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backend/internal/pluginstore/version.go

@@ -0,0 +1,69 @@
+package pluginstore
+
+import (
+	"strconv"
+	"strings"
+)
+
+// UpdateAvailable reports whether latest should be offered as an upgrade over
+// installed. A leading "v"/"V" is ignored on both sides. Versions are compared
+// numerically when both are dotted release numbers, so an installed version
+// newer than the registry one is not reported as an update; otherwise any
+// difference counts as an update.
+func UpdateAvailable(installed, latest string) bool {
+	installed = normalizeVersion(installed)
+	latest = normalizeVersion(latest)
+	if installed == "" || latest == "" || installed == latest {
+		return false
+	}
+	comparison, comparable := compareVersions(installed, latest)
+	if !comparable {
+		return true
+	}
+	return comparison < 0
+}
+
+func normalizeVersion(version string) string {
+	version = strings.TrimSpace(version)
+	if len(version) > 1 && (version[0] == 'v' || version[0] == 'V') {
+		version = version[1:]
+	}
+	return version
+}
+
+// compareVersions compares dotted numeric versions segment by segment, with
+// missing segments treated as zero. It reports false when either version
+// contains a non-numeric segment.
+func compareVersions(a, b string) (int, bool) {
+	segmentsA := strings.Split(a, ".")
+	segmentsB := strings.Split(b, ".")
+	length := len(segmentsA)
+	if len(segmentsB) > length {
+		length = len(segmentsB)
+	}
+	for index := 0; index < length; index++ {
+		numberA, okA := versionSegment(segmentsA, index)
+		numberB, okB := versionSegment(segmentsB, index)
+		if !okA || !okB {
+			return 0, false
+		}
+		if numberA != numberB {
+			if numberA < numberB {
+				return -1, true
+			}
+			return 1, true
+		}
+	}
+	return 0, true
+}
+
+func versionSegment(segments []string, index int) (int64, bool) {
+	if index >= len(segments) {
+		return 0, true
+	}
+	number, errParse := strconv.ParseInt(segments[index], 10, 64)
+	if errParse != nil || number < 0 {
+		return 0, false
+	}
+	return number, true
+}