dehub/payload_credential.go

package dehub

import (
	"errors"
	"fmt"
	"strings"
)

// PayloadCredential describes the structure of a credential payload.
type PayloadCredential struct {
	// CommitHashes represents the commits which this credential is accrediting.
	// It is only present for informational purposes, as commits don't not have
	// any bearing on the CredentialedHash itself.
	CommitHashes []string `yaml:"commits,omitempty"`
}

var _ Payload = PayloadCredential{}

// NewPayloadCredential constructs and returns a PayloadUnion populated with a
// PayloadCredential for the given fingerprint. The Credentials of the returned
// PayloadUnion will _not_ be filled in.
func (proj *Project) NewPayloadCredential(fingerprint []byte) (PayloadUnion, error) {
	return PayloadUnion{
		Credential: &PayloadCredential{},
		Common:     PayloadCommon{Fingerprint: fingerprint},
	}, nil
}

// NewPayloadCredentialFromChanges constructs and returns a PayloadUnion
// populated with a PayloadCredential. The fingerprint of the payload will be a
// change fingerprint encompassing all changes in the given range of Commits.
// The description of the last change payload in the range is used when
// generating the fingerprint.
func (proj *Project) NewPayloadCredentialFromChanges(commits []Commit) (PayloadUnion, error) {
	info, err := proj.changeRangeInfo(commits)
	if err != nil {
		return PayloadUnion{}, err
	}

	payCred, err := proj.NewPayloadCredential(info.changeFingerprint)
	if err != nil {
		return PayloadUnion{}, err
	}

	for _, commit := range info.changeCommits {
		payCred.Credential.CommitHashes = append(
			payCred.Credential.CommitHashes,
			commit.Hash.String(),
		)
	}
	return payCred, nil
}

// MessageHead implements the method for the Payload interface.
func (payCred PayloadCredential) MessageHead(common PayloadCommon) (string, error) {
	fingerprintStr := common.Fingerprint.String()
	if len(fingerprintStr) > 9 {
		fingerprintStr = fingerprintStr[:6] + "..."
	}
	credIDs := strings.Join(common.credIDs(), ", ")
	fullMsgHead := fmt.Sprintf("Credential of hash %s by %s", fingerprintStr, credIDs)
	return abbrevCommitMessage(fullMsgHead), nil
}

// Fingerprint implements the method for the Payload interface.
func (payCred PayloadCredential) Fingerprint(changes []ChangedFile) ([]byte, error) {
	if len(changes) > 0 {
		return nil, errors.New("PayloadCredential cannot have any changed files")
	}
	// a PayloadCredential can't compute its own fingerprint, it's stored in the
	// common.
	return nil, nil
}