"""Persistence round-trip fidelity for EPC Property Data (Slice 1, #1129).

The load-bearing risk of the ara_first_run rebuild: an EpcPropertyData mapped to
the epc_property tables, saved, reloaded and mapped back must reconstruct the
original object exactly. A failure here is either a missing column (a migration
the FE repo must make) or a mapper gap — either way we want it to fail loudly,
inside First Run, rather than be deferred to a later Refresh.
"""

from __future__ import annotations

import json
from pathlib import Path
from typing import Any

import pytest
from sqlalchemy import Engine
from sqlmodel import Session

from datatypes.epc.domain.epc_property_data import EpcPropertyData
from datatypes.epc.domain.mapper import EpcPropertyDataMapper
from repositories.epc.epc_postgres_repository import EpcPostgresRepository

_JSON_SAMPLES = Path(__file__).resolve().parents[3] / "backend/epc_api/json_samples"


def _load_epc(schema_dir: str) -> EpcPropertyData:
    raw: dict[str, Any] = json.loads(
        (_JSON_SAMPLES / schema_dir / "epc.json").read_text()
    )
    return EpcPropertyDataMapper.from_api_response(raw)


@pytest.mark.parametrize(
    "schema_dir",
    ["RdSAP-Schema-21.0.0", "RdSAP-Schema-21.0.1"],
)
def test_epc_property_data_round_trips(schema_dir: str, db_engine: Engine) -> None:
    # Arrange
    original = _load_epc(schema_dir)

    # Act
    with Session(db_engine) as session:
        epc_property_id = EpcPostgresRepository(session).save(original)
        session.commit()
    with Session(db_engine) as session:
        reloaded = EpcPostgresRepository(session).get(epc_property_id)

    # Assert
    assert reloaded == original


def test_non_separated_conservatory_round_trips(db_engine: Engine) -> None:
    # RdSAP 10 §6.1 — a non-separated conservatory (conservatory_type=4) maps to
    # `EpcPropertyData.sap_conservatory` (the glazed BP is split out of the
    # fabric parts). Persistence must round-trip it: scoring reads the reloaded
    # picture, so a dropped `sap_conservatory` silently disregards the
    # conservatory (persist != score). We inject the conservatory onto the
    # known-clean 21.0.1 sample so the ONLY thing that can break deep-equality
    # is `sap_conservatory` itself.

    # Arrange — known-clean base + a non-separated double-glazed conservatory.
    raw: dict[str, Any] = json.loads(
        (_JSON_SAMPLES / "RdSAP-Schema-21.0.1" / "epc.json").read_text()
    )
    raw["conservatory_type"] = 4
    raw["sap_building_parts"].append(
        {
            "floor_area": 12.0,
            "room_height": 1,
            "double_glazed": "Y",
            "glazed_perimeter": 9.0,
        }
    )
    original = EpcPropertyDataMapper.from_api_response(raw)
    assert original.sap_conservatory is not None, "mapper must split the conservatory"

    # Act
    with Session(db_engine) as session:
        epc_property_id = EpcPostgresRepository(session).save(original)
        session.commit()
    with Session(db_engine) as session:
        reloaded = EpcPostgresRepository(session).get(epc_property_id)

    # Assert — the conservatory survives the round-trip, deep-equal.
    assert reloaded == original


def test_photovoltaic_arrays_round_trip(db_engine: Engine) -> None:
    # SAP 10.2 Appendix M — a dwelling's solar PV arrays generate electricity that
    # offsets demand, worth a large slice of the SAP score (≈12 points on an
    # electrically-heated dwelling). `sap_energy_source.photovoltaic_arrays` had
    # no table, so every array was dropped on save (persist != score). We inject
    # two arrays (distinct, so ORDER is observable) onto a clean PV-free fixture
    # so the ONLY thing that can break deep-equality is the array list itself.
    from dataclasses import replace

    from datatypes.epc.domain.epc_property_data import PhotovoltaicArray

    # Arrange — a green fixture with no PV, plus two ordered arrays.
    original = _load_epc("RdSAP-Schema-21.0.1")
    assert original.sap_energy_source.photovoltaic_arrays is None, (
        "fixture must start PV-free so the array list is the only variable"
    )
    arrays = [
        PhotovoltaicArray(peak_power=3.24, pitch=3, overshading=1, orientation=3),
        PhotovoltaicArray(peak_power=1.5, pitch=2, overshading=2, orientation=None),
    ]
    original = replace(
        original,
        sap_energy_source=replace(
            original.sap_energy_source, photovoltaic_arrays=arrays
        ),
    )

    # Act
    with Session(db_engine) as session:
        epc_property_id = EpcPostgresRepository(session).save(original)
        session.commit()
    with Session(db_engine) as session:
        reloaded = EpcPostgresRepository(session).get(epc_property_id)

    # Assert — both arrays survive in order, deep-equal.
    assert reloaded == original


def test_calculator_read_fields_round_trip(db_engine: Engine) -> None:
    # Seven fields the SAP calculator reads (cert_to_inputs / heat_transmission)
    # that had no DB column, so they were silently dropped on save (persist !=
    # score). FE columns now exist; inject all seven onto a clean fixture and
    # prove they survive the round-trip deep-equal.
    from dataclasses import replace

    # Arrange
    original = _load_epc("RdSAP-Schema-21.0.1")
    bp0 = original.sap_building_parts[0]
    assert bp0.sap_alternative_wall_1 is not None, "fixture must carry an alt wall"
    bp0 = replace(
        bp0,
        sap_alternative_wall_1=replace(bp0.sap_alternative_wall_1, is_sheltered=True),
        wall_insulation_thermal_conductivity=35,  # Union[int,str] → JSONB int
    )
    heating = original.sap_heating
    mh0 = replace(
        heating.main_heating_details[0],
        community_heating_boiler_fuel_type=35,
        community_heating_chp_fraction=0.35,
    )
    heating = replace(
        heating,
        main_heating_details=[mh0, *heating.main_heating_details[1:]],
        cylinder_volume_measured_l=180,
    )
    original = replace(
        original,
        sap_building_parts=[bp0, *original.sap_building_parts[1:]],
        sap_heating=heating,
        sap_energy_source=replace(original.sap_energy_source, pv_diverter_present=True),
        sap_ventilation=replace(
            original.sap_ventilation, air_permeability_ap50_m3_h_m2=7.5
        ),
    )

    # Act
    with Session(db_engine) as session:
        epc_property_id = EpcPostgresRepository(session).save(original)
        session.commit()
    with Session(db_engine) as session:
        reloaded = EpcPostgresRepository(session).get(epc_property_id)

    # Assert — all seven calculator-read fields survive, deep-equal.
    assert reloaded == original


def test_floor_dimension_heat_loss_flags_round_trip(db_engine: Engine) -> None:
    # SAP 10.2 §3.3 — `is_exposed_floor` and `is_above_partially_heated_space`
    # are heat-loss flags on a `SapFloorDimension`: the calculator routes a floor
    # over outside air / over a partially-heated space through a different
    # U-value path. They had no `epc_floor_dimension` column, so a True flag
    # round-tripped back to the `False` default and silently flipped the floor's
    # heat loss (persist != score). We force both True on a clean fixture so the
    # ONLY thing that can break deep-equality is these two flags.
    from dataclasses import replace

    # Arrange — a green fixture with a floor dimension, both flags forced True.
    original = _load_epc("RdSAP-Schema-21.0.0")
    assert original.sap_building_parts, "fixture must have a building part"
    bp0 = original.sap_building_parts[0]
    assert bp0.sap_floor_dimensions, "fixture building part must have a floor dimension"
    dim0 = replace(
        bp0.sap_floor_dimensions[0],
        is_exposed_floor=True,
        is_above_partially_heated_space=True,
    )
    bp0 = replace(bp0, sap_floor_dimensions=[dim0, *bp0.sap_floor_dimensions[1:]])
    original = replace(
        original, sap_building_parts=[bp0, *original.sap_building_parts[1:]]
    )

    # Act
    with Session(db_engine) as session:
        epc_property_id = EpcPostgresRepository(session).save(original)
        session.commit()
    with Session(db_engine) as session:
        reloaded = EpcPostgresRepository(session).get(epc_property_id)

    # Assert — both flags survive the round-trip, deep-equal.
    assert reloaded == original


def test_building_part_wall_insulation_thickness_preserves_int(
    db_engine: Engine,
) -> None:
    # SAP 10.2 §5.7/Table 8: when the API lodges
    # `wall_insulation_thickness == "measured"`, the mapper resolves the
    # value to an int mm. The `epc_building_part.wall_insulation_thickness`
    # column must therefore preserve int vs str on round-trip (JSONB), like
    # its `roof_insulation_thickness` sibling — a plain str column would
    # round-trip the int 100 back as "100" and corrupt the Table 8 lookup.
    from dataclasses import replace

    # Arrange — take a green fixture and force the measured-int case.
    original = _load_epc("RdSAP-Schema-21.0.0")
    assert original.sap_building_parts, "fixture must have a building part"
    bp0 = replace(original.sap_building_parts[0], wall_insulation_thickness=100)
    original = replace(
        original,
        sap_building_parts=[bp0, *original.sap_building_parts[1:]],
    )

    # Act
    with Session(db_engine) as session:
        epc_property_id = EpcPostgresRepository(session).save(original)
        session.commit()
    with Session(db_engine) as session:
        reloaded = EpcPostgresRepository(session).get(epc_property_id)

    # Assert — the int survives as an int, not the string "100".
    assert reloaded is not None
    value = reloaded.sap_building_parts[0].wall_insulation_thickness
    assert value == 100
    assert isinstance(value, int)