import { AdventOfCodeSolutionFunction } from "./solutions";

enum Direction {
    UP,
    UP_RIGHT,
    RIGHT,
    BOTTOM_RIGHT,
    BOTTOM,
    BOTTOM_LEFT,
    LEFT,
    UP_LEFT,
};

const ALL_DIRECTIONS = [
    Direction.RIGHT,
    Direction.BOTTOM_RIGHT,
    Direction.BOTTOM,
    Direction.BOTTOM_LEFT,
    Direction.LEFT,
    Direction.UP_LEFT,
    Direction.UP,
    Direction.UP_RIGHT,
];

const check_coords = (grid: Array<Array<string>>, x: number, y: number) => {
    return y >= grid.length ||
        y < 0 ||
        x >= grid[y].length ||
        x < 0
}

const search_direction = (grid: Array<Array<string>>, x: number, y: number, direction: Direction, find: Array<string>) => {
    // exit conditions
    // no more to find
    if (find.length == 0)
        return 1; // found the end

    // invalid coords
    if (check_coords(grid, x, y))
        return 0;

    // make new mutable list
    const newFind = [...find];
    const searchChar = newFind.shift();

    // wrong character
    if (grid[y][x] !== searchChar)
        return 0;

    switch (direction) {
        case Direction.UP:
            return search_direction(grid, x, y + 1, direction, newFind);

        case Direction.UP_RIGHT:
            return search_direction(grid, x + 1, y + 1, direction, newFind);

        case Direction.RIGHT:
            return search_direction(grid, x + 1, y, direction, newFind);

        case Direction.BOTTOM_RIGHT:
            return search_direction(grid, x + 1, y - 1, direction, newFind);

        case Direction.BOTTOM:
            return search_direction(grid, x, y - 1, direction, newFind);

        case Direction.BOTTOM_LEFT:
            return search_direction(grid, x - 1, y - 1, direction, newFind);

        case Direction.LEFT:
            return search_direction(grid, x - 1, y, direction, newFind);

        case Direction.UP_LEFT:
            return search_direction(grid, x - 1, y + 1, direction, newFind);

        default:
            return 0;
    }
}

const part_1_search = (grid: Array<Array<string>>, x: number, y: number, find: Array<string>) => {
    return ALL_DIRECTIONS.reduce<number>(
        (instances, direction) =>
            instances + search_direction(grid, x, y, direction, find),
        0
    );
}

const part_2_search = (grid: Array<Array<string>>, x: number, y: number, find: Array<string>) => {
    return (
        search_direction(grid, x - 1, y + 1, Direction.BOTTOM_RIGHT, find) +
        search_direction(grid, x + 1, y + 1, Direction.BOTTOM_LEFT, find) +
        search_direction(grid, x - 1, y - 1, Direction.UP_RIGHT, find) +
        search_direction(grid, x + 1, y - 1, Direction.UP_LEFT, find)
    ) == 2 ? 1 : 0;
}

export const solution_4: AdventOfCodeSolutionFunction = (input) => {
    const grid = input.split("\n").map(st => st.trim()).map(v => v.split(""));

    let part_1 = 0;
    let part_2 = 0;

    const find_1 = "XMAS".split("");
    const find_2 = "MAS".split("");

    for (let y = 0; y < grid.length; y++) {
        for (let x = 0; x < grid[y].length; x++) {
            part_1 += part_1_search(grid, x, y, find_1);
            part_2 += part_2_search(grid, x, y, find_2);
        }
    }

    return {
        part_1,
        part_2,
    };
}

func part1(W [][]rune) {
	m := len(W)
	n := len(W[0])
	xmasCount := 0

	for i := 0; i < m; i++ {
		for j := 0; j < n; j++ {
			if W[i][j] != 'X' {
				continue
			}
			if j < n-3 && W[i][j+1] == 'M' && W[i][j+2] == 'A' && W[i][j+3] == 'S' {
				// Horizontal left to right
				xmasCount++
			}
			if j >= 3 && W[i][j-1] == 'M' && W[i][j-2] == 'A' && W[i][j-3] == 'S' {
				// Horizontal right to left
				xmasCount++
			}
			if i < m-3 && W[i+1][j] == 'M' && W[i+2][j] == 'A' && W[i+3][j] == 'S' {
				// Vertical up to down
				xmasCount++
			}
			if i >= 3 && W[i-1][j] == 'M' && W[i-2][j] == 'A' && W[i-3][j] == 'S' {
				// Vertical down to up
				xmasCount++
			}
			if j < n-3 && i < m-3 && W[i+1][j+1] == 'M' && W[i+2][j+2] == 'A' && W[i+3][j+3] == 'S' {
				// Diagonal left to right and up to down
				xmasCount++
			}
			if j >= 3 && i < m-3 && W[i+1][j-1] == 'M' && W[i+2][j-2] == 'A' && W[i+3][j-3] == 'S' {
				// Diagonal right to left and up to down
				xmasCount++
			}
			if j < n-3 && i >= 3 && W[i-1][j+1] == 'M' && W[i-2][j+2] == 'A' && W[i-3][j+3] == 'S' {
				// Diagonal left to right and down to up
				xmasCount++
			}
			if j >= 3 && i >= 3 && W[i-1][j-1] == 'M' && W[i-2][j-2] == 'A' && W[i-3][j-3] == 'S' {
				// Diagonal right to left and down to up
				xmasCount++
			}
		}
	}

	fmt.Println(xmasCount)
}

func part2(W [][]rune) {
	m := len(W)
	n := len(W[0])
	xmasCount := 0

	for i := 0; i <= m-3; i++ {
		for j := 0; j <= n-3; j++ {
			if W[i+1][j+1] != 'A' {
				continue
			}
			if W[i][j] == 'M' && W[i][j+2] == 'M' && W[i+2][j] == 'S' && W[i+2][j+2] == 'S' {
				xmasCount++
			} else if W[i][j] == 'M' && W[i][j+2] == 'S' && W[i+2][j] == 'M' && W[i+2][j+2] == 'S' {
				xmasCount++
			} else if W[i][j] == 'S' && W[i][j+2] == 'S' && W[i+2][j] == 'M' && W[i+2][j+2] == 'M' {
				xmasCount++
			} else if W[i][j] == 'S' && W[i][j+2] == 'M' && W[i+2][j] == 'S' && W[i+2][j+2] == 'M' {
				xmasCount++
			}
		}
	}

	fmt.Println(xmasCount)
}

func main() {
	file, _ := os.Open("input.txt")
	defer file.Close()
	scanner := bufio.NewScanner(file)

	var W [][]rune
	for scanner.Scan() {
		line := scanner.Text()
		W = append(W, []rune(line))
	}

	part1(W)
	part2(W)
}

sub MAIN($input) {
    my $file = (open $input).slurp;
    my @grid is List = $file.lines».comb».list;
    my @transposedGrid is List = [Z] @grid;
    my @reversedGrid is List = @grid».reverse;
    my @transposedReversedGrid is List = @transposedGrid».reverse;

    my @horizontalScanRows is List = generateScanHorizontal(@grid);
    my @transposedHorizontalScanRows is List = generateScanHorizontal(@transposedGrid);

    my @part-one-counts = [];
    @part-one-counts.push(count-xmas(@grid, @horizontalScanRows)); # Right
    @part-one-counts.push(count-xmas(@transposedGrid, @transposedHorizontalScanRows)); # Down
    @part-one-counts.push(count-xmas(@reversedGrid, @horizontalScanRows)); # Left
    @part-one-counts.push(count-xmas(@transposedReversedGrid, @transposedHorizontalScanRows)); # Up

    my @diagonalScanRows is List = generateScanDiagonal(@grid);
    my @transposedDiagonalScanRows is List = generateScanDiagonal(@transposedGrid);
    @part-one-counts.push(count-xmas(@grid, @diagonalScanRows)); # Down Right
    @part-one-counts.push(count-xmas(@grid, @diagonalScanRows».reverse)); # Up Left
    @part-one-counts.push(count-xmas(@reversedGrid, @diagonalScanRows)); # Down Left
    @part-one-counts.push(count-xmas(@reversedGrid, @diagonalScanRows».reverse)); # Up Right

    my $part-one-solution = @part-one-counts.sum;
    say "part 1: $part-one-solution";


    my @part-two-counts = [];
    @part-two-counts.push(countGridMatches(@grid, (<M . S>,<. A .>,<M . S>)));
    @part-two-counts.push(countGridMatches(@grid, (<S . S>,<. A .>,<M . M>)));
    @part-two-counts.push(countGridMatches(@grid, (<S . M>,<. A .>,<S . M>)));
    @part-two-counts.push(countGridMatches(@grid, (<M . M>,<. A .>,<S . S>)));

    my $part-two-solution = @part-two-counts.sum;
    say "part 2: $part-two-solution";

}

sub count-xmas(@grid, @scanRows) {
    my $xmas-count = 0;
    for @scanRows -> @scanRow {
        my $xmas-pos = 0;
        for @scanRow -> @pos {
            my $char = @grid[@pos[0]][@pos[1]];
            if "X" eq $char {
                $xmas-pos = 1;
            }elsif <X M A S>[$xmas-pos] eq $char {
                if $xmas-pos == 3 {
                    $xmas-pos = 0;
                    $xmas-count += 1;
                } else {
                    $xmas-pos += 1;
                }
            } else {
                $xmas-pos = 0;
            }
        }
    }
    return $xmas-count;
}

sub generateScanHorizontal(@grid) {
    # Horizontal
    my $rows = @grid.elems;
    my $cols = @grid[0].elems;
    my @scanRows = ();
    for 0..^$rows -> $row {
        my @scanRow = ();
        for 0..^$cols -> $col {
            @scanRow.push(($row, $col));
        }
        @scanRows.push(@scanRow);
    }
    return @scanRows.List».List;
}

sub generateScanDiagonal(@grid) {
    # Down-right diagonal
    my $rows = @grid.elems;
    my $cols = @grid[0].elems;
    my @scanRows = ();
    for 0..^($rows + $cols - 1) -> $diag {
        my @scanRow = ();
        my $starting-row = max(-$cols + $diag + 1, 0);
        my $starting-col = max($rows - $diag - 1, 0);
        my $diag-len = min($rows - $starting-row, $cols - $starting-col);
        for 0..^$diag-len -> $diag-pos {
            @scanRow.push(($starting-row + $diag-pos, $starting-col + $diag-pos));
        }
        @scanRows.push(@scanRow);
    }
    return @scanRows.List».List;
}

sub countGridMatches(@grid, @needle) {
    my $count = 0;
    for 0..(@grid.elems - @needle.elems) -> $top {
        TOP-LEFT:
        for 0..(@grid[$top].elems - @needle[0].elems) -> $left {
            for 0..^@needle.elems -> $row-offset {
                for 0..^@needle[$row-offset].elems -> $col-offset {
                    my $needle-char = @needle[$row-offset][$col-offset];
                    next if $needle-char eq ".";
                    next TOP-LEFT if $needle-char ne @grid[$top+$row-offset][$left+$col-offset];
                }
            }
            $count += 1;
        }
    }
    return $count;
}

#include "common.h"
#define GZ 146

int main(int argc, char **argv) {
	static char g[GZ][GZ];
	static const char w[] = "XMAS";
	int p1=0,p2=0, x,y, m,i;

	if (argc > 1) DISCARD(freopen(argv[1], "r", stdin));
	for (y=3; y<GZ && fgets(g[y]+3, GZ-3, stdin); y++) ;

	for (y=3; y<GZ-3; y++)
	for (x=3; x<GZ-3; x++) {
		for (m=1,i=0; i<4; i++) {m &= g[y+i][x]==w[i];} p1+=m;
		for (m=1,i=0; i<4; i++) {m &= g[y-i][x]==w[i];} p1+=m;
		for (m=1,i=0; i<4; i++) {m &= g[y][x+i]==w[i];} p1+=m;
		for (m=1,i=0; i<4; i++) {m &= g[y][x-i]==w[i];} p1+=m;
		for (m=1,i=0; i<4; i++) {m &= g[y+i][x+i]==w[i];} p1+=m;
		for (m=1,i=0; i<4; i++) {m &= g[y-i][x-i]==w[i];} p1+=m;
		for (m=1,i=0; i<4; i++) {m &= g[y+i][x-i]==w[i];} p1+=m;
		for (m=1,i=0; i<4; i++) {m &= g[y-i][x+i]==w[i];} p1+=m;

		p2 += g[y+1][x+1]=='A' &&
		      ((g[y][x]  =='M' && g[y+2][x+2]=='S')  ||
		       (g[y][x]  =='S' && g[y+2][x+2]=='M')) &&
		      ((g[y+2][x]=='M' && g[y][x+2]  =='S')  ||
		       (g[y+2][x]=='S' && g[y][x+2]  =='M'));
	}

	printf("04: %d %d\n", p1, p2);
}

import aoc

def setup():
    return (aoc.get_lines(4, padded=(True, '.', 3)), 0)

def one():
    lines, acc = setup()
    for row, l in enumerate(lines):
        for col, c in enumerate(l):
            if c == 'X':
                w = l[col - 3:col + 1]
                e = l[col:col + 4]
                n = c + lines[row - 1][col] + \
                    lines[row - 2][col] + lines[row - 3][col]
                s = c + lines[row + 1][col] + \
                    lines[row + 2][col] + lines[row + 3][col]
                nw = c + lines[row - 1][col - 1] + \
                    lines[row - 2][col - 2] + lines[row - 3][col - 3]
                ne = c + lines[row - 1][col + 1] + \
                    lines[row - 2][col + 2] + lines[row - 3][col + 3]
                sw = c + lines[row + 1][col - 1] + \
                    lines[row + 2][col - 2] + lines[row + 3][col - 3]
                se = c + lines[row + 1][col + 1] + \
                    lines[row + 2][col + 2] + lines[row + 3][col + 3]
                for word in [w, e, n, s, nw, ne, sw, se]:
                    if word in ['XMAS', 'SAMX']:
                        acc += 1
    print(acc)

def two():
    lines, acc = setup()
    for row, l in enumerate(lines):
        for col, c in enumerate(l):
            if c == 'A':
                l = lines[row - 1][col - 1] + c + lines[row + 1][col + 1]
                r = lines[row + 1][col - 1] + c + lines[row - 1][col + 1]
                if l in ['MAS', 'SAM'] and r in ['MAS', 'SAM']:
                    acc += 1
    print(acc)

one()
two()

use euclid::{vec2, default::*};

fn count_xmas(grid: &[&[u8]], pos: (usize, usize)) -> u32 {
    if grid[pos.1][pos.0] != b'X' {
        return 0
    }

    let bounds = Rect::new(Point2D::origin(), Size2D::new(grid[0].len() as i32, grid.len() as i32));
    const DIRS: [Vector2D<i32>; 8] = [
        vec2(1, 0), vec2(-1, 0), vec2(0, 1), vec2(0, -1),
        vec2(1, 1), vec2(1, -1), vec2(-1, 1), vec2(-1, -1),
    ];
    let mut count = 0;
    for dir in DIRS {
        let mut cur = Point2D::from(pos).to_i32();
        let mut found = true;
        for letter in [b'M', b'A', b'S'] {
            cur += dir;
            if !bounds.contains(cur) || grid[cur.y as usize][cur.x as usize] != letter {
                found = false;
                break
            }
        }
        if found {
            count += 1;
        }
    }
    count
}

fn part1(input: String) {
    let grid = input.lines().map(|l| l.as_bytes()).collect::<Vec<_>>();    
    let count = (0..grid.len()).map(|y| {
            (0..grid[y].len()).map(|x| count_xmas(&grid, (x, y))).sum::<u32>()
        })
        .sum::<u32>();
    println!("{count}");
}

fn is_x_mas(grid: &[&[u8]], pos: (usize, usize)) -> bool {
    if grid[pos.1][pos.0] != b'A' {
        return false
    }

    const DIRS: [Vector2D<i32>; 4] = [vec2(1, -1), vec2(1, 1), vec2(-1, 1), vec2(-1, -1)];
    let pos = Point2D::from(pos).to_i32();
    (0..4).any(|d| {
        let m_pos = [pos + DIRS[d], pos + DIRS[(d + 1) % 4]]; // 2 adjacent positions of M
        let s_pos = [pos + DIRS[(d + 2) % 4], pos + DIRS[(d + 3) % 4]]; // others S
        m_pos.iter().all(|p| grid[p.y as usize][p.x as usize] == b'M') &&
        s_pos.iter().all(|p| grid[p.y as usize][p.x as usize] == b'S')
    })
}

fn part2(input: String) {
    let grid = input.lines().map(|l| l.as_bytes()).collect::<Vec<_>>();    
    let count = (1..grid.len() - 1).map(|y| {
            (1..grid[y].len() - 1).filter(|&x| is_x_mas(&grid, (x, y))).count()
        })
        .sum::<usize>();
    println!("{count}");
}

util::aoc_main!();

string wordsearch = "";
int width;
int height;

public void Input(IEnumerable<string> lines)
{
  wordsearch = string.Join("", lines);
  height = lines.Count();
  width = lines.First().Length;
}

public void Part1()
{
  int words = 0;
  for (int y = 0; y < height; y++)
    for (int x = 0; x < width; x++)
      words += SearchFrom(x, y);

  Console.WriteLine($"Words: {words}");
}
public void Part2()
{
  int words = 0;
  for (int y = 1; y < height - 1; y++)
    for (int x = 1; x < width - 1; x++)
      words += SearchCross(x, y);

  Console.WriteLine($"Crosses: {words}");
}

public int SearchFrom(int x, int y)
{
  char at = wordsearch[y * width + x];
  if (at != 'X')
    return 0;

  int words = 0;
  for (int ydir = -1; ydir <= 1; ++ydir)
    for (int xdir = -1; xdir <= 1; ++xdir)
    {
      if (xdir == 0 && ydir == 0)
        continue;

      if (SearchWord(x, y, xdir, ydir))
        words++;
    }

  return words;
}

private readonly string word = "XMAS";
public bool SearchWord(int x, int y, int xdir, int ydir)
{
  int wordit = 0;
  while (true)
  {
    char at = wordsearch[y * width + x];
    if (at != word[wordit])
      return false;

    if (wordit == word.Length - 1)
      return true;

    wordit++;

    x += xdir;
    y += ydir;

    if (x < 0 || y < 0 || x >= width || y >= height)
      return false;
  }
}

public int SearchCross(int x, int y)
{
  if (x == 0 || y == 0 || x == width - 1 || y == width - 1)
    return 0;

  char at = wordsearch[y * width + x];
  if (at != 'A')
    return 0;

  int found = 0;
  for (int ydir = -1; ydir <= 1; ++ydir)
    for (int xdir = -1; xdir <= 1; ++xdir)
    {
      if (xdir == 0 || ydir == 0)
        continue;

      if (wordsearch[(y + ydir) * width + (x + xdir)] != 'M')
        continue;
      if (wordsearch[(y - ydir) * width + (x - xdir)] != 'S')
        continue;

      found++;
    }

  if (found == 2)
    return 1;

  return 0;
}