package main

import (
	"flag"
	"fmt"
	"log"
	"net"
	"net/http"
	"time"

	"github.com/miekg/dns"
)

var (
	configFilePath   = flag.String("config", "./config.json", "config file path")
	httpAddress      = flag.String("bind-http", "127.0.0.1", "interface to bind the HTTP server to (0.0.0.0 for all)")
	dnsAddress       = flag.String("bind-dns", "127.0.0.1", "interface to bind the DNS server to (0.0.0.0 for all)")
	blockForwardAddr = flag.String("block-forward-ip", "127.0.0.1", "IP address to forward blocked traffic to. Preferably has https running.")
)

func main() {
	log.SetPrefix("[Entrypoint] ")
	log.SetFlags(log.LUTC | log.Lshortfile)
	flag.Parse()

	cfg, err := LoadConfig(*configFilePath)
	if err != nil {
		log.Fatal(err)
	}

	domainBlacklist, err := NewDomainBlacklist(cfg.Blocklists)
	if err != nil {
		log.Fatal(err)
	}

	go func(bm BlocklistManager) {
		httpAddr := fmt.Sprintf("%s:80", *httpAddress)
		log.Printf("HTTP server listening @ %s", httpAddr)
		handler := NewHTTPHandler(*cfg, bm)

		if err := http.ListenAndServe(httpAddr, handler); err != nil {
			log.Fatal(err)
		}
	}(domainBlacklist)

	ips := []net.IP{}
	for _, strIP := range cfg.Upstream {
		ips = append(ips, net.ParseIP(strIP))
	}

	handler, err := NewDNSHandler(*blockForwardAddr, &memoryDNSCacher{TTL: time.Minute}, domainBlacklist, DNSResolver(ips), *cfg)
	if err != nil {
		log.Fatal(err)
	}

	dnsAddr := fmt.Sprintf("%s:53", *dnsAddress)
	log.Printf("DNS server listening @ %s", dnsAddr)
	srv := &dns.Server{
		Addr:        dnsAddr,
		Net:         "udp",
		Handler:     handler,
		ReadTimeout: time.Second * 3,
	}
	if err := srv.ListenAndServe(); err != nil {
		log.Fatal(err)
	}
}