#!/usr/bin/env python3
# pylint: disable=missing-docstring,invalid-name

import random
import re
from collections import namedtuple
from datetime import date as DTDate
from datetime import timedelta as DTTimeDelta
from datetime import datetime as DTDateTime
from typing import BinaryIO, List

import mechanize as m
import PyPDF3
from dateutil.relativedelta import FR, relativedelta

Rate = namedtuple('Rate', ['abbr', 'full_name', 'ask', 'bid'])

# Constants
CARD_MASTERCARD = ['0']
CARD_VISA = ['1']

class CurrencyResult():
    def __init__(self):
        self.rates = list()
        self.card_type = str()
        self.date = None

def _parse_rate(text: str) -> float or None:
    if re.match('Keine Kursdaten vorhanden', text):
        _r = None
    else:
        text = text.strip(' ').replace(',', '.')
        try:
            _r = float(text)
        except ValueError:
            _r = None
    return _r

def _parse_card_type(text: str) -> str:
    text = text.split(':')[1]
    text = text.strip('" ')
    return text

def _parse_date(text: str) -> DTDate:
    text = text.split(': ')[1].rstrip()
    return DTDateTime.strptime(text, '%d.%m.%Y').date()

def _array_remove_empty(obj: list) -> List[str]:
    try:
        while True:
            obj.remove('')
    except ValueError:
        return obj
    return obj

def _parse_line(line: str) -> Rate or None:
    arr = line.split("   ") # 3 spaces = minimum separation in PDF
    arr = _array_remove_empty(arr)
    # process currency name
    names = arr[0].split(" ", 1)
    rate = Rate(
        abbr=names[0],
        full_name=names[1].strip("()"),
        ask=_parse_rate(arr[1]),
        bid=_parse_rate(arr[2])
        )
    return rate


def get_results_from_text(text: str, currency: str = None) -> CurrencyResult:
    rates = {}
    result = CurrencyResult()
    lines = text.splitlines()
    # skip intro lines
    lines = lines[2:]
    # card type
    result.card_type = _parse_card_type(lines.pop(0))
    # get date
    result.date = _parse_date(lines.pop(0))
    # skip more lines
    lines = lines[4:]
    # now the rates begin
    if currency is None:
        for line in lines:
            line_result = _parse_line(line)
            rates[line_result.abbr] = line_result
    else:
        pattern = re.compile("^"+currency)
        for line in lines:
            if pattern.match(line):
                line_result = _parse_line(line)
                rates[line_result.abbr] = line_result
    result.rates = rates
    return result

def get_results_from_pdf(buf: BinaryIO or str, currency: str = None) -> CurrencyResult:
    print('Parsing data... ', end='')
    reader = PyPDF3.PdfFileReader(buf)
    text = str()
    pages = []
    for num in range(0, reader.getNumPages()-1):
        pages.append(reader.getPage(num))
    for page in pages:
        text += page.extractText()
    print('Done.')
    return get_results_from_text(text, currency=currency)
def get_fileio(date: DTDate, card_type: List[str] = CARD_VISA) -> BinaryIO: # pylint: disable=dangerous-default-value
    # pylint: disable=no-member # mechanize.Browser has some lazy-loading methods that pylint doesn't see
    print('Downloading rates for ' + date.strftime('%Y-%m-%d') + '... ', end='')
    b = m.Browser()
    # Firefox 64 User-Agent
    # ua = 'Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:64.0) Gecko/20100101 Firefox/64.0'
    # b.set_header('User-Agent', ua)
    # Ignore robots.txt
    # b.set_handle_robots(False)
    # Debugging flags
    # b.set_debug_http(True)
    # b.set_debug_redirects(True)
    # b.set_debug_responses(True)
    # PDF URL
    b.open('https://misc.firstdata.eu/CurrencyCalculator/fremdwaehrungskurse/pdf')
    fm = b.forms()
    fm_i = fm[0]
    fm_i.set_all_readonly(False)
    # Configure form
    fm_i['creditCardsRadio'] = card_type # VISA
    fm_i['selectedDatesString'] = str(date.strftime('%Y%m%d') + ',')
    # Retrieve file using button click
    rq = fm_i.click(name='submitButton', coord=(random.randint(1, 119), random.randint(1, 20)))
    rq.add_header('Accept', '*/*')
    rp = b.retrieve(rq)
    print(' Done.')
    return open(rp[0], 'rb')
def get_date() -> DTDate:
    if DTDate.today().weekday() in [6, 0]:
        date = DTDate.today() + relativedelta(weekday=FR(-1))
    else:
        date = DTDate.today() - DTTimeDelta(1)
    return date