Overwrite deprecated SPDX licenses automatically (#1009)

Co-authored-by: Alex Goodman <alex.goodman@anchore.com>

internal/spdxlicense/generate/license.go

@@ -0,0 +1,104 @@
+package main
+
+import (
+	"strings"
+
+	"github.com/scylladb/go-set/strset"
+)
+
+type LicenseList struct {
+	Version  string    `json:"licenseListVersion"`
+	Licenses []License `json:"licenses"`
+}
+
+type License struct {
+	ID          string   `json:"licenseId"`
+	Name        string   `json:"name"`
+	Text        string   `json:"licenseText"`
+	Deprecated  bool     `json:"isDeprecatedLicenseId"`
+	OSIApproved bool     `json:"isOsiApproved"`
+	SeeAlso     []string `json:"seeAlso"`
+}
+
+func (l License) canReplace(other License) bool {
+	if l.Deprecated {
+		return false
+	}
+
+	if l.Name != other.Name {
+		return false
+	}
+
+	if l.OSIApproved != other.OSIApproved {
+		return false
+	}
+
+	if len(l.SeeAlso) != len(other.SeeAlso) {
+		return false
+	}
+
+	for i, sa := range l.SeeAlso {
+		if sa != other.SeeAlso[i] {
+			return false
+		}
+	}
+
+	return l.ID != other.ID
+}
+
+func (ll LicenseList) findReplacementLicense(deprecated License) *License {
+	for _, l := range ll.Licenses {
+		if l.canReplace(deprecated) {
+			return &l
+		}
+	}
+
+	return nil
+}
+
+func buildLicensePermutations(license string) (perms []string) {
+	lv := findLicenseVersion(license)
+	vp := versionPermutations(lv)
+
+	version := strings.Join(lv, ".")
+	for _, p := range vp {
+		perms = append(perms, strings.Replace(license, version, p, 1))
+	}
+
+	return perms
+}
+
+func findLicenseVersion(license string) (version []string) {
+	versionList := versionMatch.FindAllStringSubmatch(license, -1)
+
+	if len(versionList) == 0 {
+		return version
+	}
+
+	for i, v := range versionList[0] {
+		if v != "" && i != 0 {
+			version = append(version, v)
+		}
+	}
+
+	return version
+}
+
+func versionPermutations(version []string) []string {
+	ver := append([]string(nil), version...)
+	perms := strset.New()
+	for i := 1; i <= 3; i++ {
+		if len(ver) < i+1 {
+			ver = append(ver, "0")
+		}
+
+		perm := strings.Join(ver[:i], ".")
+		badCount := strings.Count(perm, "0") + strings.Count(perm, ".")
+
+		if badCount != len(perm) {
+			perms.Add(perm)
+		}
+	}
+
+	return perms.List()
+}