#/*##########################################################################
# Copyright (C) 2004-2016 V.A. Sole, European Synchrotron Radiation Facility
#
# This file is part of the PyMca X-ray Fluorescence Toolkit developed at
# the ESRF by the Software group.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
#############################################################################*/
"""
This plugin opens a window allowing to configure and compute the principal
component analysis.
Each spectrum is considered an *observation*, and each channel is considered
a *variable*.

The user can configure following parameters:

  - PCA method (*Covariance, Expectation Max, Covariance Multiple Arrays*)
  - Number of Principal Components
  - Spectral Binning
  - Spectral Regions

After the configuration dialog is validated, the eigenimages and the
eigenvectors are computed and displayed in another window.

"""
# TODO: explain PCA methods and regions
# TODO: provide a practical use case for a PCA. Isolating elements?
__author__ = "V.A. Sole - ESRF Data Analysis"
__contact__ = "sole@esrf.fr"
__license__ = "MIT"
__copyright__ = "European Synchrotron Radiation Facility, Grenoble, France"

import numpy

from PyMca5 import StackPluginBase
from PyMca5.PyMcaGui import CalculationThread

from PyMca5.PyMcaGui.math.PCAWindow import PCAParametersDialog
from PyMca5.PyMcaGui import StackPluginResultsWindow
from PyMca5.PyMcaGui import PyMca_Icons

qt = StackPluginResultsWindow.qt
DEBUG = 0


class PCAStackPlugin(StackPluginBase.StackPluginBase):
    def __init__(self, stackWindow, **kw):
        StackPluginBase.DEBUG = DEBUG
        StackPluginBase.StackPluginBase.__init__(self, stackWindow, **kw)
        self.methodDict = {'Calculate': [self.calculate, "Perform PCA", None],
                           'Show': [self._showWidget,
                                    "Show last results",
                                    PyMca_Icons.brushselect]}
        self.__methodKeys = ['Calculate', 'Show']
        self.configurationWidget = None
        self.widget = None
        self.thread = None

    def stackUpdated(self):
        if DEBUG:
            print("PCAStackPlugin.stackUpdated() called")
        self.configurationWidget = None
        self.widget = None

    def selectionMaskUpdated(self):
        if self.widget is None:
            return
        if self.widget.isHidden():
            return
        mask = self.getStackSelectionMask()
        self.widget.setSelectionMask(mask)

    def mySlot(self, ddict):
        if DEBUG:
            print("mySlot ", ddict['event'], ddict.keys())
        if ddict['event'] == "selectionMaskChanged":
            self.setStackSelectionMask(ddict['current'])
        elif ddict['event'] == "addImageClicked":
            self.addImage(ddict['image'], ddict['title'])
        elif ddict['event'] == "addAllClicked":
            for i in range(len(ddict["images"])):
                self.addImage(ddict['images'][i], ddict['titles'][i])            
        elif ddict['event'] == "removeImageClicked":
            self.removeImage(ddict['title'])
        elif ddict['event'] == "replaceImageClicked":
            self.replaceImage(ddict['image'], ddict['title'])
        elif ddict['event'] == "resetSelection":
            self.setStackSelectionMask(None)

    #Methods implemented by the plugin
    def getMethods(self):
        if self.widget is None:
            return [self.__methodKeys[0]]
        else:
            return self.__methodKeys

    def getMethodToolTip(self, name):
        return self.methodDict[name][1]

    def getMethodPixmap(self, name):
        return self.methodDict[name][2]

    def applyMethod(self, name):
        return self.methodDict[name][0]()

    #The specific part
    def calculate(self):
        if self.configurationWidget is None:
            stack = self.getStackDataObject()
            index = stack.info.get("McaIndex", -1)
            stack = None
            self.configurationWidget = PCAParametersDialog(None,
                                                           regions=True,
                                                           index=index)
            self._status = qt.QLabel(self.configurationWidget)
            self._status.setAlignment(qt.Qt.AlignHCenter)
            font = qt.QFont(self._status.font())
            font.setBold(True)
            self._status.setFont(font)
            self._status.setText("Ready")
            self.configurationWidget.layout().addWidget(self._status)
        self.configurationWidget.setEnabled(True)
        activeCurve = self.getActiveCurve()
        if activeCurve is None:
            #I could get some defaults from the stack itslef
            raise ValueError("Please select an active curve")
            return
        x, spectrum, legend, info = activeCurve
        spectrumLength = max(spectrum.shape)
        oldValue = self.configurationWidget.nPC.value()
        self.configurationWidget.nPC.setMaximum(spectrumLength)
        self.configurationWidget.nPC.setValue(min(oldValue, spectrumLength))
        binningOptions = [1]
        for number in [2, 3, 4, 5, 7, 9, 10, 11, 13, 15, 17, 19]:
            if (spectrumLength % number) == 0:
                binningOptions.append(number)
        # TODO: Should inform the configuration widget about the possibility
        #       to encounter non-finite data?
        ddict = {'options': binningOptions,
                 'binning': 1,
                 'method': 0}
        self.configurationWidget.setParameters(ddict)
        y = spectrum
        self.configurationWidget.setSpectrum(x, y, legend=legend, info=info)
        ret = self.configurationWidget.exec_()
        if ret:
            self._executeFunctionAndParameters()

    def _executeFunctionAndParameters(self):
        self.widget = None
        self.configurationWidget.show()
        if DEBUG:
            self.thread = CalculationThread.CalculationThread(\
                            calculation_method=self.actualCalculation)
            self.thread.result = self.actualCalculation()
            self.threadFinished()
        else:
            self.thread = CalculationThread.CalculationThread(\
                            calculation_method=self.actualCalculation)
            self.thread.finished.connect(self.threadFinished)
            self.thread.start()
            message = "Please wait. PCA Calculation going on."
            CalculationThread.waitingMessageDialog(self.thread,
                                message=message,
                                parent=self.configurationWidget)

    def actualCalculation(self):
        pcaParameters = self.configurationWidget.getParameters()
        self._status.setText("Calculation going on")
        self.configurationWidget.setEnabled(False)
        #self.configurationWidget.close()
        self.__methodlabel = pcaParameters.get('methodlabel', "")
        function = pcaParameters['function']
        pcaParameters['ncomponents'] = pcaParameters['npc']
        # At some point I should make sure I get directly the
        # function and the parameters from the configuration widget
        del pcaParameters['npc']
        del pcaParameters['method']
        del pcaParameters['function']
        del pcaParameters['methodlabel']
        # binning = pcaParameters['binning']
        # mask = pcaParameters['mask']
        regions = pcaParameters['regions']
        spectral_mask = pcaParameters['spectral_mask']
        #print("regions = ", regions)
        #del pcaParameters['regions']
        #del pcaParameters['spectral_mask']
        #print("Regions and spectral mask not handled yet")
        if not self.isStackFinite():
            # one has to check for NaNs in the used region(s)
            # for the time being only in the global image
            # spatial_mask = numpy.isfinite(image_data)
            spatial_mask = numpy.isfinite(self.getStackOriginalImage())
            pcaParameters['mask'] = spatial_mask
        pcaParameters["legacy"] = False
        if "Multiple" in self.__methodlabel:
            stackList = self.getStackDataObjectList()
            oldShapes = []
            for stack in stackList:
                oldShapes.append(stack.data.shape)
            result = function(stackList, **pcaParameters)
            for i in range(len(stackList)):
                stackList[i].data.shape = oldShapes[i]
            return result
        else:
            stack = self.getStackDataObject()
            if isinstance(stack, numpy.ndarray):
                if stack.data.dtype not in [numpy.float, numpy.float32]:
                    print("WARNING: Non floating point data")
                    text = "Calculation going on."
                    text += " WARNING: Non floating point data."
                    self._status.setText(text)
            oldShape = stack.data.shape
            result = function(stack, **pcaParameters)
            if stack.data.shape != oldShape:
                stack.data.shape = oldShape
        return result

    def threadFinished(self):
        result = self.thread.getResult()
        self.thread = None
        if type(result) == type((1,)):
            #if we receive a tuple there was an error
            if len(result):
                if result[0] == "Exception":
                    self._status.setText("Ready after calculation error")
                    self.configurationWidget.setEnabled(True)
                    raise Exception(result[1], result[2])
                    return
        self._status.setText("Ready")
        curve = self.configurationWidget.getSpectrum(binned=True)
        if curve not in [None, []]:
            xValues = curve[0]
        else:
            xValues = None
        self.configurationWidget.setEnabled(True)
        self.configurationWidget.close()
        if hasattr(result, "keys"):
            # new way
            images = result["scores"]
            eigenValues = result["eigenvalues"]
            eigenVectors = result["eigenvectors"]
            variance = result.get("variance", None)
            if variance is not None:
                explainedVariance = []
                for value in eigenValues:
                    explainedVariance.append(100 * (value/variance))
        else:
            variance = None
            images, eigenValues, eigenVectors = result
        methodlabel = self.__methodlabel
        imageNames = None
        vectorNames = None
        nimages = images.shape[0]
        imageNames = []
        vectorNames = []
        itmp = nimages
        if " ICA " in methodlabel:
            itmp = int(nimages / 2)
            for i in range(itmp):
                imageNames.append("ICAimage %02d" % i)
                vectorNames.append("ICAvector %02d" % i)
        if "Multiple" in methodlabel:
            xValues = None
        for i in range(itmp):
            imageNames.append("Eigenimage %02d" % i)
            vectorNames.append("Eigenvector %02d" % i)
            if variance is not None:
                vectorNames[-1] = "EV%02d Explained variance %.4f %%" % \
                                  (i, explainedVariance[i])

        self.widget = StackPluginResultsWindow.StackPluginResultsWindow(\
                                        usetab=True)
        self.widget.buildAndConnectImageButtonBox(replace=True,
                                                  multiple=True)
        qt = StackPluginResultsWindow.qt
        self.widget.sigMaskImageWidgetSignal.connect(self.mySlot)
        if xValues is not None:
            xValues = [xValues] * nimages
        self.widget.setStackPluginResults(images,
                                          spectra=eigenVectors,
                                          image_names=imageNames,
                                          xvalues=xValues,
                                          spectra_names=vectorNames)
        self._showWidget()

    def _showWidget(self):
        if self.widget is None:
            return
        #Show
        self.widget.show()
        self.widget.raise_()

        #update
        self.selectionMaskUpdated()

MENU_TEXT = "PyMca PCA"


def getStackPluginInstance(stackWindow, **kw):
    ob = PCAStackPlugin(stackWindow)
    return ob
