// Copyright 2012 The Go Authors.  All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// +build darwin freebsd linux netbsd openbsd windows

// Base posix socket functions.

package net

import (
	"os"
	"syscall"
	"time"
)

type conn struct {
	fd *netFD
}

func (c *conn) ok() bool { return c != nil && c.fd != nil }

// Implementation of the Conn interface - see Conn for documentation.

// Read implements the Conn Read method.
func (c *conn) Read(b []byte) (int, error) {
	if !c.ok() {
		return 0, syscall.EINVAL
	}
	return c.fd.Read(b)
}

// Write implements the Conn Write method.
func (c *conn) Write(b []byte) (int, error) {
	if !c.ok() {
		return 0, syscall.EINVAL
	}
	return c.fd.Write(b)
}

// LocalAddr returns the local network address.
func (c *conn) LocalAddr() Addr {
	if !c.ok() {
		return nil
	}
	return c.fd.laddr
}

// RemoteAddr returns the remote network address.
func (c *conn) RemoteAddr() Addr {
	if !c.ok() {
		return nil
	}
	return c.fd.raddr
}

// SetDeadline implements the Conn SetDeadline method.
func (c *conn) SetDeadline(t time.Time) error {
	if !c.ok() {
		return syscall.EINVAL
	}
	return setDeadline(c.fd, t)
}

// SetReadDeadline implements the Conn SetReadDeadline method.
func (c *conn) SetReadDeadline(t time.Time) error {
	if !c.ok() {
		return syscall.EINVAL
	}
	return setReadDeadline(c.fd, t)
}

// SetWriteDeadline implements the Conn SetWriteDeadline method.
func (c *conn) SetWriteDeadline(t time.Time) error {
	if !c.ok() {
		return syscall.EINVAL
	}
	return setWriteDeadline(c.fd, t)
}

// SetReadBuffer sets the size of the operating system's
// receive buffer associated with the connection.
func (c *conn) SetReadBuffer(bytes int) error {
	if !c.ok() {
		return syscall.EINVAL
	}
	return setReadBuffer(c.fd, bytes)
}

// SetWriteBuffer sets the size of the operating system's
// transmit buffer associated with the connection.
func (c *conn) SetWriteBuffer(bytes int) error {
	if !c.ok() {
		return syscall.EINVAL
	}
	return setWriteBuffer(c.fd, bytes)
}

// File returns a copy of the underlying os.File, set to blocking mode.
// It is the caller's responsibility to close f when finished.
// Closing c does not affect f, and closing f does not affect c.
func (c *conn) File() (f *os.File, err error) { return c.fd.dup() }

// Close closes the connection.
func (c *conn) Close() error {
	if !c.ok() {
		return syscall.EINVAL
	}
	return c.fd.Close()
}