"""
Stock Plot Generation Script

This script generates stock gain plots using yfinance and matplotlib.
It includes robust error handling and debugging information.
"""

import os
import sys
import traceback
import platform
from datetime import datetime

# Configure matplotlib before importing pyplot
import matplotlib
matplotlib.use('Agg')  # Non-interactive backend
import matplotlib.pyplot as plt
import pandas as pd
import yfinance as yf


def setup_environment():
    """Print environment information and verify dependencies."""
    print("\n" + "=" * 80)
    print("ENVIRONMENT INFORMATION")
    print("=" * 80)
    print(f"Python: {sys.version}")
    print(f"Platform: {platform.platform()}")
    print(f"Current directory: {os.getcwd()}")
    print(f"Python executable: {sys.executable}")
    print(f"Current time: {datetime.now().isoformat()}")
    
    # Verify required packages
    print("\nChecking dependencies:")
    for pkg in [('pandas', pd), ('matplotlib', matplotlib), ('yfinance', yf)]:
        try:
            print(f"  ✓ {pkg[0]}: {pkg[1].__version__}")
        except Exception as e:
            print(f"  ✗ {pkg[0]}: Not available ({e})")


def plot_stock_gain(symbols, timeframe="3mo"):
    """
    Generate and save stock gain plots.
    
    Args:
        symbols: List of stock symbols or a single symbol string
        timeframe: Time period to fetch data for (e.g., '1mo', '3mo', '1y')
        
    Returns:
        str: Path to the saved plot file, or None if failed
    """
    # Convert single symbol to list
    if isinstance(symbols, str):
        symbols = [symbols]
    
    print(f"\nProcessing symbols: {', '.join(symbols)} for timeframe: {timeframe}")
    
    # Create output directory if it doesn't exist
    output_dir = 'generated_plots'
    os.makedirs(output_dir, exist_ok=True)
    
    plot_paths = []
    
    for symbol in symbols:
        try:
            print(f"\n{'='*40}")
            print(f"Processing: {symbol}")
            print(f"{'='*40}")
            
            # Download stock data
            print(f"Downloading {timeframe} data for {symbol}...")
            ticker = yf.Ticker(symbol)
            stock_data = ticker.history(period=timeframe)
            
            if stock_data.empty:
                print(f"⚠ No data found for {symbol}")
                continue
                
            print(f"Retrieved {len(stock_data)} data points from {stock_data.index[0].date()} to {stock_data.index[-1].date()}")
            
            # Calculate percentage gain
            stock_data['Gain'] = stock_data['Close'].pct_change().fillna(0).cumsum()
            
            # Create plot
            plt.figure(figsize=(12, 6))
            plt.plot(stock_data.index, stock_data['Gain'], 
                   linewidth=2, 
                   label=f'{symbol} Gain')
            
            # Format plot
            plt.title(f'{symbol} Cumulative Gain - {timeframe.upper()}', fontsize=14)
            plt.xlabel('Date', fontsize=12)
            plt.ylabel('Cumulative Gain', fontsize=12)
            plt.legend()
            plt.grid(True, linestyle='--', alpha=0.7)
            plt.tight_layout()
            
            # Save plot
            timestamp = datetime.now().strftime('%Y%m%d_%H%M%S')
            plot_filename = f"{symbol}_{timeframe}_{timestamp}.png"
            plot_path = os.path.join(output_dir, plot_filename)
            
            plt.savefig(plot_path, dpi=120, bbox_inches='tight')
            plt.close()  # Close the figure to free memory
            
            # Verify the file was created
            if os.path.exists(plot_path):
                file_size = os.path.getsize(plot_path)
                print(f"✓ Plot saved: {plot_path} ({file_size} bytes)")
                plot_paths.append(plot_path)
                
                # Also save as plot.png in root for compatibility
                if symbol == symbols[-1]:  # Only for the last symbol
                    main_plot_path = 'plot.png'
                    plt.figure(plt.get_fignums()[-1])  # Get the last figure
                    plt.savefig(main_plot_path, dpi=120, bbox_inches='tight')
                    print(f"✓ Main plot saved as: {os.path.abspath(main_plot_path)}")
            else:
                print("❌ Failed to save plot")
                
        except Exception as e:
            print(f"❌ Error processing {symbol}: {str(e)}")
            print("Traceback:")
            traceback.print_exc()
    
    return plot_paths[0] if plot_paths else None


def main():
    """Main execution function."""
    try:
        setup_environment()
        
        # Default symbols and timeframe
        symbols = ["META"]
        timeframe = "ytd"
        
        # Generate plots
        plot_path = plot_stock_gain(symbols, timeframe)
        
        if plot_path:
            print(f"\n✅ Successfully generated plot: {os.path.abspath(plot_path)}")
            return 0
        else:
            print("\n❌ Failed to generate any plots")
            return 1
            
    except Exception as e:
        print(f"\n❌ Fatal error: {str(e)}")
        print("Traceback:")
        traceback.print_exc()
        return 1


if __name__ == "__main__":
    sys.exit(main())