package dnsforward

import (
	"net"
	"strings"
	"time"

	"github.com/AdguardTeam/AdGuardHome/internal/filtering"
	"github.com/AdguardTeam/AdGuardHome/internal/querylog"
	"github.com/AdguardTeam/AdGuardHome/internal/stats"
	"github.com/AdguardTeam/dnsproxy/proxy"
	"github.com/AdguardTeam/golibs/log"
	"github.com/AdguardTeam/golibs/netutil"
	"github.com/miekg/dns"
)

// Write Stats data and logs
func (s *Server) processQueryLogsAndStats(dctx *dnsContext) (rc resultCode) {
	elapsed := time.Since(dctx.startTime)
	pctx := dctx.proxyCtx

	shouldLog := true
	msg := pctx.Req

	// don't log ANY request if refuseAny is enabled
	if len(msg.Question) >= 1 && msg.Question[0].Qtype == dns.TypeANY && s.conf.RefuseAny {
		shouldLog = false
	}

	ip, _ := netutil.IPAndPortFromAddr(pctx.Addr)
	ip = netutil.CloneIP(ip)

	s.serverLock.RLock()
	defer s.serverLock.RUnlock()

	s.anonymizer.Load()(ip)

	log.Debug("client ip: %s", ip)

	// Synchronize access to s.queryLog and s.stats so they won't be suddenly
	// uninitialized while in use.  This can happen after proxy server has been
	// stopped, but its workers haven't yet exited.
	if shouldLog && s.queryLog != nil {
		p := &querylog.AddParams{
			Question:          msg,
			Answer:            pctx.Res,
			OrigAnswer:        dctx.origResp,
			Result:            dctx.result,
			Elapsed:           elapsed,
			ClientID:          dctx.clientID,
			ClientIP:          ip,
			AuthenticatedData: dctx.responseAD,
		}

		switch pctx.Proto {
		case proxy.ProtoHTTPS:
			p.ClientProto = querylog.ClientProtoDoH
		case proxy.ProtoQUIC:
			p.ClientProto = querylog.ClientProtoDoQ
		case proxy.ProtoTLS:
			p.ClientProto = querylog.ClientProtoDoT
		case proxy.ProtoDNSCrypt:
			p.ClientProto = querylog.ClientProtoDNSCrypt
		default:
			// Consider this a plain DNS-over-UDP or DNS-over-TCP request.
		}

		if pctx.Upstream != nil {
			p.Upstream = pctx.Upstream.Address()
		} else if cachedUps := pctx.CachedUpstreamAddr; cachedUps != "" {
			p.Upstream = pctx.CachedUpstreamAddr
			p.Cached = true
		}

		s.queryLog.Add(p)
	}

	s.updateStats(dctx, elapsed, *dctx.result, ip)

	return resultCodeSuccess
}

func (s *Server) updateStats(
	ctx *dnsContext,
	elapsed time.Duration,
	res filtering.Result,
	clientIP net.IP,
) {
	if s.stats == nil {
		return
	}

	pctx := ctx.proxyCtx
	e := stats.Entry{}
	e.Domain = strings.ToLower(pctx.Req.Question[0].Name)
	e.Domain = e.Domain[:len(e.Domain)-1] // remove last "."

	if clientID := ctx.clientID; clientID != "" {
		e.Client = clientID
	} else if clientIP != nil {
		e.Client = clientIP.String()
	}

	e.Time = uint32(elapsed / 1000)
	e.Result = stats.RNotFiltered

	switch res.Reason {
	case filtering.FilteredSafeBrowsing:
		e.Result = stats.RSafeBrowsing
	case filtering.FilteredParental:
		e.Result = stats.RParental
	case filtering.FilteredSafeSearch:
		e.Result = stats.RSafeSearch
	case filtering.FilteredBlockList,
		filtering.FilteredInvalid,
		filtering.FilteredBlockedService:
		e.Result = stats.RFiltered
	}

	s.stats.Update(e)
}