from __future__ import annotations

from datetime import date

import pytest

from app.services.event_comparison_ui import EventComparisonFixtureHistoricalPriceSource, EventComparisonPageService


def test_event_comparison_page_service_runs_seeded_gld_preset_deterministically() -> None:
    service = EventComparisonPageService()

    report = service.run_read_only_comparison(
        preset_slug="gld-jan-2024-selloff",
        template_slugs=("protective-put-atm-12m", "protective-put-95pct-12m"),
        underlying_units=1000.0,
        loan_amount=68000.0,
        margin_call_ltv=0.75,
    )

    assert report.event_preset.slug == "gld-jan-2024-selloff"
    assert report.scenario.start_date.isoformat() == "2024-01-02"
    assert report.scenario.end_date.isoformat() == "2024-01-08"
    assert [item.template_slug for item in report.rankings] == [
        "protective-put-atm-12m",
        "protective-put-95pct-12m",
    ]
    assert report.rankings[0].rank == 1
    assert (
        report.rankings[0].result.daily_path[-1].net_portfolio_value
        > report.rankings[-1].result.daily_path[-1].net_portfolio_value
    )


def test_event_comparison_page_service_uses_preset_default_templates_when_none_selected() -> None:
    service = EventComparisonPageService()

    report = service.run_read_only_comparison(
        preset_slug="gld-jan-2024-selloff",
        template_slugs=(),
        underlying_units=1000.0,
        loan_amount=68000.0,
        margin_call_ltv=0.75,
    )

    assert [item.template_slug for item in report.rankings] == [
        "protective-put-atm-12m",
        "ladder-50-50-atm-95pct-12m",
        "protective-put-95pct-12m",
        "protective-put-90pct-12m",
    ]


def test_event_comparison_page_service_exposes_seeded_preset_options() -> None:
    service = EventComparisonPageService()

    options = service.preset_options("GLD")

    assert options[0]["slug"] == "gld-jan-2024-selloff"
    assert options[0]["label"] == "GLD January 2024 Selloff"
    assert tuple(options[0]["default_template_slugs"]) == (
        "protective-put-atm-12m",
        "protective-put-95pct-12m",
        "protective-put-90pct-12m",
        "ladder-50-50-atm-95pct-12m",
    )


def test_event_comparison_page_service_resets_template_selection_to_preset_defaults() -> None:
    service = EventComparisonPageService()

    assert service.default_template_selection("gld-jan-2024-selloff") == (
        "protective-put-atm-12m",
        "protective-put-95pct-12m",
        "protective-put-90pct-12m",
        "ladder-50-50-atm-95pct-12m",
    )
    assert service.default_template_selection("gld-jan-2024-drawdown") == (
        "protective-put-atm-12m",
        "ladder-50-50-atm-95pct-12m",
        "ladder-33-33-33-atm-95pct-90pct-12m",
    )


def test_event_comparison_page_service_preview_uses_same_materialization_path() -> None:
    service = EventComparisonPageService()

    scenario = service.preview_scenario(
        preset_slug="gld-jan-2024-selloff",
        template_slugs=("protective-put-atm-12m",),
        underlying_units=1000.0,
        loan_amount=68000.0,
        margin_call_ltv=0.75,
    )

    assert scenario.start_date.isoformat() == "2024-01-02"
    assert scenario.end_date.isoformat() == "2024-01-08"
    assert scenario.initial_portfolio.entry_spot == 100.0
    assert [ref.slug for ref in scenario.template_refs] == ["protective-put-atm-12m"]


def test_event_comparison_fixture_fails_closed_for_unsupported_range() -> None:
    source = EventComparisonFixtureHistoricalPriceSource()

    with pytest.raises(ValueError, match="seeded 2024-01-02 through 2024-01-08"):
        source.load_daily_closes("GLD", date(2024, 1, 1), date(2024, 1, 8))


def test_event_comparison_page_service_builds_chart_model_with_unhedged_reference() -> None:
    service = EventComparisonPageService()

    report = service.run_read_only_comparison(
        preset_slug="gld-jan-2024-selloff",
        template_slugs=("protective-put-atm-12m", "protective-put-95pct-12m"),
        underlying_units=1000.0,
        loan_amount=68000.0,
        margin_call_ltv=0.75,
    )
    chart_model = service.chart_model(report)

    assert chart_model.dates == (
        "2024-01-02",
        "2024-01-03",
        "2024-01-04",
        "2024-01-05",
        "2024-01-08",
    )
    assert chart_model.series[0].name == "Unhedged collateral baseline"
    assert chart_model.series[1].name == "Protective Put ATM"
    assert len(chart_model.series[0].values) == len(chart_model.dates)