package main

import (
	"context"
	"encoding/hex"
	"fmt"
	"io"

	pb "code.hackerspace.pl/hscloud/bgpwtf/cccampix/proto"
	"code.hackerspace.pl/hscloud/bgpwtf/cccampix/verifier/model"
	"github.com/golang/glog"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
)

func (s *service) ProcessorStatus(ctx context.Context, req *pb.ProcessorStatusRequest) (*pb.ProcessorStatusResponse, error) {
	s.processorsMu.RLock()
	defer s.processorsMu.RUnlock()

	res := &pb.ProcessorStatusResponse{
		Processors: make([]*pb.ProcessorStatusResponse_Processor, len(s.processors)),
	}

	i := 0
	for _, p := range s.processors {
		res.Processors[i] = &pb.ProcessorStatusResponse_Processor{
			Name:    p.name,
			Status:  pb.ProcessorStatusResponse_Processor_STATUS_OK,
			LastRun: 0,
			NextRun: 0,
		}

		if p.lastRun != nil {
			res.Processors[i].LastRun = p.lastRun.UnixNano()
			res.Processors[i].NextRun = p.p.NextRun(*p.lastRun, p.lastErr != nil).UnixNano()
		}

		if p.lastErr != nil {
			res.Processors[i].Status = pb.ProcessorStatusResponse_Processor_STATUS_ERROR
		}

		i += 1
	}
	return res, nil
}

func (s *service) PeerSummary(req *pb.PeerSummaryRequest, stream pb.Verifier_PeerSummaryServer) error {
	peers, err := s.model.GetCheckablePeers(stream.Context())
	if err != nil {
		glog.Errorf("model.GetCheckablePeers: %v", err)
		return status.Error(codes.Unavailable, "model error")
	}

	asns := make([]int64, len(peers))
	asnToRes := make(map[int64]*pb.PeerSummaryResponse)

	for i, peer := range peers {
		routers := make([]*pb.PeeringDBMember_Router, len(peer.Routers))
		for i, router := range peer.Routers {
			routers[i] = &pb.PeeringDBMember_Router{}
			if router.V4 != nil {
				routers[i].Ipv4 = router.V4.String()
			}
			if router.V6 != nil {
				routers[i].Ipv6 = router.V6.String()
			}
		}
		p := &pb.PeeringDBMember{
			Asn:     peer.ASN,
			Name:    peer.Name,
			Routers: routers,
		}
		res := &pb.PeerSummaryResponse{
			PeeringdbInfo: p,
			CheckStatus:   pb.PeerSummaryResponse_STATUS_OK,
		}
		asnToRes[peer.ASN] = res
		asns[i] = peer.ASN
	}

	checkres, err := s.model.GetPeerCheckResults(stream.Context(), asns)
	if err != nil {
		glog.Errorf("GetPeerCheckResults(%v): %v", asns, err)
		for _, res := range asnToRes {
			res.CheckStatus = pb.PeerSummaryResponse_STATUS_UNKNOWN
		}
	} else {
		passedChecks := make(map[int64]map[string]bool)
		for _, c := range checkres {
			if _, ok := passedChecks[c.PeerASN]; !ok {
				passedChecks[c.PeerASN] = make(map[string]bool)
			}
			passedChecks[c.PeerASN][c.CheckName] = c.Status == model.PeerCheckStatus_Okay
		}

		for asn, checks := range passedChecks {
			for _, required := range s.requiredChecks {
				if !checks[required] {
					asnToRes[asn].CheckStatus = pb.PeerSummaryResponse_STATUS_FAILED
					break
				}
			}
		}
	}

	for _, res := range asnToRes {
		if err := stream.Send(res); err != nil {
			return err
		}
	}

	return nil
}

func (s *service) PeerDetails(ctx context.Context, req *pb.PeerDetailsRequest) (*pb.PeerDetailsResponse, error) {
	if req.Asn <= 0 {
		return nil, status.Error(codes.InvalidArgument, "asn must be set")
	}

	res := &pb.PeerDetailsResponse{}

	peeringdb, err := s.model.GetPeeringDBPeer(ctx, req.Asn)
	if err != nil {
		glog.Errorf("GetPeeringDBPeer(%v): %v", req.Asn, err)
		return nil, status.Error(codes.Unavailable, "could not get allowed prefixes")
	}

	if peeringdb.Asn != req.Asn {
		return nil, status.Error(codes.NotFound, "no such ASN")
	}

	res.PeeringdbInfo = peeringdb

	checkres, err := s.model.GetPeerCheckResults(ctx, []int64{req.Asn})
	if err != nil {
		glog.Errorf("GetPeerCheckResults(%v): %v", req.Asn, err)
		return nil, status.Error(codes.Unavailable, "could not get check results")
	}

	res.Checks = make([]*pb.PeerDetailsResponse_Check, len(checkres))
	for i, check := range checkres {
		status := pb.PeerDetailsResponse_Check_STATUS_INVALID
		switch check.Status {
		case model.PeerCheckStatus_Okay:
			status = pb.PeerDetailsResponse_Check_STATUS_OK
		case model.PeerCheckStatus_SoftFailed:
			status = pb.PeerDetailsResponse_Check_STATUS_OK
		case model.PeerCheckStatus_Failed:
			status = pb.PeerDetailsResponse_Check_STATUS_FAILED
		}
		res.Checks[i] = &pb.PeerDetailsResponse_Check{
			Name:   check.CheckName,
			Status: status,
			Time:   check.Time.UnixNano(),
			Msg:    check.Message,
		}
	}

	prefixes, err := s.model.GetAllowedPrefixes(ctx, req.Asn)
	if err != nil {
		glog.Errorf("GetAllowedPrefixes(%v): %v", req.Asn, err)
		return nil, status.Error(codes.Unavailable, "could not get allowed prefixes")
	}

	res.AllowedPrefixes = make([]*pb.PeerDetailsResponse_AllowedPrefix, len(prefixes))
	for i, prefix := range prefixes {
		res.AllowedPrefixes[i] = &pb.PeerDetailsResponse_AllowedPrefix{
			Prefix:    prefix.Prefix.String(),
			MaxLength: prefix.MaxLength,
			Ta:        prefix.TA,
		}
	}

	return res, nil
}

func (s *service) RouterHeartbeat(ctx context.Context, req *pb.RouterHeartbeatRequest) (*pb.RouterHeartbeatResponse, error) {
	if req.Name == "" {
		return nil, status.Error(codes.InvalidArgument, "name must be set")
	}

	pcfgM := make(map[string]*model.PeerConfiguration)
	pcfgs, err := s.model.GetPeerConfiguration(ctx)
	if err != nil {
		glog.Errorf("GetPeerConfiguration: %v", err)
		return nil, status.Error(codes.Unavailable, "could not get peer configs")
	}

	for _, pcfg := range pcfgs {
		ask := fmt.Sprintf("AS%d", pcfg.Peer.ASN)
		pcfgM[ask] = pcfg
	}

	peers, err := s.model.GetCheckablePeers(ctx)
	if err != nil {
		glog.Errorf("GetChecablePeers: %v", err)
		return nil, status.Error(codes.Unavailable, "could not get peers")
	}

	asconfs := make(map[string]*pb.RouterHeartbeatResponse_ASConfig)

	for _, peer := range peers {
		as := fmt.Sprintf("AS%d", peer.ASN)

		pcfg, ok := pcfgM[as]
		if !ok {
			continue
		}

		asconfs[as] = &pb.RouterHeartbeatResponse_ASConfig{
			Asn:      peer.ASN,
			Routers:  make([]*pb.RouterHeartbeatResponse_ASConfig_Router, len(pcfg.Peer.Routers)),
			Prefixes: []*pb.RouterHeartbeatResponse_ASConfig_AllowedPrefix{},
		}

		glog.Infof("%+v", pcfg.Peer.Routers)
		for i, r := range pcfg.Peer.Routers {
			ipv6 := ""
			if r.V6 != nil {
				ipv6 = r.V6.String()
			}
			ipv4 := ""
			if r.V4 != nil {
				ipv4 = r.V4.String()
			}
			asconfs[as].Routers[i] = &pb.RouterHeartbeatResponse_ASConfig_Router{
				Ipv6:     ipv6,
				Ipv4:     ipv4,
				Password: r.Config.BGPSecret,
			}
		}

		prefixes, err := s.model.GetAllowedPrefixes(ctx, peer.ASN)
		if err != nil {
			glog.Errorf("GetAllowedPrefixes(_, %d): %v", peer.ASN, err)
			return nil, status.Error(codes.Unavailable, "could not get peer prefixes")
		}

		for _, prefix := range prefixes {
			asconfs[as].Prefixes = append(asconfs[as].Prefixes, &pb.RouterHeartbeatResponse_ASConfig_AllowedPrefix{
				Prefix:    prefix.Prefix.String(),
				MaxLength: prefix.MaxLength,
			})
		}
	}

	res := &pb.RouterHeartbeatResponse{
		AsConfigs: make([]*pb.RouterHeartbeatResponse_ASConfig, len(asconfs)),
	}

	i := 0
	for _, asconf := range asconfs {
		res.AsConfigs[i] = asconf
		i += 1
	}

	return res, nil
}

func (s *service) PeerSecrets(ctx context.Context, req *pb.PeerSecretsRequest) (*pb.PeerSecretsResponse, error) {
	if req.Asn <= 0 {
		return nil, status.Error(codes.InvalidArgument, "asn must be set")
	}
	pcrs, err := s.model.GetPeerConfiguration(ctx)
	if err != nil {
		glog.Errorf("GetPeerConfiguration: %v", err)
		return nil, status.Error(codes.Unavailable, "error when retrieving peer configs")
	}

	var pcr *model.PeerConfiguration
	for _, p := range pcrs {
		if p.Peer.ASN == req.Asn {
			pcr = p
			break
		}
	}

	if pcr == nil {
		return nil, status.Error(codes.NotFound, "no such ASN")
	}

	plain := fmt.Sprintf(`
Hello AS %d!

Here are your config settings:
`, req.Asn)

	for _, router := range pcr.Peer.Routers {
		if router.V4 != nil {
			plain += fmt.Sprintf(`
our addresses: 185.236.243.5 (rs1), 185.236.243.6 (rs2)
      our asn: 208521
 your address: %s
     your asn: %d
   bgp secret: %s
`, router.V4.String(), req.Asn, router.Config.BGPSecret)
		}
		if router.V6 != nil {
			plain += fmt.Sprintf(`
our addresses: 2a0d:eb02:4242:4242::5 (rs1), 2a0d:eb02:4242:4242::6 (rs2)
      our asn: 208521
 your address: %s
     your asn: %d
   bgp secret: %s
`, router.V6.String(), req.Asn, router.Config.BGPSecret)
		}
	}

	plain += `
Happy exchanging!
bgp.wtf (DECT: 4735)
`

	key, err := s.model.GetPeerPGPKey(ctx, req.Asn)
	if err != nil {
		glog.Errorf("GetPeerPGPKey: %v", err)
		return nil, status.Error(codes.Unavailable, "could not get pgp key")
	}

	plainB := []byte(plain)

	stream, err := s.pgp.Encrypt(ctx)
	if err != nil {
		glog.Errorf("Encrypt: %v", err)
		return nil, status.Error(codes.Unavailable, "could not encrypt")
	}

	fingerprint, err := hex.DecodeString(key.Fingerprint)
	if err != nil {
		glog.Errorf("Invalid fingerprint %q: %v", key.Fingerprint, err)
		return nil, status.Error(codes.Unavailable, "could not encrypt")
	}

	reqE := &pb.EncryptRequest{
		Data:        plainB,
		Info:        pb.EncryptRequest_CHUNK_LAST,
		Fingerprint: fingerprint,
	}

	if err := stream.Send(reqE); err != nil {
		glog.Errorf("Encrypt.Send: %v", err)
		return nil, status.Error(codes.Unavailable, "could not encrypt")
	}
	stream.CloseSend()

	cipher := []byte{}
	for {
		in, err := stream.Recv()
		if err == io.EOF {
			break
		}
		if err != nil {
			glog.Errorf("Encrypt.Recv: %v", err)
			return nil, status.Error(codes.Unavailable, "could not encrypt")
		}
		cipher = append(cipher, in.Data...)
	}

	return &pb.PeerSecretsResponse{
		PgpData: cipher,
	}, nil
}