#!/usr/bin/env python3
import json
import os
import shutil
import datetime
import re
from pathlib import Path
from dateutil.relativedelta import relativedelta
from update_excel import update_excel_variables

def create_excel_from_template():
    """
    Create a copy of the Excel template, replacing {store_name} with the value from config.json
    and save it to the output folder.
    """
    # Define paths
    script_dir = os.path.dirname(os.path.abspath(__file__))
    config_path = os.path.join(script_dir, 'config.json')
    template_path = os.path.join(script_dir, 'template', 'Footprints AI for {store_name} - Retail Media Business Case Calculations.xlsx')
    output_dir = os.path.join(script_dir, 'output')
    
    # Ensure output directory exists
    os.makedirs(output_dir, exist_ok=True)
    
    # Read config.json to get store_name, starting_date, and duration
    try:
        with open(config_path, 'r') as f:
            config = json.load(f)
            user_data = config.get('user_data', {})
            store_name = user_data.get('store_name', '')
            starting_date = user_data.get('starting_date', '')
            duration = user_data.get('duration', 36)
            
            # If store_name is empty, use a default value
            if not store_name:
                store_name = "Your Store"
                
            # Calculate years array based on starting_date and duration
            years = calculate_years(starting_date, duration)
            print(f"Years in the period: {years}")
    except Exception as e:
        print(f"Error reading config file: {e}")
        return False
    
    # Use first and last years from the array in the filename
    year_range = ""
    if years and len(years) > 0:
        if len(years) == 1:
            year_range = f"{years[0]}"
        else:
            year_range = f"{years[0]}-{years[-1]}"
    else:
        # Fallback to current year if years array is empty
        current_year = datetime.datetime.now().year
        year_range = f"{current_year}"
    
    # Create output filename with store_name and year range
    output_filename = f"Footprints AI for {store_name} - Retail Media Business Case Calculations {year_range}.xlsx"
    output_path = os.path.join(output_dir, output_filename)
    
    # Copy the template to the output directory with the new name
    try:
        shutil.copy2(template_path, output_path)
        print(f"Excel file created successfully: {output_path}")
        
        # Update the Excel file with variables from config.json
        print("Updating Excel file with variables from config.json...")
        update_result = update_excel_variables(output_path)
        
        if update_result:
            print("Excel file updated successfully with variables from config.json")
        else:
            print("Warning: Failed to update Excel file with variables from config.json")
        
        return True
    except Exception as e:
        print(f"Error creating Excel file: {e}")
        return False

def calculate_years(starting_date, duration):
    """
    Calculate an array of years that appear in the period from starting_date for duration months.
    
    Args:
        starting_date (str): Date in format dd/mm/yyyy or dd.mm.yyyy
        duration (int): Number of months, including the starting month
        
    Returns:
        list: Array of years in the period [year1, year2, ...]
    """
    # Default result if we can't parse the date
    default_years = [datetime.datetime.now().year]
    
    # If starting_date is empty, return current year
    if not starting_date:
        return default_years
    
    try:
        # Try to parse the date, supporting both dd/mm/yyyy and dd.mm.yyyy formats
        if '/' in starting_date:
            day, month, year = map(int, starting_date.split('/'))
        elif '.' in starting_date:
            day, month, year = map(int, starting_date.split('.'))
        elif '-' in starting_date:
            # Handle ISO format (yyyy-mm-dd)
            date_parts = starting_date.split('-')
            if len(date_parts) == 3:
                year, month, day = map(int, date_parts)
            else:
                # Default to current date if format is not recognized
                return default_years
        else:
            # If format is not recognized, return default
            return default_years
        
        # Create datetime object for starting date
        start_date = datetime.datetime(year, month, day)
        
        # Calculate end date (starting date + duration months - 1 day)
        end_date = start_date + relativedelta(months=duration-1)
        
        # Create a set of years (to avoid duplicates)
        years_set = set()
        
        # Add starting year
        years_set.add(start_date.year)
        
        # Add ending year
        years_set.add(end_date.year)
        
        # If there are years in between, add those too
        for y in range(start_date.year + 1, end_date.year):
            years_set.add(y)
        
        # Convert set to sorted list
        return sorted(list(years_set))
    
    except Exception as e:
        print(f"Error calculating years: {e}")
        return default_years

if __name__ == "__main__":
    create_excel_from_template()