1 files changed, 115 insertions, 0 deletions
diff --git a/rdfloader/parser2v2/license_utils.go b/rdfloader/parser2v2/license_utils.go
new file mode 100644
index 0000000..2641b27
--- /dev/null
+++ b/rdfloader/parser2v2/license_utils.go
@@ -0,0 +1,115 @@
+package parser2v2
+
+import (
+	"fmt"
+	gordfParser "github.com/RishabhBhatnagar/gordf/rdfloader/parser"
+	"strings"
+)
+
+/* util methods for licenses and checksums below:*/
+
+// Given the license URI, returns the name of the license defined
+// in the last part of the uri.
+// This function is susceptible to false-positives.
+func getLicenseStringFromURI(uri string) string {
+	licenseEnd := strings.TrimSpace(getLastPartOfURI(uri))
+	lower := strings.ToLower(licenseEnd)
+	if lower == "none" || lower == "noassertion" {
+		return strings.ToUpper(licenseEnd)
+	}
+	return licenseEnd
+}
+
+// returns the checksum algorithm and it's value
+// In the newer versions, these two strings will be bound to a single checksum struct
+// whose pointer will be returned.
+func (parser *rdfParser2_2) getChecksumFromNode(checksumNode *gordfParser.Node) (algorithm string, value string, err error) {
+	var checksumValue, checksumAlgorithm string
+	for _, checksumTriple := range parser.nodeToTriples(checksumNode) {
+		switch checksumTriple.Predicate.ID {
+		case RDF_TYPE:
+			continue
+		case SPDX_CHECKSUM_VALUE:
+			// cardinality: exactly 1
+			checksumValue = strings.TrimSpace(checksumTriple.Object.ID)
+		case SPDX_ALGORITHM:
+			// cardinality: exactly 1
+			checksumAlgorithm, err = getAlgorithmFromURI(checksumTriple.Object.ID)
+			if err != nil {
+				return
+			}
+		default:
+			err = fmt.Errorf("unknown predicate '%s' while parsing checksum node", checksumTriple.Predicate.ID)
+			return
+		}
+	}
+	return checksumAlgorithm, checksumValue, nil
+}
+
+func getAlgorithmFromURI(algorithmURI string) (checksumAlgorithm string, err error) {
+	fragment := getLastPartOfURI(algorithmURI)
+	if !strings.HasPrefix(fragment, "checksumAlgorithm_") {
+		return "", fmt.Errorf("checksum algorithm uri must begin with checksumAlgorithm_. found %s", fragment)
+	}
+	algorithm := strings.TrimPrefix(fragment, "checksumAlgorithm_")
+	algorithm = strings.ToLower(strings.TrimSpace(algorithm))
+	switch algorithm {
+	case "md2", "md4", "md5", "md6":
+		checksumAlgorithm = strings.ToUpper(algorithm)
+	case "sha1", "sha224", "sha256", "sha384", "sha512":
+		checksumAlgorithm = strings.ToUpper(algorithm)
+	default:
+		return "", fmt.Errorf("unknown checksum algorithm %s", algorithm)
+	}
+	return
+}
+
+// from a list of licenses, it returns a
+// list of string representation of those licenses.
+func mapLicensesToStrings(licences []AnyLicenseInfo) []string {
+	res := make([]string, len(licences), len(licences))
+	for i, lic := range licences {
+		res[i] = lic.ToLicenseString()
+	}
+	return res
+}
+
+/****** Type Functions ******/
+
+// TODO: should probably add brackets while linearizing a nested license.
+func (lic ConjunctiveLicenseSet) ToLicenseString() string {
+	return strings.Join(mapLicensesToStrings(lic.members), " AND ")
+}
+
+// TODO: should probably add brackets while linearizing a nested license.
+func (lic DisjunctiveLicenseSet) ToLicenseString() string {
+	return strings.Join(mapLicensesToStrings(lic.members), " OR ")
+}
+
+func (lic ExtractedLicensingInfo) ToLicenseString() string {
+	return lic.licenseID
+}
+
+func (operator OrLaterOperator) ToLicenseString() string {
+	return operator.member.ToLicenseString()
+}
+
+func (lic License) ToLicenseString() string {
+	return lic.licenseID
+}
+
+func (lic ListedLicense) ToLicenseString() string {
+	return lic.licenseID
+}
+
+func (lic WithExceptionOperator) ToLicenseString() string {
+	return lic.member.ToLicenseString()
+}
+
+func (lic SpecialLicense) ToLicenseString() string {
+	return string(lic.value)
+}
+
+func (lic SimpleLicensingInfo) ToLicenseString() string {
+	return lic.licenseID
+}