package util

import (
	"log"
	"strings"

	"github.com/babolivier/go-doh-client"
	"github.com/xvzc/SpoofDPI/config"
)

func ExtractDomain(message *[]byte) (string) {
    i := 0
    for ; i < len(*message); i++ {
        if (*message)[i] == '\n' {
            i++
            break;
        }
    }

    for ; i < len(*message); i++ {
        if (*message)[i] == ' ' {
            i++
            break;
        }
    }

    j := i
    for ; j < len(*message); j++ {
        if (*message)[j] == '\n' {
            break;
        }
    }

    domain := strings.Split(string((*message)[i:j]), ":")[0]

    return strings.TrimSpace(domain)
}

func DnsLookupOverHttps(dns string, domain string)(string, error) {
    // Perform a A lookup on example.com
    resolver := doh.Resolver{
        Host:  dns, // Change this with your favourite DoH-compliant resolver.
        Class: doh.IN,
    }

    Debug(domain)
    a, _, err := resolver.LookupA(domain)
    if err != nil {
        log.Println("Error looking up dns. ", err)
        return "", err
    }

    ip := a[0].IP4 

    return ip, nil
}

func ExtractMethod(message *[]byte) (string) {
    i := 0
    for ; i < len(*message); i++ {
        if (*message)[i] == ' ' {
            break;
        }
    }

    method := strings.TrimSpace(string((*message)[:i]))
    Debug(method)

    return strings.ToUpper(method)
}

func Debug(v ...interface{}) {
    if config.GetConfig().Debug == false {
        return
    }

    log.Println(v...)
}

func BytesToChunks(buf []byte) ([][]byte) {
    if len(buf) < 1 {
        return [][]byte{buf}
    }

    return [][]byte{buf[:1], buf[1:]}
}