"""
test_integration.py — Step 8: End-to-end integration tests.

Tests the full workflow:
  Load LDF → edit signals → start scheduler → see Rx → stop
  Verifies all components work together correctly.
"""

import sys
import pytest
from pathlib import Path

sys.path.insert(0, str(Path(__file__).parent.parent / "src"))

from PyQt6.QtWidgets import QApplication
from PyQt6.QtCore import Qt
from PyQt6.QtTest import QTest

SAMPLE_LDF = str(Path(__file__).parent.parent.parent / "resources" / "sample.ldf")


@pytest.fixture(scope="session")
def app():
    application = QApplication.instance() or QApplication(sys.argv)
    yield application


@pytest.fixture
def window(app):
    from main_window import MainWindow
    w = MainWindow()
    return w


class TestFullWorkflow:
    """Test the complete user workflow from start to finish."""

    def test_load_edit_run_stop(self, window):
        """
        Complete flow:
          1. Load LDF
          2. Edit a signal value
          3. Start scheduler
          4. Verify Rx data arrives
          5. Stop scheduler
        """
        # 1. Load LDF
        window._load_ldf_file(SAMPLE_LDF)
        assert window._ldf_data is not None
        assert window.tx_table.topLevelItemCount() == 2
        assert window.rx_table.topLevelItemCount() == 2

        # 2. Edit a signal — set MotorSpeed to 200
        frame_item = window.tx_table.topLevelItem(0)  # Motor_Command
        speed_sig = frame_item.child(2)  # MotorSpeed
        speed_sig.setText(4, "200")

        # Verify frame bytes updated
        frame_data = frame_item.data(0, Qt.ItemDataRole.UserRole)
        assert frame_data['bytes'][1] == 200

        # 3. Start scheduler
        window.combo_schedule.setCurrentIndex(0)
        window._on_start_scheduler()
        assert window._scheduler.is_running

        # 4. Wait for Rx data
        QTest.qWait(100)

        # Verify Rx timestamps appeared
        has_rx = False
        for i in range(window.rx_table.topLevelItemCount()):
            if window.rx_table.topLevelItem(i).text(0) != "—":
                has_rx = True
                break
        assert has_rx, "Should have received mock Rx data"

        # 5. Stop
        window._on_stop_scheduler()
        assert not window._scheduler.is_running

    def test_hex_dec_toggle_during_run(self, window):
        """Toggle hex/dec while scheduler is running."""
        window._load_ldf_file(SAMPLE_LDF)
        window.combo_schedule.setCurrentIndex(0)
        window._on_start_scheduler()
        QTest.qWait(50)

        # Toggle to decimal
        window.chk_hex_mode.setChecked(False)
        QTest.qWait(50)

        # Toggle back to hex
        window.chk_hex_mode.setChecked(True)
        QTest.qWait(50)

        window._on_stop_scheduler()
        # No crash = pass

    def test_pause_resume_during_run(self, window):
        """Pause and resume the scheduler."""
        window._load_ldf_file(SAMPLE_LDF)
        window.combo_schedule.setCurrentIndex(0)
        window._on_start_scheduler()
        QTest.qWait(50)

        # Pause
        window._on_pause_scheduler()
        assert window._scheduler.is_paused
        QTest.qWait(50)

        # Resume
        window._on_pause_scheduler()
        assert not window._scheduler.is_paused
        QTest.qWait(50)

        window._on_stop_scheduler()

    def test_clear_rx_during_run(self, window):
        """Clear Rx data while scheduler is running."""
        window._load_ldf_file(SAMPLE_LDF)
        window.combo_schedule.setCurrentIndex(0)
        window._on_start_scheduler()
        QTest.qWait(100)

        window._on_clear_rx()

        # All timestamps should be reset
        for i in range(window.rx_table.topLevelItemCount()):
            assert window.rx_table.topLevelItem(i).text(0) == "—"

        # But scheduler should still be running
        assert window._scheduler.is_running
        window._on_stop_scheduler()

    def test_change_global_rate_live(self, window):
        """Change global rate while scheduler is running."""
        window._load_ldf_file(SAMPLE_LDF)
        window.combo_schedule.setCurrentIndex(0)
        window._on_start_scheduler()
        QTest.qWait(50)

        window.spin_global_rate.setValue(10)
        QTest.qWait(50)

        window.spin_global_rate.setValue(100)
        QTest.qWait(50)

        window._on_stop_scheduler()

    def test_reload_ldf_stops_scheduler(self, window):
        """Reloading LDF while scheduler runs should stop first."""
        window._load_ldf_file(SAMPLE_LDF)
        window.combo_schedule.setCurrentIndex(0)
        window._on_start_scheduler()
        QTest.qWait(50)

        # Reload — scheduler should handle this gracefully
        window._load_ldf_file(SAMPLE_LDF)

        # Tables should still be populated
        assert window.tx_table.topLevelItemCount() == 2


class TestBackendIntegration:
    """Test BabyLinBackend integration (mock mode)."""

    def test_backend_exists(self, window):
        assert window._backend is not None
        assert window._backend.is_mock_mode

    def test_backend_scan_from_gui(self, window):
        """Backend scan should return mock device."""
        devices = window._backend.scan_devices()
        assert len(devices) >= 1


class TestEdgeCase:
    """Test edge cases and error conditions."""

    def test_start_without_ldf(self, window, monkeypatch):
        """Starting scheduler without LDF loaded should not crash."""
        from PyQt6.QtWidgets import QMessageBox
        monkeypatch.setattr(QMessageBox, "warning", lambda *args: None)
        window._on_start_scheduler()
        assert not window._scheduler.is_running

    def test_manual_send_without_selection(self, window, monkeypatch):
        """Manual send without selecting a frame should warn."""
        from PyQt6.QtWidgets import QMessageBox
        warned = []
        monkeypatch.setattr(QMessageBox, "warning",
                            lambda *args: warned.append(True))
        window._load_ldf_file(SAMPLE_LDF)
        window._on_manual_send()
        assert len(warned) > 0

    def test_double_stop(self, window):
        """Stopping when already stopped should not crash."""
        window._load_ldf_file(SAMPLE_LDF)
        window._on_stop_scheduler()
        window._on_stop_scheduler()  # No crash