"""S1-T05: Solar simulation unit tests."""

import numpy as np

from remodel_engine.generation.solar import annual_cuf, simulate_solar
from remodel_engine.schemas.generation import SolarConfig

SMALL_SOLAR = SolarConfig(
    location_id="RJ",
    capacity_dc_mwp=100.0,
    capacity_ac_mw=80.0,
)


def test_output_shape() -> None:
    df = simulate_solar(SMALL_SOLAR)
    assert df.shape == (25 * 8760, 6)
    assert set(df.columns) == {
        "year", "hour", "dc_power_mw", "ac_power_mw_pre_clip", "ac_power_mw", "degradation_factor"
    }


def test_year_range() -> None:
    df = simulate_solar(SMALL_SOLAR)
    assert df["year"].min() == 1
    assert df["year"].max() == 25


def test_hour_range() -> None:
    df = simulate_solar(SMALL_SOLAR)
    y1 = df[df["year"] == 1]
    assert y1["hour"].min() == 0
    assert y1["hour"].max() == 8759


def test_cuf_in_reasonable_range() -> None:
    """Solar CUF in Rajasthan should be between 15 % and 30 %."""
    df = simulate_solar(SMALL_SOLAR)
    cuf = annual_cuf(df, SMALL_SOLAR.capacity_ac_mw)
    assert all(0.15 <= v <= 0.30 for v in cuf), f"CUF out of range: {cuf.values}"


def test_no_negative_power() -> None:
    df = simulate_solar(SMALL_SOLAR)
    assert (df["ac_power_mw"] >= 0).all()
    assert (df["dc_power_mw"] >= 0).all()


def test_ac_never_exceeds_ac_capacity() -> None:
    """Clipping must hold: AC power ≤ capacity_ac_mw (with small float tolerance)."""
    df = simulate_solar(SMALL_SOLAR)
    assert (df["ac_power_mw"] <= SMALL_SOLAR.capacity_ac_mw + 1e-9).all()


def test_clipping_occurs() -> None:
    """High DC/AC ratio should produce some clipped hours."""
    cfg = SolarConfig(
        location_id="RJ",
        capacity_dc_mwp=140.0,  # DC/AC = 1.75 — aggressive over-panel
        capacity_ac_mw=80.0,
    )
    df = simulate_solar(cfg)
    y1 = df[df["year"] == 1]
    # ac_power_mw_pre_clip should exceed ac_power_mw in some hours
    clipped_hours = (y1["ac_power_mw_pre_clip"] > y1["ac_power_mw"] + 1e-9).sum()
    assert clipped_hours > 0, "Expected clipping for DC/AC ratio 1.75"


def test_no_clipping_when_dc_le_ac() -> None:
    """When DC capacity = AC capacity, ac_power_mw_pre_clip should never reach the AC cap
    (losses reduce AC output below DC nameplate, so the clip never bites)."""
    cfg = SolarConfig(
        location_id="RJ",
        capacity_dc_mwp=80.0,
        capacity_ac_mw=80.0,
    )
    df = simulate_solar(cfg)
    y1 = df[df["year"] == 1]
    # pre-clip column (before availability/soiling) must be < capacity_ac_mw everywhere
    assert (y1["ac_power_mw_pre_clip"] <= cfg.capacity_ac_mw + 1e-9).all()


def test_degradation_monotonically_decreasing() -> None:
    df = simulate_solar(SMALL_SOLAR)
    yearly_deg = (
        df.groupby("year")["degradation_factor"]
        .first()
        .values
    )
    diffs = np.diff(yearly_deg)
    assert (diffs < 0).all(), "Degradation factors must decrease each year"


def test_degradation_y1_applied() -> None:
    df = simulate_solar(SMALL_SOLAR)
    y1_deg = df[df["year"] == 1]["degradation_factor"].iloc[0]
    expected = 1.0 - SMALL_SOLAR.degradation_y1
    assert abs(y1_deg - expected) < 1e-9


def test_year25_degradation() -> None:
    df = simulate_solar(SMALL_SOLAR)
    y25_deg = df[df["year"] == 25]["degradation_factor"].iloc[0]
    expected = (1.0 - SMALL_SOLAR.degradation_y1) * (1.0 - SMALL_SOLAR.degradation_annual) ** 24
    assert abs(y25_deg - expected) < 1e-9


def test_dc_always_ge_ac_pre_clip() -> None:
    """DC output should always >= AC output before losses convert it down."""
    df = simulate_solar(SMALL_SOLAR)
    assert (df["dc_power_mw"] >= df["ac_power_mw"] - 1e-9).all()


def test_location_ka_cuf_reasonable() -> None:
    cfg = SolarConfig(location_id="KA", capacity_dc_mwp=100.0, capacity_ac_mw=80.0)
    df = simulate_solar(cfg)
    cuf = annual_cuf(df, cfg.capacity_ac_mw)
    assert all(0.15 <= v <= 0.35 for v in cuf)