import filecmp
import json
import mock
import os
import shutil

import pytest

import mlflow
from mlflow.entities import RunStatus
from mlflow.projects import databricks, ExecutionException
from mlflow.utils import file_utils

from tests.projects.utils import validate_exit_status, TEST_PROJECT_DIR, assert_dirs_equal
from tests.projects.utils import tracking_uri_mock  # pylint: disable=unused-import


@pytest.fixture()
def runs_cancel_mock():
    """Mocks the Jobs Runs Cancel API request"""
    with mock.patch("mlflow.projects.databricks._jobs_runs_cancel") as runs_cancel_mock:
        runs_cancel_mock.return_value = None
        yield runs_cancel_mock


@pytest.fixture()
def runs_submit_mock():
    """Mocks the Jobs Runs Submit API request"""
    with mock.patch("mlflow.projects.databricks._jobs_runs_submit") as runs_submit_mock:
        runs_submit_mock.return_value = {"run_id": "-1"}
        yield runs_submit_mock


@pytest.fixture()
def runs_get_mock():
    """Mocks the Jobs Runs Get API request"""
    with mock.patch("mlflow.projects.databricks._jobs_runs_get") as runs_get_mock:
        yield runs_get_mock


@pytest.fixture()
def cluster_spec_mock(tmpdir):
    cluster_spec_handle = tmpdir.join("cluster_spec.json")
    cluster_spec_handle.write(json.dumps(dict()))
    yield str(cluster_spec_handle)


@pytest.fixture()
def dbfs_root_mock(tmpdir):
    yield str(tmpdir.join("dbfs-root"))


@pytest.fixture()
def upload_to_dbfs_mock(dbfs_root_mock):
    def upload_mock_fn(src_path, dbfs_uri):
        mock_dbfs_dst = os.path.join(dbfs_root_mock, dbfs_uri.split("/dbfs/")[1])
        os.makedirs(os.path.dirname(mock_dbfs_dst))
        shutil.copy(src_path, mock_dbfs_dst)

    with mock.patch.object(
            mlflow.projects.databricks, "_upload_to_dbfs",
            new=upload_mock_fn) as upload_mock:
        yield upload_mock


@pytest.fixture()
def dbfs_path_exists_mock(dbfs_root_mock):  # pylint: disable=unused-argument
    with mock.patch("mlflow.projects.databricks._dbfs_path_exists") as path_exists_mock:
        yield path_exists_mock


@pytest.fixture()
def dbfs_mocks(dbfs_path_exists_mock, upload_to_dbfs_mock):  # pylint: disable=unused-argument
    yield


@pytest.fixture()
def before_run_validations_mock():  # pylint: disable=unused-argument
    with mock.patch("mlflow.projects.databricks._before_run_validations"):
        yield


def _get_mock_run_state(succeeded):
    if succeeded is None:
        return {"life_cycle_state": "RUNNING", "state_message": ""}
    if succeeded:
        run_result_state = "SUCCESS"
    else:
        run_result_state = "FAILED"
    return {"life_cycle_state": "TERMINATED", "state_message": "", "result_state": run_result_state}


def mock_runs_get_result(succeeded):
    run_state = _get_mock_run_state(succeeded)
    return {"state": run_state, "run_page_url": ""}


def run_databricks_project(cluster_spec_path, block=False):
    return mlflow.projects.run(
        uri=TEST_PROJECT_DIR, mode="databricks", cluster_spec=cluster_spec_path, block=block,
        parameters={"alpha": "0.4"})


def test_upload_project_to_dbfs(
        dbfs_root_mock, tmpdir, dbfs_path_exists_mock,
        upload_to_dbfs_mock):  # pylint: disable=unused-argument
    # Upload project to a mock directory
    dbfs_path_exists_mock.return_value = False
    dbfs_uri = databricks._upload_project_to_dbfs(
        project_dir=TEST_PROJECT_DIR, experiment_id=0)
    # Get expected tar
    local_tar_path = os.path.join(dbfs_root_mock, dbfs_uri.split("/dbfs/")[1])
    expected_tar_path = str(tmpdir.join("expected.tar.gz"))
    file_utils.make_tarfile(
        output_filename=expected_tar_path, source_dir=TEST_PROJECT_DIR,
        archive_name=databricks.DB_TARFILE_ARCHIVE_NAME)
    # Extract the tarred project, verify its contents
    assert filecmp.cmp(local_tar_path, expected_tar_path, shallow=False)


def test_upload_existing_project_to_dbfs(dbfs_path_exists_mock):  # pylint: disable=unused-argument
    # Check that we don't upload the project if it already exists on DBFS
    with mock.patch("mlflow.projects.databricks._upload_to_dbfs") as upload_to_dbfs_mock:
        dbfs_path_exists_mock.return_value = True
        databricks._upload_project_to_dbfs(
            project_dir=TEST_PROJECT_DIR, experiment_id=0)
        assert upload_to_dbfs_mock.call_count == 0


def test_run_databricks_validations(
        tmpdir, cluster_spec_mock,  # pylint: disable=unused-argument
        tracking_uri_mock, dbfs_mocks):  # pylint: disable=unused-argument
    """
    Tests that running on Databricks fails before making any API requests if validations fail.
    """
    with mock.patch("mlflow.utils.rest_utils.databricks_api_request") as db_api_req_mock,\
            mock.patch("mlflow.projects.databricks._check_databricks_auth_available"):
        # Test bad tracking URI
        tracking_uri_mock.return_value = tmpdir.strpath
        with pytest.raises(ExecutionException):
            run_databricks_project(cluster_spec_mock, block=True)
        assert db_api_req_mock.call_count == 0
        db_api_req_mock.reset_mock()
        tracking_uri_mock.return_value = "http://"
        # Test misspecified parameters
        with pytest.raises(ExecutionException):
            mlflow.projects.run(
                TEST_PROJECT_DIR, mode="databricks", entry_point="greeter",
                cluster_spec=cluster_spec_mock)
        assert db_api_req_mock.call_count == 0
        db_api_req_mock.reset_mock()
        # Test bad cluster spec
        with pytest.raises(ExecutionException):
            mlflow.projects.run(TEST_PROJECT_DIR, mode="databricks", block=True, cluster_spec=None)
        assert db_api_req_mock.call_count == 0
        db_api_req_mock.reset_mock()
        # Test that validations pass with good tracking URIs
        databricks._before_run_validations("http://", cluster_spec_mock)
        databricks._before_run_validations("databricks", cluster_spec_mock)


def test_run_databricks(
        before_run_validations_mock,  # pylint: disable=unused-argument
        tracking_uri_mock, runs_cancel_mock, dbfs_mocks,  # pylint: disable=unused-argument
        runs_submit_mock, runs_get_mock, cluster_spec_mock):
    """Test running on Databricks with mocks."""
    # Test that MLflow gets the correct run status when performing a Databricks run
    for run_succeeded, expected_status in [(True, RunStatus.FINISHED), (False, RunStatus.FAILED)]:
        runs_get_mock.return_value = mock_runs_get_result(succeeded=run_succeeded)
        submitted_run = run_databricks_project(cluster_spec_mock)
        assert submitted_run.wait() == run_succeeded
        assert runs_submit_mock.call_count == 1
        runs_submit_mock.reset_mock()
        validate_exit_status(submitted_run.get_status(), expected_status)


def test_run_databricks_cancel(
        before_run_validations_mock, tracking_uri_mock,  # pylint: disable=unused-argument
        runs_submit_mock, dbfs_mocks,  # pylint: disable=unused-argument
        runs_cancel_mock, runs_get_mock, cluster_spec_mock):
    # Test that MLflow properly handles Databricks run cancellation. We mock the result of
    # the runs-get API to indicate run failure so that cancel() exits instead of blocking while
    # waiting for run status.
    runs_get_mock.return_value = mock_runs_get_result(succeeded=False)
    submitted_run = run_databricks_project(cluster_spec_mock)
    submitted_run.cancel()
    validate_exit_status(submitted_run.get_status(), RunStatus.FAILED)
    assert runs_cancel_mock.call_count == 1
    # Test that we raise an exception when a blocking Databricks run fails
    runs_get_mock.return_value = mock_runs_get_result(succeeded=False)
    with pytest.raises(mlflow.projects.ExecutionException):
        run_databricks_project(cluster_spec_mock, block=True)


def test_fetch_and_clean_project(tmpdir):
    project_with_mlruns = tmpdir.mkdir("with-mlruns")
    project_with_mlruns.mkdir("mlruns").join("some-file").write("hi")
    project_without_mlruns = tmpdir.mkdir("without-mlruns")
    for proj in [project_with_mlruns, project_without_mlruns]:
        proj.join("MLproject").write("Hello")
    fetched0 = databricks._fetch_and_clean_project(project_with_mlruns.strpath)
    fetched1 = databricks._fetch_and_clean_project(project_without_mlruns.strpath)
    assert_dirs_equal(fetched0, fetched1)
    for fetched_dir in [fetched0, fetched1]:
        with open(os.path.join(fetched_dir, "MLproject")) as handle:
            assert handle.read() == "Hello"
