package main

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

func loadPrimes() []int64 {
	return loadPrimesTxt()
}

func loadPrimesTxt() []int64 {
	file, err := os.Open("prime.txt")
	if err != nil {
		log.Fatal(err)
	}

	var primes []int64

	scanner := bufio.NewScanner(file)

	for scanner.Scan() {
		nextPrime, err := strconv.ParseInt(scanner.Text(), 10, 64)
		if err != nil {
			log.Fatal(err)
		}
		primes = append(primes, nextPrime)
	}

	file.Close()

	return primes
}

func writePrimes(primes []int64) {
	writePrimesTxt(primes)
}

func writePrimesTxt(primes []int64) {
	file, err := os.Create("prime.txt")
	if err != nil {
		log.Fatal(err)
	}

	writer := bufio.NewWriter(file)

	for _, prime := range primes {
		writer.WriteString(fmt.Sprintf("%d\n", prime))
	}

	writer.Flush()
	file.Close()
}