"""
Integration tests for the laser control module.

Tests the full call chain: LaserController → Protocol → Serial,
using mock serial ports. No real hardware required.
"""

import pytest
import time
from unittest.mock import MagicMock, patch, call
from laser_control.controller import LaserController
from laser_control.models import VariationType, DeviceState
from laser_control.exceptions import (
    ValidationError,
    CommunicationError,
    TemperatureOutOfRangeError,
    CurrentOutOfRangeError,
)
from laser_control.protocol import Protocol, CommandCode
from .conftest import make_valid_response


class TestManualModeIntegration:
    """Integration tests for manual mode operation."""

    def test_full_manual_mode_flow(self, connected_controller, mock_serial):
        """Test complete manual mode command flow."""
        connected_controller.set_manual_mode(
            temp1=25.0, temp2=30.0,
            current1=40.0, current2=35.0
        )

        # Verify command was sent
        assert mock_serial.write.called
        sent_data = mock_serial.write.call_args[0][0]
        assert len(sent_data) == 30  # SEND_PARAMS_TOTAL_LENGTH

        # Verify command code (bytes 0-1, little-endian 0x1111 → 0x11 0x11)
        assert sent_data[0] == 0x11
        assert sent_data[1] == 0x11

    def test_manual_mode_validation_rejects_invalid_temp(self, connected_controller):
        """Test that manual mode rejects out-of-range temperature."""
        with pytest.raises(TemperatureOutOfRangeError) as exc_info:
            connected_controller.set_manual_mode(
                temp1=50.0,  # Too high
                temp2=30.0,
                current1=40.0,
                current2=35.0
            )
        assert "temp1" in str(exc_info.value)
        assert "50.0" in str(exc_info.value)

    def test_manual_mode_validation_rejects_invalid_current(self, connected_controller):
        """Test that manual mode rejects out-of-range current."""
        with pytest.raises(CurrentOutOfRangeError) as exc_info:
            connected_controller.set_manual_mode(
                temp1=25.0,
                temp2=30.0,
                current1=40.0,
                current2=70.0  # Too high
            )
        assert "current2" in str(exc_info.value)

    def test_manual_mode_no_serial_call_on_validation_failure(
        self, connected_controller, mock_serial
    ):
        """Serial write must not be called when validation fails."""
        mock_serial.write.reset_mock()
        with pytest.raises(ValidationError):
            connected_controller.set_manual_mode(
                temp1=5.0,  # Invalid
                temp2=30.0,
                current1=40.0,
                current2=35.0
            )
        mock_serial.write.assert_not_called()

    def test_message_id_increments(self, connected_controller, mock_serial):
        """Message ID should increment with each command."""
        initial_id = connected_controller._message_id
        connected_controller.set_manual_mode(25.0, 30.0, 40.0, 35.0)
        assert connected_controller._message_id == (initial_id + 1) & 0xFFFF

        connected_controller.set_manual_mode(26.0, 31.0, 41.0, 36.0)
        assert connected_controller._message_id == (initial_id + 2) & 0xFFFF


class TestVariationModeIntegration:
    """Integration tests for variation mode operation."""

    def test_current_ld1_variation_flow(self, connected_controller, mock_serial):
        """Test complete current variation for laser 1."""
        params = {
            'min_value': 20.0,
            'max_value': 50.0,
            'step': 0.5,
            'time_step': 50,
            'delay_time': 5,
            'static_temp1': 25.0,
            'static_temp2': 30.0,
            'static_current1': 35.0,
            'static_current2': 35.0,
        }
        connected_controller.start_variation(VariationType.CHANGE_CURRENT_LD1, params)

        assert mock_serial.write.called
        sent_data = mock_serial.write.call_args[0][0]
        assert len(sent_data) == 32  # TASK_ENABLE_COMMAND_LENGTH

        # Verify command code (0x7777)
        assert sent_data[0] == 0x77
        assert sent_data[1] == 0x77

    def test_current_ld2_variation_flow(self, connected_controller, mock_serial):
        """Test complete current variation for laser 2."""
        params = {
            'min_value': 20.0,
            'max_value': 50.0,
            'step': 0.5,
            'time_step': 50,
            'delay_time': 5,
            'static_temp1': 25.0,
            'static_temp2': 30.0,
            'static_current1': 35.0,
            'static_current2': 35.0,
        }
        connected_controller.start_variation(VariationType.CHANGE_CURRENT_LD2, params)
        assert mock_serial.write.called

    def test_variation_rejects_invalid_step(self, connected_controller, mock_serial):
        """Variation must reject step below minimum."""
        mock_serial.write.reset_mock()
        params = {
            'min_value': 20.0,
            'max_value': 50.0,
            'step': 0.001,  # Too small
            'time_step': 50,
            'delay_time': 5,
            'static_temp1': 25.0,
            'static_temp2': 30.0,
            'static_current1': 35.0,
            'static_current2': 35.0,
        }
        with pytest.raises(ValidationError):
            connected_controller.start_variation(VariationType.CHANGE_CURRENT_LD1, params)
        mock_serial.write.assert_not_called()

    def test_variation_rejects_inverted_range(self, connected_controller):
        """Variation must reject min > max."""
        params = {
            'min_value': 50.0,  # min > max
            'max_value': 20.0,
            'step': 0.5,
            'time_step': 50,
            'delay_time': 5,
            'static_temp1': 25.0,
            'static_temp2': 30.0,
            'static_current1': 35.0,
            'static_current2': 35.0,
        }
        with pytest.raises(ValidationError) as exc_info:
            connected_controller.start_variation(VariationType.CHANGE_CURRENT_LD1, params)
        assert "min" in str(exc_info.value).lower()


class TestMeasurementsIntegration:
    """Integration tests for measurement retrieval."""

    def test_get_measurements_returns_data(self, connected_controller, mock_serial):
        """get_measurements should decode and return device data."""
        mock_serial.read.return_value = make_valid_response()
        measurements = connected_controller.get_measurements()

        assert measurements is not None
        assert isinstance(measurements.current1, float)
        assert isinstance(measurements.current2, float)
        assert isinstance(measurements.temp1, float)
        assert isinstance(measurements.temp2, float)
        assert isinstance(measurements.voltage_3v3, float)

    def test_get_measurements_calls_callback(self, mock_serial):
        """on_data callback should be triggered on new measurements."""
        received = []
        mock_serial.read.return_value = make_valid_response()
        mock_serial.is_open = True

        ctrl = LaserController(
            port='/dev/ttyUSB0',
            on_data=lambda m: received.append(m)
        )
        ctrl._protocol._serial = mock_serial

        ctrl.get_measurements()
        assert len(received) == 1
        assert received[0].voltage_3v3 > 0

    def test_get_measurements_no_data(self, connected_controller, mock_serial):
        """get_measurements returns None when no data received."""
        mock_serial.read.return_value = b''
        result = connected_controller.get_measurements()
        assert result is None

    def test_voltage_rail_check(self, connected_controller, mock_serial):
        """Test power rail health check on measurements."""
        mock_serial.read.return_value = make_valid_response(
            mon_3v3_n=2703,   # ~3.3V
            mon_5v1_n=2731,   # ~5.0V
            mon_5v2_n=2731,
            mon_7v0_n=1042,   # ~7.0V
        )
        measurements = connected_controller.get_measurements()
        if measurements:
            rails = measurements.check_power_rails()
            assert isinstance(rails, dict)
            assert '3v3' in rails
            assert '5v1' in rails
            assert '5v2' in rails
            assert '7v0' in rails


class TestConnectionManagement:
    """Integration tests for connection handling."""

    def test_context_manager(self, mock_serial):
        """Test using LaserController as context manager."""
        mock_serial.is_open = True
        with patch('serial.Serial', return_value=mock_serial):
            with LaserController(port='/dev/ttyUSB0') as ctrl:
                assert ctrl.is_connected
        mock_serial.close.assert_called()

    def test_send_without_connection_raises(self):
        """Sending command without connection raises CommunicationError."""
        ctrl = LaserController(port='/dev/ttyUSB0')
        # Don't call connect()
        with pytest.raises(CommunicationError) as exc_info:
            ctrl.set_manual_mode(25.0, 30.0, 40.0, 35.0)
        assert "connect" in str(exc_info.value).lower()

    def test_stop_task_sends_default_enable(self, connected_controller, mock_serial):
        """stop_task should send DEFAULT_ENABLE (0x2222)."""
        mock_serial.write.reset_mock()
        connected_controller.stop_task()

        assert mock_serial.write.called
        sent_data = mock_serial.write.call_args[0][0]
        # DEFAULT_ENABLE: 0x2222 → flipped to bytes 0x22 0x22
        assert sent_data[0] == 0x22
        assert sent_data[1] == 0x22

    def test_reset_sends_default_enable(self, connected_controller, mock_serial):
        """reset() should also send DEFAULT_ENABLE."""
        mock_serial.write.reset_mock()
        connected_controller.reset()
        assert mock_serial.write.called


class TestConversionsRoundtrip:
    """Test that physical unit conversions are self-consistent."""

    def test_temperature_roundtrip(self):
        """temp_c_to_n and temp_n_to_c should be inverse of each other."""
        from laser_control.conversions import temp_c_to_n, temp_n_to_c
        for temp in [15.0, 20.0, 25.0, 30.0, 35.0, 40.0]:
            n = temp_c_to_n(temp)
            recovered = temp_n_to_c(n)
            assert abs(recovered - temp) < 0.05, \
                f"Temperature roundtrip failed for {temp}°C: got {recovered}°C"

    def test_current_roundtrip(self):
        """current_ma_to_n and current_n_to_ma should be approximately inverse."""
        from laser_control.conversions import current_ma_to_n, current_n_to_ma
        # Note: current_n_to_ma is for photodiode readback, not exact inverse
        # of current_ma_to_n (different calibration paths).
        # We just test that values are in plausible range.
        for current in [15.0, 30.0, 45.0, 60.0]:
            n = current_ma_to_n(current)
            assert 0 <= n <= 65535

    def test_voltage_conversions_nominal(self):
        """Test voltage conversions at nominal counts."""
        from laser_control.conversions import (
            voltage_3v3_n_to_v, voltage_5v_n_to_v, voltage_7v_n_to_v
        )
        # Approximate nominal ADC counts for each rail
        v33 = voltage_3v3_n_to_v(2703)
        assert 3.1 <= v33 <= 3.5, f"3.3V rail: {v33}"

        v5 = voltage_5v_n_to_v(2731)
        assert 4.8 <= v5 <= 5.3, f"5V rail: {v5}"

        v7 = voltage_7v_n_to_v(1042)
        assert 6.5 <= v7 <= 7.5, f"7V rail: {v7}"