// Fenrir console screen reader.
// Copyright (c) 2026 Storm Dragon
// SPDX-License-Identifier: GPL-3.0-or-later
//
// This program is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
// more details.
//
// You should have received a copy of the GNU General Public License along with
// this program. If not, see <https://www.gnu.org/licenses/gpl-3.0.html>.

//go:build linux && cgo

package console

import (
	"os"
	"syscall"
	"testing"
	"time"
)

func TestInputWatcherReadinessRearmAndHotplug(t *testing.T) {
	watcher, err := newReadinessWatcher(syscall.EPOLLIN)
	if err != nil {
		t.Fatal(err)
	}
	defer watcher.close()
	for device := 0; device < 2; device++ {
		readEnd, writeEnd, err := os.Pipe()
		if err != nil {
			t.Fatal(err)
		}
		t.Cleanup(func() { readEnd.Close(); writeEnd.Close() })
		if err := watcher.add(int(readEnd.Fd())); err != nil {
			t.Fatal(err)
		}
		for press := 0; press < 2; press++ {
			if _, err := writeEnd.Write([]byte{1}); err != nil {
				t.Fatal(err)
			}
			select {
			case err := <-watcher.events:
				if err != nil {
					t.Fatal(err)
				}
			case <-time.After(time.Second):
				t.Fatal("input did not wake epoll")
			}
			var data [1]byte
			if _, err := readEnd.Read(data[:]); err != nil {
				t.Fatal(err)
			}
			if err := watcher.arm(int(readEnd.Fd())); err != nil {
				t.Fatal(err)
			}
		}
		readEnd.Close()
		writeEnd.Close()
	}
}

func TestInputWatcherIdleShutdown(t *testing.T) {
	watcher, err := newReadinessWatcher(syscall.EPOLLIN)
	if err != nil {
		t.Fatal(err)
	}
	closed := make(chan error, 1)
	go func() { closed <- watcher.close() }()
	select {
	case err := <-closed:
		if err != nil {
			t.Fatal(err)
		}
	case <-time.After(time.Second):
		t.Fatal("idle watcher failed to wake on shutdown")
	}
}

func BenchmarkInputReadiness(b *testing.B) {
	watcher, err := newReadinessWatcher(syscall.EPOLLIN)
	if err != nil {
		b.Fatal(err)
	}
	defer watcher.close()
	readEnd, writeEnd, err := os.Pipe()
	if err != nil {
		b.Fatal(err)
	}
	defer readEnd.Close()
	defer writeEnd.Close()
	if err := watcher.add(int(readEnd.Fd())); err != nil {
		b.Fatal(err)
	}
	var data [1]byte
	for b.Loop() {
		if _, err := writeEnd.Write(data[:]); err != nil {
			b.Fatal(err)
		}
		if err := <-watcher.events; err != nil {
			b.Fatal(err)
		}
		if _, err := readEnd.Read(data[:]); err != nil {
			b.Fatal(err)
		}
		if err := watcher.arm(int(readEnd.Fd())); err != nil {
			b.Fatal(err)
		}
	}
}