# coding: utf-8
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"""This module provides the :class:`Scatter` item of the :class:`Plot`.
"""

__authors__ = ["H. Payno"]
__license__ = "MIT"
__date__ = "06/06/2018"


import numpy
from silx.gui.plot.items.curve import Curve as CurveItem
from silx.gui.plot.items.image import ImageBase as ImageItem
from silx.gui.plot.items.scatter import Scatter as ScatterItem
from silx.gui.plot.items.histogram import Histogram as HistogramItem
from silx.math.combo import min_max
from collections import OrderedDict
import logging

logger = logging.getLogger(__name__)


class Stats(OrderedDict):
    """Class to define a set of statistic relative to a dataset
    (image, curve...).

    The goal of this class is to avoid multiple recalculation of some
    basic operations such as filtering data area where the statistics has to
    be apply.
    Min and max are also stored because they can be used several time.

    :param List statslist: List of the :class:`Stat` object to be computed.
    """
    def __init__(self, statslist=None):
        OrderedDict.__init__(self)
        _statslist = statslist if not None else []
        if statslist is not None:
            for stat in _statslist:
                self.add(stat)

    def calculate(self, item, plot, onlimits):
        """
        Call all :class:`Stat` object registred and return the result of the
        computation.

        :param item: the item for which we want statistics
        :param plot: plot containing the item
        :param bool onlimits: True if we want to apply statistic only on
                              visible data.
        :return dict: dictionary with :class:`Stat` name as ket and result
                      of the calculation as value
        """
        res = {}
        if isinstance(item, CurveItem):
            context = _CurveContext(item, plot, onlimits)
        elif isinstance(item, ImageItem):
            context = _ImageContext(item, plot, onlimits)
        elif isinstance(item, ScatterItem):
            context = _ScatterContext(item, plot, onlimits)
        elif isinstance(item, HistogramItem):
            context = _HistogramContext(item, plot, onlimits)
        else:
            raise ValueError('Item type not managed')
        for statName, stat in list(self.items()):
            if context.kind not in stat.compatibleKinds:
                logger.debug('kind %s not managed by statistic %s'
                             % (context.kind, stat.name))
                res[statName] = None
            else:
                res[statName] = stat.calculate(context)
        return res

    def __setitem__(self, key, value):
        assert isinstance(value, StatBase)
        OrderedDict.__setitem__(self, key, value)

    def add(self, stat):
        self.__setitem__(key=stat.name, value=stat)


class _StatsContext(object):
    """
    The context is designed to be a simple buffer and avoid repetition of
    calculations that can appear during stats evaluation.

    .. warning:: this class gives access to the data to be used for computation
                 . It deal with filtering data visible by the user on plot.
                 The filtering is a simple data sub-sampling. No interpolation
                 is made to fit data to boundaries.

    :param item: the item for which we want to compute the context
    :param str kind: the kind of the item
    :param plot: the plot containing the item
    :param bool onlimits: True if we want to apply statistic only on
                          visible data.
    """
    def __init__(self, item, kind, plot, onlimits):
        assert item
        assert plot
        assert type(onlimits) is bool
        self.kind = kind
        self.min = None
        self.max = None
        self.data = None
        self.values = None
        self.createContext(item, plot, onlimits)

    def createContext(self, item, plot, onlimits):
        raise NotImplementedError("Base class")


class _CurveContext(_StatsContext):
    """
    StatsContext for :class:`Curve`

    :param item: the item for which we want to compute the context
    :param plot: the plot containing the item
    :param bool onlimits: True if we want to apply statistic only on
                          visible data.
    """
    def __init__(self, item, plot, onlimits):
        _StatsContext.__init__(self, kind='curve', item=item,
                               plot=plot, onlimits=onlimits)

    def createContext(self, item, plot, onlimits):
        xData, yData = item.getData(copy=True)[0:2]

        if onlimits:
            minX, maxX = plot.getXAxis().getLimits()
            yData = yData[(minX <= xData) & (xData <= maxX)]
            xData = xData[(minX <= xData) & (xData <= maxX)]

        self.xData = xData
        self.yData = yData
        if len(yData) > 0:
            self.min, self.max = min_max(yData)
        else:
            self.min, self.max = None, None
        self.data = (xData, yData)
        self.values = yData


class _HistogramContext(_StatsContext):
    """
    StatsContext for :class:`Curve`

    :param item: the item for which we want to compute the context
    :param plot: the plot containing the item
    :param bool onlimits: True if we want to apply statistic only on
                          visible data.
    """
    def __init__(self, item, plot, onlimits):
        _StatsContext.__init__(self, kind='histogram', item=item,
                               plot=plot, onlimits=onlimits)

    def createContext(self, item, plot, onlimits):
        xData, edges = item.getData(copy=True)[0:2]
        yData = item._revertComputeEdges(x=edges, histogramType=item.getAlignment())
        if onlimits:
            minX, maxX = plot.getXAxis().getLimits()
            yData = yData[(minX <= xData) & (xData <= maxX)]
            xData = xData[(minX <= xData) & (xData <= maxX)]

        self.xData = xData
        self.yData = yData
        if len(yData) > 0:
            self.min, self.max = min_max(yData)
        else:
            self.min, self.max = None, None
        self.data = (xData, yData)
        self.values = yData


class _ScatterContext(_StatsContext):
    """
    StatsContext for :class:`Scatter`

    :param item: the item for which we want to compute the context
    :param plot: the plot containing the item
    :param bool onlimits: True if we want to apply statistic only on
                          visible data.
    """
    def __init__(self, item, plot, onlimits):
        _StatsContext.__init__(self, kind='scatter', item=item, plot=plot,
                               onlimits=onlimits)

    def createContext(self, item, plot, onlimits):
        xData, yData, valueData, xerror, yerror = item.getData(copy=True)
        assert plot
        if onlimits:
            minX, maxX = plot.getXAxis().getLimits()
            minY, maxY = plot.getYAxis().getLimits()
            # filter on X axis
            valueData = valueData[(minX <= xData) & (xData <= maxX)]
            yData = yData[(minX <= xData) & (xData <= maxX)]
            xData = xData[(minX <= xData) & (xData <= maxX)]
            # filter on Y axis
            valueData = valueData[(minY <= yData) & (yData <= maxY)]
            xData = xData[(minY <= yData) & (yData <= maxY)]
            yData = yData[(minY <= yData) & (yData <= maxY)]
        if len(valueData) > 0:
            self.min, self.max = min_max(valueData)
        else:
            self.min, self.max = None, None
        self.data = (xData, yData, valueData)
        self.values = valueData


class _ImageContext(_StatsContext):
    """
    StatsContext for :class:`ImageBase`

    :param item: the item for which we want to compute the context
    :param plot: the plot containing the item
    :param bool onlimits: True if we want to apply statistic only on
                          visible data.
    """
    def __init__(self, item, plot, onlimits):
        _StatsContext.__init__(self, kind='image', item=item,
                               plot=plot, onlimits=onlimits)

    def createContext(self, item, plot, onlimits):
        self.origin = item.getOrigin()
        self.scale = item.getScale()
        self.data = item.getData()

        if onlimits:
            minX, maxX = plot.getXAxis().getLimits()
            minY, maxY = plot.getYAxis().getLimits()

            XMinBound = int((minX - self.origin[0]) / self.scale[0])
            YMinBound = int((minY - self.origin[1]) / self.scale[1])
            XMaxBound = int((maxX - self.origin[0]) / self.scale[0])
            YMaxBound = int((maxY - self.origin[1]) / self.scale[1])

            XMinBound = max(XMinBound, 0)
            YMinBound = max(YMinBound, 0)

            if XMaxBound <= XMinBound or YMaxBound <= YMinBound:
                return self.noDataSelected()
            data = item.getData()
            self.data = data[YMinBound:YMaxBound + 1, XMinBound:XMaxBound + 1]
        else:
            self.data = item.getData()

        if self.data.size > 0:
            self.min, self.max = min_max(self.data)
        else:
            self.min, self.max = None, None
        self.values = self.data


BASIC_COMPATIBLE_KINDS = {
    'curve': CurveItem,
    'image': ImageItem,
    'scatter': ScatterItem,
    'histogram': HistogramItem,
}


class StatBase(object):
    """
    Base class for defining a statistic.

    :param str name: the name of the statistic. Must be unique.
    :param compatibleKinds: the kind of items (curve, scatter...) for which
                            the statistic apply.
    :rtype: List or tuple
    """
    def __init__(self, name, compatibleKinds=BASIC_COMPATIBLE_KINDS, description=None):
        self.name = name
        self.compatibleKinds = compatibleKinds
        self.description = description

    def calculate(self, context):
        """
        compute the statistic for the given :class:`StatsContext`

        :param context:
        :return dict: key is stat name, statistic computed is the dict value
        """
        raise NotImplementedError('Base class')

    def getToolTip(self, kind):
        """
        If necessary add a tooltip for a stat kind

        :param str kinf: the kind of item the statistic is compute for.
        :return: tooltip or None if no tooltip
        """
        return None


class Stat(StatBase):
    """
    Create a StatBase class based on a function pointer.

    :param str name: name of the statistic. Used as id
    :param fct: function which should have as unique mandatory parameter the
                data. Should be able to adapt to all `kinds` defined as
                compatible
    :param tuple kinds: the compatible item kinds of the function (curve,
                        image...)
    """
    def __init__(self, name, fct, kinds=BASIC_COMPATIBLE_KINDS):
        StatBase.__init__(self, name, kinds)
        self._fct = fct

    def calculate(self, context):
        if context.kind in self.compatibleKinds:
            return self._fct(context.values)
        else:
            raise ValueError('Kind %s not managed by %s'
                             '' % (context.kind, self.name))


class StatMin(StatBase):
    """
    Compute the minimal value on data
    """
    def __init__(self):
        StatBase.__init__(self, name='min')

    def calculate(self, context):
        return context.min


class StatMax(StatBase):
    """
    Compute the maximal value on data
    """
    def __init__(self):
        StatBase.__init__(self, name='max')

    def calculate(self, context):
        return context.max


class StatDelta(StatBase):
    """
    Compute the delta between minimal and maximal on data
    """
    def __init__(self):
        StatBase.__init__(self, name='delta')

    def calculate(self, context):
        return context.max - context.min


class StatCoordMin(StatBase):
    """
    Compute the first coordinates of the data minimal value
    """
    def __init__(self):
        StatBase.__init__(self, name='coords min')

    def calculate(self, context):
        if context.kind in ('curve', 'histogram'):
            return context.xData[numpy.argmin(context.yData)]
        elif context.kind == 'scatter':
            xData, yData, valueData = context.data
            return (xData[numpy.argmin(valueData)],
                    yData[numpy.argmin(valueData)])
        elif context.kind == 'image':
            scaleX, scaleY = context.scale
            originX, originY = context.origin
            index1D = numpy.argmin(context.data)
            ySize = (context.data.shape[1])
            x = index1D % context.data.shape[1]
            y = (index1D - x) / ySize
            x = x * scaleX + originX
            y = y * scaleY + originY
            return (x, y)
        else:
            raise ValueError('kind not managed')

    def getToolTip(self, kind):
        if kind in ('scatter', 'image'):
            return '(x, y)'
        else:
            return None

class StatCoordMax(StatBase):
    """
    Compute the first coordinates of the data minimal value
    """
    def __init__(self):
        StatBase.__init__(self, name='coords max')

    def calculate(self, context):
        if context.kind in ('curve', 'histogram'):
            return context.xData[numpy.argmax(context.yData)]
        elif context.kind == 'scatter':
            xData, yData, valueData = context.data
            return (xData[numpy.argmax(valueData)],
                    yData[numpy.argmax(valueData)])
        elif context.kind == 'image':
            scaleX, scaleY = context.scale
            originX, originY = context.origin
            index1D = numpy.argmax(context.data)
            ySize = (context.data.shape[1])
            x = index1D % context.data.shape[1]
            y = (index1D - x) / ySize
            x = x * scaleX + originX
            y = y * scaleY + originY
            return (x, y)
        else:
            raise ValueError('kind not managed')

    def getToolTip(self, kind):
        if kind in ('scatter', 'image'):
            return '(x, y)'
        else:
            return None

class StatCOM(StatBase):
    """
    Compute data center of mass
    """
    def __init__(self):
        StatBase.__init__(self, name='COM', description='Center of mass')

    def calculate(self, context):
        if context.kind in ('curve', 'histogram'):
            xData, yData = context.data
            deno = numpy.sum(yData).astype(numpy.float32)
            if deno == 0.:
                return numpy.nan
            else:
                return numpy.sum(xData * yData).astype(numpy.float32) / deno
        elif context.kind == 'scatter':
            xData, yData, values = context.data
            deno = numpy.sum(values).astype(numpy.float32)
            if deno == 0.:
                return numpy.nan, numpy.nan
            else:
                xcom = numpy.sum(xData * values).astype(numpy.float32) / deno
                ycom = numpy.sum(yData * values).astype(numpy.float32) / deno
                return (xcom, ycom)
        elif context.kind == 'image':
            yData = numpy.sum(context.data, axis=1)
            xData = numpy.sum(context.data, axis=0)
            dataXRange = range(context.data.shape[1])
            dataYRange = range(context.data.shape[0])
            xScale, yScale = context.scale
            xOrigin, yOrigin = context.origin

            denoY = numpy.sum(yData)
            if denoY == 0.:
                ycom = numpy.nan
            else:
                ycom = numpy.sum(yData * dataYRange) / denoY
                ycom = ycom * yScale + yOrigin

            denoX = numpy.sum(xData)
            if denoX == 0.:
                xcom = numpy.nan
            else:
                xcom = numpy.sum(xData * dataXRange) / denoX
                xcom = xcom * xScale + xOrigin
            return (xcom, ycom)
        else:
            raise ValueError('kind not managed')

    def getToolTip(self, kind):
        if kind in ('scatter', 'image'):
            return '(x, y)'
        else:
            return None