package audit

import "strconv"

// MergeMetadata combines multiple metadata maps into one.
func MergeMetadata(parts ...map[string]string) map[string]string {
	merged := make(map[string]string)
	for _, part := range parts {
		for key, value := range part {
			if value != "" {
				merged[key] = value
			}
		}
	}
	if len(merged) == 0 {
		return nil
	}
	return merged
}

// FlagMetadata returns a single boolean flag metadata entry when condition is true.
func FlagMetadata(key string, condition bool) map[string]string {
	if !condition {
		return nil
	}
	return map[string]string{key: "true"}
}

// StringMetadata returns metadata for a non-empty string value.
func StringMetadata(key, value string) map[string]string {
	if value == "" {
		return nil
	}
	return map[string]string{key: value}
}

// OptionalStringMetadata returns metadata when a pointer string is set and non-empty.
func OptionalStringMetadata(key string, value *string) map[string]string {
	if value == nil || *value == "" {
		return nil
	}
	return map[string]string{key: *value}
}

// PaginationMetadata returns safe pagination metadata for list audit events.
func PaginationMetadata(limit, offset int, totalCount int64) map[string]string {
	return map[string]string{
		"limit":        strconv.Itoa(limit),
		"offset":       strconv.Itoa(offset),
		"result_count": strconv.FormatInt(totalCount, 10),
	}
}