feat: add data source

backend/app/connectors/factory.py

@@ -0,0 +1,53 @@
+from typing import Dict, Any, Optional
+import json
+import functools
+from app.connectors.postgres import PostgresConnector
+from app.connectors.clickhouse import ClickHouseConnector
+from app.connectors.parquet import ParquetConnector
+from app.models.datasource import DataSource
+
+@functools.lru_cache(maxsize=32)
+def _get_cached_connector(ds_type: str, config_json: str):
+    config = json.loads(config_json)
+    
+    if ds_type in ["postgres", "postgresql", "supabase"]:
+        # Supabase is just postgres
+        db_url = config.get("connection_string") or \
+                 f"postgresql://{config.get('user')}:{config.get('password')}@{config.get('host')}:{config.get('port', 5432)}/{config.get('database')}"
+        return PostgresConnector(db_url=db_url)
+        
+    elif ds_type == "sqlite":
+        # SQLite uses connection string usually file path
+        db_url = config.get("connection_string")
+        if not db_url and config.get("file_path"):
+             db_url = f"sqlite:///{config.get('file_path')}"
+        return PostgresConnector(db_url=db_url)
+
+    elif ds_type == "clickhouse":
+        return ClickHouseConnector(
+            host=config.get("host"),
+            port=config.get("port", 9000),
+            user=config.get("user", "default"),
+            password=config.get("password", ""),
+            database=config.get("database", "default")
+        )
+        
+    elif ds_type == "parquet":
+        return ParquetConnector(file_path=config.get("file_path"))
+        
+    else:
+        raise ValueError(f"Unsupported data source type: {ds_type}")
+
+def get_connector(datasource: DataSource):
+    # Use JSON string of config as cache key
+    # Ensure stable ordering of keys
+    config_str = json.dumps(datasource.config, sort_keys=True)
+    return _get_cached_connector(datasource.type.lower(), config_str)
+
+def get_connector_from_config(ds_type: str, config: Dict[str, Any]):
+    # Helper for testing connection without saving to DB
+    # We can use the cached function too, or bypass if we want fresh check
+    # Usually for testing we want fresh check, so let's bypass cache or clear it if needed.
+    # But reusing cache is fine if config is same.
+    config_str = json.dumps(config, sort_keys=True)
+    return _get_cached_connector(ds_type.lower(), config_str)