"""
Interactive setup wizard for configuring the sales analysis template
Asks clarifying questions to configure config.py for your specific company and data
"""
import os
import sys
from pathlib import Path

def print_header(text):
    """Print a formatted header"""
    print("\n" + "="*70)
    print(f"  {text}")
    print("="*70 + "\n")

def ask_question(prompt, default=None, validator=None):
    """
    Ask a question and return the answer
    
    Args:
        prompt: Question to ask
        default: Default value if user just presses Enter
        validator: Optional function to validate input
    
    Returns:
        User's answer (or default)
    """
    if default:
        full_prompt = f"{prompt} [{default}]: "
    else:
        full_prompt = f"{prompt}: "
    
    while True:
        answer = input(full_prompt).strip()
        if not answer and default:
            return default
        elif not answer:
            print("  Please provide an answer.")
            continue
        
        if validator:
            try:
                return validator(answer)
            except Exception as e:
                print(f"  Invalid input: {e}")
                continue
        
        return answer

def validate_yes_no(answer):
    """Validate yes/no answer"""
    answer_lower = answer.lower()
    if answer_lower in ['y', 'yes', 'true', '1']:
        return True
    elif answer_lower in ['n', 'no', 'false', '0']:
        return False
    else:
        raise ValueError("Please answer 'yes' or 'no'")

def validate_int(answer):
    """Validate integer answer"""
    return int(answer)

def validate_file_exists(answer):
    """Validate that file exists"""
    if not Path(answer).exists():
        raise ValueError(f"File not found: {answer}")
    return answer

def main():
    """Run the setup wizard"""
    print_header("Sales Analysis Template - Setup Wizard")
    print("This wizard will help you configure the template for your company's data.")
    print("You can press Enter to accept defaults (shown in brackets).\n")
    
    responses = {}
    
    # Company Information
    print_header("Company Information")
    responses['company_name'] = ask_question("Company Name", default="Your Company Name")
    responses['analysis_date'] = ask_question("Analysis Date (YYYY-MM-DD)", default="2026-01-12")
    
    # Data File
    print_header("Data File Configuration")
    print("Where is your sales data CSV file located?")
    data_file = ask_question("Data file name (e.g., sales_data.csv)", default="sales_data.csv")
    
    # Check if file exists
    if Path(data_file).exists():
        print(f"  ✓ Found: {data_file}")
    else:
        print(f"  ⚠ Warning: {data_file} not found. Make sure to place it in the template directory.")
    
    responses['data_file'] = data_file
    
    # Column Mapping
    print_header("Column Mapping")
    print("What are the column names in your CSV file?")
    print("(Press Enter to accept defaults if your columns match common names)\n")
    
    responses['revenue_column'] = ask_question("Revenue/Amount column name", default="USD")
    responses['date_column'] = ask_question("Primary date column name", default="InvoiceDate")
    
    has_fallback = ask_question("Do you have fallback date columns (Month, Year)?", default="yes", validator=validate_yes_no)
    if has_fallback:
        fallback_str = ask_question("Fallback date columns (comma-separated)", default="Month, Year")
        responses['date_fallback'] = [col.strip() for col in fallback_str.split(',')]
    else:
        responses['date_fallback'] = []
    
    responses['customer_column'] = ask_question("Customer/Account column name", default="Customer")
    responses['item_column'] = ask_question("Item/Product column name", default="Item")
    
    has_quantity = ask_question("Do you have a Quantity column?", default="yes", validator=validate_yes_no)
    if has_quantity:
        responses['quantity_column'] = ask_question("Quantity column name", default="Quantity")
    else:
        responses['quantity_column'] = None
    
    # Date Range
    print_header("Date Range Configuration")
    responses['min_year'] = ask_question("Minimum year to include in analysis", default="2021", validator=validate_int)
    responses['max_date'] = ask_question("Maximum date (YYYY-MM-DD)", default="2025-09-30")
    
    years_str = ask_question("Analysis years (comma-separated, e.g., 2021,2022,2023,2024,2025)", default="2021,2022,2023,2024,2025")
    responses['analysis_years'] = [int(y.strip()) for y in years_str.split(',')]
    
    # LTM Configuration
    print_header("LTM (Last Twelve Months) Configuration")
    print("LTM is used for the most recent partial year to enable apples-to-apples comparison.")
    print("Example: If your latest data is through September 2025, use Oct 2024 - Sep 2025.\n")
    
    use_ltm = ask_question("Do you need LTM for the most recent year?", default="yes", validator=validate_yes_no)
    responses['ltm_enabled'] = use_ltm
    
    if use_ltm:
        responses['ltm_start_month'] = ask_question("LTM start month (1-12)", default="10", validator=validate_int)
        responses['ltm_start_year'] = ask_question("LTM start year", default="2024", validator=validate_int)
        responses['ltm_end_month'] = ask_question("LTM end month (1-12)", default="9", validator=validate_int)
        responses['ltm_end_year'] = ask_question("LTM end year", default="2025", validator=validate_int)
    else:
        responses['ltm_start_month'] = 10
        responses['ltm_start_year'] = 2024
        responses['ltm_end_month'] = 9
        responses['ltm_end_year'] = 2025
    
    # Exclusion Filters
    print_header("Exclusion Filters (Optional)")
    use_exclusions = ask_question("Do you need to exclude specific segments (e.g., test accounts, business units)?", default="no", validator=validate_yes_no)
    responses['exclusions_enabled'] = use_exclusions
    
    if use_exclusions:
        responses['exclude_column'] = ask_question("Column name to filter on", default="Country")
        exclude_values_str = ask_question("Values to exclude (comma-separated)", default="")
        responses['exclude_values'] = [v.strip() for v in exclude_values_str.split(',') if v.strip()]
    else:
        responses['exclude_column'] = None
        responses['exclude_values'] = []
    
    # Generate config.py
    print_header("Generating Configuration")
    print("Updating config.py with your settings...")
    
    # Read current config.py
    config_path = Path('config.py')
    if not config_path.exists():
        print("ERROR: config.py not found!")
        return
    
    with open(config_path, 'r', encoding='utf-8') as f:
        config_content = f.read()
    
    # Replace values
    replacements = {
        "COMPANY_NAME = \"Your Company Name\"": f"COMPANY_NAME = \"{responses['company_name']}\"",
        "ANALYSIS_DATE = \"2026-01-12\"": f"ANALYSIS_DATE = \"{responses['analysis_date']}\"",
        "DATA_FILE = 'sales_data.csv'": f"DATA_FILE = '{responses['data_file']}'",
        "REVENUE_COLUMN = 'USD'": f"REVENUE_COLUMN = '{responses['revenue_column']}'",
        "DATE_COLUMN = 'InvoiceDate'": f"DATE_COLUMN = '{responses['date_column']}'",
        "DATE_FALLBACK_COLUMNS = ['Month', 'Year']": f"DATE_FALLBACK_COLUMNS = {responses['date_fallback']}",
        "CUSTOMER_COLUMN = 'Customer'": f"CUSTOMER_COLUMN = '{responses['customer_column']}'",
        "ITEM_COLUMN = 'Item'": f"ITEM_COLUMN = '{responses['item_column']}'",
        "QUANTITY_COLUMN = 'Quantity'": f"QUANTITY_COLUMN = '{responses['quantity_column']}'" if responses['quantity_column'] else "QUANTITY_COLUMN = None",
        "MIN_YEAR = 2021": f"MIN_YEAR = {responses['min_year']}",
        "MAX_DATE = pd.Timestamp('2025-09-30')": f"MAX_DATE = pd.Timestamp('{responses['max_date']}')",
        "ANALYSIS_YEARS = [2021, 2022, 2023, 2024, 2025]": f"ANALYSIS_YEARS = {responses['analysis_years']}",
        "LTM_ENABLED = True": f"LTM_ENABLED = {responses['ltm_enabled']}",
        "LTM_START_MONTH = 10": f"LTM_START_MONTH = {responses['ltm_start_month']}",
        "LTM_START_YEAR = 2024": f"LTM_START_YEAR = {responses['ltm_start_year']}",
        "LTM_END_MONTH = 9": f"LTM_END_MONTH = {responses['ltm_end_month']}",
        "LTM_END_YEAR = 2025": f"LTM_END_YEAR = {responses['ltm_end_year']}",
    }
    
    # Handle exclusions
    if responses['exclusions_enabled']:
        exclusions_config = f"""EXCLUSION_FILTERS = {{
    'enabled': True,
    'exclude_by_column': '{responses['exclude_column']}',
    'exclude_values': {responses['exclude_values']}
}}"""
        # Replace the exclusion filters section
        import re
        pattern = r"EXCLUSION_FILTERS = \{.*?\}"
        config_content = re.sub(pattern, exclusions_config, config_content, flags=re.DOTALL)
    else:
        exclusions_config = """EXCLUSION_FILTERS = {
    'enabled': False,
    'exclude_by_column': None,
    'exclude_values': []
}"""
        import re
        pattern = r"EXCLUSION_FILTERS = \{.*?\}"
        config_content = re.sub(pattern, exclusions_config, config_content, flags=re.DOTALL)
    
    # Apply replacements
    for old, new in replacements.items():
        if old in config_content:
            config_content = config_content.replace(old, new)
    
    # Write updated config
    with open(config_path, 'w', encoding='utf-8') as f:
        f.write(config_content)
    
    print("  ✓ Configuration updated successfully!")
    
    # Summary
    print_header("Setup Complete")
    print("Your configuration has been saved to config.py")
    print("\nNext steps:")
    print("1. Place your data file in the template directory (if not already there)")
    print("2. Test data loading: python -c \"from data_loader import load_sales_data; from config import get_data_path; df = load_sales_data(get_data_path()); print(f'Loaded {len(df):,} rows')\"")
    print("3. Review config.py and adjust any settings as needed")
    print("4. Start creating your analysis scripts using analysis_template.py")
    print("\nFor help, see README.md")

if __name__ == "__main__":
    try:
        main()
    except KeyboardInterrupt:
        print("\n\nSetup cancelled by user.")
        sys.exit(0)