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)