// Copyright 2016 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 fuchsia

// Package fdio provides unix-style IO, implementing Zircon's "system/ulib/fdio"
package fdio

import (
	"syscall/zx"
	"syscall/zx/io"
)

// MaxUnderlyingHandles is the maximum number of handles which are
// necessary to implement any FDIO object.
const MaxUnderlyingHandles = 2

// FDIO provides classic unix-style IO over various transports
type FDIO interface {
	Handles() []zx.Handle

	Clone() (FDIO, error)
	Close() error

	Sync() error
	GetAttr() (io.NodeAttributes, error)
	SetAttr(flags uint32, attr io.NodeAttributes) error
	Ioctl(op uint32, max uint64, in []byte, handles []zx.Handle) ([]byte, []zx.Handle, error)

	Read(data []byte) (int, error)
	ReadAt(data []byte, off int64) (int, error)
	Write(data []byte) (int, error)
	WriteAt(data []byte, off int64) (int, error)
	Seek(offset int64, whence int) (int64, error)
	Truncate(length uint64) error

	Open(path string, flags uint32, mode uint32) (FDIO, error)
	Link(oldpath, newpath string) error
	Rename(oldpath, newpath string) error
	Unlink(path string) error
	ReadDirents(max uint64) ([]byte, error)
	Rewind() error
}

type Vtype uint32

// bit-compatible with POSIX stat
const (
	VtypeMask Vtype = 0170000
	VtypeSock Vtype = 0140000
	VtypeLink Vtype = 0120000
	VtypeFile Vtype = 0100000
	VtypeBdev Vtype = 0060000
	VtypeDir  Vtype = 0040000
	VtypeCdev Vtype = 0020000
	VtypePipe Vtype = 0010000

	VtypeISUID Vtype = 0004000
	VtypeISGID Vtype = 0002000
	VtypeISVTX Vtype = 0001000
	VtypeIRWXU Vtype = 0000700
	VtypeIRUSR Vtype = 0000400
	VtypeIWUSR Vtype = 0000200
	VtypeIXUSR Vtype = 0000100
	VtypeIRWXG Vtype = 0000070
	VtypeIRGRP Vtype = 0000040
	VtypeIWGRP Vtype = 0000020
	VtypeIXGRP Vtype = 0000010
	VtypeIRWXO Vtype = 0000007
	VtypeIROTH Vtype = 0000004
	VtypeIWOTH Vtype = 0000002
	VtypeIXOTH Vtype = 0000001
)

const (
	HandleTypeRemote = 0x32
	HandleTypeLogger = 0x35
	HandleTypeSocket = 0x36
)