import os
import pandas as pd
from typing import Optional, Union, Dict, Any, List
import logging

from .data_loader import DataLoader
from .data_saver import DataSaver
from .result_formatter import ResultFormatter
from .storage_utils import DataLoadingError, DataSavingError

RESULTS_DIR = "../results"
DATA_DIR = "../data"


class Storage:
    """Unified storage interface for data and results operations
    
    Acts as a coordinator for DataLoader, DataSaver, and ResultFormatter components,
    maintaining backward compatibility while providing a clean separation of concerns.
    """
    
    def __init__(self, logging=None, results_dir=RESULTS_DIR, data_dir=DATA_DIR):
        """Initialize storage with component instances
        
        Args:
            logging: Optional logging instance
            results_dir: Directory for results files
            data_dir: Directory for data files
        """
        self.results_dir = results_dir
        self.data_dir = data_dir
        self.logging = logging

        # Create directories if they don't exist
        os.makedirs(self.results_dir, exist_ok=True)
        os.makedirs(self.data_dir, exist_ok=True)

        # Initialize component instances
        self.data_loader = DataLoader(data_dir, logging)
        self.data_saver = DataSaver(data_dir, logging)
        self.result_formatter = ResultFormatter(results_dir, logging)

    def load_data(self, file_path: str, start_date: Union[str, pd.Timestamp], 
                  stop_date: Union[str, pd.Timestamp]) -> pd.DataFrame:
        """Load data with optimized dtypes and filtering, supporting CSV and JSON input
        
        Args:
            file_path: path to the data file
            start_date: start date (string or datetime-like)
            stop_date: stop date (string or datetime-like)
            
        Returns:
            pandas DataFrame with timestamp index
            
        Raises:
            DataLoadingError: If data loading fails
        """
        return self.data_loader.load_data(file_path, start_date, stop_date)

    def save_data(self, data: pd.DataFrame, file_path: str) -> None:
        """Save processed data to a CSV file
        
        Args:
            data: DataFrame to save
            file_path: path to the data file relative to the data_dir
            
        Raises:
            DataSavingError: If saving fails
        """
        self.data_saver.save_data(data, file_path)

    def format_row(self, row: Dict[str, Any]) -> Dict[str, str]:
        """Format a row for a combined results CSV file
        
        Args:
            row: Dictionary containing row data
            
        Returns:
            Dictionary with formatted values
        """
        return self.result_formatter.format_row(row)

    def write_results_chunk(self, filename: str, fieldnames: List[str], 
                           rows: List[Dict], write_header: bool = False, 
                           initial_usd: Optional[float] = None) -> None:
        """Write a chunk of results to a CSV file
        
        Args:
            filename: filename to write to
            fieldnames: list of fieldnames
            rows: list of rows
            write_header: whether to write the header
            initial_usd: initial USD value for header comment
        """
        self.result_formatter.write_results_chunk(
            filename, fieldnames, rows, write_header, initial_usd
        )

    def write_backtest_results(self, filename: str, fieldnames: List[str], 
                              rows: List[Dict], metadata_lines: Optional[List[str]] = None) -> str:
        """Write combined backtest results to a CSV file
        
        Args:
            filename: filename to write to
            fieldnames: list of fieldnames
            rows: list of result dictionaries
            metadata_lines: optional list of strings to write as header comments
            
        Returns:
            Full path to the written file
        """
        return self.result_formatter.write_backtest_results(
            filename, fieldnames, rows, metadata_lines
        )

    def write_trades(self, all_trade_rows: List[Dict], trades_fieldnames: List[str]) -> None:
        """Write trades to separate CSV files grouped by timeframe and stop loss
        
        Args:
            all_trade_rows: list of trade dictionaries
            trades_fieldnames: list of trade fieldnames
        """
        self.result_formatter.write_trades(all_trade_rows, trades_fieldnames)