wavelet init

Wavelet/pkg/push/template.go

@@ -0,0 +1,78 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package push
+
+import (
+	"encoding/json"
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// ParseTemplate parses template strings by replacing {{placeholder}} structures with values from body.
+// It is a single-pass parser designed for high performance and low allocations.
+func ParseTemplate(template string, body map[string]any) string {
+	var buf strings.Builder
+	buf.Grow(len(template))
+
+	i := 0
+	for {
+		pos := strings.Index(template[i:], "{{")
+		if pos == -1 {
+			buf.WriteString(template[i:])
+			break
+		}
+		// Write prefix
+		buf.WriteString(template[i : i+pos])
+		i += pos + 2 // skip "{{"
+
+		endPos := strings.Index(template[i:], "}}")
+		if endPos == -1 {
+			// Unbalanced "{{"
+			buf.WriteString("{{")
+			buf.WriteString(template[i:])
+			break
+		}
+		key := template[i : i+endPos]
+		if val, ok := body[key]; ok {
+			buf.WriteString(formatValue(val))
+		} else {
+			// Keep the placeholder if key not found
+			buf.WriteString("{{")
+			buf.WriteString(key)
+			buf.WriteString("}}")
+		}
+		i += endPos + 2 // skip "}}"
+	}
+	return buf.String()
+}
+
+func formatValue(v any) string {
+	if v == nil {
+		return ""
+	}
+	switch val := v.(type) {
+	case string:
+		return val
+	case []byte:
+		return string(val)
+	case int:
+		return strconv.Itoa(val)
+	case int32:
+		return strconv.FormatInt(int64(val), 10)
+	case int64:
+		return strconv.FormatInt(val, 10)
+	case float64:
+		return strconv.FormatFloat(val, 'f', -1, 64)
+	case bool:
+		return strconv.FormatBool(val)
+	default:
+		// If it's a map, slice, or struct, marshal it to JSON.
+		b, err := json.Marshal(v)
+		if err == nil {
+			return string(b)
+		}
+		return fmt.Sprintf("%v", v)
+	}
+}