from app.core.time_utils import utc_now
from typing import Any
from uuid import uuid4

from sqlalchemy import or_, text
from sqlalchemy.exc import OperationalError, SQLAlchemyError

from app.db.mock_database import SessionMockLocal
from app.db.mock_models import Order, User, Vehicle
from app.services.domain.common import is_legacy_schema_issue
from app.services.domain.credit_service import validar_cliente_venda
from app.services.domain.tool_errors import raise_tool_http_error
from app.services.integrations.events import ORDER_CANCELLED_EVENT, ORDER_CREATED_EVENT
from app.services.integrations.service import publish_business_event_safely
from app.services.orchestration.technical_normalizer import normalize_cpf
from app.services.user.mock_customer_service import hydrate_mock_customer_from_cpf

# Responsabilidade: regra de pedido.


def _get_vehicle_for_update(db, vehicle_id: int) -> Vehicle | None:
    return (
        db.query(Vehicle)
        .filter(Vehicle.id == vehicle_id)
        .with_for_update()
        .first()
    )


def _get_active_order_for_vehicle(db, vehicle_id: int) -> Order | None:
    return (
        db.query(Order)
        .filter(Order.vehicle_id == vehicle_id)
        .filter(Order.status != "Cancelado")
        .first()
    )


def _acquire_vehicle_reservation_lock(db, vehicle_id: int, timeout_seconds: int = 5) -> str | None:
    lock_name = f"orquestrador:vehicle_reservation:{vehicle_id}"
    try:
        acquired = db.execute(
            text("SELECT GET_LOCK(:lock_name, :timeout_seconds)"),
            {"lock_name": lock_name, "timeout_seconds": timeout_seconds},
        ).scalar()
    except (OperationalError, SQLAlchemyError):
        return None

    if int(acquired or 0) != 1:
        raise_tool_http_error(
            status_code=409,
            code="vehicle_reservation_busy",
            message="Outro atendimento esta finalizando a reserva deste veiculo. Tente novamente.",
            retryable=True,
            field="vehicle_id",
        )
    return lock_name


def _release_vehicle_reservation_lock(db, lock_name: str | None) -> None:
    if not lock_name:
        return
    try:
        db.execute(
            text("SELECT RELEASE_LOCK(:lock_name)"),
            {"lock_name": lock_name},
        )
    except (OperationalError, SQLAlchemyError):
        pass


async def listar_pedidos(
    user_id: int | None = None,
    cpf: str | None = None,
    status: str | None = None,
    limite: int = 20,
) -> list[dict[str, Any]]:
    cpf_norm = normalize_cpf(cpf) if cpf else None
    db = SessionMockLocal()
    try:
        user = None
        if user_id is not None:
            user = db.query(User).filter(User.id == user_id).first()
            if user and not cpf_norm:
                cpf_norm = normalize_cpf(user.cpf)

        query = db.query(Order)
        if user_id is not None and cpf_norm:
            query = query.filter(
                or_(
                    Order.user_id == user_id,
                    (Order.user_id.is_(None) & (Order.cpf == cpf_norm)),
                )
            )
        elif user_id is not None:
            query = query.filter(Order.user_id == user_id)
        elif cpf_norm:
            query = query.filter(Order.cpf == cpf_norm)
        else:
            raise_tool_http_error(
                status_code=400,
                code="order_list_missing_identity",
                message="Preciso identificar o cliente para listar os pedidos.",
                retryable=True,
                field="cpf",
            )

        normalized_status = str(status or "").strip()
        if normalized_status:
            query = query.filter(Order.status == normalized_status)

        safe_limit = max(1, min(int(limite or 20), 50))
        pedidos = query.order_by(Order.created_at.desc()).limit(safe_limit).all()

        if user_id is not None and pedidos:
            attached_legacy_orders = False
            for pedido in pedidos:
                if pedido.user_id is None:
                    pedido.user_id = user_id
                    attached_legacy_orders = True
            if attached_legacy_orders:
                db.commit()
                for pedido in pedidos:
                    db.refresh(pedido)

        return [
            {
                "numero_pedido": pedido.numero_pedido,
                "user_id": pedido.user_id,
                "cpf": pedido.cpf,
                "vehicle_id": pedido.vehicle_id,
                "modelo_veiculo": pedido.modelo_veiculo,
                "valor_veiculo": pedido.valor_veiculo,
                "status": pedido.status,
                "motivo": pedido.motivo_cancelamento,
                "data_cancelamento": pedido.data_cancelamento.isoformat() if pedido.data_cancelamento else None,
                "created_at": pedido.created_at.isoformat() if pedido.created_at else None,
            }
            for pedido in pedidos
        ]
    finally:
        db.close()


async def cancelar_pedido(
    numero_pedido: str,
    motivo: str,
    user_id: int | None = None,
) -> dict[str, Any]:
    db = SessionMockLocal()
    try:
        query = db.query(Order).filter(Order.numero_pedido == numero_pedido)
        if user_id is not None:
            query = query.filter(Order.user_id == user_id)

        pedido = query.first()
        if not pedido and user_id is not None:
            legado = (
                db.query(Order)
                .filter(Order.numero_pedido == numero_pedido)
                .filter(Order.user_id.is_(None))
                .first()
            )
            if legado:
                legado.user_id = user_id
                db.commit()
                db.refresh(legado)
                pedido = legado

        if not pedido:
            raise_tool_http_error(
                status_code=404,
                code="order_not_found",
                message=(
                    "Pedido nao encontrado para este usuario."
                    if user_id is not None
                    else "Pedido nao encontrado na base ficticia."
                ),
                retryable=True,
                field="numero_pedido",
            )

        if pedido.status.lower() == "cancelado":
            return {
                "numero_pedido": pedido.numero_pedido,
                "user_id": pedido.user_id,
                "status": pedido.status,
                "motivo": pedido.motivo_cancelamento,
                "data_cancelamento": pedido.data_cancelamento.isoformat() if pedido.data_cancelamento else None,
            }

        pedido.status = "Cancelado"
        pedido.motivo_cancelamento = motivo
        pedido.data_cancelamento = utc_now()
        db.commit()
        db.refresh(pedido)

        result = {
            "numero_pedido": pedido.numero_pedido,
            "user_id": pedido.user_id,
            "status": pedido.status,
            "motivo": pedido.motivo_cancelamento,
            "data_cancelamento": pedido.data_cancelamento.isoformat() if pedido.data_cancelamento else None,
        }
        await publish_business_event_safely(ORDER_CANCELLED_EVENT, result)
        return result
    finally:
        db.close()


async def realizar_pedido(
    cpf: str,
    vehicle_id: int,
    user_id: int | None = None,
) -> dict[str, Any]:
    cpf_norm = normalize_cpf(cpf)
    db = SessionMockLocal()
    reservation_lock_name: str | None = None
    try:
        vehicle = db.query(Vehicle).filter(Vehicle.id == vehicle_id).first()
        if not vehicle:
            raise_tool_http_error(
                status_code=404,
                code="vehicle_not_found",
                message="Veiculo nao encontrado no estoque.",
                retryable=True,
                field="vehicle_id",
            )

        valor_veiculo = float(vehicle.preco)
        modelo_veiculo = str(vehicle.modelo)

        try:
            await hydrate_mock_customer_from_cpf(cpf=cpf_norm, user_id=user_id)
        except ValueError as exc:
            if str(exc) == "cpf_already_linked":
                raise_tool_http_error(
                    status_code=409,
                    code="cpf_already_linked",
                    message="Este CPF ja esta vinculado a outro usuario.",
                    retryable=True,
                    field="cpf",
                )
            raise_tool_http_error(
                status_code=400,
                code="invalid_cpf",
                message="CPF invalido para realizar o pedido.",
                retryable=True,
                field="cpf",
            )

        avaliacao = await validar_cliente_venda(cpf=cpf_norm, valor_veiculo=valor_veiculo)
        if not avaliacao.get("aprovado"):
            raise_tool_http_error(
                status_code=400,
                code="credit_not_approved",
                message=(
                    "Cliente nao aprovado para este valor. "
                    f"Limite disponivel: R$ {avaliacao.get('limite_credito', 0):.2f}."
                ),
                retryable=False,
                field="cpf",
            )

        reservation_lock_name = _acquire_vehicle_reservation_lock(db, vehicle_id)

        try:
            locked_vehicle = _get_vehicle_for_update(db, vehicle_id)
        except (OperationalError, SQLAlchemyError) as exc:
            db.rollback()
            if not is_legacy_schema_issue(exc):
                raise
            locked_vehicle = db.query(Vehicle).filter(Vehicle.id == vehicle_id).first()

        if not locked_vehicle:
            raise_tool_http_error(
                status_code=404,
                code="vehicle_not_found",
                message="Veiculo nao encontrado no estoque.",
                retryable=True,
                field="vehicle_id",
            )

        existing_order = None
        try:
            existing_order = _get_active_order_for_vehicle(db, vehicle_id)
        except (OperationalError, SQLAlchemyError) as exc:
            if not is_legacy_schema_issue(exc):
                raise
            db.rollback()
        if existing_order:
            raise_tool_http_error(
                status_code=409,
                code="vehicle_already_reserved",
                message="Este veiculo ja esta reservado e nao aparece mais no estoque disponivel.",
                retryable=True,
                field="vehicle_id",
            )

        numero_pedido = f"PED-{utc_now().strftime('%Y%m%d%H%M%S')}-{uuid4().hex[:6].upper()}"

        pedido = Order(
            numero_pedido=numero_pedido,
            user_id=user_id,
            cpf=cpf_norm,
            vehicle_id=locked_vehicle.id,
            modelo_veiculo=modelo_veiculo,
            valor_veiculo=valor_veiculo,
            status="Ativo",
        )
        db.add(pedido)
        try:
            db.commit()
            db.refresh(pedido)
        except (OperationalError, SQLAlchemyError) as exc:
            db.rollback()
            if not is_legacy_schema_issue(exc):
                raise

            db.execute(
                text(
                    "INSERT INTO orders (numero_pedido, user_id, cpf, status) "
                    "VALUES (:numero_pedido, :user_id, :cpf, :status)"
                ),
                {
                    "numero_pedido": numero_pedido,
                    "user_id": user_id,
                    "cpf": cpf_norm,
                    "status": "Ativo",
                },
            )
            db.commit()
            result = {
                "numero_pedido": numero_pedido,
                "user_id": user_id,
                "cpf": cpf_norm,
                "vehicle_id": locked_vehicle.id,
                "modelo_veiculo": modelo_veiculo,
                "status": "Ativo",
                "status_veiculo": "Reservado",
                "valor_veiculo": valor_veiculo,
                "aprovado_credito": True,
            }
            await publish_business_event_safely(ORDER_CREATED_EVENT, result)
            return result

        result = {
            "numero_pedido": pedido.numero_pedido,
            "user_id": pedido.user_id,
            "cpf": pedido.cpf,
            "vehicle_id": pedido.vehicle_id,
            "modelo_veiculo": pedido.modelo_veiculo,
            "status": pedido.status,
            "status_veiculo": "Reservado",
            "valor_veiculo": pedido.valor_veiculo,
            "aprovado_credito": True,
        }
        await publish_business_event_safely(ORDER_CREATED_EVENT, result)
        return result
    finally:
        _release_vehicle_reservation_lock(db, reservation_lock_name)
        db.close()