from __future__ import annotations

from collections.abc import Iterator
from datetime import datetime, timezone

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


def test_project_repository_count_and_recent(session: Session) -> None:
    repo = ProjectRepository(session)
    project_alpha = Project(name="Alpha", operation_type=MiningOperationType.OPEN_PIT)
    project_bravo = Project(name="Bravo", operation_type=MiningOperationType.UNDERGROUND)

    repo.create(project_alpha)
    repo.create(project_bravo)

    project_alpha.updated_at = datetime(2025, 1, 1, tzinfo=timezone.utc)
    project_bravo.updated_at = datetime(2025, 1, 2, tzinfo=timezone.utc)
    session.flush()

    assert repo.count() == 2
    recent = repo.recent(limit=1)
    assert len(recent) == 1
    assert recent[0].name == "Bravo"


def test_scenario_repository_counts_and_filters(session: Session) -> None:
    project = Project(name="Project", operation_type=MiningOperationType.PLACER)
    session.add(project)
    session.flush()

    repo = ScenarioRepository(session)
    draft = Scenario(name="Draft", project_id=project.id,
                     status=ScenarioStatus.DRAFT)
    active = Scenario(name="Active", project_id=project.id,
                      status=ScenarioStatus.ACTIVE)

    repo.create(draft)
    repo.create(active)

    draft.updated_at = datetime(2025, 1, 1, tzinfo=timezone.utc)
    active.updated_at = datetime(2025, 1, 3, tzinfo=timezone.utc)
    session.flush()

    assert repo.count() == 2
    assert repo.count_by_status(ScenarioStatus.ACTIVE) == 1

    recent = repo.recent(limit=1, with_project=True)
    assert len(recent) == 1
    assert recent[0].name == "Active"
    assert recent[0].project.name == "Project"

    drafts = repo.list_by_status(ScenarioStatus.DRAFT, limit=2, with_project=True)
    assert len(drafts) == 1
    assert drafts[0].name == "Draft"
    assert drafts[0].project_id == project.id


def test_financial_input_repository_latest_created_at(session: Session) -> None:
    project = Project(name="Project FI", operation_type=MiningOperationType.OTHER)
    scenario = Scenario(name="Scenario FI", project=project)
    session.add(project)
    session.flush()

    repo = FinancialInputRepository(session)
    old_timestamp = datetime(2024, 12, 31, 15, 0)
    new_timestamp = datetime(2025, 1, 2, 8, 30)

    repo.bulk_upsert(
        [
            FinancialInput(
                scenario_id=scenario.id,
                name="Legacy Entry",
                category=FinancialCategory.OPERATING_EXPENDITURE,
                amount=1000,
                currency="usd",
                created_at=old_timestamp,
                updated_at=old_timestamp,
            ),
            FinancialInput(
                scenario_id=scenario.id,
                name="New Entry",
                category=FinancialCategory.OPERATING_EXPENDITURE,
                amount=2000,
                currency="usd",
                created_at=new_timestamp,
                updated_at=new_timestamp,
            ),
        ]
    )

    latest = repo.latest_created_at()
    assert latest == new_timestamp