_x_movement % bx != 0) return 0; // Fuuuuuuuuuuuuuuck this
  long long b_cost = b_x_movement / bx;
  long long a_x_movement = px - b_x_movement;
  if (a_x_movement % ax != 0) return 0; // Fuuuuuuuuuuuuuuck this
  long long a_cost = (a_x_movement / ax) * 3;
  printf("b: %lld, a: %lld\n", b_x_movement, a_x_movement);
  printf("b presses: %lld, a presses: %lld\n", b_x_movement / bx, a_x_movement / ax);
  if (b_x_movement < 0 || a_x_movement < 0) return 0;
  printf("cost: %lld\n", b_cost + a_cost);
  return b_cost + a_cost;
}

int main() {
  int ax, ay, bx, by;
  long long px, py;
  char *line;

  long long cost = 0;
  long long cost_2 = 0;
  while((line = aoc_read_line()) != NULL) {
    sscanf(line, "Button A: X+%d, Y+%d", &ax, &ay);
    sscanf(aoc_read_line(), "Button B: X+%d, Y+%d", &bx, &by);
    sscanf(aoc_read_line(), "Prize: X=%d, Y=%d", &px, &py);
    aoc_read_line();

    cost += li_cost(ax, ay, bx, by, px, py);
    cost_2 += li_cost(ax, ay, bx, by, px + 10000000000000, py + 10000000000000);
    printf("\n");
  }

  printf("Part 1: %lld\n", cost);
  printf("Part 2: %lld\n", cost_2);
  
  aoc_free();
  return 0;
}