package main

import (
	"bytes"
	"io"
	"log"
	"math/rand"
	"net/http"
	"time"
)

func main() {
	fs := http.FileServer(http.Dir("./static"))
	nextId := func(w http.ResponseWriter, _ *http.Request) {
		next := base56Id3()
		//log.Printf("Generating ID: %s", next)
		io.WriteString(w, next+"\n")
	}
	http.Handle("/", fs)
	http.HandleFunc("/next", nextId)

	log.Println("Listening on :8080...")
	err := http.ListenAndServe(":8080", nil)
	if err != nil {
		log.Fatal(err)
	}
}

func base56Id3() string {
	//Base56 alphabet with "ambiguous" characters removed: [0oOIl1]
	alphabet := "23456789abcdefghijkmnpqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ"
	//Initialize rand with the time - this is a problem with multiple requests in the same ns
	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	var b bytes.Buffer
	for i := 0; i < 3; i++ {
		n := r.Intn(len(alphabet))
		char := alphabet[n]
		b.WriteByte(char)
	}

	return b.String()
}