import time

import pytest
from PySide6.QtCore import QCoreApplication
from PySide6.QtWidgets import QApplication

from agr_assistent.core.memory import MemoryStore
from agr_assistent.ui.chat_window import ChatWindow
from tests.fake_llm import FakeLLMServer
from tests.test_assistant_flow import _assistant


def _pump(seconds: float = 0.1) -> None:
    deadline = time.monotonic() + seconds
    while time.monotonic() < deadline:
        QCoreApplication.processEvents()
        time.sleep(0.005)


@pytest.fixture
def window(qapp: QApplication, fake_llm: FakeLLMServer, tmp_path) -> ChatWindow:  # type: ignore[no-untyped-def]
    memory = MemoryStore(tmp_path / "memory.sqlite3")
    chat = ChatWindow(_assistant(fake_llm, memory))
    chat.resize(500, 300)
    chat.show()
    yield chat
    chat.hide()
    memory.close()


def _scrollbar(window: ChatWindow):  # type: ignore[no-untyped-def]
    return window._transcript.verticalScrollBar()


def _stream_reply(window: ChatWindow, request: str, chunks: int) -> None:
    assistant = window._assistant
    assistant.request_added.emit(request, False)
    assistant.reply_started.emit()
    for index in range(chunks):
        assistant.reply_chunk.emit(f"Строка ответа номер {index}.\n\n")
        _pump(0.01)
    assistant.reply_finished.emit("")
    _pump(0.2)


def test_journal_follows_new_content(window: ChatWindow) -> None:
    for request in range(3):
        _stream_reply(window, f"Вопрос {request}", chunks=15)

    scrollbar = _scrollbar(window)
    assert scrollbar.maximum() > 0
    assert scrollbar.value() == scrollbar.maximum()


def test_journal_keeps_position_when_user_scrolled_up(window: ChatWindow) -> None:
    _stream_reply(window, "Длинный вопрос", chunks=30)
    scrollbar = _scrollbar(window)
    scrollbar.setValue(10)
    _pump()

    assistant = window._assistant
    assistant.reply_started.emit()
    for index in range(10):
        assistant.reply_chunk.emit(f"Ещё строка {index}.\n\n")
        _pump(0.01)
    _pump(0.2)
    assert scrollbar.value() == 10

    # Новый запрос пользователя снова прокручивает вниз
    assistant.request_added.emit("Новый вопрос", False)
    _pump(0.2)
    assert scrollbar.value() == scrollbar.maximum()