#!/usr/bin/env python3
"""
Revolut CSV aggregator to process and consolidate account statements
"""

import csv
import os
import glob
import argparse
from datetime import datetime
from collections import defaultdict


def parse_revolut_csv(csv_file):
    """Parse a single Revolut CSV file and return list of transactions"""
    transactions = []

    with open(csv_file, 'r', encoding='utf-8') as f:
        reader = csv.DictReader(f)
        for row in reader:
            # Skip if not completed
            if row.get('State', '').upper() != 'COMPLETED':
                continue

            # Parse date
            started_date = row.get('Started Date', '')
            try:
                # Format: 2026-01-03 04:39:38
                date_obj = datetime.strptime(started_date, '%Y-%m-%d %H:%M:%S')
                formatted_date = date_obj.strftime('%d/%m/%Y')
            except (ValueError, TypeError):
                formatted_date = started_date

            # Determine amount (negative = expense, positive = income)
            try:
                amount = float(row.get('Amount', '0'))
            except ValueError:
                amount = 0.0

            # Get fee
            try:
                fee = float(row.get('Fee', '0'))
            except ValueError:
                fee = 0.0

            # Calculate net amount (amount includes fee already in Revolut)
            net_amount = amount

            transaction = {
                'Date': formatted_date,
                'Description': row.get('Description', ''),
                'Type': row.get('Type', ''),
                'Product': row.get('Product', ''),
                'Amount': net_amount,
                'Fee': fee,
                'Currency': row.get('Currency', 'EUR'),
                'State': row.get('State', ''),
                'Balance': row.get('Balance', ''),
                'Source': os.path.basename(csv_file)
            }

            transactions.append(transaction)

    return transactions


def categorize_transaction(description, trans_type):
    """Categorize transaction based on description and type"""
    description_upper = description.upper()
    trans_type_upper = trans_type.upper()

    if 'POCKET' in description_upper or 'ÉPARGNE' in description_upper:
        return 'Savings Transfer'
    elif trans_type_upper == 'TRANSFER':
        return 'Transfer'
    elif trans_type_upper == 'CARD_PAYMENT':
        return 'Card Payment'
    elif trans_type_upper == 'CARD_REFUND':
        return 'Card Refund'
    elif trans_type_upper == 'EXCHANGE':
        return 'Currency Exchange'
    elif trans_type_upper == 'TOPUP':
        return 'Top Up'
    elif trans_type_upper == 'REWARD':
        return 'Reward'
    else:
        return 'Other'


def process_revolut_csv_files(directory, output_csv=False, output_dir='output/csv'):
    """Process all Revolut CSV files and aggregate transactions"""
    # Get all CSV files in the directory
    csv_files = glob.glob(os.path.join(directory, "*.csv"))
    all_transactions = []

    for csv_file in csv_files:
        try:
            transactions = parse_revolut_csv(csv_file)
            all_transactions.extend(transactions)
            print(f"Processed {os.path.basename(csv_file)}: {len(transactions)} transactions")
        except Exception as e:
            print(f"Error processing {csv_file}: {e}")

    # Sort transactions by date
    all_transactions.sort(key=lambda x: datetime.strptime(x['Date'], '%d/%m/%Y') if x['Date'] else datetime.min)

    # Add categories
    for trans in all_transactions:
        trans['Category'] = categorize_transaction(trans['Description'], trans['Type'])

    # Output CSV
    if output_csv and all_transactions:
        csv_file = os.path.join(output_dir, 'revolut_all_transactions.csv')
        os.makedirs(output_dir, exist_ok=True)

        with open(csv_file, 'w', newline='', encoding='utf-8') as csvfile:
            fieldnames = ['Date', 'Description', 'Category', 'Type', 'Product', 'Amount', 'Fee',
                         'Currency', 'State', 'Balance', 'Source']
            writer = csv.DictWriter(csvfile, fieldnames=fieldnames)
            writer.writeheader()
            writer.writerows(all_transactions)

        print(f"\nTransaction data saved to {csv_file}")

    print(f"\n--- Revolut Account Statements ---")
    print(f"Found {len(csv_files)} statement files")
    print(f"Total transactions: {len(all_transactions)}")

    # Calculate totals
    total_income = sum(t['Amount'] for t in all_transactions if t['Amount'] > 0)
    total_expenses = sum(t['Amount'] for t in all_transactions if t['Amount'] < 0)
    total_fees = sum(t['Fee'] for t in all_transactions)

    print(f"Total Income: €{total_income:,.2f}")
    print(f"Total Expenses: €{total_expenses:,.2f}")
    print(f"Total Fees: €{total_fees:,.2f}")
    print(f"Net Flow: €{(total_income + total_expenses):,.2f}")

    return all_transactions


if __name__ == "__main__":
    parser = argparse.ArgumentParser(description='Process and aggregate Revolut CSV account statements')
    parser.add_argument('--csv-dir', default='data/csv/revolut',
                       help='Directory containing Revolut CSV files')
    parser.add_argument('--output-dir', default='output/csv',
                       help='Directory to save CSV output files')
    parser.add_argument('--csv', action='store_true',
                       help='Output aggregated data to CSV file')

    args = parser.parse_args()

    # Process all CSV files in the directory
    process_revolut_csv_files(args.csv_dir, args.csv, args.output_dir)