package kubernetes

import (
	"bytes"
	"crypto"
	"crypto/sha256"
	"fmt"
	"slices"

	"forge.cadoles.com/cadoles/bouncer/internal/jwk"
	"github.com/pkg/errors"
)

func getKeySetThumbprint(set jwk.Set) (string, error) {
	data := make([][]byte, 0, set.Len())

	for i := 0; i < set.Len(); i++ {
		key, exists := set.Key(i)
		if !exists {
			continue
		}

		thumbprint, err := key.Thumbprint(crypto.SHA256)
		if err != nil {
			return "", errors.WithStack(err)
		}

		data = append(data, thumbprint)
	}

	slices.SortFunc(data, bytes.Compare)

	hash := sha256.New()
	for _, d := range data {
		if _, err := hash.Write(d); err != nil {
			return "", errors.WithStack(err)
		}
	}

	return fmt.Sprintf("%x", hash.Sum(nil)), nil
}