#!/usr/bin/python

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


def calculate_new_corner_positions( beam_x, beam_y ):

    # make df of current corner positions
    positions = { "current_x" : [ 607, 1646, 607, 1646, 607, 1646, 538, 1577, 538, 1577, 538, 1577, 538, 3212, 514, 3143 ],
                  "current_y" : [ 0, 69, 550, 619, 1100, 1169, 1650, 1719, 2200, 2269, 2750, 2819, 597, 667, 1636, 1706 ]
                 }
    corner_df = pd.DataFrame( positions )

    # 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

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 ) / 0.000000075
    poni2_p = float( poni2_m ) / 0.000000075

    # 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 )*1000, 5 )


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

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

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

    # replace current corner positions with new ones
    for i in range(0, 16):
       
        # 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+"
    new_energy = r"photon_energy = " + str( energy )
    current_geom_file = re.sub( current_energy, new_energy, current_geom_file )

    # create geom new file
    geom_start = path_to_geom[:-5]
    new_geom_name = "{0}_{1}.geom".format( geom_start, 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",
        "--path_to_geom",
        help="give the path to the cristallina 8M geom file to be updated",
        type=str,
        default="/sf/cristallina/data/p20558/work/geom/optimised_geom_file/p20558_hewl_op.geom",
    )
    parser.add_argument(
        "-x",
        "--beam_x",
        help="beam_x in pixels",
        type=float,
        default=1603.73
    )
    parser.add_argument(
        "-y",
        "--beam_y",
        help="beam_y in pixels",
        type=float,
        default=1661.99
    )
    parser.add_argument(
        "-c",
        "--clen",
        help="detector distance in m",
        type=int,
        default=0.111
    )
    parser.add_argument(
        "-e",
        "--energy",
        help="photon energy",
        type=int,
        default=12400
    )
    parser.add_argument(
        "-p",
        "--poni",
        help="path to poni file",
        type=str,
    )
    args = parser.parse_args()
    # run geom converter

    # import pdb;pdb.set_trace()
    if 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}\nphoton_energy = {2}\nclen = {3}".format( beam_x, beam_y, eV, clen ) )
        new_geom_name = write_new_positions( args.path_to_geom, beam_x, beam_y, clen, eV )
        print( "updated .geom file with poni calculations\n new .geom = {0}".format( new_geom_name ) )
    else:
        print( "manually input positions" )
        print( "beam x, beam_y = {0}, {1}\nphoton_energy = {2}\nclen = {3}".format( args.beam_x, args.beam_y, args.energy, args.clen ) )
        new_geom_name = write_new_positions( args.path_to_geom, args.beam_x, args.beam_y, args.clen, args.energy )
        print( "updated .geom file with poni calculations\nnew .geom = {0}".format( new_geom_name ) )