from __future__ import annotations

import numpy as np

from galileo_rx.tracking.lock_detector import BocLockDetectorConfig, LockDetector
from galileo_rx.types import CorrelatorOutputs


def _correlators(phase_rad: float) -> CorrelatorOutputs:
    prompt = complex(np.exp(1j * phase_rad))
    return CorrelatorOutputs(0.2 * prompt, 0.5 * prompt, prompt, 0.5 * prompt, 0.2 * prompt)


def test_data_lock_detector_ignores_bpsk_transition_but_detects_quadrature_jump() -> None:
    detector = LockDetector(data_sign_insensitive=True)
    detector.update(_correlators(0.0))
    assert detector.update(_correlators(np.pi)).cycle_slip is False
    assert detector.update(_correlators(np.pi + 0.49 * np.pi)).cycle_slip is True


def _detector() -> LockDetector:
    return LockDetector(
        data_sign_insensitive=True,
        config=BocLockDetectorConfig(
            smoothing_epochs=4,
            confirmation_epochs=2,
            failure_epochs=3,
        ),
    )


def _repeat(detector: LockDetector, values: CorrelatorOutputs, count: int):
    return [detector.update(values) for _ in range(count)]


def test_boc_lock_metric_validity_is_separate_from_lock_state() -> None:
    detector = _detector()
    statuses = _repeat(detector, _correlators(0.0), 5)
    assert [status.metric_valid for status in statuses] == [False, False, False, True, True]
    assert statuses[3].code_locked is False
    assert statuses[4].code_locked is True


def test_boc_quarter_chip_shoulder_does_not_cause_false_unlock() -> None:
    detector = _detector()
    centered = CorrelatorOutputs(0.25 + 0j, 0.25 + 0j, 1.0 + 0j, 0.25 + 0j, 0.25 + 0j)
    _repeat(detector, centered, 8)
    # Ideal BOC(1,1) at +0.25 chip: one E/L tap is at the main peak,
    # while P is only 0.25 in amplitude.  The legacy P/E/L ratio is 0.1.
    shoulder = CorrelatorOutputs(-0.5 + 0j, 1.0 + 0j, 0.25 + 0j, -0.5 + 0j, 0j)
    statuses = _repeat(detector, shoulder, 12)
    assert min(status.code_metric for status in statuses) < 0.11
    assert all(status.code_locked for status in statuses)
    assert not any(status.side_peak_suspected for status in statuses)


def test_boc_outer_tap_side_peak_and_signal_loss_are_detected_after_debounce() -> None:
    detector = _detector()
    centered = CorrelatorOutputs(0.25 + 0j, 0.25 + 0j, 1.0 + 0j, 0.25 + 0j, 0.25 + 0j)
    _repeat(detector, centered, 8)
    side_peak = CorrelatorOutputs(1.0 + 0j, 0.5 + 0j, 0.25 + 0j, 0j, 0j)
    side_status = _repeat(detector, side_peak, 8)
    assert any(status.side_peak_suspected for status in side_status)
    assert side_status[-1].code_locked is False

    detector = _detector()
    _repeat(detector, centered, 8)
    lost = _repeat(detector, CorrelatorOutputs(), 8)
    assert lost[-1].signal_present is False
    assert lost[-1].code_locked is False


def test_boc_negative_half_chip_prompt_side_peak_is_detected_by_tap_coherence() -> None:
    detector = _detector()
    centered = CorrelatorOutputs(-0.25 + 0j, 0.25 + 0j, 1.0 + 0j, 0.25 + 0j, -0.25 + 0j)
    _repeat(detector, centered, 8)
    # At +0.5 chip the Prompt is the negative BOC sidelobe. E and L have
    # opposing signs, so powers alone are ambiguous but Re{(E+L)P*} is zero.
    half_chip_side = CorrelatorOutputs(0.25 + 0j, 0.25 + 0j, -0.5 + 0j, -0.25 + 0j, 0j)
    statuses = _repeat(detector, half_chip_side, 8)
    assert statuses[-1].boc_main_peak_coherence <= 0.15
    assert statuses[-1].side_peak_suspected is True
    assert statuses[-1].code_locked is False


def test_single_bad_boc_epoch_is_debounced() -> None:
    detector = _detector()
    centered = CorrelatorOutputs(0.25 + 0j, 0.25 + 0j, 1.0 + 0j, 0.25 + 0j, 0.25 + 0j)
    _repeat(detector, centered, 8)
    side_peak = CorrelatorOutputs(1.0 + 0j, 0.5 + 0j, 0.25 + 0j, 0j, 0j)
    assert detector.update(side_peak).code_locked is True
    assert detector.update(centered).code_locked is True


def test_invalid_integration_does_not_enter_power_smoother() -> None:
    detector = _detector()
    centered = CorrelatorOutputs(0.25 + 0j, 0.25 + 0j, 1.0 + 0j, 0.25 + 0j, 0.25 + 0j)
    for _ in range(10):
        status = detector.update(centered, metric_input_valid=False)
        assert status.metric_valid is False
        assert status.code_locked is False
    statuses = _repeat(detector, centered, 5)
    assert statuses[-1].metric_valid is True
    assert statuses[-1].code_locked is True