#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file 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 "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

import os
import shutil
import tempfile
from contextlib import contextmanager

import pandas as pd
import numpy as np

from pyspark import pandas as ps
from pyspark.testing.pandasutils import PandasOnSparkTestCase, TestUtils


def normalize_text(s):
    return "\n".join(map(str.strip, s.strip().split("\n")))


class CsvTest(PandasOnSparkTestCase, TestUtils):
    def setUp(self):
        self.tmp_dir = tempfile.mkdtemp(prefix=CsvTest.__name__)

    def tearDown(self):
        shutil.rmtree(self.tmp_dir, ignore_errors=True)

    @property
    def csv_text(self):
        return normalize_text(
            """
            name,amount
            Alice,100
            Bob,-200
            Charlie,300
            Dennis,400
            Edith,-500
            Frank,600
            Alice,200
            Frank,-200
            Bob,600
            Alice,400
            Frank,200
            Alice,300
            Edith,600
            """
        )

    @property
    def csv_text_2(self):
        return normalize_text(
            """
            A,B
            item1,1
            item2,1,2
            item3,1,2,3,4
            item4,1
            """
        )

    @property
    def csv_text_with_comments(self):
        return normalize_text(
            """
            # header
            %s
            # comment
            Alice,400
            Edith,600
            # footer
            """
            % self.csv_text
        )

    @property
    def tab_delimited_csv_text(self):
        return normalize_text(
            """
            name\tamount
            Alice\t100
            Bob\t-200
            Charlie\t300
            """
        )

    @property
    def q_quoted_csv_text(self):
        return normalize_text(
            """
            QnameQ,QamountQ
            QA,liceQ,Q100Q
            QB,obQ,Q-200Q
            QC,harlieQ,Q300Q
            """
        )

    @property
    def e_escapeted_csv_text(self):
        return normalize_text(
            """
            name,amount
            "AE"lice",100
            "BE"ob",-200
            "CE"harlie",300
            """
        )

    @contextmanager
    def csv_file(self, csv):
        with self.temp_file() as tmp:
            with open(tmp, "w") as f:
                f.write(csv)
            yield tmp

    def test_read_csv(self):
        with self.csv_file(self.csv_text) as fn:

            def check(header="infer", names=None, usecols=None, index_col=None):
                expected = pd.read_csv(
                    fn, header=header, names=names, usecols=usecols, index_col=index_col
                )
                actual = ps.read_csv(
                    fn, header=header, names=names, usecols=usecols, index_col=index_col
                )
                self.assert_eq(expected, actual, almost=True)

            check()
            check(header=0)
            check(header=None)
            check(names=["n", "a"])
            check(names=[("x", "n"), ("y", "a")])
            check(names=[10, 20])
            check(header=0, names=["n", "a"])
            check(usecols=[1])
            check(usecols=[1, 0])
            check(usecols=["amount"])
            check(usecols=["amount", "name"])
            check(usecols=[])
            check(usecols=[1, 1])
            check(usecols=["amount", "amount"])
            check(header=None, usecols=[1])
            check(names=["n", "a"], usecols=["a"])
            check(header=None, names=["n", "a"], usecols=["a"])
            check(index_col=["amount"])
            check(header=None, index_col=[1])
            check(names=["n", "a"], index_col=["a"])
            check(names=["n", "a"], index_col="a")

            # check with pyspark patch.
            expected = pd.read_csv(fn)
            actual = ps.read_csv(fn)
            self.assert_eq(expected, actual, almost=True)

            self.assertRaisesRegex(
                ValueError, "non-unique", lambda: ps.read_csv(fn, names=["n", "n"])
            )
            self.assertRaisesRegex(
                ValueError,
                "does not match the number.*3",
                lambda: ps.read_csv(fn, names=["n", "a", "b"]),
            )
            self.assertRaisesRegex(
                ValueError,
                "does not match the number.*3",
                lambda: ps.read_csv(fn, header=0, names=["n", "a", "b"]),
            )
            self.assertRaisesRegex(
                ValueError, "Usecols do not match.*3", lambda: ps.read_csv(fn, usecols=[1, 3])
            )
            self.assertRaisesRegex(
                ValueError,
                "Usecols do not match.*col",
                lambda: ps.read_csv(fn, usecols=["amount", "col"]),
            )
            self.assertRaisesRegex(
                ValueError, "Unknown header argument 1", lambda: ps.read_csv(fn, header="1")
            )
            expected_error_message = (
                "'usecols' must either be list-like of all strings, "
                "all unicode, all integers or a callable."
            )
            self.assertRaisesRegex(
                ValueError, expected_error_message, lambda: ps.read_csv(fn, usecols=[1, "amount"])
            )

            # check with index_col
            expected = pd.read_csv(fn).set_index("name")
            actual = ps.read_csv(fn, index_col="name")
            self.assert_eq(expected, actual, almost=True)

    def test_read_with_spark_schema(self):
        with self.csv_file(self.csv_text_2) as fn:
            actual = ps.read_csv(fn, names="A string, B string, C long, D long, E long")
            expected = pd.read_csv(fn, names=["A", "B", "C", "D", "E"])
            self.assert_eq(expected, actual)

    def test_read_csv_with_comment(self):
        with self.csv_file(self.csv_text_with_comments) as fn:
            expected = pd.read_csv(fn, comment="#")
            actual = ps.read_csv(fn, comment="#")
            self.assert_eq(expected, actual, almost=True)

            self.assertRaisesRegex(
                ValueError,
                "Only length-1 comment characters supported",
                lambda: ps.read_csv(fn, comment="").show(),
            )
            self.assertRaisesRegex(
                ValueError,
                "Only length-1 comment characters supported",
                lambda: ps.read_csv(fn, comment="##").show(),
            )
            self.assertRaisesRegex(
                ValueError,
                "Only length-1 comment characters supported",
                lambda: ps.read_csv(fn, comment=1),
            )
            self.assertRaisesRegex(
                ValueError,
                "Only length-1 comment characters supported",
                lambda: ps.read_csv(fn, comment=[1]),
            )

    def test_read_csv_with_limit(self):
        with self.csv_file(self.csv_text_with_comments) as fn:
            expected = pd.read_csv(fn, comment="#", nrows=2)
            actual = ps.read_csv(fn, comment="#", nrows=2)
            self.assert_eq(expected, actual, almost=True)

    def test_read_csv_with_encoding(self):
        # SPARK-37181: Read csv supporting latin-1 encoding.
        with self.csv_file(self.csv_text) as fn:
            expected = pd.read_csv(fn, encoding="latin-1")
            actual = ps.read_csv(fn, encoding="latin-1")
            self.assert_eq(expected, actual, almost=True)

    def test_read_csv_with_sep(self):
        with self.csv_file(self.tab_delimited_csv_text) as fn:
            expected = pd.read_csv(fn, sep="\t")
            actual = ps.read_csv(fn, sep="\t")
            self.assert_eq(expected, actual, almost=True)

    def test_read_csv_with_squeeze(self):
        with self.csv_file(self.csv_text) as fn:
            expected = pd.read_csv(fn, squeeze=True, usecols=["name"])
            actual = ps.read_csv(fn, squeeze=True, usecols=["name"])
            self.assert_eq(expected, actual, almost=True)

            expected = pd.read_csv(fn, squeeze=True, usecols=["name", "amount"])
            actual = ps.read_csv(fn, squeeze=True, usecols=["name", "amount"])
            self.assert_eq(expected, actual, almost=True)

            expected = pd.read_csv(fn, squeeze=True, usecols=["name", "amount"], index_col=["name"])
            actual = ps.read_csv(fn, squeeze=True, usecols=["name", "amount"], index_col=["name"])
            self.assert_eq(expected, actual, almost=True)

    def test_read_csv_with_mangle_dupe_cols(self):
        self.assertRaisesRegex(
            ValueError, "mangle_dupe_cols", lambda: ps.read_csv("path", mangle_dupe_cols=False)
        )

    def test_read_csv_with_parse_dates(self):
        self.assertRaisesRegex(
            ValueError, "parse_dates", lambda: ps.read_csv("path", parse_dates=True)
        )

    def test_read_csv_with_dtype(self):
        with self.csv_file(self.csv_text) as fn:
            self.assert_eq(ps.read_csv(fn), pd.read_csv(fn), almost=True)
            self.assert_eq(ps.read_csv(fn, dtype=str), pd.read_csv(fn, dtype=str))
            self.assert_eq(
                ps.read_csv(fn, dtype={"amount": "int64"}),
                pd.read_csv(fn, dtype={"amount": "int64"}),
            )

    def test_read_csv_with_quotechar(self):
        with self.csv_file(self.q_quoted_csv_text) as fn:
            self.assert_eq(
                ps.read_csv(fn, quotechar="Q"), pd.read_csv(fn, quotechar="Q"), almost=True
            )

    def test_read_csv_with_escapechar(self):
        with self.csv_file(self.e_escapeted_csv_text) as fn:
            self.assert_eq(
                ps.read_csv(fn, escapechar="E"), pd.read_csv(fn, escapechar="E"), almost=True
            )

            self.assert_eq(
                ps.read_csv(fn, escapechar="ABC", escape="E"),
                pd.read_csv(fn, escapechar="E"),
                almost=True,
            )

    def test_to_csv(self):
        pdf = pd.DataFrame({"aa": [1, 2, 3], "bb": [4, 5, 6]}, index=[0, 1, 3])
        psdf = ps.DataFrame(pdf)

        self.assert_eq(psdf.to_csv(), pdf.to_csv(index=False))
        self.assert_eq(psdf.to_csv(columns=["aa"]), pdf.to_csv(columns=["aa"], index=False))
        self.assert_eq(psdf.aa.to_csv(), pdf.aa.to_csv(index=False, header=True))

        pdf = pd.DataFrame({"a": [1, np.nan, 3], "b": ["one", "two", None]}, index=[0, 1, 3])
        psdf = ps.from_pandas(pdf)

        self.assert_eq(psdf.to_csv(na_rep="null"), pdf.to_csv(na_rep="null", index=False))
        self.assert_eq(
            psdf.a.to_csv(na_rep="null"), pdf.a.to_csv(na_rep="null", index=False, header=True)
        )

        self.assertRaises(KeyError, lambda: psdf.to_csv(columns=["ab"]))

        pdf = pd.DataFrame({"a": [1.0, 2.0, 3.0], "b": [4.0, 5.0, 6.0]}, index=[0, 1, 3])
        psdf = ps.from_pandas(pdf)

        self.assert_eq(psdf.to_csv(), pdf.to_csv(index=False))
        self.assert_eq(psdf.to_csv(header=False), pdf.to_csv(header=False, index=False))
        self.assert_eq(psdf.to_csv(), pdf.to_csv(index=False))

        # non-string names
        pdf = pd.DataFrame({10: [1, 2, 3], 20: [4, 5, 6]}, index=[0, 1, 3])
        psdf = ps.DataFrame(pdf)

        self.assert_eq(psdf.to_csv(), pdf.to_csv(index=False))
        self.assert_eq(psdf.to_csv(columns=[10]), pdf.to_csv(columns=[10], index=False))

        self.assertRaises(TypeError, lambda: psdf.to_csv(columns=10))

    def _check_output(self, dir, expected):
        output_paths = [path for path in os.listdir(dir) if path.startswith("part-")]
        assert len(output_paths) > 0
        output_path = "%s/%s" % (dir, output_paths[0])
        with open(output_path) as f:
            self.assertEqual(f.read(), expected)

    def test_to_csv_with_path(self):
        pdf = pd.DataFrame({"a": [1, 2, 3], "b": ["a", "b", "c"]})
        psdf = ps.DataFrame(pdf)

        tmp_dir = "{}/tmp1".format(self.tmp_dir)

        psdf.to_csv(tmp_dir, num_files=1)
        self._check_output(tmp_dir, pdf.to_csv(index=False))

        tmp_dir = "{}/tmp2".format(self.tmp_dir)

        self.assertRaises(KeyError, lambda: psdf.to_csv(tmp_dir, columns=["c"], num_files=1))

        # non-string names
        pdf = pd.DataFrame({10: [1, 2, 3], 20: ["a", "b", "c"]})
        psdf = ps.DataFrame(pdf)

        tmp_dir = "{}/tmp3".format(self.tmp_dir)

        psdf.to_csv(tmp_dir, num_files=1)
        self._check_output(tmp_dir, pdf.to_csv(index=False))

        tmp_dir = "{}/tmp4".format(self.tmp_dir)

        psdf.to_csv(tmp_dir, columns=[10], num_files=1)
        self._check_output(tmp_dir, pdf.to_csv(columns=[10], index=False))

        tmp_dir = "{}/tmp5".format(self.tmp_dir)

        self.assertRaises(TypeError, lambda: psdf.to_csv(tmp_dir, columns=10, num_files=1))

    def test_to_csv_with_path_and_basic_options(self):
        pdf = pd.DataFrame({"aa": [1, 2, 3], "bb": ["a", "b", "c"]})
        psdf = ps.DataFrame(pdf)

        psdf.to_csv(self.tmp_dir, num_files=1, sep="|", header=False, columns=["aa"])
        expected = pdf.to_csv(index=False, sep="|", header=False, columns=["aa"])

        self._check_output(self.tmp_dir, expected)

    def test_to_csv_with_path_and_basic_options_multiindex_columns(self):
        pdf = pd.DataFrame({("x", "a"): [1, 2, 3], ("y", "b"): ["a", "b", "c"]})
        psdf = ps.DataFrame(pdf)

        with self.assertRaises(ValueError):
            psdf.to_csv(self.tmp_dir, num_files=1, sep="|", columns=[("x", "a")])

        psdf.to_csv(self.tmp_dir, num_files=1, sep="|", header=["a"], columns=[("x", "a")])
        pdf.columns = ["a", "b"]
        expected = pdf.to_csv(index=False, sep="|", columns=["a"])

        self._check_output(self.tmp_dir, expected)

    def test_to_csv_with_path_and_pyspark_options(self):
        pdf = pd.DataFrame({"a": [1, 2, 3, None], "b": ["a", "b", "c", None]})
        psdf = ps.DataFrame(pdf)

        psdf.to_csv(self.tmp_dir, nullValue="null", num_files=1)
        expected = pdf.to_csv(index=False, na_rep="null")

        self._check_output(self.tmp_dir, expected)

    def test_to_csv_with_partition_cols(self):
        pdf = pd.DataFrame({"a": [1, 2, 3], "b": ["a", "b", "c"]})
        psdf = ps.DataFrame(pdf)

        psdf.to_csv(self.tmp_dir, partition_cols="b", num_files=1)

        partition_paths = [path for path in os.listdir(self.tmp_dir) if path.startswith("b=")]
        assert len(partition_paths) > 0
        for partition_path in partition_paths:
            column, value = partition_path.split("=")
            expected = pdf[pdf[column] == value].drop("b", axis=1).to_csv(index=False)

            output_paths = [
                path
                for path in os.listdir("%s/%s" % (self.tmp_dir, partition_path))
                if path.startswith("part-")
            ]
            assert len(output_paths) > 0
            output_path = "%s/%s/%s" % (self.tmp_dir, partition_path, output_paths[0])
            with open(output_path) as f:
                self.assertEqual(f.read(), expected)


if __name__ == "__main__":
    import unittest
    from pyspark.pandas.tests.test_csv import *  # noqa: F401

    try:
        import xmlrunner

        testRunner = xmlrunner.XMLTestRunner(output="target/test-reports", verbosity=2)
    except ImportError:
        testRunner = None
    unittest.main(testRunner=testRunner, verbosity=2)
