from __future__ import annotations

import numpy as np
import pytest

from galileo_rx.io.signalsim_reader import SignalSimReader, SignalSimSampleSpec


def test_iq8_signed_i_then_q_and_double_precision(tmp_path) -> None:
    path = tmp_path / "iq8.bin"
    path.write_bytes(bytes([0x80, 0x7F, 0xFF, 0x01, 0x02, 0xFE]))
    samples = SignalSimReader(path, SignalSimSampleSpec("IQ8")).read()
    assert samples.dtype == np.complex128
    np.testing.assert_array_equal(samples, [-128 + 127j, -1 + 1j, 2 - 2j])


def test_iq16_little_endian_scaling_and_qi_order(tmp_path) -> None:
    path = tmp_path / "iq16.bin"
    np.asarray([100, -200, -300, 400], dtype="<i2").tofile(path)
    spec = SignalSimSampleSpec("IQ16", iq_order="QI", scale_counts_per_unit=100.0)
    np.testing.assert_allclose(SignalSimReader(path, spec).read(), [-2 + 1j, 4 - 3j], rtol=0.0, atol=0.0)


def test_iq4_sign_magnitude(tmp_path) -> None:
    path = tmp_path / "iq4.bin"
    path.write_bytes(bytes([0x17, 0xA9, 0x80]))
    np.testing.assert_array_equal(SignalSimReader(path, SignalSimSampleSpec("IQ4")).read(), [1 + 7j, -2 - 1j, 0 + 0j])


def test_iq2_packed_order_and_offset(tmp_path) -> None:
    path = tmp_path / "iq2.bin"
    # sample 0: I=+1,Q=-1 -> 0xd; sample 1: I=-1,Q=+1 -> 0x7
    path.write_bytes(bytes([0x7D]))
    reader = SignalSimReader(path, SignalSimSampleSpec("IQ2"))
    np.testing.assert_array_equal(reader.read(), [1 - 1j, -1 + 1j])
    np.testing.assert_array_equal(reader.read(1, 1), [-1 + 1j])


def test_truncation_odd_iq_and_block_streaming(tmp_path) -> None:
    path = tmp_path / "odd.bin"
    path.write_bytes(b"\x01\x02\x03")
    reader = SignalSimReader(path, SignalSimSampleSpec("IQ8"))
    with pytest.raises(ValueError, match="truncated"):
        _ = reader.sample_count

    complete = tmp_path / "complete.bin"
    complete.write_bytes(bytes(range(12)))
    reader = SignalSimReader(complete, SignalSimSampleSpec("IQ8"), memory_map=True)
    blocks = list(reader.blocks(2, offset_samples=1, count=4))
    assert [block.size for block in blocks] == [2, 2]
    np.testing.assert_array_equal(np.concatenate(blocks), [2 + 3j, 4 + 5j, 6 + 7j, 8 + 9j])
    with pytest.raises(EOFError, match="only 1 remain"):
        reader.read(2, 5)