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

package nfs4server

import (
	"testing"

	"sourcedock.dev/petrbalvin/nfs/internal/nfs4"
	"sourcedock.dev/petrbalvin/nfs/internal/nfsfs"
	"sourcedock.dev/petrbalvin/nfs/internal/xdr"
)

func TestXattrOverCompound(t *testing.T) {
	h := testTree(t)
	sid, seq := newSession(t, h)
	run := func(s uint32, ops [][]byte) (nfs4.CompoundRes, [][]byte) {
		t.Helper()
		all := append([][]byte{nfs4.AppendSequenceArgs(nil, sid, s, 0, defaultSlots-1, true)}, ops...)
		payload := nfs4.AppendCompoundArgs(nil, "xattr", nfs4.MinorVersion, all)
		body, ok := h.compound(payload, cred{uid: 0, gid: 0})
		if !ok {
			t.Fatal("garbage")
		}
		r, bodies, derr := nfs4.DecodeCompoundResBodies(body)
		if derr != nil {
			t.Fatalf("decode: %v", derr)
		}
		return r, bodies[1:]
	}

	seq++
	res, _ := run(seq, [][]byte{
		nfs4.AppendPutRootfh(nil),
		nfs4.AppendLookup(nil, "a.txt"),
		nfs4.AppendGetXattrArgs(nil, "user.comment"),
	})
	wantStatus(t, "get before set", res.Status, nfs4.ErrNoXattr)

	// Set, read back, list, remove: the whole life of one attribute.
	seq++
	res, _ = run(seq, [][]byte{
		nfs4.AppendPutRootfh(nil),
		nfs4.AppendLookup(nil, "a.txt"),
		nfs4.AppendSetXattrArgs(nil, nfs4.SetXattrUnchecked, "user.comment", []byte("hello")),
	})
	wantStatus(t, "set", res.Status, nfs4.ErrOK)
	seq++
	res, bodies := run(seq, [][]byte{
		nfs4.AppendPutRootfh(nil),
		nfs4.AppendLookup(nil, "a.txt"),
		nfs4.AppendGetXattrArgs(nil, "user.comment"),
	})
	wantStatus(t, "get", res.Status, nfs4.ErrOK)
	value, gerr := nfs4.DecodeGetXattrRes(bodies[2])
	if gerr != nil || string(value) != "hello" {
		t.Fatalf("value %q: %v", value, gerr)
	}

	// CREATE on a live attribute is refused; REPLACE on it succeeds.
	seq++
	res, _ = run(seq, [][]byte{
		nfs4.AppendPutRootfh(nil),
		nfs4.AppendLookup(nil, "a.txt"),
		nfs4.AppendSetXattrArgs(nil, nfs4.SetXattrCreate, "user.comment", []byte("again")),
	})
	if res.Status == nfs4.ErrOK {
		t.Fatal("create over a live attribute succeeded")
	}
	seq++
	res, _ = run(seq, [][]byte{
		nfs4.AppendPutRootfh(nil),
		nfs4.AppendLookup(nil, "a.txt"),
		nfs4.AppendSetXattrArgs(nil, nfs4.SetXattrReplace, "user.comment", []byte("second")),
	})
	wantStatus(t, "replace", res.Status, nfs4.ErrOK)
	seq++
	res, bodies = run(seq, [][]byte{
		nfs4.AppendPutRootfh(nil),
		nfs4.AppendLookup(nil, "a.txt"),
		nfs4.AppendListXattrArgs(nil, 0, 1<<16),
	})
	wantStatus(t, "list", res.Status, nfs4.ErrOK)
	ld := xdr.NewDecoder(bodies[2])
	if ck, lerr := ld.Uint64(); lerr != nil || ck != 0 {
		t.Fatalf("cookie %d: %v", ck, lerr)
	}
	n, lerr := ld.Uint32()
	if lerr != nil || n != 1 {
		t.Fatalf("names %d: %v", n, lerr)
	}
	name, lerr := ld.String()
	if lerr != nil || name != "user.comment" {
		t.Fatalf("name %q: %v", name, lerr)
	}
	if eof, lerr := ld.Bool(); lerr != nil || !eof {
		t.Fatalf("eof %v: %v", eof, lerr)
	}
	seq++
	res, _ = run(seq, [][]byte{
		nfs4.AppendPutRootfh(nil),
		nfs4.AppendLookup(nil, "a.txt"),
		nfs4.AppendRemoveXattrArgs(nil, "user.comment"),
	})
	wantStatus(t, "remove", res.Status, nfs4.ErrOK)
	seq++
	res, _ = run(seq, [][]byte{
		nfs4.AppendPutRootfh(nil),
		nfs4.AppendLookup(nil, "a.txt"),
		nfs4.AppendGetXattrArgs(nil, "user.comment"),
	})
	wantStatus(t, "get after remove", res.Status, nfs4.ErrNoXattr)
}

// A bare FS wrapper hides the backend's xattr half: the xattr family must
// answer NOT_SUPP against it.
type bareFS struct {
	nfsfs.FS
}

func TestXattrWithoutBackend(t *testing.T) {
	h := testTree(t)
	h.FS = bareFS{h.FS}
	sid, seq := newSession(t, h)
	all := [][]byte{
		nfs4.AppendSequenceArgs(nil, sid, seq, 0, defaultSlots-1, true),
		nfs4.AppendPutRootfh(nil),
		nfs4.AppendLookup(nil, "a.txt"),
		nfs4.AppendGetXattrArgs(nil, "user.comment"),
		nfs4.AppendSetXattrArgs(nil, nfs4.SetXattrUnchecked, "user.comment", []byte("v")),
		nfs4.AppendListXattrArgs(nil, 0, 1<<16),
		nfs4.AppendRemoveXattrArgs(nil, "user.comment"),
	}
	payload := nfs4.AppendCompoundArgs(nil, "xattr", nfs4.MinorVersion, all)
	body, ok := h.compound(payload, cred{uid: 0, gid: 0})
	if !ok {
		t.Fatal("garbage")
	}
	res, _, err := nfs4.DecodeCompoundResBodies(body)
	if err != nil {
		t.Fatal(err)
	}
	// ops: sequence, putrootfh, lookup, then four xattr ops.
	for i, op := range res.Ops[3:] {
		if op.Status != nfs4.ErrNotSupp {
			t.Fatalf("xattr op %d: status %d, want NOT_SUPP", i, op.Status)
		}
	}
}

func TestXattrWithoutFileHandle(t *testing.T) {
	h := testTree(t)
	sid, seq := newSession(t, h)
	table := []struct {
		name string
		op   []byte
	}{
		{"get", nfs4.AppendGetXattrArgs(nil, "user.a")},
		{"set", nfs4.AppendSetXattrArgs(nil, nfs4.SetXattrUnchecked, "user.a", []byte("v"))},
		{"list", nfs4.AppendListXattrArgs(nil, 0, 1<<16)},
		{"remove", nfs4.AppendRemoveXattrArgs(nil, "user.a")},
	}
	for _, row := range table {
		seq++
		all := append([][]byte{nfs4.AppendSequenceArgs(nil, sid, seq, 0, defaultSlots-1, true)}, row.op)
		payload := nfs4.AppendCompoundArgs(nil, "no-fh", nfs4.MinorVersion, all)
		body, ok := h.compound(payload, cred{uid: 0, gid: 0})
		if !ok {
			t.Fatalf("%s: garbage", row.name)
		}
		res, _, err := nfs4.DecodeCompoundResBodies(body)
		if err != nil {
			t.Fatalf("%s: decode %v", row.name, err)
		}
		if res.Status != nfs4.ErrNoFileHandle {
			t.Fatalf("%s: status %d, want NOFILE_HANDLE", row.name, res.Status)
		}
	}
}