"""CRUD de datasets en Google BigQuery."""

from .client import BQClient
from google.cloud import bigquery


def bq_create_dataset(
    client: BQClient,
    dataset_id: str,
    location: str = "US",
    description: str = "",
    labels: dict[str, str] | None = None,
    default_table_expiration_ms: int = 0,
) -> dict:
    """Crea un dataset en BigQuery.

    Args:
        client: Cliente autenticado.
        dataset_id: ID del dataset (solo el nombre, sin proyecto).
        location: Ubicacion geografica (US, EU, us-central1, etc.).
        description: Descripcion opcional.
        labels: Labels key-value opcionales.
        default_table_expiration_ms: Expiracion por defecto de tablas en ms. 0 = sin expiracion.

    Returns:
        Dict con: dataset_id, project, full_id, location, description, labels, created, modified,
        default_table_expiration_ms.

    Raises:
        google.api_core.exceptions.Conflict: Si el dataset ya existe (409).

    Example:
        >>> ds = bq_create_dataset(client, "analytics", location="EU", description="Data warehouse")
    """
    ref = f"{client.project_id}.{dataset_id}"
    ds = bigquery.Dataset(ref)
    ds.location = location
    if description:
        ds.description = description
    if labels:
        ds.labels = labels
    if default_table_expiration_ms > 0:
        ds.default_table_expiration_ms = default_table_expiration_ms
    created = client._client.create_dataset(ds)
    return _dataset_to_dict(created)


def bq_get_dataset(client: BQClient, dataset_id: str) -> dict:
    """Obtiene los detalles de un dataset.

    Args:
        client: Cliente autenticado.
        dataset_id: ID del dataset.

    Returns:
        Dict con: dataset_id, project, full_id, location, description, labels,
        created, modified, default_table_expiration_ms.

    Raises:
        google.api_core.exceptions.NotFound: Si el dataset no existe (404).

    Example:
        >>> ds = bq_get_dataset(client, "analytics")
        >>> print(ds["location"], ds["description"])
    """
    ref = f"{client.project_id}.{dataset_id}"
    ds = client._client.get_dataset(ref)
    return _dataset_to_dict(ds)


def bq_list_datasets(client: BQClient) -> list[dict]:
    """Lista todos los datasets del proyecto.

    Args:
        client: Cliente autenticado.

    Returns:
        Lista de dicts con: dataset_id, project, full_id.

    Example:
        >>> datasets = bq_list_datasets(client)
        >>> for ds in datasets:
        ...     print(ds["dataset_id"], ds["full_id"])
    """
    return [
        {
            "dataset_id": ds.dataset_id,
            "project": ds.project,
            "full_id": f"{ds.project}.{ds.dataset_id}",
        }
        for ds in client._client.list_datasets()
    ]


def bq_update_dataset(
    client: BQClient,
    dataset_id: str,
    description: str | None = None,
    labels: dict[str, str] | None = None,
    default_table_expiration_ms: int | None = None,
) -> dict:
    """Actualiza campos de un dataset.

    Solo se modifican los campos pasados (no-None).

    Args:
        client: Cliente autenticado.
        dataset_id: ID del dataset.
        description: Nueva descripcion (None = no cambiar).
        labels: Nuevos labels (None = no cambiar).
        default_table_expiration_ms: Nueva expiracion de tablas en ms (None = no cambiar).

    Returns:
        Dict con el dataset actualizado.

    Raises:
        google.api_core.exceptions.NotFound: Si el dataset no existe.

    Example:
        >>> bq_update_dataset(client, "analytics", description="Updated description")
    """
    ref = f"{client.project_id}.{dataset_id}"
    ds = client._client.get_dataset(ref)
    fields = []
    if description is not None:
        ds.description = description
        fields.append("description")
    if labels is not None:
        ds.labels = labels
        fields.append("labels")
    if default_table_expiration_ms is not None:
        ds.default_table_expiration_ms = default_table_expiration_ms
        fields.append("default_table_expiration_ms")
    if not fields:
        return _dataset_to_dict(ds)
    updated = client._client.update_dataset(ds, fields)
    return _dataset_to_dict(updated)


def bq_delete_dataset(
    client: BQClient,
    dataset_id: str,
    delete_contents: bool = False,
) -> None:
    """Elimina un dataset.

    Args:
        client: Cliente autenticado.
        dataset_id: ID del dataset.
        delete_contents: Si True, elimina todas las tablas del dataset.
            Si False y el dataset tiene tablas, falla.

    Raises:
        google.api_core.exceptions.NotFound: Si el dataset no existe.
        google.api_core.exceptions.BadRequest: Si tiene tablas y delete_contents=False.

    Example:
        >>> bq_delete_dataset(client, "temp_analytics", delete_contents=True)
    """
    ref = f"{client.project_id}.{dataset_id}"
    client._client.delete_dataset(ref, delete_contents=delete_contents)


def _dataset_to_dict(ds) -> dict:
    """Convierte un objeto Dataset del SDK a dict plano."""
    return {
        "dataset_id": ds.dataset_id,
        "project": ds.project,
        "full_id": f"{ds.project}.{ds.dataset_id}",
        "location": ds.location,
        "description": ds.description or "",
        "labels": dict(ds.labels) if ds.labels else {},
        "created": ds.created.isoformat() if ds.created else None,
        "modified": ds.modified.isoformat() if ds.modified else None,
        "default_table_expiration_ms": ds.default_table_expiration_ms,
    }