#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""Tools to help with calibrations
"""

# Part of the PsychoPy library
# Copyright (C) 2018 Jonathan Peirce
# Distributed under the terms of the GNU General Public License (GPL).

from __future__ import absolute_import, division, print_function

# from future import standard_library
# standard_library.install_aliases()
from builtins import str
from builtins import range
from past.builtins import basestring
from past.utils import old_div
from builtins import object
from .calibData import wavelength_5nm, juddVosXYZ1976_5nm, cones_SmithPokorny
from psychopy import __version__, logging, hardware, constants

try:
    import serial
    haveSerial = True
except Exception:
    haveSerial = False
import os
import time
import glob
import pickle
import sys
from copy import deepcopy, copy

import numpy as np
import scipy.optimize as optim
from scipy import interpolate
import json_tricks  # allows json to dump/load np.arrays and dates

DEBUG = False

# set and create (if necess) the data folder
# this will be the
#   Linux/Mac:  ~/.psychopy2/monitors
#   win32:   <UserDocs>/Application Data/PsychoPy/monitors
join = os.path.join
if sys.platform == 'win32':
    # we used this for a while (until 0.95.4) but not the proper place for
    # windows app data
    oldMonitorFolder = join(os.path.expanduser('~'), '.psychopy3', 'monitors')
    monitorFolder = join(os.environ['APPDATA'], 'psychopy3', 'monitors')
    if os.path.isdir(oldMonitorFolder) and not os.path.isdir(monitorFolder):
        os.renames(oldMonitorFolder, monitorFolder)
else:
    monitorFolder = join(os.environ['HOME'], '.psychopy3', 'monitors')

# HACK for Python2.7! On system where `monitorFolder` contains special characters,
# for example because the Windows profile name does, `monitorFolder` must be
# decoded to Unicode to prevent errors later on. However, this is not a proper
# fix, since *everything* should be decoded to Unicode, and not just this
# specific pathname. Right now, errors will still occur if `monitorFolder` is
# combined with `str`-type objects that contain non-ASCII characters.
if isinstance(monitorFolder, bytes):
    monitorFolder = monitorFolder.decode(sys.getfilesystemencoding())

if not os.path.isdir(monitorFolder):
    os.makedirs(monitorFolder)


class Monitor(object):
    """Creates a monitor object for storing calibration details.
    This will be loaded automatically from disk if the
    monitor name is already defined (see methods).

    Many settings from the stored monitor can easilly be overridden
    either by adding them as arguments during the initial call.

    **arguments**:

        - ``width, distance, gamma`` are details about the calibration
        - ``notes`` is a text field to store any useful info
        - ``useBits`` True, False, None
        - ``verbose`` True, False, None
        - ``currentCalib`` is a dictionary object containing various
            fields for a calibration. Use with caution since the
            dictionary may not contain all the necessary fields that
            a monitor object expects to find.

    **eg**:

    ``myMon = Monitor('sony500', distance=114)``
    Fetches the info on the sony500 and overrides its usual distance
    to be 114cm for this experiment.

    These can be saved to the monitor file using
    :func:`~psychopy.monitors.Monitor.save`
    or not (in which case the changes will be lost)
    """

    def __init__(self, name,
                 width=None,
                 distance=None,
                 gamma=None,
                 notes=None,
                 useBits=None,
                 verbose=True,
                 currentCalib=None,
                 autoLog=True):
        """
        """

        # make sure that all necessary settings have some value
        super(Monitor, self).__init__()
        self.__type__ = 'psychoMonitor'
        self.name = name
        self.autoLog = autoLog
        self.currentCalib = currentCalib or {}
        self.currentCalibName = strFromDate(time.mktime(time.localtime()))
        self.calibs = {}
        self.calibNames = []
        self._gammaInterpolator = None
        self._gammaInterpolator2 = None
        self._loadAll()
        if len(self.calibNames) > 0:
            self.setCurrent(-1)  # will fetch previous vals if monitor exists
            if self.autoLog:
                logging.info('Loaded monitor calibration from %s' %
                             self.calibNames)
        else:
            self.newCalib()
            logging.warning("Monitor specification not found. "
                            "Creating a temporary one...")

        # overide current monitor settings with the vals given
        if width:
            self.setWidth(width)
        if distance:
            self.setDistance(distance)
        if gamma:
            self.setGamma(gamma)
        if notes:
            self.setNotes(notes)
        if useBits != None:
            self.setUseBits(useBits)

    def gammaIsDefault(self):
        """Determine whether we're using the default gamma values
        """
        thisGamma = self.getGamma()
        # run the test just on this
        array = np.array
        return (thisGamma is None or
                np.alltrue(array(thisGamma) == array([1, 1, 1])))

# functions to set params of current calibration
    def setSizePix(self, pixels):
        """Set the size of the screen in pixels x,y
        """
        self.currentCalib['sizePix'] = pixels

    def setWidth(self, width):
        """Of the viewable screen (cm)
        """
        self.currentCalib['width'] = width

    def setDistance(self, distance):
        """To the screen (cm)
        """
        self.currentCalib['distance'] = distance

    def setCalibDate(self, date=None):
        """Sets the current calibration to have a date/time or to the current
        date/time if none given. (Also returns the date as set)
        """
        if date is None:
            date = time.mktime(time.localtime())
        self.currentCalib['calibDate'] = date
        return date

    def setGamma(self, gamma):
        """Sets the gamma value(s) for the monitor.
        This only uses a single gamma value for the three
        guns, which is fairly approximate. Better to use
        setGammaGrid (which uses one gamma value for each gun)
        """
        self.currentCalib['gamma'] = gamma

    def setGammaGrid(self, gammaGrid):
        """Sets the min,max,gamma values for the each gun
        """
        self.currentCalib['gammaGrid'] = gammaGrid

    def setLineariseMethod(self, method):
        """Sets the method for linearising
        0 uses y=a+(bx)^gamma
        1 uses y=(a+bx)^gamma
        2 uses linear interpolation over the curve
        """
        self.currentCalib['linearizeMethod'] = method

    def setMeanLum(self, meanLum):
        """Records the mean luminance (for reference only)
        """
        self.currentCalib['meanLum'] = meanLum

    def setLumsPre(self, lums):
        """Sets the last set of luminance values measured during calibration
        """
        self.currentCalib['lumsPre'] = lums

    def setLumsPost(self, lums):
        """Sets the last set of luminance values measured AFTER calibration
        """
        self.currentCalib['lumsPost'] = lums

    def setLevelsPre(self, levels):
        """Sets the last set of luminance values measured during calibration
        """
        self.currentCalib['levelsPre'] = levels

    def setLevelsPost(self, levels):
        """Sets the last set of luminance values measured AFTER calibration
        """
        self.currentCalib['levelsPost'] = levels

    def setDKL_RGB(self, dkl_rgb):
        """Sets the DKL->RGB conversion matrix for a chromatically
        calibrated monitor (matrix is a 3x3 num array).
        """
        self.currentCalib['dkl_rgb'] = dkl_rgb

    def setSpectra(self, nm, rgb):
        """Sets the phosphor spectra measured by the spectrometer
        """
        self.currentCalib['spectraNM'] = nm
        self.currentCalib['spectraRGB'] = rgb

    def setLMS_RGB(self, lms_rgb):
        """Sets the LMS->RGB conversion matrix for a chromatically
        calibrated monitor (matrix is a 3x3 num array).
        """
        self.currentCalib['lms_rgb'] = lms_rgb
        self.setPsychopyVersion(__version__)

    def setPsychopyVersion(self, version):
        """To store the version of PsychoPy that this calibration used
        """
        self.currentCalib['psychopyVersion'] = version

    def setNotes(self, notes):
        """For you to store notes about the calibration
        """
        self.currentCalib['notes'] = notes

    def setUseBits(self, usebits):
        """DEPRECATED: Use the new hardware classes to control these devices
        """
        self.currentCalib['usebits'] = usebits

    # equivalent get functions
    def getSizePix(self):
        """Returns the size of the current calibration in pixels,
        or None if not defined
        """
        size = None
        if 'sizePix' in self.currentCalib:
            size = self.currentCalib['sizePix']
        # check various invalid sizes
        if not hasattr(size, '__iter__') or len(size)!=2:
            return None
        # make sure it's a list (not tuple) with no None vals
        sizeOut = [(val or 0) for val in size]
        return sizeOut

    def getWidth(self):
        """Of the viewable screen in cm, or None if not known
        """
        return self.currentCalib['width']

    def getDistance(self):
        """Returns distance from viewer to the screen in cm,
        or None if not known
        """
        return self.currentCalib['distance']

    def getCalibDate(self):
        """As a python date object (convert to string using
        calibTools.strFromDate"""
        return self.currentCalib['calibDate']

    def getGamma(self):
        """Returns just the gamma value (not the whole grid)
        """
        gridInCurrent = 'gammaGrid' in self.currentCalib
        if (gridInCurrent and
                not np.alltrue(self.getGammaGrid()[1:, 2] == 1)):
            return self.getGammaGrid()[1:, 2]
        elif 'gamma' in self.currentCalib:
            return self.currentCalib['gamma']
        else:
            return None

    def getGammaGrid(self):
        """Gets the min,max,gamma values for the each gun
        """
        if 'gammaGrid' in self.currentCalib:
            # Make sure it's an array, so you can look at the shape
            grid = np.asarray(self.currentCalib['gammaGrid'])
            if grid.shape != [4, 6]:
                newGrid = np.zeros([4, 6], 'f') * np.nan  # start as NaN
                newGrid[:grid.shape[0], :grid.shape[1]] = grid
                grid = self.currentCalib['gammaGrid'] = newGrid
            return grid
        else:
            return None

    def getLinearizeMethod(self):
        """Gets the method that this monitor is using to linearize the guns
        """
        if 'linearizeMethod' in self.currentCalib:
            return self.currentCalib['linearizeMethod']
        elif 'lineariseMethod' in self.currentCalib:
            return self.currentCalib['lineariseMethod']
        else:
            return None

    def getMeanLum(self):
        """Returns the mean luminance of the screen if explicitly stored
        """
        if 'meanLum' in self.currentCalib:
            return self.currentCalib['meanLum']
        else:
            return None

    def getLumsPre(self):
        """Gets the measured luminance values from last calibration"""
        if 'lumsPre' in self.currentCalib:
            return self.currentCalib['lumsPre']
        else:
            return None

    def getLumsPost(self):
        """Gets the measured luminance values from last calibration TEST"""
        if 'lumsPost' in self.currentCalib:
            return self.currentCalib['lumsPost']
        else:
            return None

    def getLevelsPre(self):
        """Gets the measured luminance values from last calibration"""
        if 'levelsPre' in self.currentCalib:
            return self.currentCalib['levelsPre']
        else:
            return None

    def getLevelsPost(self):
        """Gets the measured luminance values from last calibration TEST"""
        if 'levelsPost' in self.currentCalib:
            return self.currentCalib['levelsPost']
        else:
            return None

    def getSpectra(self):
        """Gets the wavelength values from the last spectrometer measurement
        (if available)

        usage:
            - nm, power = monitor.getSpectra()

            """
        if 'spectraNM' in self.currentCalib:
            return (self.currentCalib['spectraNM'],
                    self.currentCalib['spectraRGB'])
        else:
            return None, None

    def getDKL_RGB(self, RECOMPUTE=False):
        """Returns the DKL->RGB conversion matrix. If one has been saved
        this will be returned. Otherwise, if power spectra are available
        for the monitor a matrix will be calculated.
        """
        if not 'dkl_rgb' in self.currentCalib:
            RECOMPUTE = True
        if RECOMPUTE:
            nm, power = self.getSpectra()
            if nm is None:
                return None
            else:
                return makeDKL2RGB(nm, power)
        else:
            return self.currentCalib['dkl_rgb']

    def getLMS_RGB(self, recompute=False):
        """Returns the LMS->RGB conversion matrix.
        If one has been saved this will be returned.
        Otherwise (if power spectra are available for the
        monitor) a matrix will be calculated.
        """
        if not 'lms_rgb' in self.currentCalib:
            recompute = True
        if recompute:
            nm, power = self.getSpectra()
            if nm is None:
                return None
            else:
                return makeLMS2RGB(nm, power)
        else:
            return self.currentCalib['lms_rgb']

    def getPsychopyVersion(self):
        """Returns the version of PsychoPy that was used to create
        this calibration
        """
        return self.currentCalib['psychopyVersion']

    def getNotes(self):
        """Notes about the calibration
        """
        return self.currentCalib['notes']

    def getUseBits(self):
        """Was this calibration carried out witha a bits++ box
        """
        return self.currentCalib['usebits']

    # other (admin functions)
    def _loadAll(self):
        """Fetches the calibrations for this monitor from disk, storing them
        as self.calibs
        """
        if constants.PY3:
            ext = ".json"
        else:
            ext = ".calib"
        # the name of the actual file:
        thisFileName = os.path.join(monitorFolder, self.name + ext)
        if not os.path.exists(thisFileName):
            self.calibNames = []
        else:
            if ext==".json":
                with open(thisFileName, 'r') as thisFile:
                    self.calibs = json_tricks.load(thisFile, ignore_comments=False,
                                                   encoding='utf-8', preserve_order=False)
            else:
                with open(thisFileName, 'rb') as thisFile:
                    self.calibs = pickle.load(thisFile)
            self.calibNames = sorted(self.calibs)
            
            if not constants.PY3:  # saving for future (not needed if we are IN future!)
                # save JSON copies of our calibrations
                self._saveJSON()

    def newCalib(self, calibName=None, width=None,
                 distance=None, gamma=None, notes=None, useBits=False,
                 verbose=True):
        """create a new (empty) calibration for this monitor and
        makes this the current calibration
        """
        dateTime = time.mktime(time.localtime())
        if calibName is None:
            calibName = strFromDate(dateTime)
        # add to the list of calibrations
        self.calibNames.append(calibName)
        self.calibs[calibName] = {}

        self.setCurrent(calibName)
        # populate with some default values:
        self.setCalibDate(dateTime)
        self.setGamma(gamma)
        self.setWidth(width)
        self.setDistance(distance)
        self.setNotes(notes)
        self.setPsychopyVersion(__version__)
        self.setUseBits(useBits)
        newGrid = np.ones((4, 3), 'd')
        newGrid[:, 0] *= 0
        self.setGammaGrid(newGrid)
        self.setLineariseMethod(1)

    def setCurrent(self, calibration=-1):
        """Sets the current calibration for this monitor.
        Note that a single file can hold multiple calibrations each
        stored under a different key (the date it was taken)

        The argument is either a string (naming the calib) or an integer
        **eg**:

            ``myMon.setCurrent('mainCalib')``
            fetches the calibration named mainCalib. You can name
            calibrations what you want but PsychoPy will give them names
            of date/time by default. In Monitor Center you can 'copy...'
            a calibration and give it a new name to keep a second version.

            ``calibName = myMon.setCurrent(0)``
            fetches the first calibration (alphabetically) for this monitor

            ``calibName = myMon.setCurrent(-1)``
            fetches the last **alphabetical** calibration for this monitor
            (this is default). If default names are used for calibrations
            (ie date/time stamp) then this will import the most recent.
        """
        # find the appropriate file
        # get desired calibration name if necess
        if (isinstance(calibration, basestring) and
                calibration in self.calibNames):
            self.currentCalibName = calibration
        elif type(calibration) == int and calibration <= len(self.calibNames):
            self.currentCalibName = self.calibNames[calibration]
        else:
            print("No record of that calibration")
            return False

        # do the import
        self.currentCalib = self.calibs[self.currentCalibName]
        return self.currentCalibName

    def delCalib(self, calibName):
        """Remove a specific calibration from the current monitor.
        Won't be finalised unless monitor is saved
        """
        # remove from our list
        self.calibNames.remove(calibName)
        self.calibs.pop(calibName)
        if self.currentCalibName == calibName:
            self.setCurrent(-1)
        return 1

    def save(self):
        """Save the current calibrations to disk.

        This will write a `json` file to the `monitors` subfolder of your
        PsychoPy configuration folder (typically `~/.psychopy3/monitors` on
        Linux and macOS, and `%APPDATA%\psychopy3\monitors` on Windows).

        Additionally saves a pickle (`.calib`) file if you are running
        Python 2.7.

        """
        if not constants.PY3:  # don't ever save pickle files form PY3
            thisFileName = os.path.join(monitorFolder, self.name + ".calib")
            with open(thisFileName, 'wb') as thisFile:
                pickle.dump(self.calibs, thisFile)

        # also save as JSON (at the moment)
        # (When we're sure this works we should ONLY save as JSON)
        self._saveJSON()

    def saveMon(self):
        """Equivalent of :func:`~psychopy.monitors.Monitor.save`.
        """
        self.save()

    def _saveJSON(self):
        thisFileName = os.path.join(monitorFolder, self.name + ".json")
        # convert time structs to timestamps (floats)
        for calibName in self.calibs:
            calib = self.calibs[calibName]
            if isinstance(calib['calibDate'], time.struct_time):
                calib['calibDate'] = time.mktime(calib['calibDate'])
        with open(thisFileName, 'w') as outfile:
            json_tricks.dump(self.calibs, outfile, indent=2,
                             allow_nan=True)


    def copyCalib(self, calibName=None):
        """Stores the settings for the current calibration settings as
        new monitor.
        """
        if calibName is None:
            calibName = strFromDate(time.mktime(time.localtime()))
        # add to the list of calibrations
        self.calibNames.append(calibName)
        self.calibs[calibName] = deepcopy(self.currentCalib)
        self.setCurrent(calibName)

    def linearizeLums(self, desiredLums, newInterpolators=False,
                      overrideGamma=None):
        """lums should be uncalibrated luminance values (e.g. a linear ramp)
        ranging 0:1
        """
        linMethod = self.getLinearizeMethod()
        desiredLums = np.asarray(desiredLums)
        output = desiredLums * 0.0  # needs same size as input

        # gamma interpolation
        if linMethod == 3:
            lumsPre = copy(self.getLumsPre())
            if self._gammaInterpolator is not None and not newInterpolators:
                pass  # we already have an interpolator
            elif lumsPre is not None:
                if self.autoLog:
                    logging.info('Creating linear interpolation for gamma')
                # we can make an interpolator
                self._gammaInterpolator = []
                self._gammaInterpolator2 = []
                # each of these interpolators is a function!
                levelsPre = old_div(self.getLevelsPre(), 255.0)
                for gun in range(4):
                    # scale to 0:1
                    lumsPre[gun, :] = (old_div((lumsPre[gun, :] - lumsPre[gun, 0]),
                                       (lumsPre[gun, -1] - lumsPre[gun, 0])))
                    self._gammaInterpolator.append(
                        interpolate.interp1d(lumsPre[gun, :],
                                             levelsPre,
                                             kind='linear'))
                    # interpFunc = Interpolation.InterpolatingFunction(
                    #    (lumsPre[gun,:],), levelsPre)
                    # polyFunc = interpFunc.fitPolynomial(3)
                    # self._gammaInterpolator2.append( [polyFunc.coeff])
            else:
                # no way to do this! Calibrate the monitor
                logging.error("Can't do a gamma interpolation on your "
                              "monitor without calibrating!")
                return desiredLums

            # then do the actual interpolations
            if len(desiredLums.shape) > 1:
                for gun in range(3):
                    # gun+1 because we don't want luminance interpolator
                    _gammaIntrpGun = self._gammaInterpolator[gun + 1]
                    output[:, gun] = _gammaIntrpGun(desiredLums[:, gun])

            else:
                # just luminance
                output = self._gammaInterpolator[0](desiredLums)

        # use a fitted gamma equation (1 or 2)
        elif linMethod in [1, 2, 4]:

            # get the min,max lums
            gammaGrid = self.getGammaGrid()
            if gammaGrid is not None:
                # if we have info about min and max luminance then use it
                minLum = gammaGrid[1, 0]
                maxLum = gammaGrid[1:4, 1]
                b = gammaGrid[1:4, 4]
                if overrideGamma is not None:
                    gamma = overrideGamma
                else:
                    gamma = gammaGrid[1:4, 2]
                maxLumWhite = gammaGrid[0, 1]
                gammaWhite = gammaGrid[0, 2]
                if self.autoLog:
                    logging.debug('using gamma grid' + str(gammaGrid))
            else:
                # just do the calculation using gamma
                minLum = 0
                maxLumR, maxLumG, maxLumB, maxLumWhite = 1, 1, 1, 1
                gamma = self.currentCalib['gamma']
                gammaWhite = np.average(gamma)

            # get the inverse gamma
            if len(desiredLums.shape) > 1:
                for gun in range(3):
                    output[:, gun] = gammaInvFun(desiredLums[:, gun],
                                                 minLum, maxLum[gun],
                                                 gamma[gun],
                                                 eq=linMethod, b=b[gun])
            else:
                output = gammaInvFun(desiredLums, minLum, maxLumWhite,
                                     gammaWhite, eq=linMethod)

        else:
            msg = "Don't know how to linearise with method %i"
            logging.error(msg % linMethod)
            output = desiredLums

        return output

    def lineariseLums(self, desiredLums, newInterpolators=False,
                      overrideGamma=None):
        """Equivalent of :func:`~psychopy.monitors.Monitor.linearizeLums`.
        """
        return self.linearizeLums(desiredLums=desiredLums,
                                  newInterpolators=newInterpolators,
                                  overrideGamma=overrideGamma)


class GammaCalculator(object):
    """Class for managing gamma tables

    **Parameters:**

    - inputs (required)= values at which you measured screen luminance either
        in range 0.0:1.0, or range 0:255. Should include the min
        and max of the monitor

    Then give EITHER "lums" or "gamma":

        - lums = measured luminance at given input levels
        - gamma = your own gamma value (single float)
        - bitsIN = number of values in your lookup table
        - bitsOUT = number of bits in the DACs

    myTable.gammaModel
    myTable.gamma

    """

    def __init__(self,
                 inputs=(),
                 lums=(),
                 gamma=None,
                 bitsIN=8,  # how values in the LUT
                 bitsOUT=8,
                 eq=1):  # how many values can the DACs output
        super(GammaCalculator, self).__init__()
        self.lumsInitial = list(lums)
        self.inputs = inputs
        self.bitsIN = bitsIN
        self.bitsOUT = bitsOUT
        self.eq = eq
        # set or or get input levels
        if len(inputs) == 0 and len(lums) > 0:
            self.inputs = DACrange(len(lums))
        else:
            self.inputs = list(inputs)

        # set or get gammaVal
        # user is specifying their own gamma value
        if len(lums) == 0 or gamma != None:
            self.gamma = gamma
        elif len(lums) > 0:
            self.min, self.max, self.gammaModel = self.fitGammaFun(
                self.inputs, self.lumsInitial)
            if eq == 4:
                self.gamma, self.a, self.k = self.gammaModel
                self.b = (lums[0] - self.a)**(old_div(1.0, self.gamma))
            else:
                self.gamma = self.gammaModel[0]
                self.a = self.b = self.k = None
        else:
            raise AttributeError("gammaTable needs EITHER a gamma value"
                                   " or some luminance measures")

    def fitGammaFun(self, x, y):
        """
        Fits a gamma function to the monitor calibration data.

        **Parameters:**
            -xVals are the monitor look-up-table vals, either 0-255 or 0.0-1.0
            -yVals are the measured luminances from a photometer/spectrometer

        """
        minGamma = 0.8
        maxGamma = 20.0
        gammaGuess = 2.0
        y = np.asarray(y)
        minLum = y[0]
        maxLum = y[-1]
        if self.eq == 4:
            aGuess = old_div(minLum, 5.0)
            kGuess = (maxLum - aGuess)**(old_div(1.0, gammaGuess)) - aGuess
            guess = [gammaGuess, aGuess, kGuess]
            bounds = [[0.8, 5.0], [0.00001, minLum - 0.00001], [2, 200]]
        else:
            guess = [gammaGuess]
            bounds = [[0.8, 5.0]]
        # gamma = optim.fmin(self.fitGammaErrFun, guess, (x, y, minLum, maxLum))
        # gamma = optim.fminbound(self.fitGammaErrFun,
        #    minGamma, maxGamma,
        #    args=(x,y, minLum, maxLum))
        params = optim.fmin_tnc(self.fitGammaErrFun, np.array(guess),
                                approx_grad=True,
                                args=(x, y, minLum, maxLum),
                                bounds=bounds, messages=0)
        return minLum, maxLum, params[0]

    def fitGammaErrFun(self, params, x, y, minLum, maxLum):
        """Provides an error function for fitting gamma function

        (used by fitGammaFun)
        """
        if self.eq == 4:
            gamma, a, k = params
            _m = gammaFun(x, minLum, maxLum, gamma, eq=self.eq, a=a, k=k)
            model = np.asarray(_m)
        else:
            gamma = params[0]
            _m = gammaFun(x, minLum, maxLum, gamma, eq=self.eq)
            model = np.asarray(_m)
        SSQ = np.sum((model - y)**2)
        return SSQ

def makeDKL2RGB(nm, powerRGB):
    """Creates a 3x3 DKL->RGB conversion matrix from the spectral input powers
    """
    interpolateCones = interpolate.interp1d(wavelength_5nm,
                                            cones_SmithPokorny)
    interpolateJudd = interpolate.interp1d(wavelength_5nm,
                                           juddVosXYZ1976_5nm)
    judd = interpolateJudd(nm)
    cones = interpolateCones(nm)
    judd = np.asarray(judd)
    cones = np.asarray(cones)
    rgb_to_cones = np.dot(cones, np.transpose(powerRGB))
    # get LMS weights for Judd vl
    lumwt = np.dot(judd[1, :], np.linalg.pinv(cones))

    # cone weights for achromatic primary
    dkl_to_cones = np.dot(rgb_to_cones, [[1, 0, 0], [1, 0, 0], [1, 0, 0]])

    # cone weights for L-M primary
    dkl_to_cones[0, 1] = old_div(lumwt[1], lumwt[0])
    dkl_to_cones[1, 1] = -1
    dkl_to_cones[2, 1] = lumwt[2]

    # weights for S primary
    dkl_to_cones[0, 2] = 0
    dkl_to_cones[1, 2] = 0
    dkl_to_cones[2, 2] = -1
    # Now have primaries expressed as cone excitations

    # get coefficients for cones ->monitor
    cones_to_rgb = np.linalg.inv(rgb_to_cones)

    # get coefficients for DKL cone weights to monitor
    dkl_to_rgb = np.dot(cones_to_rgb, dkl_to_cones)
    # normalise each col
    dkl_to_rgb[:, 0] /= max(abs(dkl_to_rgb[:, 0]))
    dkl_to_rgb[:, 1] /= max(abs(dkl_to_rgb[:, 1]))
    dkl_to_rgb[:, 2] /= max(abs(dkl_to_rgb[:, 2]))
    return dkl_to_rgb


def makeLMS2RGB(nm, powerRGB):
    """Creates a 3x3 LMS->RGB conversion matrix from the spectral input powers
    """

    interpolateCones = interpolate.interp1d(wavelength_5nm,
                                            cones_SmithPokorny)
    coneSens = interpolateCones(nm)
    rgb_to_cones = np.dot(coneSens, np.transpose(powerRGB))
    cones_to_rgb = np.linalg.inv(rgb_to_cones)

    return cones_to_rgb

def makeXYZ2RGB(red_xy,
                green_xy,
                blue_xy,
                whitePoint_xy=(0.3127, 0.329),
                reverse=False):
    """Create a linear sRGB conversion matrix.

    Returns a matrix to convert CIE-XYZ (1931) tristimulus values to linear sRGB
    given CIE-xy (1931) primaries and white point. By default, the returned
    matrix transforms CIE-XYZ to linear sRGB coordinates. Use 'reverse=True' to
    get the inverse transformation. The chromaticity coordinates of the
    display's phosphor 'guns' are usually measured with a spectrophotometer.

    The routines here are based on methods found at:
        http://www.ryanjuckett.com/programming/rgb-color-space-conversion/

    :param red_xy: tuple, list or ndarray
        Chromaticity coordinate (CIE-xy) of the 'red' gun.
    :param green_xy: tuple, list or ndarray
        Chromaticity coordinate (CIE-xy) of the 'green' gun.
    :param blue_xy: tuple, list or ndarray
        Chromaticity coordinate (CIE-xy) of the 'blue' gun.
    :param whtp_xy: tuple, list or ndarray
        Chromaticity coordinate (CIE-xy) of the white point, default is D65.
    :param reverse:
        Return the inverse transform XYZ -> sRGB
    :return: 3x3 conversion matrix

    """
    # convert CIE-xy chromaticity coordinates to xyY and put them into a matrix
    mat_xyY_primaries = np.asmatrix((
        (red_xy[0], red_xy[1], 1.0 - red_xy[0] - red_xy[1]),
        (green_xy[0], green_xy[1], 1.0 - green_xy[0] - green_xy[1]),
        (blue_xy[0], blue_xy[1], 1.0 - blue_xy[0] - blue_xy[1])
    )).T
    # convert white point to CIE-XYZ
    whtp_XYZ = np.asmatrix(
        np.dot(1.0 / whitePoint_xy[1],
            np.asarray((
                whitePoint_xy[0],
                whitePoint_xy[1],
                1.0 - whitePoint_xy[0] - whitePoint_xy[1])
            )
        )
    ).T
    # compute the final matrix (sRGB -> XYZ)
    to_return = mat_xyY_primaries * np.diag(
        (np.linalg.inv(mat_xyY_primaries) * whtp_XYZ).A1)

    if not reverse:  # for XYZ -> sRGB conversion matrix (we usually want this!)
        return np.linalg.inv(to_return)

    return to_return

def getLumSeries(lumLevels=8,
                 winSize=(800, 600),
                 monitor=None,
                 gamma=1.0,
                 allGuns=True,
                 useBits=False,
                 autoMode='auto',
                 stimSize=0.3,
                 photometer=None,
                 screen=0):
    """Automatically measures a series of gun values and measures
    the luminance with a photometer.

    :Parameters:

        photometer : a photometer object
            e.g. a :class:`~psychopy.hardware.pr.PR65` or
            :class:`~psychopy.hardware.minolta.LS100` from
            hardware.findPhotometer()

        lumLevels : (default=8)
            array of values to test or single value for n evenly spaced
            test values

        gamma : (default=1.0) the gamma value at which to test

        autoMode : 'auto' or 'semi'(='auto')

            If 'auto' the program will present the screen
            and automatically take a measurement before moving on.

            If set to 'semi' the program will wait for a keypress before
            moving on but will not attempt to make a measurement (use this
            to make a measurement with your own device).

            Any other value will simply move on without pausing on each
            screen (use this to see that the display is performing as
            expected).

    """
    import psychopy.event
    import psychopy.visual
    from psychopy import core
    if photometer is None:
        havePhotom = False
    elif not hasattr(photometer, 'getLum'):
        msg = ("photometer argument to monitors.getLumSeries should be a "
               "type of photometer object, not a %s")
        logging.error(msg % type(photometer))
        return None
    else:
        havePhotom = True

    if useBits:
        # all gamma transforms will occur in calling the Bits++ LUT
        # which improves the precision (14bit not 8bit gamma)
        bitsMode = 'fast'
    else:
        bitsMode = None

    if gamma == 1:
        initRGB = 0.5**(old_div(1, 2.0)) * 2 - 1
    else:
        initRGB = 0.8
    # setup screen and "stimuli"
    myWin = psychopy.visual.Window(fullscr=0, size=winSize,
                                   gamma=gamma, units='norm', monitor=monitor,
                                   allowGUI=True, winType='pyglet',
                                   bitsMode=bitsMode, screen=screen)
    instructions = ("Point the photometer at the central bar. "
                    "Hit a key when ready (or wait 30s)")
    message = psychopy.visual.TextStim(myWin, text=instructions, height=0.1,
                                       pos=(0, -0.85), rgb=[1, -1, -1])
    noise = np.random.rand(512, 512).round() * 2 - 1
    backPatch = psychopy.visual.PatchStim(myWin, tex=noise, size=2,
                                          units='norm',
                                          sf=[old_div(winSize[0], 512.0),
                                              old_div(winSize[1], 512.0)])
    testPatch = psychopy.visual.PatchStim(myWin,
                                          tex='sqr',
                                          size=stimSize,
                                          rgb=initRGB,
                                          units='norm')

    # stay like this until key press (or 30secs has passed)
    waitClock = core.Clock()
    tRemain = 30
    while tRemain > 0:
        tRemain = 30 - waitClock.getTime()
        backPatch.draw()
        testPatch.draw()
        instructions = ("Point the photometer at the central white bar. "
                        "Hit a key when ready (or wait %iss)")
        message.setText(instructions % tRemain, log=False)
        message.draw()
        myWin.flip()
        if len(psychopy.event.getKeys()):
            break  # we got a keypress so move on

    if autoMode != 'semi':
        message.setText('Q to quit at any time')
    else:
        message.setText('Spacebar for next patch')

    # LS100 likes to take at least one bright measurement
    if havePhotom and photometer.type == 'LS100':
        junk = photometer.getLum()

    # what are the test values of luminance
    if type(lumLevels) in (int, float):
        toTest = DACrange(lumLevels)
    else:
        toTest = np.asarray(lumLevels)

    if allGuns:
        guns = [0, 1, 2, 3]  # gun=0 is the white luminance measure
    else:
        allGuns = [0]
    # this will hold the measured luminance values
    lumsList = np.zeros((len(guns), len(toTest)), 'd')
    # for each gun, for each value run test
    for gun in guns:
        for valN, DACval in enumerate(toTest):
            lum = old_div(DACval, 127.5) - 1  # get into range -1:1
            # only do luminanc=-1 once
            if lum == -1 and gun > 0:
                continue
            # set the patch color
            if gun > 0:
                rgb = [-1, -1, -1]
                rgb[gun - 1] = lum
            else:
                rgb = [lum, lum, lum]

            backPatch.draw()
            testPatch.setColor(rgb)
            testPatch.draw()
            message.draw()
            myWin.flip()

            # allowing the screen to settle (no good reason!)
            time.sleep(0.2)

            # take measurement
            if havePhotom and autoMode == 'auto':
                actualLum = photometer.getLum()
                print("At DAC value %i\t: %.2fcd/m^2" % (DACval, actualLum))
                if lum == -1 or not allGuns:
                    # if the screen is black set all guns to this lum value!
                    lumsList[:, valN] = actualLum
                else:
                    # otherwise just this gun
                    lumsList[gun, valN] = actualLum

                # check for quit request
                for thisKey in psychopy.event.getKeys():
                    if thisKey in ('q', 'Q', 'escape'):
                        myWin.close()
                        return np.array([])

            elif autoMode == 'semi':
                print("At DAC value %i" % DACval)

                done = False
                while not done:
                    # check for quit request
                    for thisKey in psychopy.event.getKeys():
                        if thisKey in ('q', 'Q', 'escape'):
                            myWin.close()
                            return np.array([])
                        elif thisKey in (' ', 'space'):
                            done = True

    myWin.close()  # we're done with the visual stimuli
    if havePhotom:
        return lumsList
    else:
        return np.array([])


def getLumSeriesPR650(lumLevels=8,
                      winSize=(800, 600),
                      monitor=None,
                      gamma=1.0,
                      allGuns=True,
                      useBits=False,
                      autoMode='auto',
                      stimSize=0.3,
                      photometer='COM1'):
    """DEPRECATED (since v1.60.01): Use
    :class:`psychopy.monitors.getLumSeries()` instead
    """

    logging.warning(
        "DEPRECATED (since v1.60.01): Use monitors.getLumSeries() instead")
    val = getLumSeries(lumLevels,
                       winSize, monitor,
                       gamma, allGuns, useBits,
                       autoMode, stimSize, photometer)
    return val


def getRGBspectra(stimSize=0.3, winSize=(800, 600), photometer='COM1'):
    """
    usage:
        getRGBspectra(stimSize=0.3, winSize=(800,600), photometer='COM1')

    :params:

        - 'photometer' could be a photometer object or a serial port
        name on which a photometer might be found (not recommended)

    """
    import psychopy.event
    import psychopy.visual

    if hasattr(photometer, 'getLastSpectrum'):
        photom = photometer
    else:
        # setup photom
        photom = hardware.Photometer(photometer)
    if photom != None:
        havephotom = 1
    else:
        havephotom = 0

    # setup screen and "stimuli"
    myWin = psychopy.visual.Window(fullscr=0, rgb=0.0, size=winSize,
                                   units='norm')

    instructions = ("Point the photometer at the central square. "
                    "Hit a key when ready")
    message = psychopy.visual.TextStim(myWin, text=instructions, height=0.1,
                                       pos=(0.0, -0.8), rgb=-1.0)
    message.draw()
    testPatch = psychopy.visual.PatchStim(myWin, tex=None,
                                          size=stimSize * 2, rgb=0.3)
    testPatch.draw()
    myWin.flip()
    # stay like this until key press (or 30secs has passed)
    psychopy.event.waitKeys(30)
    spectra = []
    for thisColor in [[1, -1, -1], [-1, 1, -1], [-1, -1, 1]]:
        # update stimulus
        testPatch.setColor(thisColor)
        testPatch.draw()
        myWin.flip()
        # make measurement
        photom.measure()
        spectra.append(photom.getLastSpectrum(parse=False))
    myWin.close()
    nm, power = photom.parseSpectrumOutput(spectra)
    return nm, power


def DACrange(n):
    """Returns an array of n DAC values spanning 0-255
    """
    # NB python ranges exclude final val
    return np.arange(0.0, 256.0, old_div(255.0, (n - 1))).astype(np.uint8)


def getAllMonitors():
    """Find the names of all monitors for which calibration files exist
    """
    monitorList = glob.glob(os.path.join(monitorFolder, '*.calib'))
    if constants.PY3:
        monitorList = glob.glob(os.path.join(monitorFolder, '*.json'))
    split = os.path.split
    splitext = os.path.splitext
    # skip the folder and the extension for each file
    monitorList = [splitext(split(thisFile)[-1])[0]
                   for thisFile in monitorList]
    return monitorList


def gammaFun(xx, minLum, maxLum, gamma, eq=1, a=None, b=None, k=None):
    """Returns gamma-transformed luminance values.
    y = gammaFun(x, minLum, maxLum, gamma)

    a and b are calculated directly from minLum, maxLum, gamma

    **Parameters:**

        - **xx** are the input values (range 0-255 or 0.0-1.0)
        - **minLum** = the minimum luminance of your monitor
        - **maxLum** = the maximum luminance of your monitor (for this gun)
        - **gamma** = the value of gamma (for this gun)

    """
    # scale x to be in range minLum:maxLum
    xx = np.array(xx, 'd')
    maxXX = max(xx)
    if maxXX > 2.0:
        # xx = xx * maxLum / 255.0 + minLum
        xx = old_div(xx, 255.0)
    else:  # assume data are in range 0:1
        pass
        # xx = xx * maxLum + minLum

    # eq1: y = a + (b*xx)**gamma
    # eq2: y = (a + b * xx)**gamma
    # eq4: y = a + (b + k*xx)**gamma  # Pelli & Zhang 1991
    if eq == 1:
        a = minLum
        b = (maxLum - a)**(old_div(1, gamma))
        yy = a + (b * xx)**gamma
    elif eq == 2:
        a = minLum**(old_div(1, gamma))
        b = maxLum**(old_div(1, gamma)) - a
        yy = (a + b * xx)**gamma
    elif eq == 3:
        # NB method 3 was an interpolation method that didn't work well
        pass
    elif eq == 4:
        nMissing = sum([a is None, b is None, k is None])
        # check params
        if nMissing > 1:
            msg = "For eq=4, gammaFun needs 2 of a, b, k to be specified"
            raise AttributeError(msg)
        elif nMissing == 1:
            if a is None:
                a = minLum - b**(old_div(1.0, gamma))  # when y=min, x=0
            elif b is None:
                if a >= minLum:
                    b = 0.1**(old_div(1.0, gamma))  # can't take inv power of -ve
                else:
                    b = (minLum - a)**(old_div(1.0, gamma))  # when y=min, x=0
            elif k is None:
                k = (maxLum - a)**(old_div(1.0, gamma)) - b  # when y=max, x=1
        # this is the same as Pelli and Zhang (but different inverse function)
        yy = a + (b + k * xx)**gamma  # Pelli and Zhang (1991)

    return yy


def gammaInvFun(yy, minLum, maxLum, gamma, b=None, eq=1):
    """Returns inverse gamma function for desired luminance values.
    x = gammaInvFun(y, minLum, maxLum, gamma)

    a and b are calculated directly from minLum, maxLum, gamma
    **Parameters:**

        - **xx** are the input values (range 0-255 or 0.0-1.0)
        - **minLum** = the minimum luminance of your monitor
        - **maxLum** = the maximum luminance of your monitor (for this gun)
        - **gamma** = the value of gamma (for this gun)
        - **eq** determines the gamma equation used;
            eq==1[default]: yy = a + (b * xx)**gamma
            eq==2: yy = (a + b*xx)**gamma

    """

    # x should be 0:1
    # y should be 0:1, then converted to minLum:maxLum

    # eq1: y = a + (b * xx)**gamma
    # eq2: y = (a + b * xx)**gamma
    # eq4: y = a + (b + kxx)**gamma
    if max(yy) == 255:
        yy = old_div(np.asarray(yy, 'd'), 255.0)
    elif min(yy) < 0 or max(yy) > 1:
        logging.warning(
            'User supplied values outside the expected range (0:1)')
    else:
        yy = np.asarray(yy, 'd')

    if eq == 1:
        xx = np.asarray(yy)**(old_div(1.0, gamma))
    elif eq == 2:
        yy = np.asarray(yy) * (maxLum - minLum) + minLum
        a = minLum**(old_div(1, gamma))
        b = maxLum**(old_div(1, gamma)) - a
        xx = old_div((yy**(old_div(1, gamma)) - a), b)
        maxLUT = old_div((maxLum**(old_div(1, gamma)) - a), b)
        minLUT = old_div((minLum**(old_div(1, gamma)) - a), b)
        xx = old_div(xx, (maxLUT - minLUT)) - minLUT
    elif eq == 3:
        # NB method 3 was an interpolation method that didn't work well
        pass
    elif eq == 4:
        # this is not the same as Zhang and Pelli's inverse
        # see http://www.psychopy.org/general/gamma.html for derivation
        a = minLum - b**gamma
        k = (maxLum - a)**(old_div(1., gamma)) - b
        xx = old_div((((1 - yy) * b**gamma + yy * (b + k)**gamma)**(old_div(1, gamma)) - b), k)

    # then return to range (0:1)
    # xx = xx / (maxLUT - minLUT) - minLUT
    return xx


def strFromDate(date):
    """Simply returns a string with a std format from a date object
    """
    if type(date) == float:
        date = time.localtime(date)
    return time.strftime("%Y_%m_%d %H:%M", date)
