#!/usr/bin/env python3

from beancount.core import data
from beancount.core import account
from beancount.core import getters
from beancount.core import amount
from beancount.core import account_types
from beancount.core import realization
from beancount.core.number import D
from beancount.parser import options

import re

__plugins__ = ('optional_balance_plugin',)

def optional_balance_plugin(entries, options_map, config):
    try:
        match_enabled = re.compile(config)
    except Exception as e:
        print(f"exception {e}")
        return entries, [e]

    errors = []
    new_entries = []
    for entry in entries:
        if isinstance(entry, data.Custom):
            if entry.type == "optional-balance":
                try:
                    assert(len(entry.values) == 4)
                    type, acc, units, curr = entry.values
                    if not match_enabled.match(type.value):
                        continue
                    v = amount.Amount(number=D(units.value), currency=curr.value)
                    entry = data.Balance(meta=entry.meta, date=entry.date, account=acc.value, amount=v, tolerance=None, diff_amount=None)
                except Exception as e:
                    print(f"exception {e}")
                    errors.append(e)
        
        new_entries.append(entry)

    return new_entries, errors