package ws

import (
	"testing"
	"time"
)

func TestDocRoomCursorPresenceAndEchoProtection(t *testing.T) {
	hub := NewHub()
	room := hub.GetOrCreateDocRoom("doc_test_presence")

	c1 := &DocWSClient{
		hub:      hub,
		room:     room,
		userID:   "user_1",
		clientID: "cli_1",
		canWrite: true,
		send:     make(chan []byte, 10),
	}
	c2 := &DocWSClient{
		hub:      hub,
		room:     room,
		userID:   "user_2",
		clientID: "cli_2",
		canWrite: false, // read-only viewer
		send:     make(chan []byte, 10),
	}

	room.mu.Lock()
	room.wsClients[c1] = true
	room.wsClients[c2] = true
	room.mu.Unlock()

	// 1. Send cursor_moved from c1
	selStart := 5
	selEnd := 5
	room.HandleEvent(DocSyncEvent{
		Type:           "cursor_moved",
		DocID:          "doc_test_presence",
		ClientID:       "cli_1",
		UserID:         "user_1",
		UserName:       "Alice",
		UserColor:      "#3b82f6",
		BlockID:        "blk_123",
		SelectionStart: &selStart,
		SelectionEnd:   &selEnd,
	}, c1)

	// c1 should NOT have received its own echo
	select {
	case <-c1.send:
		t.Fatal("c1 received echo of its own cursor_moved event!")
	default:
	}

	// c2 SHOULD receive the event
	select {
	case msg := <-c2.send:
		if len(msg) == 0 {
			t.Fatal("empty message received by c2")
		}
	case <-time.After(500 * time.Millisecond):
		t.Fatal("timed out waiting for cursor_moved event on c2")
	}

	// Room should have registered c1's presence
	room.mu.Lock()
	cp, exists := room.activeCursors["cli_1"]
	room.mu.Unlock()

	if !exists || cp == nil {
		t.Fatal("expected active cursor for cli_1 in room")
	}
	if cp.UserName != "Alice" || cp.BlockID != "blk_123" {
		t.Fatalf("unexpected cursor data: %+v", cp)
	}

	// Ephemeral cursor events must NOT mark the room dirty for disk flush
	room.mu.Lock()
	dirty := room.dirty
	room.mu.Unlock()
	if dirty {
		t.Fatal("cursor_moved should not mark room dirty")
	}
}