"""
YFilters pass an additional data array on filter instantenation that is
used to modify the RGBA array

Since we do not know, however, the order or subset of items
"""

import numpy as np

from .filters import ColorFilter
from .models import color_model
from .utils import color, rgb

class YFilter(ColorFilter):
    """
    Class to modify data color array before returning based separate
    data array provided on initialisation.

    The filter takes as call arguments RGBA normalized to 0...1.

    When used as a _filter function, parameters must be passes by
    keyword.
    """

    _filter = None

    def __init__(self, *args, **kwargs):
        kw = kwargs.copy()
        self._data = kwargs.pop('data')
        self._ndim = kwargs.pop('ndim', max(0, self._data.ndim - 2))

        index = kw.get('index', None)
        if isinstance(index, np.ndarray):
            assert index.shape == self._data.shape[:self._ndim]
        else:
            self._index = np.arange(self._data.size, dtype=int64)
            if isinstance(index, list):
                index.append(self._index)
            elif isinstance(index, dict):
                index['index'] = self._index
            else:
                raise AttributeError('unknown index type')

        func = kw.pop('func', lambda x: x)
        if np.isscalar(func):
            self._func = lambda x : np.tile(func, x.shape)
        else:
            self._func = func

        self._data_func = kw.pop('data_func', lambda x: x)

        super().__init__(*args, **kw)

    @property
    def index(self):
        return self._index


    def _yfilter(self, rgba):
        """
        take rgba, filter, replace data in place, return modified array
        """
        raise NotImplementedError()

    def __call__(self, *args, **kwargs):
        # use as _yfilter
        print('[yfilter]', args[0].shape, self._data.shape)

        if (self._color is None and
                len(args) == 2 and
                len(kwargs) == 0 and
                isinstance(args[0], np.ndarray) and
                isinstance(self._data, np.ndarray) and
                len(args[0].shape) == 3 and
                args[0].shape[-1] == 4 and
                np.allclose(args[0].shape[:-1], self._data.shape[:2])):
            data = self._data_func(args[1])
            return self._yfilter(*args), data

        print('[yfilter] Error: did not run.')
        return super().__call__(*args, **kwargs)

class FuncAlphaYFilter(YFilter):
    """
    set alpha based on data array
    """
    def _yfilter(self, rgba):
        ii = (0 <= self._data) & (self._data <= 1)
        breakpoint()
        rgba[ii, 3] = np.clip(self._func(self._data[ii]), 0, 1)
        return rgba


class FuncShadeYFilter(YFilter):
    """
    Shade colors according to scalar data processed by function (default=identity)
    """
    def _yfilter(self, rgba, data):
        print('xxx')
        breakpoint()
        ii = (0 <= self._data) & (self._data <= 1)
        rgba[ii, 0:3] = np.clip(rgba[ii, 0:3] * self._func(self._data[ii, np.newaxis]), 0, 1)
        return rgba