import os
import csv
import glob
import numpy as np
import collections


Prices = collections.namedtuple('Prices', field_names=['open', 'high', 'low', 'close', 'volume'])


def read_csv(file_name, sep=',', filter_data=True, fix_open_price=False):
    print("Wczytywanie", file_name)
    with open(file_name, 'rt', encoding='utf-8') as fd:
        reader = csv.reader(fd, delimiter=sep)
        h = next(reader)
        if '<OPEN>' not in h and sep == ',':
            return read_csv(file_name, ';')
        indices = [h.index(s) for s in ('<OPEN>', '<HIGH>', '<LOW>', '<CLOSE>', '<VOL>')]
        o, h, l, c, v = [], [], [], [], []
        count_out = 0
        count_filter = 0
        count_fixed = 0
        prev_vals = None
        for row in reader:
            vals = list(map(float, [row[idx] for idx in indices]))
            if filter_data and all(map(lambda v: abs(v-vals[0]) < 1e-8, vals[:-1])):
                count_filter += 1
                continue

            po, ph, pl, pc, pv = vals

            # ustal cenę otwarcia dla danego wiersza, aby odpowiadała cenie zamknięcia dla wiersza poprzedniego
            if fix_open_price and prev_vals is not None:
                ppo, pph, ppl, ppc, ppv = prev_vals
                if abs(po - ppc) > 1e-8:
                    count_fixed += 1
                    po = ppc
                    pl = min(pl, po)
                    ph = max(ph, po)
            count_out += 1
            o.append(po)
            c.append(pc)
            h.append(ph)
            l.append(pl)
            v.append(pv)
            prev_vals = vals
    print("Wczytano. Istnieje %d wierszy, %d z nich wyfiltrowano, zmodyfikowano %d cen otwarcia" % (
        count_filter + count_out, count_filter, count_fixed))
    return Prices(open=np.array(o, dtype=np.float32),
                  high=np.array(h, dtype=np.float32),
                  low=np.array(l, dtype=np.float32),
                  close=np.array(c, dtype=np.float32),
                  volume=np.array(v, dtype=np.float32))


def prices_to_relative(prices):
    """
    Zamienia ceny na wartości względne w odniesieniu do ceny otwarcia
    :param ochl: krotka z cenami otwarcia, zamknięcia, najwyższymi, najniższymi
    :return: krotka z cenami otwarcia, względnymi zamknięcia, względnymi najwyższymi, względnymi najniższymi
    """
    assert isinstance(prices, Prices)
    rh = (prices.high - prices.open) / prices.open
    rl = (prices.low - prices.open) / prices.open
    rc = (prices.close - prices.open) / prices.open
    return Prices(open=prices.open, high=rh, low=rl, close=rc, volume=prices.volume)


def load_relative(csv_file):
    return prices_to_relative(read_csv(csv_file))


def price_files(dir_name):
    result = []
    for path in glob.glob(os.path.join(dir_name, "*.csv")):
        result.append(path)
    return result


def load_year_data(year, basedir='data'):
    y = str(year)[-2:]
    result = {}
    for path in glob.glob(os.path.join(basedir, "*_%s*.csv" % y)):
        result[path] = load_relative(path)
    return result
