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# to you under the Apache License, Version 2.0 (the
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#
#   http://www.apache.org/licenses/LICENSE-2.0
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import os
import pickle
import pytest
import random
import unittest

from io import BytesIO
from os.path import join as pjoin

import numpy as np
import pyarrow as pa
import pyarrow.tests.test_parquet as test_parquet

from pyarrow.pandas_compat import _pandas_api
from pyarrow.tests import util
from pyarrow.util import guid


# ----------------------------------------------------------------------
# HDFS tests


def hdfs_test_client():
    host = os.environ.get('ARROW_HDFS_TEST_HOST', 'default')
    user = os.environ.get('ARROW_HDFS_TEST_USER', None)
    try:
        port = int(os.environ.get('ARROW_HDFS_TEST_PORT', 0))
    except ValueError:
        raise ValueError('Env variable ARROW_HDFS_TEST_PORT was not '
                         'an integer')

    with pytest.warns(DeprecationWarning):
        return pa.hdfs.connect(host, port, user)


@pytest.mark.hdfs
class HdfsTestCases:

    def _make_test_file(self, hdfs, test_name, test_path, test_data):
        base_path = pjoin(self.tmp_path, test_name)
        hdfs.mkdir(base_path)

        full_path = pjoin(base_path, test_path)

        with hdfs.open(full_path, 'wb') as f:
            f.write(test_data)

        return full_path

    @classmethod
    def setUpClass(cls):
        cls.check_driver()
        cls.hdfs = hdfs_test_client()
        cls.tmp_path = '/tmp/pyarrow-test-{}'.format(random.randint(0, 1000))
        cls.hdfs.mkdir(cls.tmp_path)

    @classmethod
    def tearDownClass(cls):
        cls.hdfs.delete(cls.tmp_path, recursive=True)
        cls.hdfs.close()

    def test_pickle(self):
        s = pickle.dumps(self.hdfs)
        h2 = pickle.loads(s)
        assert h2.is_open
        assert h2.host == self.hdfs.host
        assert h2.port == self.hdfs.port
        assert h2.user == self.hdfs.user
        assert h2.kerb_ticket == self.hdfs.kerb_ticket
        # smoketest unpickled client works
        h2.ls(self.tmp_path)

    def test_cat(self):
        path = pjoin(self.tmp_path, 'cat-test')

        data = b'foobarbaz'
        with self.hdfs.open(path, 'wb') as f:
            f.write(data)

        contents = self.hdfs.cat(path)
        assert contents == data

    def test_capacity_space(self):
        capacity = self.hdfs.get_capacity()
        space_used = self.hdfs.get_space_used()
        disk_free = self.hdfs.df()

        assert capacity > 0
        assert capacity > space_used
        assert disk_free == (capacity - space_used)

    def test_close(self):
        client = hdfs_test_client()
        assert client.is_open
        client.close()
        assert not client.is_open

        with pytest.raises(Exception):
            client.ls('/')

    def test_mkdir(self):
        path = pjoin(self.tmp_path, 'test-dir/test-dir')
        parent_path = pjoin(self.tmp_path, 'test-dir')

        self.hdfs.mkdir(path)
        assert self.hdfs.exists(path)

        self.hdfs.delete(parent_path, recursive=True)
        assert not self.hdfs.exists(path)

    def test_mv_rename(self):
        path = pjoin(self.tmp_path, 'mv-test')
        new_path = pjoin(self.tmp_path, 'mv-new-test')

        data = b'foobarbaz'
        with self.hdfs.open(path, 'wb') as f:
            f.write(data)

        assert self.hdfs.exists(path)
        self.hdfs.mv(path, new_path)
        assert not self.hdfs.exists(path)
        assert self.hdfs.exists(new_path)

        assert self.hdfs.cat(new_path) == data

        self.hdfs.rename(new_path, path)
        assert self.hdfs.cat(path) == data

    def test_info(self):
        path = pjoin(self.tmp_path, 'info-base')
        file_path = pjoin(path, 'ex')
        self.hdfs.mkdir(path)

        data = b'foobarbaz'
        with self.hdfs.open(file_path, 'wb') as f:
            f.write(data)

        path_info = self.hdfs.info(path)
        file_path_info = self.hdfs.info(file_path)

        assert path_info['kind'] == 'directory'

        assert file_path_info['kind'] == 'file'
        assert file_path_info['size'] == len(data)

    def test_exists_isdir_isfile(self):
        dir_path = pjoin(self.tmp_path, 'info-base')
        file_path = pjoin(dir_path, 'ex')
        missing_path = pjoin(dir_path, 'this-path-is-missing')

        self.hdfs.mkdir(dir_path)
        with self.hdfs.open(file_path, 'wb') as f:
            f.write(b'foobarbaz')

        assert self.hdfs.exists(dir_path)
        assert self.hdfs.exists(file_path)
        assert not self.hdfs.exists(missing_path)

        assert self.hdfs.isdir(dir_path)
        assert not self.hdfs.isdir(file_path)
        assert not self.hdfs.isdir(missing_path)

        assert not self.hdfs.isfile(dir_path)
        assert self.hdfs.isfile(file_path)
        assert not self.hdfs.isfile(missing_path)

    def test_disk_usage(self):
        path = pjoin(self.tmp_path, 'disk-usage-base')
        p1 = pjoin(path, 'p1')
        p2 = pjoin(path, 'p2')

        subdir = pjoin(path, 'subdir')
        p3 = pjoin(subdir, 'p3')

        if self.hdfs.exists(path):
            self.hdfs.delete(path, True)

        self.hdfs.mkdir(path)
        self.hdfs.mkdir(subdir)

        data = b'foobarbaz'

        for file_path in [p1, p2, p3]:
            with self.hdfs.open(file_path, 'wb') as f:
                f.write(data)

        assert self.hdfs.disk_usage(path) == len(data) * 3

    def test_ls(self):
        base_path = pjoin(self.tmp_path, 'ls-test')
        self.hdfs.mkdir(base_path)

        dir_path = pjoin(base_path, 'a-dir')
        f1_path = pjoin(base_path, 'a-file-1')

        self.hdfs.mkdir(dir_path)

        f = self.hdfs.open(f1_path, 'wb')
        f.write(b'a' * 10)

        contents = sorted(self.hdfs.ls(base_path, False))
        assert contents == [dir_path, f1_path]

    def test_chmod_chown(self):
        path = pjoin(self.tmp_path, 'chmod-test')
        with self.hdfs.open(path, 'wb') as f:
            f.write(b'a' * 10)

    def test_download_upload(self):
        base_path = pjoin(self.tmp_path, 'upload-test')

        data = b'foobarbaz'
        buf = BytesIO(data)
        buf.seek(0)

        self.hdfs.upload(base_path, buf)

        out_buf = BytesIO()
        self.hdfs.download(base_path, out_buf)
        out_buf.seek(0)
        assert out_buf.getvalue() == data

    def test_file_context_manager(self):
        path = pjoin(self.tmp_path, 'ctx-manager')

        data = b'foo'
        with self.hdfs.open(path, 'wb') as f:
            f.write(data)

        with self.hdfs.open(path, 'rb') as f:
            assert f.size() == 3
            result = f.read(10)
            assert result == data

    def test_open_not_exist_error_message(self):
        # ARROW-226
        path = pjoin(self.tmp_path, 'does-not-exist-123')

        try:
            self.hdfs.open(path)
        except Exception as e:
            assert 'file does not exist' in e.args[0].lower()

    def test_read_whole_file(self):
        path = pjoin(self.tmp_path, 'read-whole-file')

        data = b'foo' * 1000
        with self.hdfs.open(path, 'wb') as f:
            f.write(data)

        with self.hdfs.open(path, 'rb') as f:
            result = f.read()

        assert result == data

    def _write_multiple_hdfs_pq_files(self, tmpdir):
        import pyarrow.parquet as pq
        nfiles = 10
        size = 5
        test_data = []
        for i in range(nfiles):
            df = test_parquet._test_dataframe(size, seed=i)

            df['index'] = np.arange(i * size, (i + 1) * size)

            # Hack so that we don't have a dtype cast in v1 files
            df['uint32'] = df['uint32'].astype(np.int64)

            path = pjoin(tmpdir, '{}.parquet'.format(i))

            table = pa.Table.from_pandas(df, preserve_index=False)
            with self.hdfs.open(path, 'wb') as f:
                pq.write_table(table, f)

            test_data.append(table)

        expected = pa.concat_tables(test_data)
        return expected

    @pytest.mark.pandas
    @pytest.mark.parquet
    def test_read_multiple_parquet_files(self):

        tmpdir = pjoin(self.tmp_path, 'multi-parquet-' + guid())

        self.hdfs.mkdir(tmpdir)

        expected = self._write_multiple_hdfs_pq_files(tmpdir)
        result = self.hdfs.read_parquet(tmpdir)

        _pandas_api.assert_frame_equal(result.to_pandas()
                                       .sort_values(by='index')
                                       .reset_index(drop=True),
                                       expected.to_pandas())

    @pytest.mark.pandas
    @pytest.mark.parquet
    def test_read_multiple_parquet_files_with_uri(self):
        import pyarrow.parquet as pq

        tmpdir = pjoin(self.tmp_path, 'multi-parquet-uri-' + guid())

        self.hdfs.mkdir(tmpdir)

        expected = self._write_multiple_hdfs_pq_files(tmpdir)
        path = _get_hdfs_uri(tmpdir)
        # TODO for URI it should not be needed to pass this argument
        result = pq.read_table(path, use_legacy_dataset=True)

        _pandas_api.assert_frame_equal(result.to_pandas()
                                       .sort_values(by='index')
                                       .reset_index(drop=True),
                                       expected.to_pandas())

    @pytest.mark.pandas
    @pytest.mark.parquet
    def test_read_write_parquet_files_with_uri(self):
        import pyarrow.parquet as pq

        tmpdir = pjoin(self.tmp_path, 'uri-parquet-' + guid())
        self.hdfs.mkdir(tmpdir)
        path = _get_hdfs_uri(pjoin(tmpdir, 'test.parquet'))

        size = 5
        df = test_parquet._test_dataframe(size, seed=0)
        # Hack so that we don't have a dtype cast in v1 files
        df['uint32'] = df['uint32'].astype(np.int64)
        table = pa.Table.from_pandas(df, preserve_index=False)

        pq.write_table(table, path, filesystem=self.hdfs)

        result = pq.read_table(
            path, filesystem=self.hdfs, use_legacy_dataset=True
        ).to_pandas()

        _pandas_api.assert_frame_equal(result, df)

    @pytest.mark.parquet
    @pytest.mark.pandas
    def test_read_common_metadata_files(self):
        tmpdir = pjoin(self.tmp_path, 'common-metadata-' + guid())
        self.hdfs.mkdir(tmpdir)
        test_parquet._test_read_common_metadata_files(self.hdfs, tmpdir)

    @pytest.mark.parquet
    @pytest.mark.pandas
    def test_write_to_dataset_with_partitions(self):
        tmpdir = pjoin(self.tmp_path, 'write-partitions-' + guid())
        self.hdfs.mkdir(tmpdir)
        test_parquet._test_write_to_dataset_with_partitions(
            tmpdir, filesystem=self.hdfs)

    @pytest.mark.parquet
    @pytest.mark.pandas
    def test_write_to_dataset_no_partitions(self):
        tmpdir = pjoin(self.tmp_path, 'write-no_partitions-' + guid())
        self.hdfs.mkdir(tmpdir)
        test_parquet._test_write_to_dataset_no_partitions(
            tmpdir, filesystem=self.hdfs)


class TestLibHdfs(HdfsTestCases, unittest.TestCase):

    @classmethod
    def check_driver(cls):
        if not pa.have_libhdfs():
            message = 'No libhdfs available on system'
            if os.environ.get('PYARROW_HDFS_TEST_LIBHDFS_REQUIRE'):
                pytest.fail(message)
            else:
                pytest.skip(message)

    def test_orphaned_file(self):
        hdfs = hdfs_test_client()
        file_path = self._make_test_file(hdfs, 'orphaned_file_test', 'fname',
                                         b'foobarbaz')

        f = hdfs.open(file_path)
        hdfs = None
        f = None  # noqa


def _get_hdfs_uri(path):
    host = os.environ.get('ARROW_HDFS_TEST_HOST', 'localhost')
    try:
        port = int(os.environ.get('ARROW_HDFS_TEST_PORT', 0))
    except ValueError:
        raise ValueError('Env variable ARROW_HDFS_TEST_PORT was not '
                         'an integer')
    uri = "hdfs://{}:{}{}".format(host, port, path)

    return uri


@pytest.mark.hdfs
@pytest.mark.pandas
@pytest.mark.parquet
@pytest.mark.fastparquet
def test_fastparquet_read_with_hdfs():
    from pandas.testing import assert_frame_equal

    try:
        import snappy  # noqa
    except ImportError:
        pytest.skip('fastparquet test requires snappy')

    import pyarrow.parquet as pq
    fastparquet = pytest.importorskip('fastparquet')

    fs = hdfs_test_client()

    df = util.make_dataframe()

    table = pa.Table.from_pandas(df)

    path = '/tmp/testing.parquet'
    with fs.open(path, 'wb') as f:
        pq.write_table(table, f)

    parquet_file = fastparquet.ParquetFile(path, open_with=fs.open)

    result = parquet_file.to_pandas()
    assert_frame_equal(result, df)
