package processor

import (
	"fmt"
	"io"
	"os"
)

// validateAudio confirms the audio source file exists and is readable.
func validateAudio(srcPath string) error {
	f, err := os.Open(srcPath)
	if err != nil {
		return fmt.Errorf("open audio %s: %w", srcPath, err)
	}
	return f.Close()
}

// copyFile copies the file at src to dst, creating dst if it does not exist.
func copyFile(src, dst string) error {
	in, err := os.Open(src)
	if err != nil {
		return fmt.Errorf("open source %s: %w", src, err)
	}
	defer in.Close()

	out, err := os.Create(dst)
	if err != nil {
		return fmt.Errorf("create dest %s: %w", dst, err)
	}
	defer out.Close()

	if _, err := io.Copy(out, in); err != nil {
		return fmt.Errorf("copy %s → %s: %w", src, dst, err)
	}

	return nil
}