package smartconfig

import (
	"fmt"
	"os"
	"strings"
)

// FileResolver reads file contents.
// Usage: ${FILE:/path/to/file}
type FileResolver struct{}

// Resolve reads the file and returns its contents.
func (r *FileResolver) Resolve(value string) (string, error) {
	data, err := os.ReadFile(value)
	if err != nil {
		return "", fmt.Errorf("failed to read file %s: %w", value, err)
	}
	return strings.TrimSpace(string(data)), nil
}