"""Test that SVD component 1 scores match compass x positions for current_parliament.

Bug: The compass filters current_parliament to active MPs only (still seated) at
explorer.py line 1473. The SVD components tab previously did NOT do this filter,
causing party means to differ (e.g. VVD: ~0.108 vs ~0.335).

Fix: get_aligned_party_scores() now accepts an active_mps parameter and filters
current_parliament when provided.
"""

import numpy as np


def test_svd_comp1_matches_compass_for_current_parliament_with_active_filter():
    """VVD comp1 from get_aligned_party_scores should match compass when active_mps provided.

    REGRESSION TEST: Without the active_mps filter, VVD comp1 ≈ 0.108 (wrong).
    With the active_mps filter, VVD comp1 ≈ 0.335 (matching compass).
    """
    from explorer import get_aligned_party_scores, load_active_mps, load_party_map
    from analysis.political_axis import compute_2d_axes, compute_nd_axes
    from analysis.explorer_data import get_uniform_dim_windows

    db_path = "data/motions.db"
    windows = get_uniform_dim_windows(db_path)
    active_mps = load_active_mps(db_path)
    party_map = load_party_map(db_path)

    # --- Compass reference: VVD mean x position ---
    # Compass uses compute_2d_axes + filters to active_mps for current_parliament
    pos2d, _ = compute_2d_axes(db_path, window_ids=windows)
    cp_pos2d_active = {
        mp: xy
        for mp, xy in pos2d.get("current_parliament", {}).items()
        if mp in active_mps
    }
    vvd_mps_2d = [mp for mp in cp_pos2d_active if party_map.get(mp) == "VVD"]
    compass_vvd_mean = float(np.mean([cp_pos2d_active[mp][0] for mp in vvd_mps_2d]))

    # --- SVD tab: WITH active_mps filter ---
    svd_with_filter = get_aligned_party_scores(
        db_path, "current_parliament", active_mps
    )
    vvd_comp1_with = float(svd_with_filter["VVD"][0])

    # These MUST match (within tolerance)
    diff = abs(compass_vvd_mean - vvd_comp1_with)
    assert diff < 0.001, (
        f"VVD comp1 mismatch: compass={compass_vvd_mean:.6f}, "
        f"SVD with filter={vvd_comp1_with:.6f}, diff={diff:.6f}"
    )


def test_without_active_filter_gives_wrong_mean():
    """Without active_mps filter, get_aligned_party_scores gives a different VVD mean.

    The unfiltered mean includes all historical VVD MPs, while the filtered
    mean includes only currently-seated MPs. These must differ significantly.
    The exact values drift with the database; only the delta is asserted here.
    The compass-match assertion lives in the test above.
    """
    from explorer import get_aligned_party_scores, load_active_mps
    from analysis.explorer_data import get_uniform_dim_windows

    db_path = "data/motions.db"
    windows = get_uniform_dim_windows(db_path)
    active_mps = load_active_mps(db_path)

    # Without filter (BUGGY)
    svd_no_filter = get_aligned_party_scores(
        db_path, "current_parliament", active_mps=None
    )
    vvd_no_filter = float(svd_no_filter["VVD"][0])

    # With filter (CORRECT)
    svd_with_filter = get_aligned_party_scores(
        db_path, "current_parliament", active_mps=active_mps
    )
    vvd_with_filter = float(svd_with_filter["VVD"][0])

    # The two values must differ significantly
    diff = abs(vvd_no_filter - vvd_with_filter)
    assert diff > 0.1, (
        f"Expected large diff between unfiltered ({vvd_no_filter:.4f}) and "
        f"filtered ({vvd_with_filter:.4f}), got diff={diff:.4f}"
    )


def test_historical_window_unchanged():
    """Historical windows (e.g. '2025') should NOT be affected by active_mps filter."""
    from explorer import get_aligned_party_scores

    db_path = "data/motions.db"

    svd_no_filter = get_aligned_party_scores(db_path, "2025", active_mps=None)
    svd_with_filter = get_aligned_party_scores(db_path, "2025", active_mps={"fake_mp"})

    # For historical windows, the output should be identical regardless of active_mps
    # (the filter is only applied for current_parliament)
    for party in svd_no_filter:
        if party in svd_with_filter:
            diff = abs(svd_no_filter[party][0] - svd_with_filter[party][0])
            assert diff < 1e-6, (
                f"Historical window changed with active_mps filter for {party}"
            )