import numpy
import math
import ConfigParser
import os
import sys
import subprocess
import scipy.sparse.linalg
import time


def confusionMatrix(expected, predicted):

    #print expected.shape, predicted.shape
    #print numpy.unique(numpy.asarray(expected))

    yUni = numpy.asmatrix(numpy.unique(numpy.asarray(expected)))
    confMat = numpy.asmatrix(numpy.zeros((yUni.shape[1], yUni.shape[1])))

    for expc, pred in zip(expected, predicted):
        confMat[numpy.where(yUni == expc)[1], numpy.where(yUni == pred)[1]] += 1

    if numpy.sum(confMat) != max(predicted.shape):
        print numpy.sum(confMat), '!=', max(predicted.shape), '(', predicted.shape, ')'
        print 'cls expected: ', numpy.unique(numpy.asarray(expected))
        print 'cls predicted:', numpy.unique(numpy.asarray(predicted))
        raise Exception('# predicted cls > # expected cls')

    return confMat


def getAvgAcc(confMat):

    return numpy.mean(numpy.diagonal(confMat)/numpy.sum(confMat, axis=1).T)


def getConfig(pathtoConfig, section, option, default=None, dtype='str', verbose=False):

    # set default
    value = default
    defaultUsed = True

    # check if file is available
    if pathtoConfig is not None and os.path.isfile(pathtoConfig):

        # init
        config = ConfigParser.ConfigParser()
        configFile = open(pathtoConfig)
        config.readfp(configFile)
        configFile.close()

        # check if section and option is available
        if config.has_section(section) and config.has_option(section, option):

            # get requested type
            if dtype == 'str':
                value = config.get(section, option)
            elif dtype == 'int':
                value = config.getint(section, option)
            elif dtype == 'float':
                value = config.getfloat(section, option)
            elif dtype == 'bool':
                value = config.getboolean(section, option)
            elif dtype == 'strList':
                value = config.get(section, option).split(',')
            elif dtype == 'intList':
                value = [int(entry) for entry in config.get(section, option).split(',')]
            elif dtype == 'floatList':
                value = [float(entry) for entry in config.get(section, option).split(',')]
            elif dtype == 'boolList':
                value = [bool(entry) for entry in config.get(section, option).split(',')]
            else:
                raise Exception('Unknown dtype!')

            defaultUsed = False

    # print config
    if verbose:
        aux = ''
        if 'List' in dtype and len(value) > 0:
            aux = '| entryDtype:' + str(type(value[0]))
        print 'default:', defaultUsed, '| section:', section, '| option:', option, '| value:', value, '| dtype:', type(value), aux

    # return
    return value


def getGitHash(gitPath=os.path.dirname(os.path.abspath(__file__))):
    curDir = os.getcwd()
    os.chdir(gitPath)
    gitHash = subprocess.check_output(['git', 'rev-parse', '--short', 'HEAD'], stderr=subprocess.STDOUT).strip()
    os.chdir(curDir)
    return gitHash


def getYfromYbin(yBin, yUni):

    y = numpy.asmatrix(numpy.zeros((yBin.shape[0],1), dtype=numpy.int))
    for idx in range(yBin.shape[0]):
        y[idx,0] = int(yUni[0,numpy.ravel(yBin[idx,:] == 1)])
    return y


def solveW(x, y, sigmaN, initW=None, maxIter=None):

    linOpX = scipy.sparse.linalg.aslinearoperator(x)
    w = numpy.asmatrix(numpy.empty((x.shape[1], y.shape[1])))

    def matvecFunc(curW):
        return linOpX.rmatvec(linOpX.matvec(curW)) + sigmaN*curW

    for clsIdx in range(y.shape[1]):

        if initW is not None:
            initWbin = numpy.ravel(numpy.asarray(initW[:,clsIdx])).T
        else:
            initWbin = None

        linOpW = scipy.sparse.linalg.LinearOperator((x.shape[1], x.shape[1]), matvec=matvecFunc, dtype=x.dtype)

        solvedWbin,info = scipy.sparse.linalg.cg(linOpW, linOpX.rmatvec(y[:, clsIdx]), x0=initWbin, maxiter=maxIter)

        if info != 0 and maxIter is None:
            print ''
            print 'WARNING: cg not converged!'
            print ''

        w[:,clsIdx] = numpy.asmatrix(solvedWbin).T

    return w


def getClsWeights(y, yUni):

    clsWeights = numpy.empty(yUni.shape[1])
    for clsIdx in range(yUni.shape[1]):
        clsWeights[clsIdx] = y.shape[0] / (float(yUni.shape[1])*numpy.argwhere(y==yUni[0,clsIdx]).shape[0])

    return clsWeights


def writeNotification(notificationPath, statusStr):

    try:
        open(os.path.join(notificationPath, statusStr), 'a').close()
    except:
        print ''
        print 'ERROR: writing notification to {} failed!'.format(notificationPath)
        sys.stdout.flush()


def getReweightDiagMat(y, yUni=None, clsWeights=None):

    if yUni is None:
        yUni = numpy.asmatrix(numpy.unique(numpy.asarray(y)))

    if clsWeights is None:
        clsWeights = getClsWeights(y, yUni)

    sampleWeights = clsWeights[numpy.searchsorted(numpy.ravel(numpy.asarray(yUni)), numpy.ravel(numpy.asarray(y)))]
    sampleWeights = numpy.prod([sampleWeights], axis=0)

    return numpy.asmatrix(numpy.diag(numpy.sqrt(sampleWeights*numpy.ones(y.shape[0]))))


def showProgressBarTerminal(current, total, pre):

    sys.stdout.write('\r%s %0.2f %%'%(pre,(float(current)/float(total))*100.0))
    sys.stdout.flush()