#include "aoc.h"

int main(int argc, char **argv) {
    Arena *arena = make_arena(Megabytes(1));
    str input = read_file(arena, argv[1]);
    Grid grid = parse_grid(input, arena);

    i32 directions[][2] = {
        {  1,   0 },  // horizontally forwards
        { -1,   0 },  // horizontally backwards
        {  0,   1 },  // vertically downwards
        {  0,  -1 },  // vertically upwards
        {  1,   1 },  // diagonally down-right
        { -1,  -1 },  // diagonally up-left
        {  1,  -1 },  // diagonally up-right
        { -1,   1 },  // diagonally down-left
    };
    char XMAS[] = "XMAS";

    i32 part_1 = 0;
    for (i32 y = 0; y < grid.height; y++) {
        for (i32 x = 0; x < grid.width; x++) {
            for (usize direction_index = 0; direction_index < ARRAY_SIZE(directions); direction_index++) {
                i32 dx = directions[direction_index][0];
                i32 dy = directions[direction_index][1];

                i32 end_x = x + 3 * dx;
                i32 end_y = y + 3 * dy;
                if (end_x < 0 || end_x >= grid.width || end_y < 0 || end_y >= grid.height) {
                    continue;
                }

                bool found = true;
                for (i32 i = 0; i < 4; i++) {
                    if (grid_at(&grid, x + i * dx, y + i * dy) != XMAS[i]) {
                        found = false;
                        break;
                    }
                }
                part_1 += found;
            }
        }
    }

    i32 part_2 = 0;
    for (i32 y = 1; y < grid.height - 1; y++) {
        for (i32 x = 1; x < grid.width - 1; x++) {
            if (grid_at(&grid, x, y) != 'A') {
                continue;
            }

            bool first_diagonal = 
                ((grid_at(&grid, x - 1, y - 1) == 'M') && (grid_at(&grid, x + 1, y + 1) == 'S'))
                || ((grid_at(&grid, x - 1, y - 1) == 'S') && (grid_at(&grid, x + 1, y + 1) == 'M'));
            bool second_diagonal = 
                ((grid_at(&grid, x + 1, y - 1) == 'M') && (grid_at(&grid, x - 1, y + 1) == 'S'))
                || ((grid_at(&grid, x + 1, y - 1) == 'S') && (grid_at(&grid, x - 1, y + 1) == 'M'));
            part_2 += first_diagonal && second_diagonal;
        }
    }

    printf("%d\n", part_1);
    printf("%d\n", part_2);
}