package hlog

import (
	"os"
	"path/filepath"

	"github.com/pkg/errors"
)

// newLogFile creates or opens the log file based on the configuration.
// The file is created in the specified directory with the configured filename.
// File permissions are set to 0663 (rw-rw--w-).
//
// If append is true, the file is opened in append mode and new logs are added
// to the end. If append is false, the file is truncated on open, overwriting
// any existing content.
//
// Returns an error if the file cannot be opened or created.
func newLogFile(dir, filename string, append bool) (*os.File, error) {
	logPath := filepath.Join(dir, filename)

	flags := os.O_CREATE | os.O_WRONLY
	if append {
		flags |= os.O_APPEND
	} else {
		flags |= os.O_TRUNC
	}

	file, err := os.OpenFile(logPath, flags, 0663)
	if err != nil {
		return nil, errors.Wrap(err, "os.OpenFile")
	}
	return file, nil
}

// CloseLogFile closes the underlying log file if one is open.
// This should be called when shutting down the application to ensure
// all buffered logs are flushed to disk.
//
// If no log file is open, this is a no-op and returns nil.
// Returns an error if the file cannot be closed.
func (l *Logger) CloseLogFile() error {
	if l.logFile == nil {
		return nil
	}
	err := l.logFile.Close()
	if err != nil {
		return err
	}
	return nil
}