"""Tests for CFTC COT extraction package."""

import gzip
import zipfile
from io import BytesIO
from unittest.mock import MagicMock

from cftc_cot.normalize import find_csv_inner_filename, normalize_zipped_csv


# =============================================================================
# normalize.py
# =============================================================================


def _make_zip(inner_name: str, content: bytes) -> BytesIO:
    """Helper: create a ZIP buffer containing a single named file."""
    buf = BytesIO()
    with zipfile.ZipFile(buf, "w") as zf:
        zf.writestr(inner_name, content)
    buf.seek(0)
    return buf


def test_find_csv_inner_filename_returns_txt_file():
    buf = _make_zip("f_year.txt", b"col1,col2\nv1,v2\n")
    assert find_csv_inner_filename(buf) == "f_year.txt"


def test_find_csv_inner_filename_case_insensitive():
    buf = _make_zip("FUT_DISAGG_2015.TXT", b"data")
    assert find_csv_inner_filename(buf) == "FUT_DISAGG_2015.TXT"


def test_find_csv_inner_filename_asserts_on_zero_txt_files():
    buf = BytesIO()
    with zipfile.ZipFile(buf, "w") as zf:
        zf.writestr("readme.md", b"not a txt file")
    buf.seek(0)
    try:
        find_csv_inner_filename(buf)
        assert False, "Should have raised AssertionError"
    except AssertionError as e:
        assert "Expected exactly 1" in str(e)


def test_find_csv_inner_filename_asserts_on_multiple_txt_files():
    buf = BytesIO()
    with zipfile.ZipFile(buf, "w") as zf:
        zf.writestr("a.txt", b"data a")
        zf.writestr("b.txt", b"data b")
    buf.seek(0)
    try:
        find_csv_inner_filename(buf)
        assert False, "Should have raised AssertionError"
    except AssertionError:
        pass


def test_normalize_zipped_csv_produces_valid_gzip():
    csv_content = b"Market_and_Exchange_Names,CFTC_Commodity_Code\nCOFFEE C,083731\n"
    buf = _make_zip("f_year.txt", csv_content)
    result = normalize_zipped_csv(buf, "f_year.txt")

    # Decompress and verify content round-trips
    with gzip.open(result, "rb") as gz:
        decompressed = gz.read()
    assert decompressed == csv_content


def test_normalize_zipped_csv_resets_seek_position():
    buf = _make_zip("f_year.txt", b"data")
    result = normalize_zipped_csv(buf, "f_year.txt")
    assert result.tell() == 0, "Result BytesIO should be seeked to position 0"


def test_normalize_zipped_csv_asserts_on_wrong_inner_name():
    buf = _make_zip("actual.txt", b"data")
    try:
        normalize_zipped_csv(buf, "expected.txt")
        assert False, "Should have raised AssertionError"
    except AssertionError as e:
        assert "expected.txt" in str(e)


# =============================================================================
# execute.py — pipeline registry integration
# =============================================================================


def test_extract_cot_pipeline_registered():
    """extract_cot must appear in the materia pipeline registry."""
    from materia.pipelines import PIPELINES

    assert "extract_cot" in PIPELINES
    entry = PIPELINES["extract_cot"]
    assert entry["command"] == ["uv", "run", "--package", "cftc_cot", "extract_cot"]
    assert entry["timeout_seconds"] == 1800


def test_extract_cot_year_skips_existing_file(tmp_path, monkeypatch):
    """extract_cot_year returns False and skips download when file already exists."""
    import pathlib

    monkeypatch.setenv("LANDING_DIR", str(tmp_path))

    # Pre-create the etag file to simulate existing data
    dest = tmp_path / "cot" / "2024"
    dest.mkdir(parents=True)
    etag = "abc123"
    (dest / f"{etag}.csv.gzip").write_bytes(b"existing")

    from cftc_cot import execute as cot_execute

    # Reload LANDING_DIR after monkeypatch
    cot_execute.LANDING_DIR = pathlib.Path(str(tmp_path))

    mock_session = MagicMock()
    mock_head = MagicMock()
    mock_head.status_code = 200
    mock_head.headers = {"etag": f'"{etag}"'}
    mock_session.head.return_value = mock_head

    result = cot_execute.extract_cot_year(2024, mock_session)

    assert result == 0
    mock_session.get.assert_not_called()  # No download should occur


def test_extract_cot_year_returns_false_on_404(tmp_path, monkeypatch):
    """extract_cot_year returns False when CFTC returns 404 for a year."""
    import pathlib

    monkeypatch.setenv("LANDING_DIR", str(tmp_path))

    from cftc_cot import execute as cot_execute
    cot_execute.LANDING_DIR = pathlib.Path(str(tmp_path))

    mock_session = MagicMock()
    mock_head = MagicMock()
    mock_head.status_code = 404
    mock_session.head.return_value = mock_head

    result = cot_execute.extract_cot_year(2006, mock_session)

    assert result == 0
    mock_session.get.assert_not_called()