import time
from unittest.mock import Mock

import pytest

from fenrirscreenreader.core.tabCompletionManager import TabCompletionManager


def _build_env(old_text="", cursor=None, screen="pty"):
    if cursor is None:
        cursor = {"x": 0, "y": 0}
    input_manager = Mock()
    input_manager.get_last_event.return_value = {
        "event_name": "KEY_TAB",
        "event_state": 1,
    }
    env = {
        "runtime": {
            "InputManager": input_manager,
        },
        "screen": {
            "new_cursor": cursor.copy(),
            "new_content_text": old_text,
            "new_delta": "",
            "new_delta_is_typing": False,
            "newTTY": screen,
        },
        "commandBuffer": {},
    }
    manager = TabCompletionManager()
    manager.initialize(env)
    return manager, env, input_manager


def _set_screen_update(env, text, cursor, delta="", typing=False):
    env["screen"]["new_content_text"] = text
    env["screen"]["new_cursor"] = cursor.copy()
    env["screen"]["new_delta"] = delta
    env["screen"]["new_delta_is_typing"] = typing


@pytest.mark.unit
def test_unique_completion_speaks_inserted_suffix():
    manager, env, _input_manager = _build_env(
        "cd Do".ljust(20), {"x": 5, "y": 0}
    )

    manager.capture_if_tab()
    _set_screen_update(
        env,
        "cd Documents/".ljust(20),
        {"x": 13, "y": 0},
        delta="cuments/",
        typing=True,
    )

    assert manager.process_update() == "cuments/"
    state = env["commandBuffer"]["tabCompletion"]
    assert state["pending"] is None
    assert state["lastProcessedDelta"] == "cuments/"


@pytest.mark.unit
def test_candidate_list_speaks_visible_list_without_cursor_advance():
    old_text = "\n".join(["$ cd Do".ljust(20), "".ljust(20), "".ljust(20)])
    manager, env, _input_manager = _build_env(old_text, {"x": 7, "y": 0})

    manager.capture_if_tab()
    _set_screen_update(
        env,
        "\n".join(
            [
                "$ cd Do".ljust(20),
                "Documents/ Downloads/".ljust(20),
                "$ cd Do".ljust(20),
            ]
        ),
        {"x": 7, "y": 2},
        delta="Documents/ Downloads/",
    )

    assert manager.process_update() == "Documents/ Downloads/"


@pytest.mark.unit
def test_no_screen_change_stays_silent_and_keeps_pending_briefly():
    manager, env, _input_manager = _build_env(
        "cd Do".ljust(20), {"x": 5, "y": 0}
    )

    manager.capture_if_tab()

    assert manager.process_update() == ""
    assert env["commandBuffer"]["tabCompletion"]["pending"] is not None


@pytest.mark.unit
def test_timeout_clears_pending_without_speech():
    manager, env, _input_manager = _build_env(
        "cd Do".ljust(20), {"x": 5, "y": 0}
    )

    manager.capture_if_tab()
    env["commandBuffer"]["tabCompletion"]["pending"]["timestamp"] = (
        time.time() - 1
    )
    _set_screen_update(
        env,
        "unrelated output".ljust(20),
        {"x": 0, "y": 0},
        delta="unrelated output",
    )

    assert manager.process_update() == ""
    assert env["commandBuffer"]["tabCompletion"]["pending"] is None


@pytest.mark.unit
def test_non_tab_key_does_not_capture():
    manager, env, input_manager = _build_env(
        "cd Do".ljust(20), {"x": 5, "y": 0}
    )
    input_manager.get_last_event.return_value = {
        "event_name": "KEY_A",
        "event_state": 1,
    }

    manager.capture_if_tab()

    assert env["commandBuffer"]["tabCompletion"]["pending"] is None