package main

import (
	"log"
	"sync"

	"git.staur.ca/stobbsm/tind"
)

var (
	RuneSet  = []rune("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!@#$%^&*()_+-=[]{}/';:.>,<`~")
)

const runs uint64 = 10000

// CollisionChecks runs different tests to check for collisions, and get's the average
func CollisionChecks() {
	wg := new(sync.WaitGroup)
	log.Println("Using multiple configurations, test for collisions multiple times")
	sizes := []int{4,5,6,7,8,9,10,11,12,13,14,15,16}
	end := len(RuneSet)
	
	for i := 4; i < end; i++ {
		for _, v := range sizes {
			v := v
			rs :=RuneSet[:i] 
			wg.Add(1)
			go collisionCheck(v, rs, wg, len(rs))
		}
	}
	wg.Wait()
}

func collisionCheck(size int, runeset []rune, wg *sync.WaitGroup, runesize int) {
	defer wg.Done()
	var total uint64
	for i := uint64(0); i < runs; i++ {
		total += runCheck(tind.New().WithSize(size).WithRuneset(runeset))
	}
	log.Printf("runset size: %d, id size: %d, average iterations before collision: %d", runesize, size, total/runs)
}

func runCheck(tconfig *tind.Config) uint64 {
	var i uint64
	tmap := make(map[string]struct{})
	for {
		i++
		t := tconfig.Gen()
		if _, ok := tmap[t.String()]; ok {
			return i
		}
		tmap[t.String()] = struct{}{}
	}
}