import argparse
import csv
from decimal import Decimal, getcontext, ROUND_UP

import simplejson as json


ACCOUNT_LEDGER_PRECISION = Decimal('0.01')

getcontext().prec = 18


def _format_ledger_account_entry(event_id, ledger_params):
    return {
        'abacus_event_id': event_id,
        'account_id': ledger_params.get('account_id'),
        'contract_id': ledger_params.get('contract_id'),
        'currency_amount': ledger_params.get('account_ledger_amount'),
        'currency_code': ledger_params.get('currency_code'),
        'model_type': 'account'
    }


def _format_ledger_deposit_entry(event_id, ledger_params):
    """Format ledger_deposit params. Return a dict.

    Args:
        ledger_params (dict): shared ledger parameters

    Returns:
        A dict of formatted ledger_deposit entries.
    """
    return {
        'abacus_event_id': event_id,
        'account_id': ledger_params.get('account_id'),
        'contract_id': ledger_params.get('contract_id'),
        'currency_code': ledger_params.get('currency_code'),
        'model_type': 'deposit',
        'remaining_amount': ledger_params.get('remainder'),
        'rounded_amount': ledger_params.get('rounded_amount')
    }


def _breakdown_amount(base_amount):
    """Convert amount to ledger, rounded, and remainder amounts."""
    rounded_amount = base_amount.quantize(
        ACCOUNT_LEDGER_PRECISION,
        rounding=ROUND_UP
    )
    remainder = base_amount - rounded_amount
    account_ledger_amount = rounded_amount
    return {
        'account_ledger_amount': account_ledger_amount,
        'remainder': remainder,
        'rounded_amount': rounded_amount
    }


parser = argparse.ArgumentParser(
    description='Generate account and deposit entries for bulk ledgers request')
parser.add_argument('event', type=int, 
    help='abacus_event_id for ledger entries')
parser.add_argument('file', type=argparse.FileType('r'),
    help='path to csv file (see test_data.csv for example)')
args = parser.parse_args()

amounts = []
amount_reader = csv.DictReader(args.file, delimiter=',')
for row in amount_reader:
    amounts.append(row)

entries = []
for amount in amounts:
    base_amount = Decimal(amount.get('AMOUNT'))
    ledger_params = _breakdown_amount(base_amount)
    ledger_params.update({
        'account_id': int(amount.get('ACCOUNT_ID')),
        'contract_id': int(amount.get('CONTRACT_ID')),
        'currency_code': amount.get('CURRENCY_CODE'),
    })
    if ledger_params['rounded_amount'] != Decimal(0.00):
        entries.append(_format_ledger_account_entry(args.event, ledger_params))
    if ledger_params['remainder'] != Decimal(0.00):
        entries.append(_format_ledger_deposit_entry(args.event, ledger_params))
    # In case John needs you to dump out the same file but with rounded numbers:
    # print(f"{int(amount.get('ACCOUNT_ID'))},{int(amount.get('CONTRACT_ID'))},{ledger_params['account_ledger_amount']},{amount.get('CURRENCY_CODE')}")

print(json.dumps(entries, indent=4))