from datetime import date
from decimal import Decimal

from app.engine.scenario import (PlainModifier, PlainRecurring, effective_end,
                                 modified_amount)
from app.models.tables import (Loan, PlannedItem, RecurringItem, Scenario,
                               ScenarioLoan, ScenarioModifier,
                               ScenarioPlannedItem)
from app.services.projection_service import load_scenario_inputs


def test_modifikator_helfer_oeffentlich():
    mods = [PlainModifier("recurring", 1, "percent", Decimal("10")),
            PlainModifier("recurring", 1, "ende", Decimal("0"), date(2030, 6, 30))]
    assert modified_amount(Decimal("-100.00"), None, 1, mods) == Decimal("-90.00")
    assert modified_amount(Decimal("-100.00"), None, 2, mods) == Decimal("-100.00")
    r = PlainRecurring(1, "R", Decimal("-100.00"), "monthly", 1, None,
                       date(2030, 12, 31), None)
    assert effective_end(r, mods) == date(2030, 6, 30)


def _daten(db):
    rec = RecurringItem(name="R", amount=Decimal("-10.00"), rhythm="monthly", due_day=1)
    pln = PlannedItem(name="P", amount=Decimal("-20.00"), due=date(2030, 1, 1))
    k1 = Loan(name="K1", principal=Decimal("100.00"), annual_rate_pct=Decimal("0"),
              term_months=2, payout_date=date(2030, 1, 1), repayment_type="annuity")
    k2 = Loan(name="K2", principal=Decimal("200.00"), annual_rate_pct=Decimal("0"),
              term_months=2, payout_date=date(2030, 1, 1), repayment_type="annuity")
    sc = Scenario(name="S", description="", include_recurring=True,
                  include_planned=False)
    db.add_all([rec, pln, k1, k2, sc])
    db.flush()
    db.add_all([
        ScenarioLoan(scenario_id=sc.id, loan_id=k1.id),
        ScenarioModifier(scenario_id=sc.id, target_type="recurring",
                         target_id=rec.id, kind="percent", value=Decimal("50")),
        ScenarioPlannedItem(scenario_id=sc.id, name="SP", amount=Decimal("-5.00"),
                            due=date(2030, 2, 1)),
    ])
    db.commit()
    return sc


def test_load_scenario_inputs_szenario(db):
    sc = _daten(db)
    inp = load_scenario_inputs(db, sc)
    assert [r.name for r in inp.recurring] == ["R"]
    # include_planned=False: globale Einmalposten fehlen, Szenario-eigene zählen immer.
    assert [p.name for p in inp.planned] == ["SP"]
    assert inp.planned[0].category_id is None
    assert [l.name for l in inp.loans] == ["K1"]
    assert [(m.kind, m.value) for m in inp.modifiers] == [("percent", Decimal("50"))]


def test_load_scenario_inputs_ohne_fixposten(db):
    sc = _daten(db)
    sc.include_recurring = False
    db.commit()
    assert load_scenario_inputs(db, sc).recurring == []


def test_load_scenario_inputs_system_plan(db):
    _daten(db)
    inp = load_scenario_inputs(db, None)
    assert [r.name for r in inp.recurring] == ["R"]
    assert [p.name for p in inp.planned] == ["P"]
    assert [l.name for l in inp.loans] == ["K1", "K2"]
    assert inp.modifiers == []