package main

import (
	"bufio"
	"fmt"
	"math"
	"os"
	"strconv"
	"strings"
)

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
}

func TransformInput(lines []string) [][]int {
	var result [][]int
	var temp []int
	var numb int
	for _, line := range lines {
		var numbs = strings.Split(line, " ")
		temp = make([]int, len(numbs))
		for i := 0; i < len(numbs); i++ {
			numb, _ = strconv.Atoi(numbs[i])
			temp[i] = numb
		}
		result = append(result, temp)
	}

	return result
}

func IsLineSafe(input []int) bool {
	var decreasing = input[0] > input[1]
	var dif = 0
	for i := 0; i < len(input)-1; i++ {
		if input[i] > input[i+1] && !decreasing || input[i] < input[i+1] && decreasing {
			return false
		}
		dif = int(math.Abs(float64(input[i] - input[i+1])))
		if dif < 1 || dif > 3 {
			return false
		}
	}
	return true
}

func Part1(input [][]int) int {
	var result = 0

	for _, line := range input {
		if IsLineSafe(line) {
			result++
		}
	}

	return result
}

func Part2(input [][]int) int {
	var result = 0
	var temp []int
	for _, line := range input {
		if IsLineSafe(line) {
			result++
			continue
		}

		for i := 0; i < len(line); i++ {
			temp = make([]int, 0)
			temp = append(temp, line[:i]...)
			temp = append(temp, line[i+1:]...)
			if IsLineSafe(temp) {
				result++
				break
			}
		}
	}

	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))
}