import sys
import argparse
import json
import logging
import locale

from datetime import datetime
from decimal import Decimal

import requests

from accounting.models import Transaction, Posting, Amount
from accounting.transport import AccountingDecoder, AccountingEncoder

locale.setlocale(locale.LC_ALL, '')

_log = logging.getLogger(__name__)


class Client:
    def __init__(self, host=None, json_encoder=None,
                 json_decoder=None):
        self.host = host or 'http://localhost:5000'
        self.json_encoder = json_encoder or AccountingEncoder
        self.json_decoder = json_decoder or AccountingDecoder

    def get_balance(self):
        balance = self.get('/balance')
        return balance['balance_report']

    def get(self, path):
        response = requests.get(self.host + path)

        return self._decode_response(response)

    def _decode_response(self, response):
        response_data = response.json(cls=self.json_decoder)

        _log.debug('response_data: %s', response_data)

        return response_data

    def post(self, path, payload, **kw):
        kw.update({'headers': {'Content-Type': 'application/json'}})
        kw.update({'data': json.dumps(payload, cls=self.json_encoder)})

        return self._decode_response(requests.post(self.host + path, **kw))

    def simple_transaction(self, from_acc, to_acc, amount, symbol=None,
                           payee=None):
        if symbol is None:
            # Get the currency from the environment locale
            symbol = locale.localeconv()['int_curr_symbol'].strip()

        t = Transaction(
            date=datetime.today(),
            payee=payee,
            postings=[
                Posting(account=from_acc,
                        amount=Amount(symbol=symbol, amount=-amount)),
                Posting(account=to_acc,
                        amount=Amount(symbol=symbol, amount=amount))
            ]
        )

        return self.post('/transaction', {'transactions': [t]})

    def get_register(self):
        register = self.get('/transaction')

        return register['transactions']


def print_transactions(transactions):
    for transaction in transactions:
        print('{date} {t.payee:.<69}'.format(
            date=transaction.date.strftime('%Y-%m-%d'),
            t=transaction))

        for posting in transaction.postings:
            print(' ' + posting.account +
                  ' ' * (80 - len(posting.account) -
                         len(posting.amount.symbol) -
                         len(str(posting.amount.amount)) - 1 - 1) +
                  posting.amount.symbol + ' ' + str(posting.amount.amount))


def print_balance_accounts(accounts, level=0):
    for account in accounts:
        print(' ' * level + ' + {account.name}'.format(account=account) +
              ' ' + '-' * (80 - len(str(account.name)) - level))

        for amount in account.amounts:
            print(' ' * level + '   {amount.symbol} {amount.amount}'.format(
                amount=amount))

        print_balance_accounts(account.accounts, level + 1)


def main(argv=None, prog=None):
    global HOST
    if argv is None:
        prog = sys.argv[0]
        argv = sys.argv[1:]

    parser = argparse.ArgumentParser(prog=prog)
    actions = parser.add_subparsers(title='Actions', dest='action')

    insert = actions.add_parser('insert',
                                aliases=['in'])
    insert.add_argument('payee',
                        help='The payee line of the transaction')
    insert.add_argument('from_account')
    insert.add_argument('to_account')
    insert.add_argument('amount', type=Decimal,
                        help='The amount deducted from from_account and added'
                             ' to to_account')
    insert.add_argument('-s', '--symbol',
                        help='The symbol for the amount, e.g. $ or USD for'
                             ' USD. Defaults to your locale\'s setting.')

    actions.add_parser('balance', aliases=['bal'])

    actions.add_parser('register', aliases=['reg'])

    parser.add_argument('-v', '--verbosity',
                        default='WARNING',
                        help=('Filter logging output. Possible values:' +
                              ' CRITICAL, ERROR, WARNING, INFO, DEBUG'))
    parser.add_argument('--host', default='http://localhost:5000')

    args = parser.parse_args(argv)

    logging.basicConfig(level=getattr(logging, args.verbosity))

    client = Client(args.host)

    if args.action in ['insert', 'in']:
        print(client.simple_transaction(args.from_account, args.to_account,
                                        args.amount, payee=args.payee,
                                        symbol=args.symbol))
    elif args.action in ['balance', 'bal']:
        print_balance_accounts(client.get_balance())
    elif args.action in ['register', 'reg']:
        print_transactions(client.get_register())
    else:
        parser.print_help()

if __name__ == '__main__':
    sys.exit(main())