package node

import (
	"strings"
	"time"

	grpc_retry "github.com/grpc-ecosystem/go-grpc-middleware/retry"
	"github.com/prometheus/common/log"
	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials"
)

// splitAndTrimEmpty slices s into all subslices separated by sep and returns a
// slice of the string s with all leading and trailing Unicode code points
// contained in cutset removed. If sep is empty, SplitAndTrim splits after each
// UTF-8 sequence. First part is equivalent to strings.SplitN with a count of
// -1.  also filter out empty strings, only return non-empty strings.
func splitAndTrimEmpty(s, sep, cutset string) []string {
	if s == "" {
		return []string{}
	}

	spl := strings.Split(s, sep)
	nonEmptyStrings := make([]string, 0, len(spl))
	for i := 0; i < len(spl); i++ {
		element := strings.Trim(spl[i], cutset)
		if element != "" {
			nonEmptyStrings = append(nonEmptyStrings, element)
		}
	}
	return nonEmptyStrings
}

// ConstructDialOptions constructs a list of grpc dial options
func ConstructDialOptions(
	withCert string,
	extraOpts ...grpc.DialOption,
) []grpc.DialOption {
	var transportSecurity grpc.DialOption
	if withCert != "" {
		creds, err := credentials.NewClientTLSFromFile(withCert, "")
		if err != nil {
			log.Errorf("Could not get valid credentials: %v", err)
			return nil
		}
		transportSecurity = grpc.WithTransportCredentials(creds)
	} else {
		transportSecurity = grpc.WithInsecure()
		log.Warn("You are using an insecure gRPC connection! Please provide a certificate and key to use a secure connection.")
	}

	const (
		retries            = 50 // 50 * 100ms = 5s total
		timeout            = 100 * time.Millisecond
		maxCallRecvMsgSize = 10 << 20 // Default 10Mb
	)

	opts := []grpc_retry.CallOption{
		grpc_retry.WithBackoff(grpc_retry.BackoffExponential(timeout)),
	}

	dialOpts := []grpc.DialOption{
		transportSecurity,
		grpc.WithDefaultCallOptions(
			grpc.MaxCallRecvMsgSize(maxCallRecvMsgSize),
			grpc_retry.WithMax(retries),
		),
		grpc.WithUnaryInterceptor(
			grpc_retry.UnaryClientInterceptor(opts...),
		),
	}

	for _, opt := range extraOpts {
		dialOpts = append(dialOpts, opt)
	}

	return dialOpts
}