from payit import (
    GatewayManager,
    gateways,
    Transaction,
    TransactionAlreadyPaidError
)

# Configure:
config = {
    'mellat': {
        'terminal_id': '1234',
        'username': 'demo',
        'password': 'demo',
        'callback_url': 'http://localhost/callback/mellat'
    },
    'zarinpal1': {
        'merchant': '534534534532225234234',
        'description': '',
        'callback_url': 'http://localhost/callback/zarinpal1'
    },
    'zarinpal2': {
        'merchant': '33333333532225234234',
        'description': '',
        'callback_url': 'http://localhost/callback/zarinpal2'
    }
}
manager = GatewayManager()
manager.register('mellat', gateways.MellatGateway)
manager.register('zarinpal1', gateways.ZarinpalGateway)
manager.register('zarinpal2', gateways.ZarinpalGateway)
manager.configure(config)


# Make Transaction:
my_database = {}
selected_gateway = 'zarinpal1'
try:
    transaction = Transaction(amount=1500, order_id=11002)
    transaction = manager.request(selected_gateway, transaction)
    # Store `transaction.id` on your database
    my_database['transaction_id'] = transaction.id

    # Get redirection details
    redirection = manager.get_redirection(selected_gateway, transaction)

    # Now redirect your client to gateway by redirection details

except PayitException:
    print('Something wrong on payment')
    raise


# Callback
# Now user backs from gateway to complete payment procedure
selected_gateway = 'zarinpal1'
try:
    callback_data = {
        'Authority': 101
    }
    transaction = manager.validate(selected_gateway, callback_data)
    if not transaction.validate_status:
        raise RuntimeError('Transaction is not valid')

    # Check `transaction.id` exist on your database
    if transaction.id not in my_database:
        raise RuntimeError('Transaction is not exists')

    # Now verify transaction
    manager.verify(selected_gateway, callback_data)

except TransactionAlreadyPaidError:
    print('Transaction Already Paid')
    raise

except PayitException:
    print('Something wrong on payment')
    raise

# Payment succeed! 🎉