package dayone

import (
	"bufio"
	"fmt"
	"log"
	"os"
	"strings"
	"unicode"
)

func Run() {
	file, err := os.Open("./day1/input")
	if err != nil {
		log.Print("error opening file")
		return
	}
	defer file.Close()

	scanner := bufio.NewScanner(file)

	result := 0

	for scanner.Scan() {
		line := scanner.Text()
		allDigits := getDigits(line)
		first := allDigits[0]
		last := allDigits[len(allDigits) - 1]

		num := first * 10 + last
		result += num
	}

	fmt.Printf(">> day 1 result is %d", result)
}

func getDigits(line string) []int {
	result := make([]int, 0)
	for ind, ch := range line {
		if unicode.IsDigit(ch) {
			result = append(result, int(ch - '0'))
		}
		wordDigit, found := getTheDigitSubstringAt(line, ind)
		if found {
			result = append(result, wordDigit)
		}
	}
	return result
}

var theDigits map[string]int = map[string]int{
	"one": 1,
	"two": 2,
	"three": 3,
	"four": 4,
	"five": 5,
	"six": 6,
	"seven": 7,
	"eight": 8,
	"nine": 9,
}

func getTheDigitSubstringAt(line string, index int) (digit int, found bool) {
	lineFromIndex := line[index:]
	for key, num := range theDigits {
		if strings.HasPrefix(lineFromIndex, key) {
			return num, true
		}
	}

	return 0, false
}

func getFirstDigit(line string) int {
	for _, ch := range line {
		if unicode.IsDigit(ch) {
			return int(ch - '0')
		}
	}
	return 0
}

func getLastDigit(line string) int {
	for i := len(line) - 1; i >= 0; i-- {
		simbols := []rune(line)
		ch := simbols[i]
		if unicode.IsDigit(ch) {
			return int(ch - '0')
		}
	}
	return 0
}