import json
from datetime import UTC, datetime

from production_analytics.calculations.material_consumption import (
    MaterialConsumptionIntegrator,
    MaterialIntegrationState,
    MaterialIntegratorConfig,
    MaterialSample,
)
from production_analytics.calculations.material_state import (
    load_material_state,
    material_state_from_dict,
    material_state_to_dict,
    save_material_state,
)


def test_material_state_dict_roundtrip() -> None:
    original = MaterialIntegrationState(
        cumulative_consumption_kg=51.42714233398436,
        integrated_running_seconds=180.0,
        last_processed_timestamp=datetime(2026, 9, 3, 5, 10, 50, tzinfo=UTC),
        last_material_rate_kg_per_hour=1028.5428466796875,
        last_gate_value=2.1673481464385986,
        integration_active=True,
    )

    restored = material_state_from_dict(material_state_to_dict(original))

    assert restored == original


def test_material_state_json_file_roundtrip(tmp_path) -> None:
    original = MaterialIntegrationState(
        cumulative_consumption_kg=12.5,
        integrated_running_seconds=90.0,
        last_processed_timestamp=datetime(2026, 9, 3, 5, 10, 50, tzinfo=UTC),
        last_material_rate_kg_per_hour=500.0,
        last_gate_value=2.0,
        integration_active=True,
    )

    path = tmp_path / "material-state.json"

    save_material_state(str(path), original)
    restored = load_material_state(str(path))

    assert restored == original

    raw = json.loads(path.read_text(encoding="utf-8"))
    assert raw["last_processed_timestamp"] == "2026-09-03T05:10:50+00:00"


def test_integrator_restore_continues_without_double_counting(tmp_path) -> None:
    config = MaterialIntegratorConfig(
        gate_threshold=0.5,
        max_sample_gap_seconds=20.0,
    )

    samples = [
        MaterialSample(
            timestamp=datetime(2026, 9, 3, 5, 9, 40, tzinfo=UTC),
            material_rate_kg_per_hour=3600.0,
            gate_value=1.0,
        ),
        MaterialSample(
            timestamp=datetime(2026, 9, 3, 5, 9, 50, tzinfo=UTC),
            material_rate_kg_per_hour=3600.0,
            gate_value=1.0,
        ),
        MaterialSample(
            timestamp=datetime(2026, 9, 3, 5, 10, 0, tzinfo=UTC),
            material_rate_kg_per_hour=3600.0,
            gate_value=1.0,
        ),
    ]

    continuous = MaterialConsumptionIntegrator(config)
    continuous.process_many(samples)

    before_restart = MaterialConsumptionIntegrator(config)
    before_restart.process_many(samples[:2])

    path = tmp_path / "material-state.json"
    save_material_state(str(path), before_restart.state)

    restored = MaterialConsumptionIntegrator(
        config,
        initial_state=load_material_state(str(path)),
    )

    # Polling deliberately starts inclusively at the last processed timestamp.
    restored.process_many(samples[1:])

    assert restored.state == continuous.state
    assert restored.state.cumulative_consumption_kg == 20.0
    assert restored.state.integrated_running_seconds == 20.0