feat: enhance RefreshModule to support legacy ASN resolution and improve prefix handling. Introduce sorting of ASNs and manage announced prefixes with polite pauses for better API interaction. Update buildPreviewFragments to streamline route rendering for BIRD configurations.

internal/birdfmt/community_bird.go

@@ -0,0 +1,123 @@
+package birdfmt
+
+import (
+	"encoding/json"
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+var standardPairRE = regexp.MustCompile(`^\s*(\d{1,5}):(\d{1,5})\s*$`)
+
+// RouteCommunityAttrs returns BIRD 2 lines (indented with 4 spaces) for use inside a static `route … { … }` block.
+// Empty string means no community attributes.
+func RouteCommunityAttrs(kind, name, valueJSON string) (string, error) {
+	name = strings.TrimSpace(name)
+	raw := strings.TrimSpace(valueJSON)
+	if raw == "" {
+		raw = "{}"
+	}
+
+	if s, ok := parseLargeFromJSONLoose(raw); ok {
+		return s, nil
+	}
+	_ = kind // reserved for future kinds (e.g. extended communities)
+
+	if m := standardPairRE.FindStringSubmatch(name); len(m) == 3 {
+		return standardAddLine(m[1], m[2])
+	}
+
+	var obj map[string]any
+	if json.Unmarshal([]byte(raw), &obj) == nil {
+		if v, ok := obj["standard"].(string); ok {
+			if m := standardPairRE.FindStringSubmatch(v); len(m) == 3 {
+				return standardAddLine(m[1], m[2])
+			}
+		}
+		if arr, ok := obj["standard"].([]any); ok && len(arr) == 2 {
+			a, aok := numberToUint32String(arr[0])
+			b, bok := numberToUint32String(arr[1])
+			if aok && bok {
+				return standardAddLine(a, b)
+			}
+		}
+	}
+
+	var strVal string
+	if json.Unmarshal([]byte(raw), &strVal) == nil {
+		if m := standardPairRE.FindStringSubmatch(strVal); len(m) == 3 {
+			return standardAddLine(m[1], m[2])
+		}
+	}
+
+	return "", nil
+}
+
+func standardAddLine(a, b string) (string, error) {
+	ai, err1 := strconv.ParseUint(strings.TrimSpace(a), 10, 16)
+	bi, err2 := strconv.ParseUint(strings.TrimSpace(b), 10, 16)
+	if err1 != nil || err2 != nil {
+		return "", fmt.Errorf("birdfmt: standard community parts must be 0..65535 (%s:%s)", a, b)
+	}
+	return fmt.Sprintf("    bgp_community.add((%d,%d));", ai, bi), nil
+}
+
+func parseLargeFromJSONLoose(raw string) (string, bool) {
+	var obj map[string]any
+	if json.Unmarshal([]byte(raw), &obj) != nil {
+		return "", false
+	}
+	arr, ok := obj["large"].([]any)
+	if !ok || len(arr) == 0 {
+		return "", false
+	}
+	var b strings.Builder
+	for _, row := range arr {
+		triple, ok := row.([]any)
+		if !ok || len(triple) != 3 {
+			continue
+		}
+		a, ok1 := numberToUint32String(triple[0])
+		bb, ok2 := numberToUint32String(triple[1])
+		c, ok3 := numberToUint32String(triple[2])
+		if !ok1 || !ok2 || !ok3 {
+			continue
+		}
+		ai, _ := strconv.ParseUint(a, 10, 32)
+		bi, _ := strconv.ParseUint(bb, 10, 32)
+		ci, _ := strconv.ParseUint(c, 10, 32)
+		fmt.Fprintf(&b, "    bgp_large_community.add((%d,%d,%d));\n", ai, bi, ci)
+	}
+	s := strings.TrimRight(b.String(), "\r\n")
+	return s, s != ""
+}
+
+func numberToUint32String(v any) (string, bool) {
+	switch x := v.(type) {
+	case float64:
+		if x < 0 || x > 4294967295 {
+			return "", false
+		}
+		return strconv.FormatUint(uint64(x), 10), true
+	case json.Number:
+		n, err := x.Int64()
+		if err != nil || n < 0 || n > 4294967295 {
+			return "", false
+		}
+		return strconv.FormatUint(uint64(n), 10), true
+	case int:
+		if x < 0 || x > 4294967295 {
+			return "", false
+		}
+		return strconv.FormatUint(uint64(x), 10), true
+	case string:
+		n, err := strconv.ParseUint(strings.TrimSpace(x), 10, 32)
+		if err != nil {
+			return "", false
+		}
+		return strconv.FormatUint(n, 10), true
+	default:
+		return "", false
+	}
+}