package main

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

func main() {
	// iterate over all IDs
	joltages := Decode("input.txt")

	var joltagessum int = 0

	for _, i := range joltages {
		var tensColumn int = 0
		var onesColumn int = 0

		for iteration, x := range i {
			num, err := strconv.Atoi(string(x))
			if err != nil {
				panic(err)
			}

			if tensColumn == 0 {
				tensColumn = num
			} else if num > tensColumn && iteration != len(i)-1 {
				tensColumn = num
				onesColumn = 0
			} else if num > onesColumn && onesColumn >= tensColumn {
				tensColumn = onesColumn
				onesColumn = num
			} else if num > onesColumn {
				onesColumn = num
			}
		}

		sum := tensColumn*10 + onesColumn
		fmt.Printf("joltage found for %s, %d%d %d\n", i, tensColumn, onesColumn, sum)
		joltagessum = joltagessum + sum
	}

	fmt.Println("total joltage sum", joltagessum)
}

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

	if err != nil {
		panic(err)
	}

	defer f.Close()

	scanner := bufio.NewScanner(f)
	var joltages []string

	for scanner.Scan() {
		// extract joltage numbers into struct to go over
		joltages = append(joltages, scanner.Text())
	}

	return joltages
}