from numpy import (
    float64,
    uint32,
    int64,
)
from bcolz import ctable

from catalyst.data.us_equity_pricing import (
    BcolzDailyBarWriter,
    OHLC,
    UINT32_MAX
)


class DailyBarWriterFromDataFrames(BcolzDailyBarWriter):
    _csv_dtypes = {
        'open': float64,
        'high': float64,
        'low': float64,
        'close': float64,
        'volume': float64,
    }

    def __init__(self, asset_map):
        self._asset_map = asset_map

    def gen_tables(self, assets):
        for asset in assets:
            yield asset, ctable.fromdataframe(assets[asset])

    def to_uint32(self, array, colname):
        arrmax = array.max()
        if colname in OHLC:
            self.check_uint_safe(arrmax * 1000, colname)
            return (array * 1000).astype(uint32)
        elif colname == 'volume':
            self.check_uint_safe(arrmax, colname)
            return array.astype(uint32)
        elif colname == 'day':
            nanos_per_second = (1000 * 1000 * 1000)
            self.check_uint_safe(arrmax.view(int64) / nanos_per_second,
                                 colname)
            return (array.view(int64) / nanos_per_second).astype(uint32)

    @staticmethod
    def check_uint_safe(value, colname):
        if value >= UINT32_MAX:
            raise ValueError(
                "Value %s from column '%s' is too large" % (value, colname)
            )
