feat: Add new timegrains and convert_dttm to Druid engine spec (#10160)

* feat: Add new timegrains and convert_dttm to Druid engine spec

* Add TemporalType enum and fix test case

* Remove DATETIME for athena (original spec)

tests/db_engine_specs/druid_tests.py

@@ -0,0 +1,56 @@
+# 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.
+from sqlalchemy import column
+
+from superset.db_engine_specs.druid import DruidEngineSpec
+from tests.db_engine_specs.base_tests import DbEngineSpecTestCase
+
+
+class DruidTestCase(DbEngineSpecTestCase):
+    def test_convert_dttm(self):
+        dttm = self.get_dttm()
+
+        self.assertEqual(
+            DruidEngineSpec.convert_dttm("DATETIME", dttm),
+            "TIME_PARSE('2019-01-02T03:04:05')",
+        )
+
+        self.assertEqual(
+            DruidEngineSpec.convert_dttm("TIMESTAMP", dttm),
+            "TIME_PARSE('2019-01-02T03:04:05')",
+        )
+
+        self.assertEqual(
+            DruidEngineSpec.convert_dttm("DATE", dttm),
+            "CAST(TIME_PARSE('2019-01-02') AS DATE)",
+        )
+
+    def test_timegrain_expressions(self):
+        """
+        DB Eng Specs (druid): Test time grain expressions
+        """
+        col = "__time"
+        sqla_col = column(col)
+        test_cases = {
+            "PT1S": f"FLOOR({col} TO SECOND)",
+            "PT5M": f"TIME_FLOOR({col}, 'PT5M')",
+        }
+        for grain, expected in test_cases.items():
+            actual = DruidEngineSpec.get_timestamp_expr(
+                col=sqla_col, pdf=None, time_grain=grain
+            )
+            self.assertEqual(str(actual), expected)