package main

import (
	"bufio"
	"fmt"
	"os"
)

const FILE_PATH = "./input.txt"

//const FILE_PATH = "./sample.txt"

func LoadInput(filename string) ([]string, error) {
	file, err := os.Open(filename)
	if err != nil {
		return nil, err
	}
	defer file.Close()

	var lines []string
	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		lines = append(lines, scanner.Text())
	}

	if err := scanner.Err(); err != nil {
		return nil, err
	}

	return lines, nil
}

type structuredInput = []string

func TransformInput(lines []string) structuredInput {
	return lines
}

const PART1_SEARCH_STRING = "XMAS"

func SearchStringCount(input structuredInput, search_string string, s_x int, s_y int) int {
	var x = s_x
	var y = s_y
	var i = 0
	var result = 0
	var error = false
	for m := -1; m <= 1; m++ {
		for n := -1; n <= 1; n++ {
			if m == 0 && n == 0 {
				continue
			}
			x = s_x - m
			y = s_y - n
			error = false

			for i = 0; i < len(search_string); i++ {
				if y+n < 0 || y+n >= len(input) || x+m < 0 || x+m >= len(input[y+n]) {
					error = true
					break
				}

				x += m
				y += n

				if input[y][x] != search_string[i] {
					error = true
					break
				}
			}

			if !error {
				result++
			}
		}
	}

	return result
}

func Part1(input structuredInput) int {
	var result = 0

	for y := 0; y < len(input); y++ {
		for x := 0; x < len(input[y]); x++ {
			if input[y][x] == PART1_SEARCH_STRING[0] {
				result += SearchStringCount(input, PART1_SEARCH_STRING, x, y)
			}
		}
	}

	return result
}

func Part2(input structuredInput) int {
	var result = 0

	for y := 1; y < len(input)-1; y++ {
		for x := 1; x < len(input[y])-1; x++ {
			if input[y][x] == 'A' {
				if input[y-1][x-1]+input[y+1][x+1] == 'M'+'S' && input[y+1][x-1]+input[y-1][x+1] == 'M'+'S' {
					result++
				}
			}
		}
	}

	return result
}

func main() {
	input, err := LoadInput(FILE_PATH)
	if err != nil {
		fmt.Println("Error loading input:", err)
		return
	}

	structuredInput := TransformInput(input)
	fmt.Println("Structured Input:", structuredInput)

	fmt.Println("Solution Part 1: ", Part1(structuredInput))
	fmt.Println("Solution Part 2: ", Part2(structuredInput))
}