#  Copyright 2021 Collate
#  Licensed 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.

"""
Validate query parser logic
"""

from unittest import TestCase

from metadata.generated.schema.type.tableUsageCount import TableColumn, TableColumnJoin
from metadata.ingestion.lineage.parser import LineageParser


class QueryParserTests(TestCase):
    """
    Check methods from query_parser.py
    """

    query = col_lineage = """
        SELECT
          a.col1,
          a.col2 + b.col2 AS col2,
          case 
            when col1 = 3 then 'hello'
            else 'bye'
          end as new_col
        FROM foo a
        JOIN db.grault b
          ON a.col1 = b.col1
        JOIN db.holis c
          ON a.col1 = c.abc
        JOIN db.random d
          ON a.col2 = d.col2
        WHERE a.col3 = 'abc'
    """

    parser = LineageParser(col_lineage)

    def test_involved_tables(self):
        tables = {str(table) for table in self.parser.involved_tables}
        self.assertEqual(
            tables, {"db.grault", "db.holis", "<default>.foo", "db.random"}
        )

    def test_clean_parser_table_list(self):
        clean_tables = set(self.parser.clean_table_list)
        self.assertEqual(clean_tables, {"db.grault", "db.holis", "foo", "db.random"})

    def test_parser_table_aliases(self):
        aliases = self.parser.table_aliases
        self.assertEqual(
            aliases, {"b": "db.grault", "c": "db.holis", "a": "foo", "d": "db.random"}
        )

    def test_get_table_joins(self):
        """
        main logic point
        """
        joins = self.parser.table_joins

        self.assertEqual(
            joins["foo"],
            [
                TableColumnJoin(
                    tableColumn=TableColumn(table="foo", column="col1"),
                    joinedWith=[
                        TableColumn(table="db.grault", column="col1"),
                        TableColumn(table="db.holis", column="abc"),
                    ],
                ),
                TableColumnJoin(
                    tableColumn=TableColumn(table="foo", column="col2"),
                    joinedWith=[
                        TableColumn(table="db.random", column="col2"),
                    ],
                ),
            ],
        )

    def test_capitals(self):
        """
        Example on how LineageRunner keeps capitals
        for column names
        """

        query = """
         SELECT
           USERS.ID,
           li.id
        FROM TESTDB.PUBLIC.USERS
        JOIN testdb.PUBLIC."lowercase_users" li
          ON USERS.id = li.ID
        ;
        """

        parser = LineageParser(query)

        joins = parser.table_joins

        self.assertEqual(
            joins["testdb.public.users"],
            [
                TableColumnJoin(
                    tableColumn=TableColumn(
                        table="testdb.public.users", column="id"
                    ),  # lowercase col
                    joinedWith=[
                        TableColumn(
                            table="testdb.public.lowercase_users", column="ID"
                        ),  # uppercase col
                    ],
                ),
            ],
        )

    def test_clean_raw_query_copy_grants(self):
        """
        Validate COPY GRANT query cleaning logic
        """
        query = "create or replace view my_view copy grants as select * from my_table"
        self.assertEqual(
            LineageParser.clean_raw_query(query),
            "create or replace view my_view as select * from my_table",
        )

    def test_clean_raw_query_merge_into(self):
        """
        Validate MERGE INTO query cleaning logic
        """
        query = """
            /* comment */ merge into table_1 using (select a, b from table_2) when matched update set t.a = 'value' 
            when not matched then insert (table_1.a, table_2.b) values ('value1', 'value2')
        """
        self.assertEqual(
            LineageParser.clean_raw_query(query),
            "/* comment */ merge into table_1 using (select a, b from table_2)",
        )

    def test_clean_raw_query_copy_from(self):
        """
        Validate COPY FROM query cleaning logic
        """
        query = "COPY my_schema.my_table FROM 's3://bucket/path/object.csv';"
        self.assertEqual(
            LineageParser.clean_raw_query(query),
            None,
        )