package grpcserver

import (
	"context"
	"errors"

	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
	"google.golang.org/protobuf/types/known/timestamppb"

	pb "git.wntrmute.dev/kyle/mcns/gen/mcns/v1"
	"git.wntrmute.dev/kyle/mcns/internal/db"
)

type zoneService struct {
	pb.UnimplementedZoneServiceServer
	db *db.DB
}

func (s *zoneService) ListZones(_ context.Context, _ *pb.ListZonesRequest) (*pb.ListZonesResponse, error) {
	zones, err := s.db.ListZones()
	if err != nil {
		return nil, status.Error(codes.Internal, "failed to list zones")
	}

	resp := &pb.ListZonesResponse{}
	for _, z := range zones {
		resp.Zones = append(resp.Zones, zoneToProto(z))
	}
	return resp, nil
}

func (s *zoneService) GetZone(_ context.Context, req *pb.GetZoneRequest) (*pb.Zone, error) {
	zone, err := s.db.GetZone(req.Name)
	if errors.Is(err, db.ErrNotFound) {
		return nil, status.Error(codes.NotFound, "zone not found")
	}
	if err != nil {
		return nil, status.Error(codes.Internal, "failed to get zone")
	}
	return zoneToProto(*zone), nil
}

func (s *zoneService) CreateZone(_ context.Context, req *pb.CreateZoneRequest) (*pb.Zone, error) {
	refresh := int(req.Refresh)
	if refresh == 0 {
		refresh = 3600
	}
	retry := int(req.Retry)
	if retry == 0 {
		retry = 600
	}
	expire := int(req.Expire)
	if expire == 0 {
		expire = 86400
	}
	minTTL := int(req.MinimumTtl)
	if minTTL == 0 {
		minTTL = 300
	}

	zone, err := s.db.CreateZone(req.Name, req.PrimaryNs, req.AdminEmail, refresh, retry, expire, minTTL)
	if errors.Is(err, db.ErrConflict) {
		return nil, status.Error(codes.AlreadyExists, err.Error())
	}
	if err != nil {
		return nil, status.Error(codes.Internal, "failed to create zone")
	}
	return zoneToProto(*zone), nil
}

func (s *zoneService) UpdateZone(_ context.Context, req *pb.UpdateZoneRequest) (*pb.Zone, error) {
	refresh := int(req.Refresh)
	if refresh == 0 {
		refresh = 3600
	}
	retry := int(req.Retry)
	if retry == 0 {
		retry = 600
	}
	expire := int(req.Expire)
	if expire == 0 {
		expire = 86400
	}
	minTTL := int(req.MinimumTtl)
	if minTTL == 0 {
		minTTL = 300
	}

	zone, err := s.db.UpdateZone(req.Name, req.PrimaryNs, req.AdminEmail, refresh, retry, expire, minTTL)
	if errors.Is(err, db.ErrNotFound) {
		return nil, status.Error(codes.NotFound, "zone not found")
	}
	if err != nil {
		return nil, status.Error(codes.Internal, "failed to update zone")
	}
	return zoneToProto(*zone), nil
}

func (s *zoneService) DeleteZone(_ context.Context, req *pb.DeleteZoneRequest) (*pb.DeleteZoneResponse, error) {
	err := s.db.DeleteZone(req.Name)
	if errors.Is(err, db.ErrNotFound) {
		return nil, status.Error(codes.NotFound, "zone not found")
	}
	if err != nil {
		return nil, status.Error(codes.Internal, "failed to delete zone")
	}
	return &pb.DeleteZoneResponse{}, nil
}

func zoneToProto(z db.Zone) *pb.Zone {
	return &pb.Zone{
		Id:         z.ID,
		Name:       z.Name,
		PrimaryNs:  z.PrimaryNS,
		AdminEmail: z.AdminEmail,
		Refresh:    int32(z.Refresh),
		Retry:      int32(z.Retry),
		Expire:     int32(z.Expire),
		MinimumTtl: int32(z.MinimumTTL),
		Serial:     z.Serial,
		CreatedAt:  parseTimestamp(z.CreatedAt),
		UpdatedAt:  parseTimestamp(z.UpdatedAt),
	}
}

func parseTimestamp(s string) *timestamppb.Timestamp {
	// SQLite stores as "2006-01-02T15:04:05Z".
	t, err := parseTime(s)
	if err != nil {
		return nil
	}
	return timestamppb.New(t)
}