refine: reduce duplicated env expand funcs

internal/env/utils.go

@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package env
+
+import "strings"
+
+// ExpandEnvWithDefault expands template variables with optional default for {}
+func ExpandEnvWithDefault(template string, envs map[string]string, defaultValue ...string) string {
+	if template == "" {
+		return ""
+	}
+
+	result := template
+
+	// Handle special case of {} - use provided default or first available file variable
+	if strings.Contains(result, "{}") {
+		defaultVal := ""
+		if len(defaultValue) > 0 && defaultValue[0] != "" {
+			defaultVal = defaultValue[0]
+		}
+		result = strings.ReplaceAll(result, "{}", defaultVal)
+	}
+
+	// Replace named variables
+	for key, value := range envs {
+		if key != "" { // Skip empty key used for {} default
+			result = strings.ReplaceAll(result, "{"+key+"}", value)
+		}
+	}
+	return result
+}
+
+// ExpandEnvSlice expands template variables in a slice of strings
+func ExpandEnvSlice(templates []string, envs map[string]string) []string {
+	return ExpandEnvSliceWithDefault(templates, envs)
+}
+
+// ExpandEnvSliceWithDefault expands template variables in a slice with optional default for {}
+func ExpandEnvSliceWithDefault(templates []string, envs map[string]string, defaultValue ...string) []string {
+	if len(templates) == 0 {
+		return templates
+	}
+
+	result := make([]string, len(templates))
+	for i, template := range templates {
+		result[i] = ExpandEnvWithDefault(template, envs, defaultValue...)
+	}
+	return result
+}