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#
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from __future__ import annotations

import json
from unittest import mock

import pendulum
import pytest
from httpx import Response
from sqlalchemy import select

from airflow.api_fastapi.core_api.routes.public.dag_sources import REDACTED_SOURCE
from airflow.models import DagModel
from airflow.models.dagbag import DBDagBag
from airflow.models.dagcode import DagCode
from airflow.utils.state import DagRunState
from airflow.utils.types import DagRunTriggeredByType, DagRunType

from tests_common.test_utils.dag import sync_dag_to_db
from tests_common.test_utils.db import clear_db_dags, clear_db_runs, parse_and_sync_to_db
from unit.serialization.test_dag_serialization import AIRFLOW_REPO_ROOT_PATH

pytestmark = pytest.mark.db_test

API_PREFIX = "/dagSources"

# Example bash operator located here: airflow/example_dags/example_bash_operator.py
EXAMPLE_DAG_FILE = (
    AIRFLOW_REPO_ROOT_PATH / "airflow-core" / "src" / "airflow" / "example_dags" / "example_simplest_dag.py"
)
TEST_DAG_ID = "example_simplest_dag"
TEST_DAG_DISPLAY_NAME = "example_simplest_dag"


@pytest.fixture
def real_dag_bag():
    return parse_and_sync_to_db(EXAMPLE_DAG_FILE)


@pytest.fixture
def test_dag(session, real_dag_bag):
    return DBDagBag().get_latest_version_of_dag(TEST_DAG_ID, session=session)


@pytest.fixture
def force_reserialization(real_dag_bag, session):
    def _force_reserialization(dag_id, bundle_name):
        dag = real_dag_bag.get_dag(dag_id, session=session)
        sync_dag_to_db(dag, bundle_name=bundle_name, session=session)

    return _force_reserialization


class TestGetDAGSource:
    @pytest.fixture(autouse=True)
    def setup(self, url_safe_serializer) -> None:
        self.clear_db()

    def teardown_method(self) -> None:
        self.clear_db()

    @staticmethod
    def _get_dag_file_code(fileloc: str) -> str | None:
        with open(fileloc) as f:
            file_contents = f.read()
        return file_contents

    def clear_db(self):
        clear_db_dags()
        clear_db_runs()

    def test_should_respond_200_text(self, test_client, test_dag):
        dag_content = self._get_dag_file_code(test_dag.fileloc)
        response: Response = test_client.get(f"{API_PREFIX}/{TEST_DAG_ID}", headers={"Accept": "text/plain"})

        assert response.status_code == 200
        assert dag_content == response.content.decode()
        with pytest.raises(json.JSONDecodeError):
            json.loads(response.content.decode())
        assert response.headers["Content-Type"].startswith("text/plain")

    def test_should_respond_401(self, unauthenticated_test_client):
        response = unauthenticated_test_client.get(
            f"{API_PREFIX}/{TEST_DAG_ID}", headers={"Accept": "text/plain"}
        )
        assert response.status_code == 401

    def test_should_respond_403(self, unauthorized_test_client):
        response = unauthorized_test_client.get(
            f"{API_PREFIX}/{TEST_DAG_ID}", headers={"Accept": "text/plain"}
        )
        assert response.status_code == 403

    @pytest.mark.parametrize(
        "headers", [{"Accept": "application/json"}, {"Accept": "application/json; charset=utf-8"}, {}]
    )
    def test_should_respond_200_json(self, test_client, test_dag, headers):
        dag_content = self._get_dag_file_code(test_dag.fileloc)
        response: Response = test_client.get(
            f"{API_PREFIX}/{TEST_DAG_ID}",
            headers=headers,
        )
        assert response.status_code == 200
        assert response.json() == {
            "content": dag_content,
            "dag_id": TEST_DAG_ID,
            "version_number": 1,
            "dag_display_name": TEST_DAG_DISPLAY_NAME,
        }
        assert response.headers["Content-Type"].startswith("application/json")

    @pytest.mark.parametrize("accept", ["application/json", "text/plain"])
    def test_should_respond_200_version(self, test_client, accept, session, test_dag, force_reserialization):
        dag_content = self._get_dag_file_code(test_dag.fileloc)
        test_dag.create_dagrun(
            run_id="test1",
            run_after=pendulum.datetime(2025, 1, 1, tz="UTC"),
            state=DagRunState.QUEUED,
            triggered_by=DagRunTriggeredByType.TEST,
            run_type=DagRunType.MANUAL,
        )
        # force reserialization
        test_dag.doc_md = "new doc"
        force_reserialization(test_dag.dag_id, "dag-folder")
        dagcode = session.scalars(
            select(DagCode).where(DagCode.fileloc == test_dag.fileloc).order_by(DagCode.id.desc())
        ).first()
        assert dagcode.dag_version.version_number == 2
        # populate the latest dagcode with a value
        dag_content2 = "new source code"
        dagcode.source_code = dag_content2
        session.merge(dagcode)
        session.commit()

        dagcodes = session.scalars(select(DagCode).where(DagCode.fileloc == test_dag.fileloc)).all()
        assert len(dagcodes) == 2
        url = f"{API_PREFIX}/{TEST_DAG_ID}"
        response = test_client.get(url, headers={"Accept": accept})

        assert response.status_code == 200
        if accept == "text/plain":
            assert dag_content2 == response.content.decode()
            assert dag_content != response.content.decode()
            assert response.headers["Content-Type"].startswith("text/plain")
        else:
            assert dag_content2 == response.json()["content"]
            assert dag_content != response.json()["content"]
            assert response.headers["Content-Type"] == "application/json"
            assert response.json() == {
                "content": dag_content2,
                "dag_id": TEST_DAG_ID,
                "version_number": 2,
                "dag_display_name": TEST_DAG_DISPLAY_NAME,
            }

    def test_should_respond_406_unsupport_mime_type(self, test_client, test_dag):
        response = test_client.get(
            f"{API_PREFIX}/{TEST_DAG_ID}",
            headers={"Accept": "text/html"},
        )
        assert response.status_code == 406

    def test_should_respond_404(self, test_client):
        wrong_fileloc = "abcd1234"
        url = f"{API_PREFIX}/{wrong_fileloc}"
        response = test_client.get(url, headers={"Accept": "application/json"})
        assert response.status_code == 404

    @pytest.fixture
    def colocated_unreadable_dag(self, session, test_dag):
        """Insert a second ``DagModel`` sharing the requested Dag's source file."""
        requested = session.scalar(select(DagModel).where(DagModel.dag_id == TEST_DAG_ID))
        colocated = DagModel(
            dag_id="other_dag_in_same_file",
            fileloc=requested.fileloc,
            relative_fileloc=requested.relative_fileloc,
            bundle_name=requested.bundle_name,
            is_paused=False,
        )
        session.add(colocated)
        session.commit()
        return colocated

    @mock.patch("airflow.api_fastapi.core_api.routes.public.dag_sources.get_auth_manager")
    def test_source_is_redacted_when_caller_cannot_read_all_dags_in_file(
        self, mock_get_auth_manager, test_client, test_dag, colocated_unreadable_dag
    ):
        mock_get_auth_manager.return_value.get_authorized_dag_ids.return_value = {TEST_DAG_ID}

        response: Response = test_client.get(
            f"{API_PREFIX}/{TEST_DAG_ID}", headers={"Accept": "application/json"}
        )

        assert response.status_code == 200
        assert response.json() == {
            "content": REDACTED_SOURCE,
            "dag_id": TEST_DAG_ID,
            "version_number": 1,
            "dag_display_name": TEST_DAG_DISPLAY_NAME,
        }
        mock_get_auth_manager.return_value.get_authorized_dag_ids.assert_called_once_with(user=mock.ANY)

    @mock.patch("airflow.api_fastapi.core_api.routes.public.dag_sources.get_auth_manager")
    def test_source_is_returned_when_caller_can_read_all_dags_in_file(
        self, mock_get_auth_manager, test_client, test_dag, colocated_unreadable_dag
    ):
        mock_get_auth_manager.return_value.get_authorized_dag_ids.return_value = {
            TEST_DAG_ID,
            colocated_unreadable_dag.dag_id,
        }
        dag_content = self._get_dag_file_code(test_dag.fileloc)

        response: Response = test_client.get(
            f"{API_PREFIX}/{TEST_DAG_ID}", headers={"Accept": "application/json"}
        )

        assert response.status_code == 200
        assert response.json() == {
            "content": dag_content,
            "dag_id": TEST_DAG_ID,
            "version_number": 1,
            "dag_display_name": TEST_DAG_DISPLAY_NAME,
        }
