#!/usr/bin/python

# author J.Beale

"""
# aim
use .poni file from pyFAI or pixel x, y, clen inputs and energy to convert geom
file ready for initial hewl processing

# usage
<no poni file>
python update-geom-from-lab6.py -g <path-to-geom-file>, -x beam x position (in pixels),
                                -y beam y postion (in pixels), -c camera length (in m),
                                -e pulse energy (in eV), -j name of jungfrau, -p p-group name
<with poni file>
python update-geom-from-lab6.py -g <path-to-geom-file>, -i <path-to-poni-file>,
                                -j name of jungfrau, -p p-group name

# output
creates an updated .geom file with a naming convention <jungfrau>_<p-group>_<date>.geom
"""

from runpy import run_path
import pandas as pd
import numpy as np
import regex as re
from scipy import constants
from jungfrau_utils import geometry 
import argparse
from datetime import datetime
date = datetime.today().strftime('%y%m%d')


def calculate_new_corner_positions( beam_x, beam_y, jungfrau ):

    # import psi detectors from jungfrau_utils
    detectors = geometry.detector_geometry

    # get x and y detector corners for the specifc jungfrau detector
    origin_y = detectors[ jungfrau ].origin_y
    origin_x = detectors[ jungfrau ].origin_x

    # get number of panels
    panels = len( origin_y )  

    # make df of current corner positions
    x_df = pd.DataFrame( origin_x, columns=[ "current_x" ] )
    y_df = pd.DataFrame( origin_y, columns=[ "current_y" ] )
    corner_df = pd.concat( ( x_df, y_df ), axis=1 )

    # calculate new corner positions
    corner_df[ "new_x" ] = corner_df.current_x.subtract( beam_x )
    corner_df[ "new_y" ] = corner_df.current_y.subtract( beam_y )

    # drop old positions
    corner_df = corner_df[[ "new_x", "new_y" ]]

    return corner_df, panels

def scrub_poni( path_to_poni_file ):

    # open poni file
    poni_file = open( path_to_poni_file, "r" ).read()

    # regex patterns to scrub poni data
    clen_m_pattern = r"Distance:\s(\d\.\d*)"
    poni1_m_pattern = r"Poni1:\s(\d\.\d*)"
    poni2_m_pattern = r"Poni2:\s(\d\.\d*)"
    wave_pattern = r"Wavelength:\s(\d\.\d*)e(-\d+)"

    # regex seach
    clen = re.search( clen_m_pattern, poni_file ).group( 1 )
    poni1_m = re.search( poni1_m_pattern, poni_file ).group( 1 )
    poni2_m = re.search( poni2_m_pattern, poni_file ).group( 1 )
    wave = re.search( wave_pattern, poni_file ).group( 1, 2 )

    # calulate proper wavelength
    wave = float(wave[0]) * np.float_power( 10, int( wave[1]) )

    # calculate beam_centre
    poni1_p = float( poni1_m ) / 0.000075
    poni2_p = float( poni2_m ) / 0.000075

    # calculate beam energy in eV
    eV = ( ( constants.c * constants.h ) / wave ) / constants.electron_volt

    # return poni1 = y, poni2 = x and energy
    return poni1_p, poni2_p, eV, round( float( clen ), 5 )


def write_new_positions( path_to_geom, beam_x, beam_y, clen, energy, jungfrau, p_group ):

    # open current geometry file
    current_geom_file = open( path_to_geom, "r" ).read()

    # calculate new corner positions
    corner_df, panels = calculate_new_corner_positions( beam_x, beam_y, jungfrau )

    # replace current corner positions with new ones
    for i in range(0, panels):
       
        # x and y positions
        new_x, new_y = round( corner_df.new_x[i], 3 ), round( corner_df.new_y[i], 3 )

        # input new x position
        current_pattern_x = r"p" + re.escape( str(i) ) + r"/corner_x = -?\d+\.\d+"
        new_pattern_x = r"p" + re.escape( str(i) ) + r"/corner_x = " + str( new_x )
        current_geom_file = re.sub( current_pattern_x, new_pattern_x, current_geom_file )

        # input new y position
        current_pattern_y = r"p" + re.escape( str(i) ) + r"/corner_y = -?\d+\.\d+"
        new_pattern_y = r"p" + re.escape( str(i) ) + r"/corner_y = " + str( new_y )
        current_geom_file = re.sub( current_pattern_y, new_pattern_y, current_geom_file )

    # input new clen
    current_clen = r"clen = \d\.\d+"
    new_clen = r"clen = " + str( clen )
    current_geom_file = re.sub( current_clen, new_clen, current_geom_file )

    # input new energy
    current_energy = r"photon_energy = \d+\.?\d+?"
    new_energy = r"photon_energy = " + str( energy )
    current_geom_file = re.sub( current_energy, new_energy, current_geom_file )

    # create geom new file
    new_geom_name = "{0}_{1}_{2}.geom".format( jungfrau, p_group, date )
    
    # write new geom file
    f = open( new_geom_name, "w" )
    f.write( current_geom_file )
    f.close()

    # return new_geom_name
    return new_geom_name


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "-g",
        "--geom",
        help="give the path to the geom file to be updated.",
        type=str,
        required=True
    )
    parser.add_argument(
        "-j",
        "--jungfrau",
        help="SwissFEL name of jungfrau, i.e., JF17T16V01 for Cristallina 8M. Default = JF17T16V01.",
        type=str,
        required=True
    )
    parser.add_argument(
        "-p",
        "--p_group",
        help="p-group name",
        type=str,
        required=True
    )
    parser.add_argument(
        "-i",
        "--poni",
        help="AUTOMATIC option to path to poni file from pyFAI calculation. simply give <path-to-poni-file> all values taken from this.",
        type=str,
    )
    parser.add_argument(
        "-x",
        "--beam_x",
        help="manual option to add beam_x in pixels. Must be a float. You must also give following arguements.",
        type=float
    )
    parser.add_argument(
        "-y",
        "--beam_y",
        help="manual option to add beam_y in pixels. Must be a float. You must also give following arguements.",
        type=float
    )
    parser.add_argument(
        "-c",
        "--clen",
        help="manual option to add detector distance in m. Must be a float. You must also give following arguements.",
        type=float
    )
    parser.add_argument(
        "-e",
        "--energy",
        help="manual option to add photon energy in eV. Must be an int",
        type=int
    )
    args = parser.parse_args()
    # run geom converter
    if args.p_group is None:
        print( "you must specify a p-group that the .geom file is associated with\n\nfor example -p p20560" )
    elif args.poni is not None:
        print( "reading poni file" )
        beam_y, beam_x, eV, clen = scrub_poni( args.poni )
        print( "beam x, beam_y = {0}, {1} pixels\nphoton_energy = {2} eV\nclen = {3} m".format( round( beam_x, 3 ), round( beam_y, 3 ), eV, clen ) )
        new_geom_name = write_new_positions( args.geom, beam_x, beam_y, clen, eV, args.jungfrau, args.p_group )
        print( "updated .geom file with poni calculations\nnew .geom = {0}".format( new_geom_name ) )
        print( "please check the result" )
    else:
        print( "manually input positions" )
        print( "beam x, beam_y = {0}, {1} pixels\nphoton_energy = {2} eV\nclen = {3} m".format( args.beam_x, args.beam_y, args.energy, args.clen ) )
        new_geom_name = write_new_positions( args.geom, args.beam_x, args.beam_y, args.clen, args.energy, args.jungfrau, args.p_group )
        print( "updated .geom file with poni calculations\nnew .geom = {0}".format( new_geom_name ) )
        print( "please check the result" )