# -*- coding: utf-8 -*-
r"""
.. _slitDiffraction:

Diffraction on arbitrarily shaped apertures, defined by polygon.
--------------------------------------

TBD

"""
__author__ = "Roman Chernikov", "Konstantin Klementiev"
__date__ = "26 Jun 2018"

import os, sys; sys.path.append(os.path.join('..', '..', '..'))  # analysis:ignore
# sys.path.append(r"/media/sf_Ray-tracing")
# import time
#import matplotlib as mpl
#mpl.use('Agg')
import xrt.backends.raycing as raycing
import xrt.backends.raycing.sources as rs
import xrt.backends.raycing.screens as rsc
import xrt.backends.raycing.apertures as ra
import xrt.backends.raycing.run as rr
import xrt.plotter as xrtp
import xrt.runner as xrtr
import xrt.backends.raycing.waves as rw
import numpy as np

R0 = 44000
mynrays = 1e3

slitDx = 0.1
slitDz = 0.1

SCRx = 1
SCRz = 1
dE = 0.5

#nrep = 160
#nrep = 1000
nrep = 1

E0 = 7900
eMinRays = E0 - dE
eMaxRays = E0 + dE

kwargs = dict(
    period=29., n=172,
    eE=6.08, eI=0.1,  # eEspread=0.001,
    eEpsilonX=0., eEpsilonZ=0.,
    #eEpsilonX=1, eEpsilonZ=0.01,
    betaX=1.20, betaZ=3.95,
    filamentBeam=True,
    uniformRayDensity=True,
    xPrimeMax=(slitDx/R0)*2e3, zPrimeMax=(slitDz/R0)*2e3,
    targetE=[E0, 3],
    eMin=eMinRays,
    eMax=eMaxRays)

prefix = 'far{0:02.0f}m-E0{1:4.0f}-'.format(R0*1e-3, E0)
if kwargs['eEpsilonX'] == 0:
    suffix = "_zeroEmittance"
else:
    suffix = "_realEmittance"

imcnst = 128

imSizeX = imcnst
imSizeZ = imcnst
xBins = imcnst
zBins = imcnst
xppb = 2
zppb = 2
imSize = imcnst
eBins = 16
eppb = 16
xfactor = 1.
zfactor = 1.
screenName = '-plane'
xlimits = [-0.175, 0.175]
zlimits = [-0.175, 0.175]
xName = '$x$'
zName = '$z$'
unit = "mm"
nSpokes = 12

dx = (xlimits[1] - xlimits[0]) / float(xBins)
xmesh = np.linspace((xlimits[0] + dx/2) / xfactor,
                    (xlimits[1] - dx/2) / xfactor, xBins)
dz = (zlimits[1] - zlimits[0]) / float(zBins)
zmesh = np.linspace((zlimits[0] + dz/2) / zfactor,
                    (zlimits[1] - dz/2) / zfactor, zBins)


def build_beamline(nrays=mynrays):
    beamLine = raycing.BeamLine()
    beamLine.source = rs.Undulator(beamLine, nrays=nrays, **kwargs)
    beamLine.fsm0 = rsc.Screen(beamLine, 'FSM0', (0, R0, 0))

#    beamLine.slit = ra.RectangularAperture(
#        beamLine, 'squareSlit', [0, R0, 0], ('left', 'right', 'bottom', 'top'),
#        [-slitDx, slitDx, -slitDz, slitDz])
    beamLine.slit = ra.SiemensStar(
            bl=beamLine,
            name='SiemensStar',
            center=[0, R0, 0],
            nSpokes=nSpokes,
            rX=slitDx,
            rZ=slitDz,
            phi0 = 0.5*np.pi/nSpokes)

    beamLine.fsm1 = rsc.Screen(beamLine, 'FSM1', [0, R0, 0])
    return beamLine


def run_process(beamLine):
    waveOnScreen = beamLine.fsm1.prepare_wave(beamLine.slit, xmesh, zmesh)

    beamSource = None
    repeats = 10
    for repeat in range(repeats):
        waveOnSlit = beamLine.slit.prepare_wave(beamLine.source, mynrays)
        beamSource = beamLine.source.shine(accuBeam=beamSource,
                                           fixedEnergy=E0, wave=waveOnSlit)
        beamFSM0 = beamLine.fsm0.expose(beamSource)
        beamLine.slit.propagate(beamSource)
        beamFSM1 = beamLine.fsm1.expose(beamSource)
        rw.diffract(waveOnSlit, waveOnScreen)

        if waveOnScreen.diffract_repeats == 0:
            break
        if repeats > 1:
            print('wave repeats: {0} of {1} done'.format(repeat+1, repeats))

    outDict = {'beamSource': beamSource,
               'beamFSM0': beamFSM0,
               'beamFSM1': beamFSM1,
               'waveOnScreen': waveOnScreen
               }
    return outDict
rr.run_process = run_process


def define_plots(beamLine):
    plots = []

    plot = xrtp.XYCPlot(
        'beamFSM0', aspect='auto',
        xaxis=xrtp.XYCAxis(xName, unit, bins=xBins, ppb=xppb),
        yaxis=xrtp.XYCAxis(zName, unit, bins=zBins, ppb=zppb),
        caxis=xrtp.XYCAxis('energy', 'eV', bins=eBins, ppb=eppb),
        title='1-BeamSource')
    plot.baseName = plot.title + suffix
    plots.append(plot)

    plot = xrtp.XYCPlot(
        'beamFSM1', aspect='auto',
        xaxis=xrtp.XYCAxis(xName, unit, bins=xBins, ppb=xppb),
        yaxis=xrtp.XYCAxis(zName, unit, bins=zBins, ppb=zppb),
        caxis=xrtp.XYCAxis('energy', 'eV', bins=eBins, ppb=eppb),
        title='2-Screen Rays')
    plot.baseName = plot.title + suffix
    plots.append(plot)

    plot = xrtp.XYCPlot(
        'waveOnScreen', aspect='auto',
        xaxis=xrtp.XYCAxis(xName, unit, bins=xBins, ppb=xppb),
        yaxis=xrtp.XYCAxis(zName, unit, bins=zBins, ppb=zppb),
        caxis=xrtp.XYCAxis('energy', 'eV', bins=eBins, ppb=eppb),
        title='3-Screen Wave')
    plot.baseName = plot.title + suffix
    plots.append(plot)
    return plots


def plot_generator(plots, beamLine):
    for dS in [slitDx]:
#        beamLine.slit.opening[0] = -dS/2
#        beamLine.slit.opening[1] = dS/2
#        beamLine.slit.opening[2] = -dS/2
#        beamLine.slit.opening[3] = dS/2
#        beamLine.slit.set_optical_limits()

        dX = 3.7
        beamLine.fsm1.center[1] = R0+dX*1000
        for plot in plots:
            plot.ax2dHist.locator_params(nbins=4)
            plot.xaxis.fwhmFormatStr = '%.2f'
            plot.yaxis.fwhmFormatStr = '%.2f'
            plot.xaxis.limits = xlimits
            plot.yaxis.limits = zlimits
            plot.caxis.limits = [eMinRays, eMaxRays]
            plot.caxis.offset = (eMinRays + eMaxRays) / 2
            plot.fluxFormatStr = '%.2p'
            plot.saveName =\
                plot.baseName +\
                ", polygon {0:.2f} mm at {1} m, screen at {2} m.png".\
                format(2*dS, R0/1000, dX)
#            plot.persistentName = plot.saveName + '.pickle'
        yield


def main():
    beamLine = build_beamline()
    plots = define_plots(beamLine)
    xrtr.run_ray_tracing(plots, repeats=nrep, beamLine=beamLine, processes=1,
                         generator=plot_generator)

# this is necessary to use multiprocessing in Windows, otherwise the new Python
# contexts cannot be initialized:
if __name__ == '__main__':
    main()
