#!/usr/bin/env python3
"""
Backtest execution script for cryptocurrency trading strategies
Refactored for improved maintainability and error handling
"""

import logging
import datetime
import argparse
import sys
from pathlib import Path

# Import custom modules
from config_manager import ConfigManager
from backtest_runner import BacktestRunner
from result_processor import ResultProcessor
from cycles.utils.storage import Storage
from cycles.utils.system import SystemUtils


def setup_logging() -> logging.Logger:
    """Configure and return logging instance"""
    logger = logging.getLogger(__name__)
    
    logging.basicConfig(
        level=logging.INFO,
        format="%(asctime)s [%(levelname)s] %(message)s",
        handlers=[
            logging.FileHandler("backtest.log"),
            logging.StreamHandler()
        ]
    )
    
    return logger


def create_metadata_lines(config: dict, data_df, result_processor: ResultProcessor) -> list:
    """Create metadata lines for results file"""
    start_date = config['start_date']
    stop_date = config['stop_date']
    initial_usd = config['initial_usd']
    
    # Get price information
    start_time, start_price = result_processor.get_price_info(data_df, start_date)
    stop_time, stop_price = result_processor.get_price_info(data_df, stop_date)
    
    metadata_lines = [
        f"Start date\t{start_date}\tPrice\t{start_price or 'N/A'}",
        f"Stop date\t{stop_date}\tPrice\t{stop_price or 'N/A'}",
        f"Initial USD\t{initial_usd}"
    ]
    
    return metadata_lines


def main():
    """Main execution function"""
    logger = setup_logging()
    
    try:
        # Parse command line arguments
        parser = argparse.ArgumentParser(description="Run backtest with config file.")
        parser.add_argument("config", type=str, nargs="?", help="Path to config JSON file.")
        args = parser.parse_args()
        
        # Initialize configuration manager
        config_manager = ConfigManager(logging_instance=logger)
        
        # Load configuration
        logger.info("Loading configuration...")
        config = config_manager.load_config(args.config)
        
        # Initialize components
        logger.info("Initializing components...")
        storage = Storage(
            data_dir=config['data_dir'], 
            results_dir=config['results_dir'],
            logging=logger
        )
        system_utils = SystemUtils(logging=logger)
        result_processor = ResultProcessor(storage, logging_instance=logger)
        runner = BacktestRunner(storage, system_utils, result_processor, logging_instance=logger)
        
        # Validate inputs
        logger.info("Validating inputs...")
        runner.validate_inputs(
            config['timeframes'], 
            config['stop_loss_pcts'], 
            config['initial_usd']
        )
        
        # Load data
        logger.info("Loading market data...")
        data_filename = 'btcusd_1-min_data.csv'
        data_1min = runner.load_data(
            data_filename, 
            config['start_date'], 
            config['stop_date']
        )
        
        # Run backtests
        logger.info("Starting backtest execution...")
        debug_mode = True  # Can be moved to config
        
        all_results, all_trades = runner.run_backtests(
            data_1min,
            config['timeframes'],
            config['stop_loss_pcts'],
            config['initial_usd'],
            debug=debug_mode
        )
        
        # Process and save results
        logger.info("Processing and saving results...")
        timestamp = datetime.datetime.now().strftime("%Y_%m_%d_%H_%M")
        
        # Create metadata
        metadata_lines = create_metadata_lines(config, data_1min, result_processor)
        
        # Save aggregated results
        result_file = result_processor.save_backtest_results(
            all_results, 
            metadata_lines, 
            timestamp
        )
        
        logger.info(f"Backtest completed successfully. Results saved to {result_file}")
        logger.info(f"Processed {len(all_results)} result combinations")
        logger.info(f"Generated {len(all_trades)} total trades")
        
    except KeyboardInterrupt:
        logger.warning("Backtest interrupted by user")
        sys.exit(130)  # Standard exit code for Ctrl+C
        
    except FileNotFoundError as e:
        logger.error(f"File not found: {e}")
        sys.exit(1)
        
    except ValueError as e:
        logger.error(f"Invalid configuration or data: {e}")
        sys.exit(1)
        
    except RuntimeError as e:
        logger.error(f"Runtime error during backtest: {e}")
        sys.exit(1)
        
    except Exception as e:
        logger.error(f"Unexpected error: {e}", exc_info=True)
        sys.exit(1)


if __name__ == "__main__":
    main()