package main

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

func main() {
	rotations := Decode("input.txt")

	rotation := 50
	zeroamount := 0

	for _, i := range rotations {
		b := i % 100 // for large number rotations eg. L392 -> L92

		r := rotation + b
		if r > 99 {
			r = r - 100
		} else if r < 0 {
			r = r + 100
		}

		if r == 0 {
			zeroamount = zeroamount + 1
		}

		fmt.Printf("rotation is now at: %d+%d=%d, rotation %d\n", rotation, b, r, i)
		rotation = r
	}

	fmt.Println("zero amount is:", zeroamount)

}

func Decode(filename string) []int {
	f, err := os.Open(filename)

	if err != nil {
		panic(err)
	}

	defer f.Close()

	scanner := bufio.NewScanner(f)

	var rotations []int

	for scanner.Scan() {
		if strings.Contains(scanner.Text(), "L") {
			a := strings.Replace(scanner.Text(), "L", "", 1)

			b, _ := strconv.Atoi(a)
			c := b-b*2 // makes negative, this is so janky
			rotations = append(rotations, c)
			fmt.Printf("converted %s to int %d\n", scanner.Text(), c)

		} else if strings.Contains(scanner.Text(), "R") {
			a := strings.Replace(scanner.Text(), "R", "", 1)

			b, _ := strconv.Atoi(a)
			rotations = append(rotations, b)
			fmt.Printf("converted %s to int %d\n", scanner.Text(), b)
		}
	}

	return rotations
}