From d6ecfa425136fab07826c01d0a7ac271f7a37a30 Mon Sep 17 00:00:00 2001
From: AlvaroMarquesAndrade
 <45604858+AlvaroMarquesAndrade@users.noreply.github.com>
Date: Thu, 18 Feb 2021 15:14:44 -0300
Subject: [PATCH] [MLOP-636] Create migration classes (#282)

---
 butterfree/migrations/__init__.py            |  7 +++
 butterfree/migrations/cassandra_migration.py | 23 ++++++++
 butterfree/migrations/metastore_migration.py | 23 ++++++++
 butterfree/migrations/migration.py           | 62 ++++++++++++++++++++
 4 files changed, 115 insertions(+)
 create mode 100644 butterfree/migrations/__init__.py
 create mode 100644 butterfree/migrations/cassandra_migration.py
 create mode 100644 butterfree/migrations/metastore_migration.py
 create mode 100644 butterfree/migrations/migration.py

diff --git a/butterfree/migrations/__init__.py b/butterfree/migrations/__init__.py
new file mode 100644
index 00000000..5f709bfe
--- /dev/null
+++ b/butterfree/migrations/__init__.py
@@ -0,0 +1,7 @@
+"""Holds available migrations."""
+
+from butterfree.migrations.cassandra_migration import CassandraMigration
+from butterfree.migrations.metastore_migration import MetastoreMigration
+from butterfree.migrations.migration import DatabaseMigration
+
+__all__ = ["DatabaseMigration", "CassandraMigration", "MetastoreMigration"]
diff --git a/butterfree/migrations/cassandra_migration.py b/butterfree/migrations/cassandra_migration.py
new file mode 100644
index 00000000..e9cecdc7
--- /dev/null
+++ b/butterfree/migrations/cassandra_migration.py
@@ -0,0 +1,23 @@
+"""Cassandra Migration entity."""
+
+from typing import Any, Dict, List
+
+from butterfree.migrations import DatabaseMigration
+
+
+class CassandraMigration(DatabaseMigration):
+    """Cassandra class for Migrations."""
+
+    def create_query(
+        self,
+        fs_schema: List[Dict[str, Any]],
+        db_schema: List[Dict[str, Any]],
+        table_name: str,
+    ) -> Any:
+        """Create a query regarding Cassandra.
+
+        Returns:
+            Schema object.
+
+        """
+        pass
diff --git a/butterfree/migrations/metastore_migration.py b/butterfree/migrations/metastore_migration.py
new file mode 100644
index 00000000..bb208f2a
--- /dev/null
+++ b/butterfree/migrations/metastore_migration.py
@@ -0,0 +1,23 @@
+"""Metastore Migration entity."""
+
+from typing import Any, Dict, List
+
+from butterfree.migrations import DatabaseMigration
+
+
+class MetastoreMigration(DatabaseMigration):
+    """Metastore class for Migrations."""
+
+    def create_query(
+        self,
+        fs_schema: List[Dict[str, Any]],
+        db_schema: List[Dict[str, Any]],
+        table_name: str,
+    ) -> Any:
+        """Create a query regarding Metastore.
+
+        Returns:
+            Schema object.
+
+        """
+        pass
diff --git a/butterfree/migrations/migration.py b/butterfree/migrations/migration.py
new file mode 100644
index 00000000..c53945bf
--- /dev/null
+++ b/butterfree/migrations/migration.py
@@ -0,0 +1,62 @@
+"""Migration entity."""
+
+from abc import ABC, abstractmethod
+from typing import Any, Callable, Dict, List
+
+from butterfree.pipelines import FeatureSetPipeline
+
+
+class DatabaseMigration(ABC):
+    """Abstract base class for Migrations."""
+
+    @abstractmethod
+    def create_query(
+        self,
+        fs_schema: List[Dict[str, Any]],
+        db_schema: List[Dict[str, Any]],
+        table_name: str,
+    ) -> Any:
+        """Create a query regarding a data source.
+
+        Returns:
+            The desired query for the given database.
+
+        """
+
+    def _validate_schema(
+        self, fs_schema: List[Dict[str, Any]], db_schema: List[Dict[str, Any]]
+    ) -> Any:
+        """Provides schema validation for feature sets.
+
+        Compares the schema of your local feature set to the
+        corresponding table in a given database.
+
+        Args:
+            fs_schema: object that contains feature set's schemas.
+            db_schema: object that contains the table og a given db schema.
+
+        """
+
+    def _get_schema(self, db_client: Callable, table_name: str) -> List[Dict[str, Any]]:
+        """Get a table schema in the respective database.
+
+        Returns:
+            Schema object.
+        """
+        pass
+
+    def _apply_migration(self, query: str, db_client: Callable) -> None:
+        """Apply the migration in the respective database."""
+
+    def _send_logs_to_s3(self) -> None:
+        """Send all migration logs to S3."""
+        pass
+
+    def run(self, pipelines: List[FeatureSetPipeline]) -> None:
+        """Runs the migrations.
+
+        Args:
+            pipelines: the feature set pipelines.
+
+        """
+        pass