#!/usr/bin/python

import pandas as pd
import regex as re
import argparse
import os, sys
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 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()


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "-p",
        "--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
    )
    args = parser.parse_args()
    # run geom converter
    write_new_positions( args.path_to_geom, args.beam_x, args.beam_y, args.clen, args.energy )