SNOW-2306184: config refactory - top tier configuration sources

Author: sfc-gh-mraba

src/snowflake/cli/api/config_ng/__init__.py

@@ -29,9 +29,19 @@
     SourcePriority,
     ValueSource,
 )
+from snowflake.cli.api.config_ng.sources import (
+    CliArgumentSource,
+    ConfigurationSource,
+    EnvironmentSource,
+    FileSource,
+)
 
 __all__ = [
+    "CliArgumentSource",
+    "ConfigurationSource",
     "ConfigValue",
+    "EnvironmentSource",
+    "FileSource",
     "ResolutionEntry",
     "ResolutionHistory",
     "SourcePriority",

src/snowflake/cli/api/config_ng/handlers.py

@@ -0,0 +1,84 @@
+# Copyright (c) 2024 Snowflake Inc.
+#
+# 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.
+
+"""
+Configuration handlers for specific formats and schemas.
+
+This module will implement specific handlers for:
+- Environment variables (SNOWFLAKE_*, SNOWSQL_*)
+- File formats (TOML, SnowSQL config, JSON, YAML)
+
+To be implemented in Phase 3-4.
+"""
+
+from __future__ import annotations
+
+from abc import abstractmethod
+from pathlib import Path
+from typing import Dict, Optional
+
+from snowflake.cli.api.config_ng.core import ConfigValue, ValueSource
+
+
+class SourceHandler(ValueSource):
+    """
+    Specific handler for a configuration format or schema.
+    Examples: TOML files, SnowSQL config, SNOWFLAKE_* env vars, etc.
+    """
+
+    @property
+    @abstractmethod
+    def handler_type(self) -> str:
+        """
+        Type identifier for this handler.
+        Examples: 'toml', 'json', 'snowsql_env', 'snowsql_config'
+        """
+        ...
+
+    @abstractmethod
+    def can_handle(self) -> bool:
+        """
+        Check if this handler is applicable/available.
+
+        Returns:
+            True if handler can be used, False otherwise
+        """
+        ...
+
+    def can_handle_file(self, file_path: Path) -> bool:
+        """
+        Check if this handler can process the given file.
+
+        Args:
+            file_path: Path to file to check
+
+        Returns:
+            True if handler can process this file, False otherwise
+        """
+        return False
+
+    def discover_from_file(
+        self, file_path: Path, key: Optional[str] = None
+    ) -> Dict[str, ConfigValue]:
+        """
+        Discover values from a file.
+
+        Args:
+            file_path: Path to file to read
+            key: Specific key to discover, or None for all
+
+        Returns:
+            Dictionary of discovered values
+        """
+        return {}