// Copyright (c) 2026 Storm Dragon
// Authors: Storm Dragon, Angus Kola
// SPDX-License-Identifier: GPL-3.0-or-later
package i3ipc

import (
	"context"
	"net"
	"path/filepath"
	"testing"
	"time"
)

func listener(t *testing.T) net.Listener {
	t.Helper()
	l, err := net.Listen("unix", filepath.Join(t.TempDir(), "ipc"))
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { l.Close() })
	return l
}
func handshake(c net.Conn, initial string) error {
	for _, response := range []string{`{"success":true}`, `[{"id":2,"name":"A","focused":true}]`, `{"id":1,"type":"root","nodes":[]}`} {
		m, err := readMessage(c)
		if err != nil {
			return err
		}
		if initial != "" {
			if err := writeMessage(c, modeEvent, []byte(initial)); err != nil {
				return err
			}
		}
		if err := writeMessage(c, m.kind, []byte(response)); err != nil {
			return err
		}
	}
	return nil
}
func TestSessionBaselineCancellationAndReconnect(t *testing.T) {
	l := listener(t)
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	events := make(chan Event, 8)
	done := make(chan struct{})
	server := make(chan error, 1)
	go func() {
		defer close(done)
		Run(ctx, func() string { return l.Addr().String() }, func(e Event) { events <- e })
	}()
	go func() {
		for _, name := range []string{"personal", "default"} {
			c, err := l.Accept()
			if err != nil {
				server <- err
				return
			}
			if err = handshake(c, `{"change":"snapshot"}`); err == nil {
				err = writeMessage(c, modeEvent, []byte(`{"change":"`+name+`"}`))
			}
			if name == "default" && err == nil {
				var b [1]byte
				_, _ = c.Read(b[:])
			}
			c.Close()
			if err != nil {
				server <- err
				return
			}
		}
		server <- nil
	}()
	for _, name := range []string{"personal", "default"} {
		select {
		case e := <-events:
			if e.Name != name {
				t.Fatal(e)
			}
		case <-time.After(4 * time.Second):
			t.Fatal("missing event/reconnect")
		}
	}
	cancel()
	select {
	case <-done:
	case <-time.After(time.Second):
		t.Fatal("idle read did not cancel")
	}
	if err := <-server; err != nil {
		t.Fatal(err)
	}
	select {
	case e := <-events:
		t.Fatalf("snapshot announced: %+v", e)
	default:
	}
}
func TestSubscriptionFailure(t *testing.T) {
	l := listener(t)
	go func() {
		c, err := l.Accept()
		if err != nil {
			return
		}
		defer c.Close()
		m, err := readMessage(c)
		if err == nil {
			_ = writeMessage(c, m.kind, []byte(`{"success":false}`))
		}
	}()
	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()
	if err := session(ctx, l.Addr().String(), func(Event) { t.Error("unexpected event") }); err == nil {
		t.Fatal("accepted rejection")
	}
}
func TestUnavailableAndCanceledQuery(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	cancel()
	if err := session(ctx, "/nonexistent/i3", func(Event) {}); err == nil {
		t.Fatal("unavailable socket accepted")
	}
	l := listener(t)
	accepted := make(chan struct{})
	go func() {
		c, err := l.Accept()
		if err != nil {
			return
		}
		defer c.Close()
		close(accepted)
		var b [4096]byte
		for {
			if _, err := c.Read(b[:]); err != nil {
				return
			}
		}
	}()
	ctx, cancel = context.WithCancel(context.Background())
	defer cancel()
	done := make(chan error, 1)
	go func() { done <- session(ctx, l.Addr().String(), func(Event) {}) }()
	<-accepted
	cancel()
	select {
	case <-done:
	case <-time.After(time.Second):
		t.Fatal("query did not cancel")
	}
}
func TestInterleavedEventsAndBacklog(t *testing.T) {
	a, b := net.Pipe()
	defer a.Close()
	defer b.Close()
	c := connection{Conn: a}
	go func() {
		m, err := readMessage(b)
		if err != nil {
			return
		}
		_ = writeMessage(b, modeEvent, []byte(`{"change":"panel"}`))
		_ = writeMessage(b, m.kind, []byte(`{"success":true}`))
	}()
	var result struct{ Success bool }
	if err := c.request(subscribe, nil, &result); err != nil || !result.Success || len(c.pending) != 1 {
		t.Fatalf("%+v %v", c.pending, err)
	}
	c.pending = make([]message, maxPending)
	go func() {
		_, err := readMessage(b)
		if err == nil {
			_ = writeMessage(b, modeEvent, []byte(`{}`))
		}
	}()
	if err := c.request(tree, nil, &result); err == nil {
		t.Fatal("unbounded pending events")
	}
}