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

package nfs4

import (
	"bytes"
	"testing"

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

func TestOps42Shapes(t *testing.T) {
	t.Parallel()
	st := Stateid{2, 'S'}

	// SEEK args and res.
	seek := AppendSeekArgs(nil, st, 8, ContentHole)
	d := xdr.NewDecoder(seek[4:])
	if raw, err := d.Raw(16); err != nil || !bytes.Equal(raw, st[:]) {
		t.Fatalf("stateid % x: %v", raw, err)
	}
	if off, err := d.Uint64(); err != nil || off != 8 {
		t.Fatalf("offset %d: %v", off, err)
	}
	if what, err := d.Uint32(); err != nil || what != ContentHole {
		t.Fatalf("what %d: %v", what, err)
	}
	res := AppendSeekRes(nil, true, 4096)
	if n, err := resBodyLen(OpSeek, ErrOK, res); err != nil || n != len(res) {
		t.Fatalf("seek res measured %d of %d: %v", n, len(res), err)
	}

	// COPY res measures through the write response and requirements.
	verifier := [8]byte{1, 2, 3, 4, 5, 6, 7, 8}
	copyRes := AppendCopyRes(nil, st, false, 128, NfsSyncFileSync, verifier, true, true)
	if n, err := resBodyLen(OpCopy, ErrOK, copyRes); err != nil || n != len(copyRes) {
		t.Fatalf("copy res measured %d of %d: %v", n, len(copyRes), err)
	}

	// READ_PLUS res with one data segment.
	rp := AppendReadPlusDataRes(nil, false, 0, []byte("data"))
	if n, err := resBodyLen(OpReadPlus, ErrOK, rp); err != nil || n != len(rp) {
		t.Fatalf("read plus res measured %d of %d: %v", n, len(rp), err)
	}
	rph := AppendReadPlusHoleRes(nil, true, 0, 4096)
	if n, err := resBodyLen(OpReadPlus, ErrOK, rph); err != nil || n != len(rph) {
		t.Fatalf("read plus hole res measured %d of %d: %v", n, len(rph), err)
	}

	// WRITE_SAME args decode through the adb fields. The block number
	// is a count4 on the wire, RFC 7862.
	ws := AppendWriteSameArgs(nil, st, StableFileSync, 8, 512, 2, 0, 0, 0, []byte("ab"))
	d = xdr.NewDecoder(ws[4:])
	if raw, err := d.Raw(16); err != nil || !bytes.Equal(raw, st[:]) {
		t.Fatalf("stateid % x: %v", raw, err)
	}
	if stable, err := d.Uint32(); err != nil || stable != StableFileSync {
		t.Fatalf("stable %d: %v", stable, err)
	}
	if off, err := d.Uint64(); err != nil || off != 8 {
		t.Fatalf("offset %d: %v", off, err)
	}
	for _, want := range []uint64{512, 2, 0} {
		if v, err := d.Uint64(); err != nil || v != want {
			t.Fatalf("adb field %d: %v", v, err)
		}
	}
	if bn, err := d.Uint32(); err != nil || bn != 0 {
		t.Fatalf("adb block num %d: %v", bn, err)
	}
	if rp, err := d.Uint64(); err != nil || rp != 0 {
		t.Fatalf("adb rel off pattern %d: %v", rp, err)
	}
	if p, err := d.VarOpaque(); err != nil || string(p) != "ab" {
		t.Fatalf("pattern %q: %v", p, err)
	}
	wsr := AppendWriteSameRes(nil, 1024, NfsSyncFileSync, verifier)
	if n, err := resBodyLen(OpWriteSame, ErrOK, wsr); err != nil || n != len(wsr) {
		t.Fatalf("write same res measured %d of %d: %v", n, len(wsr), err)
	}

	// The small ops: allocate, io advise, offload status.
	al := AppendAllocateArgs(nil, st, 0, 100)
	d = xdr.NewDecoder(al[4:])
	if _, err := d.Raw(16); err != nil {
		t.Fatal(err)
	}
	if _, err := d.Uint64(); err != nil {
		t.Fatal(err)
	}
	if l, err := d.Uint64(); err != nil || l != 100 {
		t.Fatalf("length %d: %v", l, err)
	}
	hints := AppendIoAdviseRes(nil, Bitmap{}.With(2))
	if n, err := resBodyLen(OpIoAdvise, ErrOK, hints); err != nil || n != len(hints) {
		t.Fatalf("io advise res measured %d of %d: %v", n, len(hints), err)
	}
	os := AppendOffloadStatusRes(nil, 64, OffloadSuccess)
	if n, err := resBodyLen(OpOffloadStatus, ErrOK, os); err != nil || n != len(os) {
		t.Fatalf("offload status res measured %d of %d: %v", n, len(os), err)
	}
	clone := AppendCloneArgs(nil, st, st, 1, 2, 3)
	d = xdr.NewDecoder(clone[4:])
	if _, err := d.Raw(16); err != nil {
		t.Fatal(err)
	}
	if _, err := d.Raw(16); err != nil {
		t.Fatal(err)
	}
	for _, want := range []uint64{1, 2, 3} {
		if v, err := d.Uint64(); err != nil || v != want {
			t.Fatalf("clone field %d: %v", v, err)
		}
	}
}

func TestOps42RemainingShapes(t *testing.T) {
	t.Parallel()
	st := Stateid{4, 'C'}

	// The remaining arg encoders: op code in front, fields in order.
	bodies := map[string][]byte{
		"deallocate": AppendDeallocateArgs(nil, st, 1, 2),
		"ioadvise":   AppendIoAdviseArgs(nil, st, 1, 2, Bitmap{}.With(1)),
		"copy":       AppendCopyArgs(nil, st, st, 1, 2, 3, true, false, nil),
		"copynotify": AppendCopyNotifyArgs(nil, st, 3, "", NetAddr{Netid: "tcp", Uaddr: "1.2.3.4.8.1"}),
		"cancel":     AppendOffloadCancelArgs(nil, st),
		"status":     AppendOffloadStatusArgs(nil, st),
		"layerr":     AppendLayoutErrorArgs(nil, 1, 2, st, layoutTestDevice, ErrBadStateid, OpRead),
		"laystats":   AppendLayoutStatsArgs(nil, 1, 2, st, 1, 2, 3, 4, layoutTestDevice, 0, nil),
		"readplus":   AppendReadPlusArgs(nil, st, 1, 512),
	}
	for _, body := range bodies {
		d := xdr.NewDecoder(body[4:])
		if _, err := d.Raw(16); err != nil {
			t.Fatal(err)
		}
	}
	cn := AppendCopyNotifyRes(nil, 90, st, []CopySourceServer{{Type: 2, Name: "dst"}})
	if n, err := resBodyLen(OpCopyNotify, ErrOK, cn); err != nil || n != len(cn) {
		t.Fatalf("copy notify res measured %d of %d: %v", n, len(cn), err)
	}
	// A COPY result whose write response carries the callback stateid
	// arm measures through the same shape.
	wr := AppendCopyRes(nil, st, true, 10, NfsSyncDataSync, [8]byte{}, false, true)
	if n, err := resBodyLen(OpCopy, ErrOK, wr); err != nil || n != len(wr) {
		t.Fatalf("copy res with callback measured %d of %d: %v", n, len(wr), err)
	}
}

var layoutTestDevice = [16]byte{1, 2, 3}