from beancount.core.number import D
from beancount.ingest import importer
from beancount.core import amount
from beancount.core import flags
from beancount.core import data

from dateutil.parser import parse

from titlecase import titlecase

import csv
import os
import re

class CitiImporter(importer.ImporterProtocol):
    def __init__(self):
        self.account = 'Liabilities:CC:Citi:ThankYou'

    def identify(self, f):
        return re.match('MC_377_CURRENT_VIEW.CSV', os.path.basename(f.name))

    def file_account(self, f):
        return self.account

    def extract(self, f):
        entries = []

        with open(f.name) as f:
            for index, row in enumerate(csv.DictReader(f)):

                trans_date = parse(row['Date']).date()

                #rstrip removes trailing new line characters
                trans_desc = titlecase(row['Description'].rstrip())

                if bool(row['Debit']):
                    trans_amt = "-" + row['Debit']
                else:
                    trans_amt = row['Credit']

                meta = data.new_metadata(f.name, index)

                txn = data.Transaction(
                    meta=meta,
                    date=trans_date,
                    flag=flags.FLAG_OKAY,
                    payee=trans_desc,
                    narration="",
                    tags=set(),
                    links=set(),
                    postings=[]
                )

                txn.postings.append(
                    data.Posting(self.account, amount.Amount(D(trans_amt),
                        'USD'), None, None, None, None)
                )

                entries.append(txn)

        return entries