import os
import types

import explorer


def test_load_positions_empty_sets_diagnostics(monkeypatch):
    # Monkeypatch load_positions to return empty positions
    monkeypatch.setattr(
        explorer, "load_positions", lambda db_path, window_size: ({}, {})
    )
    monkeypatch.setenv("EXPLORER_DEBUG_TRAJECTORIES", "1")

    # Call build_trajectories_tab; it should set diagnostics and return without exception
    explorer.build_trajectories_tab(db_path="unused", window_size="annual")

    assert (
        explorer._last_trajectories_diagnostics.get("stage") == "load_positions_empty"
    )


def test_select_helper_exception_is_captured(monkeypatch):
    # Provide a minimal non-empty positions_by_window
    positions = {"W1": {"mp1": (0.1, 0.2)}}

    def fake_load_positions(db_path, window_size):
        return positions, {}

    monkeypatch.setattr(explorer, "load_positions", fake_load_positions)
    # Ensure party_map maps the mp so centroids/path that invoke select_trajectory_plot_data
    monkeypatch.setattr(explorer, "load_party_map", lambda db_path: {"mp1": "P1"})

    # Patch select_trajectory_plot_data to raise
    def bad_helper(*args, **kwargs):
        raise ValueError("boom")

    monkeypatch.setattr(explorer, "select_trajectory_plot_data", bad_helper)
    monkeypatch.setenv("EXPLORER_DEBUG_TRAJECTORIES", "1")

    explorer.build_trajectories_tab(db_path="unused", window_size="annual")

    # Ensure the helper function has diagnostics attached and module diagnostics updated
    assert getattr(explorer.select_trajectory_plot_data, "_last_diagnostics", None)
    assert "exception" in explorer.select_trajectory_plot_data._last_diagnostics
    assert (
        explorer._last_trajectories_diagnostics.get("stage")
        == "select_helper_exception"
    )
    assert "ValueError" in explorer._last_trajectories_diagnostics.get("exception", "")