Updating router to provide new advanced routing logic

services/data_service/internal/domain/pattern.go

@@ -0,0 +1,94 @@
+package domain
+
+import (
+	"sort"
+	"strings"
+)
+
+type Pattern struct {
+	Namespace string
+	Labels    map[string]map[string]string
+	Exact     bool
+}
+
+// Canonical returns a canonical string representation of the Pattern struct
+// TODO: Ensure labels and namespaces are set to lowercase
+func (p *Pattern) Canonical() string {
+	var b strings.Builder
+	b.Grow(len(p.Namespace) + 10*len(p.Labels) + 20) // preallocate a rough size estimate
+
+	b.WriteString(p.Namespace)
+	b.WriteString("::")
+
+	labelNames := make([]string, 0, len(p.Labels))
+	for name := range p.Labels {
+		labelNames = append(labelNames, name)
+	}
+	sort.Strings(labelNames) // sort the labels for determinism
+
+	for i, name := range labelNames {
+		if i > 0 {
+			b.WriteByte('|')
+		}
+		b.WriteString(name)
+
+		params := p.Labels[name]
+		if len(params) > 0 {
+			keys := make([]string, 0, len(params))
+			for k := range params {
+				keys = append(keys, k)
+			}
+			sort.Strings(keys) // sort params for determinism
+
+			b.WriteByte('[')
+			for j, k := range keys {
+				if j > 0 {
+					b.WriteByte(';')
+				}
+				b.WriteString(k)
+				b.WriteByte('=')
+				b.WriteString(params[k])
+			}
+			b.WriteByte(']')
+		}
+	}
+
+	b.WriteString("::")
+	if p.Exact {
+		b.WriteString("t")
+	} else {
+		b.WriteString("f")
+	}
+
+	return b.String()
+}
+
+// Satisfies checks if a domain.Identifier satisfies the pattern.
+func (p *Pattern) Satisfies(id Identifier) bool {
+	ns, idLabels, err := id.Parse()
+	if err != nil || ns != p.Namespace {
+		return false
+	}
+
+	// Every pattern label must be present in the identifier.
+	for lname, wantParams := range p.Labels {
+		haveParams, ok := idLabels[lname]
+		if !ok {
+			return false
+		}
+		// If pattern specifies params, they must be a subset of identifier's params.
+		for k, v := range wantParams {
+			hv, ok := haveParams[k]
+			if !ok || hv != v {
+				return false
+			}
+		}
+		// If pattern has no params for this label, it matches any/none params in the identifier.
+	}
+
+	// Exact applies to label names only: no extras allowed.
+	if p.Exact && len(idLabels) != len(p.Labels) {
+		return false
+	}
+	return true
+}