#
# 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 unittest
from typing import cast

from pyspark.rdd import PythonEvalType
from pyspark.sql import Row
from pyspark.sql.functions import (
    array,
    explode,
    col,
    lit,
    mean,
    sum,
    udf,
    pandas_udf,
    PandasUDFType,
)
from pyspark.sql.types import ArrayType, TimestampType
from pyspark.errors import AnalysisException
from pyspark.testing.sqlutils import (
    ReusedSQLTestCase,
    have_pandas,
    have_pyarrow,
    pandas_requirement_message,
    pyarrow_requirement_message,
)
from pyspark.testing.utils import QuietTest


if have_pandas:
    import pandas as pd
    from pandas.testing import assert_frame_equal


@unittest.skipIf(
    not have_pandas or not have_pyarrow,
    cast(str, pandas_requirement_message or pyarrow_requirement_message),
)
class GroupedAggPandasUDFTests(ReusedSQLTestCase):
    @property
    def data(self):
        return (
            self.spark.range(10)
            .toDF("id")
            .withColumn("vs", array([lit(i * 1.0) + col("id") for i in range(20, 30)]))
            .withColumn("v", explode(col("vs")))
            .drop("vs")
            .withColumn("w", lit(1.0))
        )

    @property
    def python_plus_one(self):
        @udf("double")
        def plus_one(v):
            assert isinstance(v, (int, float))
            return float(v + 1)

        return plus_one

    @property
    def pandas_scalar_plus_two(self):
        @pandas_udf("double", PandasUDFType.SCALAR)
        def plus_two(v):
            assert isinstance(v, pd.Series)
            return v + 2

        return plus_two

    @property
    def pandas_agg_mean_udf(self):
        @pandas_udf("double", PandasUDFType.GROUPED_AGG)
        def avg(v):
            return v.mean()

        return avg

    @property
    def pandas_agg_sum_udf(self):
        @pandas_udf("double", PandasUDFType.GROUPED_AGG)
        def sum(v):
            return v.sum()

        return sum

    @property
    def pandas_agg_weighted_mean_udf(self):
        import numpy as np

        @pandas_udf("double", PandasUDFType.GROUPED_AGG)
        def weighted_mean(v, w):
            return np.average(v, weights=w)

        return weighted_mean

    def test_manual(self):
        df = self.data
        sum_udf = self.pandas_agg_sum_udf
        mean_udf = self.pandas_agg_mean_udf
        mean_arr_udf = pandas_udf(
            self.pandas_agg_mean_udf.func,
            ArrayType(self.pandas_agg_mean_udf.returnType),
            self.pandas_agg_mean_udf.evalType,
        )

        result1 = (
            df.groupby("id")
            .agg(sum_udf(df.v), mean_udf(df.v), mean_arr_udf(array(df.v)))
            .sort("id")
        )
        expected1 = self.spark.createDataFrame(
            [
                [0, 245.0, 24.5, [24.5]],
                [1, 255.0, 25.5, [25.5]],
                [2, 265.0, 26.5, [26.5]],
                [3, 275.0, 27.5, [27.5]],
                [4, 285.0, 28.5, [28.5]],
                [5, 295.0, 29.5, [29.5]],
                [6, 305.0, 30.5, [30.5]],
                [7, 315.0, 31.5, [31.5]],
                [8, 325.0, 32.5, [32.5]],
                [9, 335.0, 33.5, [33.5]],
            ],
            ["id", "sum(v)", "avg(v)", "avg(array(v))"],
        )

        assert_frame_equal(expected1.toPandas(), result1.toPandas())

    def test_basic(self):
        df = self.data
        weighted_mean_udf = self.pandas_agg_weighted_mean_udf

        # Groupby one column and aggregate one UDF with literal
        result1 = df.groupby("id").agg(weighted_mean_udf(df.v, lit(1.0))).sort("id")
        expected1 = df.groupby("id").agg(mean(df.v).alias("weighted_mean(v, 1.0)")).sort("id")
        assert_frame_equal(expected1.toPandas(), result1.toPandas())

        # Groupby one expression and aggregate one UDF with literal
        result2 = df.groupby((col("id") + 1)).agg(weighted_mean_udf(df.v, lit(1.0))).sort(df.id + 1)
        expected2 = (
            df.groupby((col("id") + 1))
            .agg(mean(df.v).alias("weighted_mean(v, 1.0)"))
            .sort(df.id + 1)
        )
        assert_frame_equal(expected2.toPandas(), result2.toPandas())

        # Groupby one column and aggregate one UDF without literal
        result3 = df.groupby("id").agg(weighted_mean_udf(df.v, df.w)).sort("id")
        expected3 = df.groupby("id").agg(mean(df.v).alias("weighted_mean(v, w)")).sort("id")
        assert_frame_equal(expected3.toPandas(), result3.toPandas())

        # Groupby one expression and aggregate one UDF without literal
        result4 = (
            df.groupby((col("id") + 1).alias("id")).agg(weighted_mean_udf(df.v, df.w)).sort("id")
        )
        expected4 = (
            df.groupby((col("id") + 1).alias("id"))
            .agg(mean(df.v).alias("weighted_mean(v, w)"))
            .sort("id")
        )
        assert_frame_equal(expected4.toPandas(), result4.toPandas())

    def test_unsupported_types(self):
        with QuietTest(self.sc):
            with self.assertRaisesRegex(NotImplementedError, "not supported"):
                pandas_udf(
                    lambda x: x, ArrayType(ArrayType(TimestampType())), PandasUDFType.GROUPED_AGG
                )

        with QuietTest(self.sc):
            with self.assertRaisesRegex(NotImplementedError, "not supported"):

                @pandas_udf("mean double, std double", PandasUDFType.GROUPED_AGG)
                def mean_and_std_udf(v):
                    return v.mean(), v.std()

        with QuietTest(self.sc):
            with self.assertRaisesRegex(NotImplementedError, "not supported"):

                @pandas_udf(ArrayType(TimestampType()), PandasUDFType.GROUPED_AGG)
                def mean_and_std_udf(v):  # noqa: F811
                    return {v.mean(): v.std()}

    def test_alias(self):
        df = self.data
        mean_udf = self.pandas_agg_mean_udf

        result1 = df.groupby("id").agg(mean_udf(df.v).alias("mean_alias"))
        expected1 = df.groupby("id").agg(mean(df.v).alias("mean_alias"))

        assert_frame_equal(expected1.toPandas(), result1.toPandas())

    def test_mixed_sql(self):
        """
        Test mixing group aggregate pandas UDF with sql expression.
        """
        df = self.data
        sum_udf = self.pandas_agg_sum_udf

        # Mix group aggregate pandas UDF with sql expression
        result1 = df.groupby("id").agg(sum_udf(df.v) + 1).sort("id")
        expected1 = df.groupby("id").agg(sum(df.v) + 1).sort("id")

        # Mix group aggregate pandas UDF with sql expression (order swapped)
        result2 = df.groupby("id").agg(sum_udf(df.v + 1)).sort("id")

        expected2 = df.groupby("id").agg(sum(df.v + 1)).sort("id")

        # Wrap group aggregate pandas UDF with two sql expressions
        result3 = df.groupby("id").agg(sum_udf(df.v + 1) + 2).sort("id")
        expected3 = df.groupby("id").agg(sum(df.v + 1) + 2).sort("id")

        assert_frame_equal(expected1.toPandas(), result1.toPandas())
        assert_frame_equal(expected2.toPandas(), result2.toPandas())
        assert_frame_equal(expected3.toPandas(), result3.toPandas())

    def test_mixed_udfs(self):
        """
        Test mixing group aggregate pandas UDF with python UDF and scalar pandas UDF.
        """
        df = self.data
        plus_one = self.python_plus_one
        plus_two = self.pandas_scalar_plus_two
        sum_udf = self.pandas_agg_sum_udf

        # Mix group aggregate pandas UDF and python UDF
        result1 = df.groupby("id").agg(plus_one(sum_udf(df.v))).sort("id")
        expected1 = df.groupby("id").agg(plus_one(sum(df.v))).sort("id")

        # Mix group aggregate pandas UDF and python UDF (order swapped)
        result2 = df.groupby("id").agg(sum_udf(plus_one(df.v))).sort("id")
        expected2 = df.groupby("id").agg(sum(plus_one(df.v))).sort("id")

        # Mix group aggregate pandas UDF and scalar pandas UDF
        result3 = df.groupby("id").agg(sum_udf(plus_two(df.v))).sort("id")
        expected3 = df.groupby("id").agg(sum(plus_two(df.v))).sort("id")

        # Mix group aggregate pandas UDF and scalar pandas UDF (order swapped)
        result4 = df.groupby("id").agg(plus_two(sum_udf(df.v))).sort("id")
        expected4 = df.groupby("id").agg(plus_two(sum(df.v))).sort("id")

        # Wrap group aggregate pandas UDF with two python UDFs and use python UDF in groupby
        result5 = (
            df.groupby(plus_one(df.id)).agg(plus_one(sum_udf(plus_one(df.v)))).sort("plus_one(id)")
        )
        expected5 = (
            df.groupby(plus_one(df.id)).agg(plus_one(sum(plus_one(df.v)))).sort("plus_one(id)")
        )

        # Wrap group aggregate pandas UDF with two scala pandas UDF and user scala pandas UDF in
        # groupby
        result6 = (
            df.groupby(plus_two(df.id)).agg(plus_two(sum_udf(plus_two(df.v)))).sort("plus_two(id)")
        )
        expected6 = (
            df.groupby(plus_two(df.id)).agg(plus_two(sum(plus_two(df.v)))).sort("plus_two(id)")
        )

        assert_frame_equal(expected1.toPandas(), result1.toPandas())
        assert_frame_equal(expected2.toPandas(), result2.toPandas())
        assert_frame_equal(expected3.toPandas(), result3.toPandas())
        assert_frame_equal(expected4.toPandas(), result4.toPandas())
        assert_frame_equal(expected5.toPandas(), result5.toPandas())
        assert_frame_equal(expected6.toPandas(), result6.toPandas())

    def test_multiple_udfs(self):
        """
        Test multiple group aggregate pandas UDFs in one agg function.
        """
        df = self.data
        mean_udf = self.pandas_agg_mean_udf
        sum_udf = self.pandas_agg_sum_udf
        weighted_mean_udf = self.pandas_agg_weighted_mean_udf

        result1 = (
            df.groupBy("id")
            .agg(mean_udf(df.v), sum_udf(df.v), weighted_mean_udf(df.v, df.w))
            .sort("id")
            .toPandas()
        )
        expected1 = (
            df.groupBy("id")
            .agg(mean(df.v), sum(df.v), mean(df.v).alias("weighted_mean(v, w)"))
            .sort("id")
            .toPandas()
        )

        assert_frame_equal(expected1, result1)

    def test_complex_groupby(self):
        df = self.data
        sum_udf = self.pandas_agg_sum_udf
        plus_one = self.python_plus_one
        plus_two = self.pandas_scalar_plus_two

        # groupby one expression
        result1 = df.groupby(df.v % 2).agg(sum_udf(df.v))
        expected1 = df.groupby(df.v % 2).agg(sum(df.v))

        # empty groupby
        result2 = df.groupby().agg(sum_udf(df.v))
        expected2 = df.groupby().agg(sum(df.v))

        # groupby one column and one sql expression
        result3 = df.groupby(df.id, df.v % 2).agg(sum_udf(df.v)).orderBy(df.id, df.v % 2)
        expected3 = df.groupby(df.id, df.v % 2).agg(sum(df.v)).orderBy(df.id, df.v % 2)

        # groupby one python UDF
        result4 = df.groupby(plus_one(df.id)).agg(sum_udf(df.v)).sort("plus_one(id)")
        expected4 = df.groupby(plus_one(df.id)).agg(sum(df.v)).sort("plus_one(id)")

        # groupby one scalar pandas UDF
        result5 = df.groupby(plus_two(df.id)).agg(sum_udf(df.v)).sort("sum(v)")
        expected5 = df.groupby(plus_two(df.id)).agg(sum(df.v)).sort("sum(v)")

        # groupby one expression and one python UDF
        result6 = (
            df.groupby(df.v % 2, plus_one(df.id))
            .agg(sum_udf(df.v))
            .sort(["(v % 2)", "plus_one(id)"])
        )
        expected6 = (
            df.groupby(df.v % 2, plus_one(df.id)).agg(sum(df.v)).sort(["(v % 2)", "plus_one(id)"])
        )

        # groupby one expression and one scalar pandas UDF
        result7 = (
            df.groupby(df.v % 2, plus_two(df.id))
            .agg(sum_udf(df.v))
            .sort(["sum(v)", "plus_two(id)"])
        )
        expected7 = (
            df.groupby(df.v % 2, plus_two(df.id)).agg(sum(df.v)).sort(["sum(v)", "plus_two(id)"])
        )

        assert_frame_equal(expected1.toPandas(), result1.toPandas())
        assert_frame_equal(expected2.toPandas(), result2.toPandas())
        assert_frame_equal(expected3.toPandas(), result3.toPandas())
        assert_frame_equal(expected4.toPandas(), result4.toPandas())
        assert_frame_equal(expected5.toPandas(), result5.toPandas())
        assert_frame_equal(expected6.toPandas(), result6.toPandas())
        assert_frame_equal(expected7.toPandas(), result7.toPandas())

    def test_complex_expressions(self):
        df = self.data
        plus_one = self.python_plus_one
        plus_two = self.pandas_scalar_plus_two
        sum_udf = self.pandas_agg_sum_udf

        # Test complex expressions with sql expression, python UDF and
        # group aggregate pandas UDF
        result1 = (
            df.withColumn("v1", plus_one(df.v))
            .withColumn("v2", df.v + 2)
            .groupby(df.id, df.v % 2)
            .agg(
                sum_udf(col("v")),
                sum_udf(col("v1") + 3),
                sum_udf(col("v2")) + 5,
                plus_one(sum_udf(col("v1"))),
                sum_udf(plus_one(col("v2"))),
            )
            .sort(["id", "(v % 2)"])
            .toPandas()
            .sort_values(by=["id", "(v % 2)"])
        )

        expected1 = (
            df.withColumn("v1", df.v + 1)
            .withColumn("v2", df.v + 2)
            .groupby(df.id, df.v % 2)
            .agg(
                sum(col("v")),
                sum(col("v1") + 3),
                sum(col("v2")) + 5,
                plus_one(sum(col("v1"))),
                sum(plus_one(col("v2"))),
            )
            .sort(["id", "(v % 2)"])
            .toPandas()
            .sort_values(by=["id", "(v % 2)"])
        )

        # Test complex expressions with sql expression, scala pandas UDF and
        # group aggregate pandas UDF
        result2 = (
            df.withColumn("v1", plus_one(df.v))
            .withColumn("v2", df.v + 2)
            .groupby(df.id, df.v % 2)
            .agg(
                sum_udf(col("v")),
                sum_udf(col("v1") + 3),
                sum_udf(col("v2")) + 5,
                plus_two(sum_udf(col("v1"))),
                sum_udf(plus_two(col("v2"))),
            )
            .sort(["id", "(v % 2)"])
            .toPandas()
            .sort_values(by=["id", "(v % 2)"])
        )

        expected2 = (
            df.withColumn("v1", df.v + 1)
            .withColumn("v2", df.v + 2)
            .groupby(df.id, df.v % 2)
            .agg(
                sum(col("v")),
                sum(col("v1") + 3),
                sum(col("v2")) + 5,
                plus_two(sum(col("v1"))),
                sum(plus_two(col("v2"))),
            )
            .sort(["id", "(v % 2)"])
            .toPandas()
            .sort_values(by=["id", "(v % 2)"])
        )

        # Test sequential groupby aggregate
        result3 = (
            df.groupby("id")
            .agg(sum_udf(df.v).alias("v"))
            .groupby("id")
            .agg(sum_udf(col("v")))
            .sort("id")
            .toPandas()
        )

        expected3 = (
            df.groupby("id")
            .agg(sum(df.v).alias("v"))
            .groupby("id")
            .agg(sum(col("v")))
            .sort("id")
            .toPandas()
        )

        assert_frame_equal(expected1, result1)
        assert_frame_equal(expected2, result2)
        assert_frame_equal(expected3, result3)

    def test_retain_group_columns(self):
        with self.sql_conf({"spark.sql.retainGroupColumns": False}):
            df = self.data
            sum_udf = self.pandas_agg_sum_udf

            result1 = df.groupby(df.id).agg(sum_udf(df.v))
            expected1 = df.groupby(df.id).agg(sum(df.v))
            assert_frame_equal(expected1.toPandas(), result1.toPandas())

    def test_array_type(self):
        df = self.data

        array_udf = pandas_udf(lambda x: [1.0, 2.0], "array<double>", PandasUDFType.GROUPED_AGG)
        result1 = df.groupby("id").agg(array_udf(df["v"]).alias("v2"))
        self.assertEqual(result1.first()["v2"], [1.0, 2.0])

    def test_invalid_args(self):
        df = self.data
        plus_one = self.python_plus_one
        mean_udf = self.pandas_agg_mean_udf

        with QuietTest(self.sc):
            with self.assertRaisesRegex(AnalysisException, "[MISSING_AGGREGATION]"):
                df.groupby(df.id).agg(plus_one(df.v)).collect()

        with QuietTest(self.sc):
            with self.assertRaisesRegex(
                AnalysisException, "aggregate function.*argument.*aggregate function"
            ):
                df.groupby(df.id).agg(mean_udf(mean_udf(df.v))).collect()

        with QuietTest(self.sc):
            with self.assertRaisesRegex(
                AnalysisException,
                "The group aggregate pandas UDF `avg` cannot be invoked together with as other, "
                "non-pandas aggregate functions.",
            ):
                df.groupby(df.id).agg(mean_udf(df.v), mean(df.v)).collect()

    def test_register_vectorized_udf_basic(self):
        sum_pandas_udf = pandas_udf(
            lambda v: v.sum(), "integer", PythonEvalType.SQL_GROUPED_AGG_PANDAS_UDF
        )

        self.assertEqual(sum_pandas_udf.evalType, PythonEvalType.SQL_GROUPED_AGG_PANDAS_UDF)
        group_agg_pandas_udf = self.spark.udf.register("sum_pandas_udf", sum_pandas_udf)
        self.assertEqual(group_agg_pandas_udf.evalType, PythonEvalType.SQL_GROUPED_AGG_PANDAS_UDF)
        q = "SELECT sum_pandas_udf(v1) FROM VALUES (3, 0), (2, 0), (1, 1) tbl(v1, v2) GROUP BY v2"
        actual = sorted(map(lambda r: r[0], self.spark.sql(q).collect()))
        expected = [1, 5]
        self.assertEqual(actual, expected)

    def test_grouped_with_empty_partition(self):
        data = [Row(id=1, x=2), Row(id=1, x=3), Row(id=2, x=4)]
        expected = [Row(id=1, sum=5), Row(id=2, x=4)]
        num_parts = len(data) + 1
        df = self.spark.createDataFrame(self.sc.parallelize(data, numSlices=num_parts))

        f = pandas_udf(lambda x: x.sum(), "int", PandasUDFType.GROUPED_AGG)

        result = df.groupBy("id").agg(f(df["x"]).alias("sum")).collect()
        self.assertEqual(result, expected)

    def test_grouped_without_group_by_clause(self):
        @pandas_udf("double", PandasUDFType.GROUPED_AGG)
        def max_udf(v):
            return v.max()

        df = self.spark.range(0, 100)
        self.spark.udf.register("max_udf", max_udf)

        with self.tempView("table"):
            df.createTempView("table")

            agg1 = df.agg(max_udf(df["id"]))
            agg2 = self.spark.sql("select max_udf(id) from table")
            assert_frame_equal(agg1.toPandas(), agg2.toPandas())

    def test_no_predicate_pushdown_through(self):
        # SPARK-30921: We should not pushdown predicates of PythonUDFs through Aggregate.
        import numpy as np

        @pandas_udf("float", PandasUDFType.GROUPED_AGG)
        def mean(x):
            return np.mean(x)

        df = self.spark.createDataFrame([Row(id=1, foo=42), Row(id=2, foo=1), Row(id=2, foo=2)])

        agg = df.groupBy("id").agg(mean("foo").alias("mean"))
        filtered = agg.filter(agg["mean"] > 40.0)

        assert filtered.collect()[0]["mean"] == 42.0


if __name__ == "__main__":
    from pyspark.sql.tests.pandas.test_pandas_udf_grouped_agg 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)
