// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
// SPDX-License-Identifier: MIT

// The codecs of the remaining NFSv4.1 operations: the parent lookups, the
// attribute comparisons, the lock owner release and the session binding
// family.

package nfs4

import (
	"sourcedock.dev/petrbalvin/nfs/internal/xdr"
)

// Connection direction and binding values of the CREATE_SESSION and
// BIND_CONN_TO_SESSION channel directory, RFC 8881 section 2.10.1.
const (
	Cdfc4Fore       = 1
	Cdfc4Back       = 2
	Cdfc4ForeOrBoth = 3
	Cdfc4BackOrBoth = 7

	Cdfs4Fore  = 1
	Cdfs4Back  = 2
	Cdfs4Both  = 3
	Cdfs4Arrow = 4
)

// AppendLookupp appends the LOOKUPP argop, which carries no arguments.
func AppendLookupp(b []byte) []byte {
	return xdr.AppendUint32(b, OpLookupp)
}

// AppendPutPubfh appends the PUTPUBFH argop, which carries no arguments.
func AppendPutPubfh(b []byte) []byte {
	return xdr.AppendUint32(b, OpPutPubfh)
}

// AppendVerifyArgs appends the VERIFY argop: the attributes the file must
// carry for the compound to proceed. NVERIFY shares the shape and demands
// the opposite.
func AppendVerifyArgs(b []byte, request Bitmap, a Attrs) []byte {
	b = xdr.AppendUint32(b, OpVerify)
	return AppendFattr(b, request, a)
}

// AppendNverifyArgs appends the NVERIFY argop: the attributes the file
// must not carry.
func AppendNverifyArgs(b []byte, request Bitmap, a Attrs) []byte {
	b = xdr.AppendUint32(b, OpNverify)
	return AppendFattr(b, request, a)
}

// AppendReleaseLockOwnerArgs appends the RELEASE_LOCKOWNER argop: the
// client whose lock owner dies and the owner itself.
func AppendReleaseLockOwnerArgs(b []byte, clientid uint64, owner []byte) []byte {
	b = xdr.AppendUint32(b, OpReleaseLockOwner)
	b = xdr.AppendUint64(b, clientid)
	return xdr.AppendVarOpaque(b, owner)
}

// AppendDelegReturnArgs appends the DELEGRETURN argop: the stateid of the
// delegation the client gives back.
func AppendDelegReturnArgs(b []byte, st Stateid) []byte {
	b = xdr.AppendUint32(b, OpDelegReturn)
	return st.Append(b)
}

// AppendBackchannelCtlArgs appends the BACKCHANNEL_CTL argop: the program
// number of the back channel the client runs.
func AppendBackchannelCtlArgs(b []byte, program uint32) []byte {
	b = xdr.AppendUint32(b, OpBackchannelCtl)
	return xdr.AppendUint32(b, program)
}

// AppendBindConnToSessionArgs appends the BIND_CONN_TO_SESSION argop of
// RFC 7863: the session, the direction the connection should serve and
// the RDMA mode flag.
func AppendBindConnToSessionArgs(b []byte, id SessionID, dir uint32, rdma bool) []byte {
	b = xdr.AppendUint32(b, OpBindConnToSession)
	b = append(b, id[:]...)
	b = xdr.AppendUint32(b, dir)
	return xdr.AppendBool(b, rdma)
}

// AppendBindConnToSessionRes appends the result: the session and the
// direction the server granted.
func AppendBindConnToSessionRes(b []byte, id SessionID, dir uint32) []byte {
	b = append(b, id[:]...)
	return xdr.AppendUint32(b, dir)
}

// AppendFreeStateidArgs appends the FREE_STATEID argop: the lock stateid
// the client retires.
func AppendFreeStateidArgs(b []byte, st Stateid) []byte {
	b = xdr.AppendUint32(b, OpFreeStateid)
	return st.Append(b)
}

// AppendTestStateidArgs appends the TEST_STATEID argop: the stateids the
// client asks about.
func AppendTestStateidArgs(b []byte, sts []Stateid) []byte {
	b = xdr.AppendUint32(b, OpTestStateid)
	b = xdr.AppendUint32(b, uint32(len(sts)))
	for _, st := range sts {
		b = st.Append(b)
	}
	return b
}

// AppendTestStateidRes appends the result: one status per stateid, in the
// order the arguments named them.
func AppendTestStateidRes(b []byte, statuses []uint32) []byte {
	b = xdr.AppendUint32(b, uint32(len(statuses)))
	for _, s := range statuses {
		b = xdr.AppendUint32(b, s)
	}
	return b
}