import os
import git
import tempfile

from distutils import dir_util

import mock
import pytest

import mlflow
from mlflow.entities.run_status import RunStatus
from mlflow.projects import ExecutionException
from mlflow.store.file_store import FileStore
from mlflow.utils import env

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


def _build_uri(base_uri, subdirectory):
    if subdirectory != "":
        return "%s#%s" % (base_uri, subdirectory)
    return base_uri


@pytest.fixture()
def local_git_repo(tmpdir):
    local_git = tmpdir.join('git_repo').strpath
    repo = git.Repo.init(local_git)
    dir_util.copy_tree(src=TEST_PROJECT_DIR, dst=local_git)
    dir_util.copy_tree(src=os.path.dirname(TEST_PROJECT_DIR), dst=local_git)
    repo.git.add(A=True)
    repo.index.commit("test")
    yield os.path.abspath(local_git)


@pytest.fixture()
def local_git_repo_uri(local_git_repo):
    return "file://%s" % local_git_repo


def test_fetch_project(local_git_repo, local_git_repo_uri):
    # The tests are as follows:
    # 1. Fetching a locally saved project.
    # 2. Fetching a project located in a Git repo root directory.
    # 3. Fetching a project located in a Git repo subdirectory.
    # 4. Passing a subdirectory works for local directories.
    test_list = [
        (TEST_PROJECT_DIR, '', TEST_PROJECT_DIR),
        (local_git_repo_uri, '', local_git_repo),
        (local_git_repo_uri, 'example_project', os.path.join(local_git_repo, 'example_project')),
        (os.path.dirname(TEST_PROJECT_DIR), os.path.basename(TEST_PROJECT_DIR), TEST_PROJECT_DIR),
    ]
    for base_uri, subdirectory, expected in test_list:
        work_dir = mlflow.projects._fetch_project(
            uri=_build_uri(base_uri, subdirectory), force_tempdir=False)
        assert_dirs_equal(expected=expected, actual=work_dir)
    # Test that we correctly determine the dest directory to use when fetching a project.
    for force_tempdir, uri in [(True, TEST_PROJECT_DIR), (False, GIT_PROJECT_URI)]:
        dest_dir = mlflow.projects._fetch_project(uri=uri, force_tempdir=force_tempdir)
        assert os.path.commonprefix([dest_dir, tempfile.gettempdir()]) == tempfile.gettempdir()
        assert os.path.exists(dest_dir)
    for force_tempdir, uri in [(None, TEST_PROJECT_DIR), (False, TEST_PROJECT_DIR)]:
        assert mlflow.projects._fetch_project(uri=uri, force_tempdir=force_tempdir) == \
               os.path.abspath(TEST_PROJECT_DIR)


def test_fetch_project_validations(local_git_repo_uri):
    # Verify that runs fail if given incorrect subdirectories via the `#` character.
    for base_uri in [TEST_PROJECT_DIR, local_git_repo_uri]:
        with pytest.raises(ExecutionException):
            mlflow.projects._fetch_project(uri=_build_uri(base_uri, "fake"), force_tempdir=False)

    # Passing `version` raises an exception for local projects
    with pytest.raises(ExecutionException):
        mlflow.projects._fetch_project(uri=TEST_PROJECT_DIR, force_tempdir=False, version="version")

    # Passing only one of git_username, git_password results in an error
    for username, password in [(None, "hi"), ("hi", None)]:
        with pytest.raises(ExecutionException):
            mlflow.projects._fetch_project(
                local_git_repo_uri, force_tempdir=False, git_username=username,
                git_password=password)


def test_dont_remove_mlruns(tmpdir):
    # Fetching a directory containing an "mlruns" folder doesn't remove the "mlruns" folder
    src_dir = tmpdir.mkdir("mlruns-src-dir")
    src_dir.mkdir("mlruns").join("some-file.txt").write("hi")
    src_dir.join("MLproject").write("dummy MLproject contents")
    dst_dir = mlflow.projects._fetch_project(
        uri=src_dir.strpath, version=None, git_username=None,
        git_password=None, force_tempdir=False)
    assert_dirs_equal(expected=src_dir.strpath, actual=dst_dir)


def test_parse_subdirectory():
    # Make sure the parsing works as intended.
    test_uri = "uri#subdirectory"
    parsed_uri, parsed_subdirectory = mlflow.projects._parse_subdirectory(test_uri)
    assert parsed_uri == "uri"
    assert parsed_subdirectory == "subdirectory"

    # Make sure periods are restricted in Git repo subdirectory paths.
    period_fail_uri = GIT_PROJECT_URI + "#.."
    with pytest.raises(ExecutionException):
        mlflow.projects._parse_subdirectory(period_fail_uri)


def test_invalid_run_mode(tracking_uri_mock):  # pylint: disable=unused-argument
    """ Verify that we raise an exception given an invalid run mode """
    with pytest.raises(ExecutionException):
        mlflow.projects.run(uri=TEST_PROJECT_DIR, mode="some unsupported mode")


def test_use_conda(tracking_uri_mock):  # pylint: disable=unused-argument
    """ Verify that we correctly handle the `use_conda` argument."""
    # Verify we throw an exception when conda is unavailable
    old_path = os.environ["PATH"]
    env.unset_variable("PATH")
    try:
        with pytest.raises(ExecutionException):
            mlflow.projects.run(TEST_PROJECT_DIR, use_conda=True)
    finally:
        os.environ["PATH"] = old_path


@pytest.mark.parametrize("use_start_run", map(str, [0, 1]))
def test_run(tmpdir, tracking_uri_mock, use_start_run):  # pylint: disable=unused-argument
    submitted_run = mlflow.projects.run(
        TEST_PROJECT_DIR, entry_point="test_tracking",
        parameters={"use_start_run": use_start_run},
        use_conda=False, experiment_id=0)
    # Blocking runs should be finished when they return
    validate_exit_status(submitted_run.get_status(), RunStatus.FINISHED)
    # Test that we can call wait() on a synchronous run & that the run has the correct
    # status after calling wait().
    submitted_run.wait()
    validate_exit_status(submitted_run.get_status(), RunStatus.FINISHED)
    # Validate run contents in the FileStore
    run_uuid = submitted_run.run_id
    store = FileStore(tmpdir.strpath)
    run_infos = store.list_run_infos(experiment_id=0)
    assert len(run_infos) == 1
    store_run_uuid = run_infos[0].run_uuid
    assert run_uuid == store_run_uuid
    run = store.get_run(run_uuid)
    expected_params = {"use_start_run": use_start_run}
    assert run.info.status == RunStatus.FINISHED
    assert len(run.data.params) == len(expected_params)
    for param in run.data.params:
        assert param.value == expected_params[param.key]
    expected_metrics = {"some_key": 3}
    assert len(run.data.metrics) == len(expected_metrics)
    for metric in run.data.metrics:
        assert metric.value == expected_metrics[metric.key]


def test_run_async(tracking_uri_mock):  # pylint: disable=unused-argument
    submitted_run0 = mlflow.projects.run(
        TEST_PROJECT_DIR, entry_point="sleep", parameters={"duration": 2},
        use_conda=False, experiment_id=0, block=False)
    validate_exit_status(submitted_run0.get_status(), RunStatus.RUNNING)
    submitted_run0.wait()
    validate_exit_status(submitted_run0.get_status(), RunStatus.FINISHED)
    submitted_run1 = mlflow.projects.run(
        TEST_PROJECT_DIR, entry_point="sleep", parameters={"duration": -1, "invalid-param": 30},
        use_conda=False, experiment_id=0, block=False)
    submitted_run1.wait()
    validate_exit_status(submitted_run1.get_status(), RunStatus.FAILED)


@pytest.mark.parametrize(
    "mock_env,expected_conda,expected_activate",
    [
        ({}, "conda", "activate"),
        ({mlflow.projects.MLFLOW_CONDA_HOME: "/some/dir/"}, "/some/dir/bin/conda",
         "/some/dir/bin/activate")
     ]
)
def test_conda_path(mock_env, expected_conda, expected_activate):
    """Verify that we correctly determine the path to conda executables"""
    with mock.patch.dict("os.environ", mock_env):
        assert mlflow.projects._get_conda_bin_executable("conda") == expected_conda
        assert mlflow.projects._get_conda_bin_executable("activate") == expected_activate


def test_cancel_run(tracking_uri_mock):  # pylint: disable=unused-argument
    submitted_run0, submitted_run1 = [mlflow.projects.run(
        TEST_PROJECT_DIR, entry_point="sleep", parameters={"duration": 2},
        use_conda=False, experiment_id=0, block=False) for _ in range(2)]
    submitted_run0.cancel()
    validate_exit_status(submitted_run0.get_status(), RunStatus.FAILED)
    # Sanity check: cancelling one run has no effect on the other
    assert submitted_run1.wait()
    validate_exit_status(submitted_run1.get_status(), RunStatus.FINISHED)
    # Try cancelling after calling wait()
    submitted_run1.cancel()
    validate_exit_status(submitted_run1.get_status(), RunStatus.FINISHED)


def test_storage_dir(tmpdir):
    """
    Test that we correctly handle the `storage_dir` argument, which specifies where to download
    distributed artifacts passed to arguments of type `path`.
    """
    assert os.path.dirname(mlflow.projects._get_storage_dir(tmpdir.strpath)) == tmpdir.strpath
    assert os.path.dirname(mlflow.projects._get_storage_dir(None)) == tempfile.gettempdir()
