package main

import (
	"encoding/hex"
	"fmt"
	"sort"
	"testing"
	"time"

	"gitlab.com/rhogenson/roseh.moe/internal/pwhash"
)

func mustHex(s string) []byte {
	b, err := hex.DecodeString(s)
	if err != nil {
		panic(err)
	}
	return b
}

const password = "emcee polio cardiac disclose superglue clapper cruelness stonework tingly unarmored"

var salt = mustHex("a0aa6971f38827e5")

var iterations int

func BenchmarkHashIter(b *testing.B) {
	for b.Loop() {
		pwhash.HashIter(password, salt, iterations)
	}
}

func main() {
	const targetDuration = 5 * time.Second
	for iterations = 8192; time.Duration(testing.Benchmark(BenchmarkHashIter).NsPerOp()) < targetDuration; iterations *= 2 {
	}
	lo := iterations / 2
	hi := iterations
	fmt.Println(lo + sort.Search(hi-lo, func(i int) bool {
		iterations = lo + i
		return time.Duration(testing.Benchmark(BenchmarkHashIter).NsPerOp()) > targetDuration
	}))
}