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# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
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# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
from __future__ import annotations

import os
from typing import TYPE_CHECKING, Annotated

from fastapi import Depends, Header, HTTPException, Query, status
from fastapi.exceptions import RequestValidationError
from pydantic import ValidationError
from sqlalchemy import select
from sqlalchemy.exc import IntegrityError

from airflow.api_fastapi.app import get_auth_manager
from airflow.api_fastapi.auth.managers.models.resource_details import ConnectionDetails
from airflow.api_fastapi.common.db.common import SessionDep, paginated_select
from airflow.api_fastapi.common.parameters import (
    QueryConnectionIdPatternSearch,
    QueryConnectionIdPrefixPatternSearch,
    QueryLimit,
    QueryOffset,
    SortParam,
)
from airflow.api_fastapi.common.router import AirflowRouter
from airflow.api_fastapi.compat import HTTP_422_UNPROCESSABLE_CONTENT
from airflow.api_fastapi.core_api.datamodels.common import (
    BulkBody,
    BulkResponse,
)
from airflow.api_fastapi.core_api.datamodels.connections import (
    AsyncConnectionTestResponse,
    ConnectionBody,
    ConnectionBodyPartial,
    ConnectionCollectionResponse,
    ConnectionResponse,
    ConnectionTestQueuedResponse,
    ConnectionTestRequestBody,
    ConnectionTestResponse,
)
from airflow.api_fastapi.core_api.openapi.exceptions import create_openapi_http_exception_doc
from airflow.api_fastapi.core_api.security import (
    GetUserDep,
    ReadableConnectionsFilterDep,
    requires_access_connection,
    requires_access_connection_bulk,
)
from airflow.api_fastapi.core_api.services.public.connections import (
    BulkConnectionService,
    update_orm_from_pydantic,
)
from airflow.api_fastapi.logging.decorators import action_logging
from airflow.configuration import conf
from airflow.exceptions import AirflowNotFoundException
from airflow.executors.executor_loader import ExecutorLoader
from airflow.models import Connection
from airflow.models.connection_test import ConnectionTestRequest
from airflow.secrets.environment_variables import CONN_ENV_PREFIX
from airflow.utils.db import create_default_connections as db_create_default_connections
from airflow.utils.strings import get_random_string

if TYPE_CHECKING:
    from airflow.api_fastapi.auth.managers.base_auth_manager import ResourceMethod

connections_router = AirflowRouter(tags=["Connection"], prefix="/connections")


def _ensure_test_connection_enabled() -> None:
    """Raise 403 if connection testing is not enabled in the Airflow configuration."""
    if conf.get("core", "test_connection", fallback="Disabled").lower().strip() != "enabled":
        raise HTTPException(
            status.HTTP_403_FORBIDDEN,
            "Testing connections is disabled in Airflow configuration. "
            "Contact your deployment admin to enable it.",
        )


def _ensure_executor_is_configured(executor: str | None) -> None:
    """Raise 422 if the requested executor is not in the configured executors list."""
    if executor is None:
        return
    configured = ExecutorLoader.get_executor_names(validate_teams=False)
    if not any(
        executor in (name.alias, name.module_path, name.module_path.split(".")[-1]) for name in configured
    ):
        raise HTTPException(
            HTTP_422_UNPROCESSABLE_CONTENT,
            f"Executor '{executor}' is not configured. "
            f"Configured executors: {[name.alias or name.module_path for name in configured]}",
        )


@connections_router.delete(
    "/{connection_id}",
    status_code=status.HTTP_204_NO_CONTENT,
    responses=create_openapi_http_exception_doc([status.HTTP_404_NOT_FOUND]),
    dependencies=[Depends(requires_access_connection(method="DELETE")), Depends(action_logging())],
)
def delete_connection(
    connection_id: str,
    session: SessionDep,
):
    """Delete a connection entry."""
    connection = session.scalar(select(Connection).filter_by(conn_id=connection_id))

    if connection is None:
        raise HTTPException(
            status.HTTP_404_NOT_FOUND, f"The Connection with connection_id: `{connection_id}` was not found"
        )

    session.delete(connection)


@connections_router.get(
    "/enqueue-test",
    responses=create_openapi_http_exception_doc([status.HTTP_404_NOT_FOUND]),
)
def get_connection_test(
    session: SessionDep,
    user: GetUserDep,
    connection_test_token: Annotated[str, Header(alias="Airflow-Connection-Test-Token")],
) -> AsyncConnectionTestResponse:
    """Poll for the status of an enqueued connection test by its token (passed as a header)."""
    connection_test = session.scalar(select(ConnectionTestRequest).filter_by(token=connection_test_token))

    if connection_test is None:
        raise HTTPException(
            status.HTTP_404_NOT_FOUND,
            f"No connection test found for token: `{connection_test_token}`",
        )

    if not get_auth_manager().is_authorized_connection(
        method="GET",
        details=ConnectionDetails(conn_id=connection_test.connection_id, team_name=connection_test.team_name),
        user=user,
    ):
        raise HTTPException(
            status.HTTP_404_NOT_FOUND,
            f"No connection test found for token: `{connection_test_token}`",
        )

    return AsyncConnectionTestResponse(
        token=connection_test.token,
        connection_id=connection_test.connection_id,
        state=connection_test.state,
        result_message=connection_test.result_message,
        created_at=connection_test.created_at,
    )


@connections_router.get(
    "/{connection_id}",
    responses=create_openapi_http_exception_doc([status.HTTP_404_NOT_FOUND]),
    dependencies=[Depends(requires_access_connection(method="GET"))],
)
def get_connection(
    connection_id: str,
    session: SessionDep,
) -> ConnectionResponse:
    """Get a connection entry."""
    connection = session.scalar(select(Connection).filter_by(conn_id=connection_id))

    if connection is None:
        raise HTTPException(
            status.HTTP_404_NOT_FOUND, f"The Connection with connection_id: `{connection_id}` was not found"
        )

    return connection


@connections_router.get(
    "",
    responses=create_openapi_http_exception_doc([status.HTTP_404_NOT_FOUND]),
    dependencies=[Depends(requires_access_connection(method="GET"))],
)
def get_connections(
    limit: QueryLimit,
    offset: QueryOffset,
    order_by: Annotated[
        SortParam,
        Depends(
            SortParam(
                ["conn_id", "conn_type", "description", "host", "port", "id", "team_name"],
                Connection,
                {"connection_id": "conn_id"},
            ).dynamic_depends()
        ),
    ],
    readable_connections_filter: ReadableConnectionsFilterDep,
    session: SessionDep,
    connection_id_pattern: QueryConnectionIdPatternSearch,
    connection_id_prefix_pattern: QueryConnectionIdPrefixPatternSearch,
) -> ConnectionCollectionResponse:
    """Get all connection entries."""
    connection_select, total_entries = paginated_select(
        statement=select(Connection),
        filters=[connection_id_pattern, connection_id_prefix_pattern, readable_connections_filter],
        order_by=order_by,
        offset=offset,
        limit=limit,
        session=session,
    )

    connections = session.scalars(connection_select)

    return ConnectionCollectionResponse(
        connections=connections,
        total_entries=total_entries,
    )


@connections_router.post(
    "",
    status_code=status.HTTP_201_CREATED,
    responses=create_openapi_http_exception_doc(
        [status.HTTP_409_CONFLICT]
    ),  # handled by global exception handler
    dependencies=[Depends(requires_access_connection(method="POST")), Depends(action_logging())],
)
def post_connection(
    post_body: ConnectionBody,
    session: SessionDep,
) -> ConnectionResponse:
    """Create connection entry."""
    connection = Connection(**post_body.model_dump(by_alias=True))
    session.add(connection)
    return connection


@connections_router.patch(
    "", dependencies=[Depends(requires_access_connection_bulk()), Depends(action_logging())]
)
def bulk_connections(
    request: BulkBody[ConnectionBody],
    session: SessionDep,
) -> BulkResponse:
    """Bulk create, update, and delete connections."""
    return BulkConnectionService(session=session, request=request).handle_request()


@connections_router.patch(
    "/{connection_id}",
    responses=create_openapi_http_exception_doc(
        [
            status.HTTP_400_BAD_REQUEST,
            status.HTTP_404_NOT_FOUND,
        ]
    ),
    dependencies=[Depends(requires_access_connection(method="PUT")), Depends(action_logging())],
)
def patch_connection(
    connection_id: str,
    patch_body: ConnectionBody,
    session: SessionDep,
    update_mask: list[str] | None = Query(None),
) -> ConnectionResponse:
    """Update a connection entry."""
    if patch_body.connection_id != connection_id:
        raise HTTPException(
            status.HTTP_400_BAD_REQUEST,
            "The connection_id in the request body does not match the URL parameter",
        )

    connection = session.scalar(select(Connection).filter_by(conn_id=connection_id).limit(1))

    if connection is None:
        raise HTTPException(
            status.HTTP_404_NOT_FOUND, f"The Connection with connection_id: `{connection_id}` was not found"
        )

    if update_mask:
        fields_to_update = patch_body.model_fields_set & set(update_mask)
        try:
            ConnectionBodyPartial(**patch_body.model_dump(include=fields_to_update))
        except ValidationError as e:
            raise RequestValidationError(errors=e.errors())

    update_orm_from_pydantic(connection, patch_body, update_mask)
    return connection


@connections_router.post("/test", dependencies=[Depends(requires_access_connection(method="POST"))])
def test_connection(test_body: ConnectionBody) -> ConnectionTestResponse:
    """
    Test an API connection.

    This method first creates an in-memory transient conn_id & exports that to an env var,
    as some hook classes tries to find out the `conn` from their __init__ method & errors out if not found.
    It also deletes the conn id env connection after the test.
    """
    _ensure_test_connection_enabled()

    transient_conn_id = get_random_string()
    conn_env_var = f"{CONN_ENV_PREFIX}{transient_conn_id.upper()}"
    try:
        # Try to get existing connection and merge with provided values
        try:
            existing_conn: Connection | None = Connection.get_connection_from_secrets(test_body.connection_id)
        except AirflowNotFoundException:
            existing_conn = None

        if existing_conn is not None:
            # Stored credentials are only reused to test the connection's own
            # host/port; testing a different destination must supply its own.
            fields_set = test_body.model_fields_set
            if ("host" in fields_set and test_body.host != existing_conn.host) or (
                "port" in fields_set and test_body.port != existing_conn.port
            ):
                if "password" not in fields_set:
                    raise HTTPException(
                        status.HTTP_400_BAD_REQUEST,
                        "The host or port to test differs from the stored connection. "
                        "Include the credentials to test in the request body.",
                    )
                existing_conn = None

        if existing_conn is not None:
            existing_conn.conn_id = transient_conn_id
            update_orm_from_pydantic(existing_conn, test_body)
            conn = existing_conn
        else:
            data = test_body.model_dump(by_alias=True)
            data["conn_id"] = transient_conn_id
            conn = Connection(**data)

        os.environ[conn_env_var] = conn.get_uri()
        test_status, test_message = conn.test_connection()
        return ConnectionTestResponse.model_validate({"status": test_status, "message": test_message})
    finally:
        os.environ.pop(conn_env_var, None)


@connections_router.post(
    "/enqueue-test",
    status_code=status.HTTP_202_ACCEPTED,
    responses=create_openapi_http_exception_doc(
        [
            status.HTTP_403_FORBIDDEN,
            status.HTTP_409_CONFLICT,
            HTTP_422_UNPROCESSABLE_CONTENT,
        ]
    ),
    dependencies=[Depends(action_logging())],
)
def enqueue_connection_test(
    test_body: ConnectionTestRequestBody,
    session: SessionDep,
    user: GetUserDep,
) -> ConnectionTestQueuedResponse:
    """Enqueue a connection test for deferred execution on a worker; returns a polling token."""
    _ensure_test_connection_enabled()
    _ensure_executor_is_configured(test_body.executor)

    existing = session.scalar(select(Connection).filter_by(conn_id=test_body.connection_id))
    if existing is not None:
        effective_team = existing.team_name
        if test_body.team_name is not None and test_body.team_name != effective_team:
            raise HTTPException(
                status.HTTP_403_FORBIDDEN,
                f"team_name `{test_body.team_name}` does not match the team of connection "
                f"`{test_body.connection_id}`.",
            )
    else:
        effective_team = test_body.team_name

    auth_method: ResourceMethod = "PUT" if existing is not None and test_body.commit_on_success else "POST"
    if not get_auth_manager().is_authorized_connection(
        method=auth_method,
        details=ConnectionDetails(conn_id=test_body.connection_id, team_name=effective_team),
        user=user,
    ):
        raise HTTPException(
            status.HTTP_403_FORBIDDEN,
            f"You are not authorized to test connection `{test_body.connection_id}`.",
        )

    connection_test = ConnectionTestRequest(
        connection_id=test_body.connection_id,
        conn_type=test_body.conn_type,
        host=test_body.host,
        login=test_body.login,
        password=test_body.password,
        schema=test_body.schema_,
        port=test_body.port,
        extra=test_body.extra,
        commit_on_success=test_body.commit_on_success,
        executor=test_body.executor,
        queue=test_body.queue,
        team_name=effective_team,
    )
    session.add(connection_test)
    try:
        session.flush()
    except IntegrityError:
        raise HTTPException(
            status.HTTP_409_CONFLICT,
            f"An active connection test already exists for connection_id `{test_body.connection_id}`.",
        )

    return ConnectionTestQueuedResponse(
        token=connection_test.token,
        connection_id=connection_test.connection_id,
        state=connection_test.state,
    )


@connections_router.post(
    "/defaults",
    status_code=status.HTTP_204_NO_CONTENT,
    dependencies=[Depends(requires_access_connection(method="POST")), Depends(action_logging())],
)
def create_default_connections(
    session: SessionDep,
):
    """Create default connections."""
    db_create_default_connections(session=session)
