import re

from . import _csv

from .. import strparse

class SalesImporter(_csv.CSVImporterBase):

    DECIMAL_FIELDS = {

        'Products': 'products',

        'Shipping': 'shipping_fees',

        'Tax': 'tax',

        'VAT': 'vat',

        'Total': 'amount',

        'Discount': 'discount',

    }

    NEEDED_FIELDS = {'Printful ID', *DECIMAL_FIELDS}

    COPIED_FIELDS = {}

    CURRENCY_MAP = {

        '$': 'USD',

        '€': 'EUR',

        '£': 'GBP',

        'AU$': 'AUD',

        'C$': 'CAD',

    }

    currency_regexp = re.compile(r'-?(?P<currency>\D*)\d.*')

    def __init__(self, input_file):

        # Orders.csv file is in UTF-8-SIG encoding and begins with a byte order

        # mark character \ufeff. This happens *after* NEEDED_FIELDS is

        # checked. This encoding check is done conditionally to handle the

        # situation where someone has modified the CSV and saved as UTF-8.

        first_char = input_file.read(1)

        input_file.seek(0)

        if first_char == '\ufeff':

            input_file.reconfigure(encoding='UTF-8-SIG')

        super().__init__(input_file)

    def _read_row(self, row):

        if row['Date'].startswith('Total paid'):

            return None

        # Parse the currency values. A hyphen represents zero.

        record = {

            self.DECIMAL_FIELDS[key]: strparse.currency_decimal(row[key] if row[key] != '-' else '0')

            for key in self.DECIMAL_FIELDS

        }

        # Most importers don't deal with multiple currencies. There are

        # libraries that partly help with currency codes and symbols, but the

        # codes/symbols Printful use have some quirks, so it's easier to do this

        # ourselves.

        currency_code = re.match(self.currency_regexp, row['Total']).group('currency')

        record['currency'] = self.CURRENCY_MAP.get(currency_code, currency_code).replace('$', '')

        record['date'] = strparse.date(row['Date'], '%B %d, %Y')

        record['order_id'] = row['Order'].lstrip('Order ')

        record['payee'] = 'Printful'  # Not used but required to be set

        return record