"""Load-combination integration: 1.2×D + 1.6×L by superposition == one combined run."""

from __future__ import annotations

import math

import pytest

ops = pytest.importorskip("openseespy.opensees")  # skip if OpenSeesPy not installed

from otko.core import (
    ElasticBeamColumn,
    ElasticSection,
    LinearTimeSeries,
    LoadCombination,
    LoadCombinationItem,
    NodalLoad,
    Node,
    PlainLoadPattern,
    Project,
    StaticCase,
)
from otko.services import OpenSeesRunner, evaluate_combination
from otko.services.results import StaticResults

pytestmark = pytest.mark.slow


def _two_pattern_cantilever() -> Project:
    elastic_mod = 200e9
    area = 0.01
    inertia = 8.333e-6
    return Project(
        ndm=2,
        ndf=3,
        nodes=[
            Node(
                id=1,
                coords=(0.0, 0.0, 0.0),
                restraint=(True, True, False, False, False, True),
            ),
            Node(id=2, coords=(5.0, 0.0, 0.0)),
        ],
        sections=[ElasticSection(id=1, E=elastic_mod, A=area, Iz=inertia)],
        elements=[ElasticBeamColumn(id=1, nodes=(1, 2), section_id=1)],
        time_series=[LinearTimeSeries(id=1), LinearTimeSeries(id=2)],
        load_patterns=[
            PlainLoadPattern(
                id=1,
                name="Dead",
                time_series_id=1,
                nodal_loads=[NodalLoad(node_id=2, forces=(0.0, -1000.0, 0.0, 0.0, 0.0, 0.0))],
            ),
            PlainLoadPattern(
                id=2,
                name="Live",
                time_series_id=2,
                nodal_loads=[NodalLoad(node_id=2, forces=(0.0, -500.0, 0.0, 0.0, 0.0, 0.0))],
            ),
        ],
        analyses=[
            StaticCase(id=1, name="Dead", pattern_ids=[1]),
            StaticCase(id=2, name="Live", pattern_ids=[2]),
        ],
    )


def test_superposition_matches_combined_run() -> None:
    """1.2*Dead + 1.6*Live via evaluate_combination == single StaticCase run."""
    proj = _two_pattern_cantilever()
    dead = OpenSeesRunner(proj).run(proj.analyses[0])
    live = OpenSeesRunner(proj).run(proj.analyses[1])
    combo = LoadCombination(
        id=1,
        name="1.2D+1.6L",
        kind="Linear",
        items=[
            LoadCombinationItem(case_id=1, factor=1.2),
            LoadCombinationItem(case_id=2, factor=1.6),
        ],
    )
    combined = evaluate_combination({1: dead, 2: live}, combo)
    assert isinstance(combined, StaticResults)
    # Single run with both patterns factored identically.
    direct = OpenSeesRunner(proj).run(
        StaticCase(id=3, name="direct", pattern_ids=[1, 2], pattern_factors={1: 1.2, 2: 1.6})
    )
    assert math.isclose(
        combined.disp(node_id=2, dof=2), direct.disp(node_id=2, dof=2), rel_tol=1e-9
    )