package door

import (
	"syscall"
)

// OS Specific Write
// This assumes that d.writerMutex is locked.

type OSWriter struct {
	Handle int
	BaseWriter
}

func (ow *OSWriter) Init(d *Door) {
	ow.Closed = false
	ow.Handle = d.Config.Comm_handle
	ow.ansiCode = make([]byte, 0, 32)
}

// The low-lever writer function
func (ow *OSWriter) OSWrite(buffer []byte) (int, error) {
	n, err := syscall.Write(ow.Handle, buffer)
	if (err != nil) || (n != len(buffer)) {
		if !ow.Closed {
			ow.Closed = true
			// Don't need to close reader, it will close itself.
			// It knows when the caller is gone before the writer ever will!
		}
	}
	return n, err
}

func (ow *OSWriter) Write(buffer []byte) (int, error) {
	if ow.Closed {
		return 0, ErrDisconnected
	}

	return ow.OSWrite(buffer)
}

func (ow *OSWriter) Stop() {
	ow.Closed = true
}

// Safe way to check if OSWriter is closed
func (ow *OSWriter) IsClosed() bool {
	return ow.Closed
}