import datetime
import decimal
import io
import json

from . import relpath

import oxrlib.rate
import pytest

HIST1_AED_RATE = decimal.Decimal('3.67246')
HIST1_ALL_RATE = decimal.Decimal('144.529793')

@pytest.fixture
def historical1_rate():
    with open(relpath('historical1.json').as_posix()) as rate_file:
        return oxrlib.rate.Rate.from_json_file(rate_file)

def test_rate_from_json(historical1_rate):
    assert historical1_rate.base == 'USD'
    assert historical1_rate.timestamp == datetime.datetime(2001, 2, 16, 12, 0, 0)

def test_serialize(historical1_rate):
    with open(relpath('historical1.json').as_posix()) as rate_file:
        expected = json.load(rate_file)
    assert expected == historical1_rate.serialize()

def test_convert(historical1_rate):
    assert historical1_rate.convert(2, 'USD', 'ALL') == (2 * HIST1_ALL_RATE)
    assert historical1_rate.convert(10, 'AED', 'USD') == (10 / HIST1_AED_RATE)
    assert historical1_rate.convert(1, 'AED', 'ALL') == (HIST1_ALL_RATE / HIST1_AED_RATE)