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

package nfsclient

import (
	"net"
	"testing"

	"sourcedock.dev/petrbalvin/nfs/internal/nfs4"
	"sourcedock.dev/petrbalvin/nfs/internal/rpc"
)

// The accessors answer copies of what the callback demux recorded.
func TestNotifiedAccessors(t *testing.T) {
	c := &Client{}
	if got := c.Notified(); len(got) != 0 {
		t.Fatal("notified before any delivery")
	}
	if got := c.NotifiedLocks(); len(got) != 0 {
		t.Fatal("locks notified before any delivery")
	}
	c.recMu.Lock()
	c.notified = append(c.notified, nfs4.CBNotify{FH: []byte("d")})
	c.notifiedLocks = append(c.notifiedLocks, nfs4.CBNotifyLock{Clientid: 5})
	c.recMu.Unlock()
	if n := c.Notified(); len(n) != 1 || string(n[0].FH) != "d" {
		t.Fatalf("notified %+v", n)
	}
	if n := c.NotifiedLocks(); len(n) != 1 || n[0].Clientid != 5 {
		t.Fatalf("locks %+v", n)
	}
}

// The callback demux answers CB_NOTIFY and CB_NOTIFY_LOCK and records
// them for the caller.
func TestCBCompoundNotifies(t *testing.T) {
	// The demux answers every callback on the wire; a pipe with a
	// draining side stands in for the connection.
	a, b := net.Pipe()
	defer a.Close()
	defer b.Close()
	go func() {
		buf := make([]byte, 4096)
		for {
			if _, err := b.Read(buf); err != nil {
				return
			}
		}
	}()
	c := &Client{conn: a, cbProgram: 0x40000000}
	st := nfs4.Stateid{1, 'D', 'D'}

	notify := nfs4.AppendCBNotifyArgs(nil, st, []byte("dir"),
		[]nfs4.Notify4{{Mask: nfs4.OfBits(nfs4.NotifyAddEntry),
			Vals: nfs4.AppendNotifyAdd(nil, "new", 0, true)}})
	lock := nfs4.AppendCBNotifyLockArgs(nil, []byte("f"), 9, []byte("owner"))

	c.handleCBCall(1, buildCBCall(t, [][]byte{notify, lock}))
	notes := c.Notified()
	if len(notes) != 1 || !notes[0].Changes[0].Mask.Has(nfs4.NotifyAddEntry) {
		t.Fatalf("notified %+v", notes)
	}
	if n := c.NotifiedLocks(); len(n) != 1 || n[0].Clientid != 9 {
		t.Fatalf("locks %+v", n)
	}

}

// buildCBCall frames one CB_COMPOUND call record the way the server
// sends it.
func buildCBCall(t *testing.T, ops [][]byte) []byte {
	t.Helper()
	args := nfs4.AppendCBCompoundArgs(nil, "cb", nfs4.MinorVersion, 0, ops)
	record, err := rpc.AppendCall(nil, rpc.Call{
		XID: 1, Program: nfs4.CBDefaultProgram, Version: nfs4.Version,
		Procedure: 1,
		Cred:      rpc.Auth{Flavor: rpc.FlavorNone},
		Verifier:  rpc.Auth{Flavor: rpc.FlavorNone},
	})
	if err != nil {
		t.Fatal(err)
	}
	return append(record, args...)
}