from __future__ import annotations

from collections.abc import Iterator

import pytest
from sqlalchemy import create_engine
from sqlalchemy.orm import Session, sessionmaker

from config.database import Base
from models import (
    DistributionType,
    FinancialCategory,
    FinancialInput,
    MiningOperationType,
    Project,
    Scenario,
    ScenarioStatus,
    SimulationParameter,
    StochasticVariable,
)
from services.repositories import (
    FinancialInputRepository,
    ProjectRepository,
    ScenarioRepository,
    SimulationParameterRepository,
)
from services.unit_of_work import UnitOfWork


@pytest.fixture()
def engine():
    engine = create_engine("sqlite:///:memory:", future=True)
    Base.metadata.create_all(bind=engine)
    try:
        yield engine
    finally:
        Base.metadata.drop_all(bind=engine)


@pytest.fixture()
def session(engine) -> Iterator[Session]:
    TestingSession = sessionmaker(bind=engine, expire_on_commit=False, future=True)
    session = TestingSession()
    try:
        yield session
    finally:
        session.close()


def test_project_repository_create_and_list(session: Session) -> None:
    repo = ProjectRepository(session)
    project = Project(name="Project Alpha", operation_type=MiningOperationType.OPEN_PIT)
    repo.create(project)

    projects = repo.list()

    assert len(projects) == 1
    assert projects[0].name == "Project Alpha"


def test_scenario_repository_get_with_children(session: Session) -> None:
    project = Project(name="Project Beta", operation_type=MiningOperationType.UNDERGROUND)
    scenario = Scenario(name="Scenario 1", project=project, status=ScenarioStatus.ACTIVE)
    scenario.financial_inputs.append(
        FinancialInput(
            name="Lease Payment",
            category=FinancialCategory.OPERATING_EXPENDITURE,
            amount=10000,
            currency="usd",
        )
    )
    scenario.simulation_parameters.append(
        SimulationParameter(
            name="Copper Price",
            distribution=DistributionType.NORMAL,
            mean_value=3.5,
            variable=StochasticVariable.METAL_PRICE,
        )
    )

    session.add(project)
    session.flush()

    repo = ScenarioRepository(session)
    retrieved = repo.get(scenario.id, with_children=True)

    assert retrieved.project.name == "Project Beta"
    assert len(retrieved.financial_inputs) == 1
    assert retrieved.financial_inputs[0].currency == "USD"
    assert len(retrieved.simulation_parameters) == 1
    assert (
        retrieved.simulation_parameters[0].variable
        == StochasticVariable.METAL_PRICE
    )

    param_repo = SimulationParameterRepository(session)
    params = param_repo.list_for_scenario(scenario.id)
    assert len(params) == 1


def test_financial_input_repository_bulk_upsert(session: Session) -> None:
    project = Project(name="Project Gamma", operation_type=MiningOperationType.QUARRY)
    scenario = Scenario(name="Scenario Bulk", project=project)
    session.add(project)
    session.flush()

    repo = FinancialInputRepository(session)
    created = repo.bulk_upsert(
        [
            FinancialInput(
                scenario_id=scenario.id,
                name="Explosives",
                category=FinancialCategory.OPERATING_EXPENDITURE,
                amount=5000,
                currency="cad",
            ),
            FinancialInput(
                scenario_id=scenario.id,
                name="Equipment Lease",
                category=FinancialCategory.OPERATING_EXPENDITURE,
                amount=12000,
                currency="cad",
            ),
        ]
    )

    assert len(created) == 2
    stored = repo.list_for_scenario(scenario.id)
    assert len(stored) == 2
    assert all(item.currency == "CAD" for item in stored)


def test_unit_of_work_commit_and_rollback(engine) -> None:
    TestingSession = sessionmaker(bind=engine, expire_on_commit=False, future=True)

    # Commit path
    with UnitOfWork(session_factory=TestingSession) as uow:
        uow.projects.create(
            Project(name="Project Delta", operation_type=MiningOperationType.PLACER)
        )

    with TestingSession() as session:
        projects = ProjectRepository(session).list()
        assert len(projects) == 1

    # Rollback path
    with pytest.raises(RuntimeError):
        with UnitOfWork(session_factory=TestingSession) as uow:
            uow.projects.create(
                Project(name="Project Epsilon", operation_type=MiningOperationType.OTHER)
            )
            raise RuntimeError("trigger rollback")

    with TestingSession() as session:
        projects = ProjectRepository(session).list()
        assert len(projects) == 1