#!/usr/bin/env python3
############################################################
# Program is part of PySAR                                 #
# Copyright(c) 2017-2018, Zhang Yunjun                     #
# Author:  Zhang Yunjun                                    #
############################################################


import os
import sys
import re
import argparse
import numpy as np
from pysar.utils import readfile, writefile, utils as ut


##################################################################################################
EXAMPLE = """example:
  prep_roipac.py  filt_100901-110117-sim_HDR_4rlks_c10.unw
  prep_roipac.py  IFGRAM*/filt_*.unw
  prep_roipac.py  IFGRAM*/filt_*rlks.cor
  prep_roipac.py  IFGRAM*/filt_*rlks.int
  prep_roipac.py  IFGRAM*/filt_*_snap_connect.byt
"""

DESCRIPTION = """
  For each binary file (unwrapped/wrapped interferogram, spatial coherence file), there are 2 .rsc files:
  1) basic metadata file and 2) baseline parameter file. This script find those two rsc files based on
  input binary file name, and merge those two metadata files into one.

  For example, if input binary file is filt_100901-110117-sim_HDR_4rlks_c10.unw, this script will find
  1) filt_100901-110117-sim_HDR_4rlks_c10.unw.rsc and 2) 100901-110117_baseline.rsc and merge 1) and 2) into
  one file: filt_100901-110117-sim_HDR_4rlks_c10.unw.rsc
"""


def create_parser():
    parser = argparse.ArgumentParser(description='Prepare attributes file for ROI_PAC products for PySAR.\n' +
                                     DESCRIPTION,
                                     formatter_class=argparse.RawTextHelpFormatter,
                                     epilog=EXAMPLE)

    parser.add_argument('file', nargs='+', help='Gamma file(s)')
    parser.add_argument('--no-parallel', dest='parallel', action='store_false', default=True,
                        help='Disable parallel processing. Diabled auto for 1 input file.')
    return parser


def cmd_line_parse(iargs=None):
    parser = create_parser()
    inps = parser.parse_args(args=iargs)
    return inps


######################################## Sub Functions ############################################
def extract_metadata(fname):
    """Read/extract attributes for PySAR from ROI_PAC .unw, .int, .cor file.

    For each unwrapped interferogram or spatial coherence file, there are 2 .rsc files:
        basic metadata file and baseline parameter file. 
        e.g. filt_100901-110117-sim_HDR_4rlks_c10.unw
             filt_100901-110117-sim_HDR_4rlks_c10.unw.rsc
             100901-110117_baseline.rsc
    Inputs:
        fname : string, ROI_PAC interferogram filename or path,
                i.e. /KujuT422F650AlosA/filt_100901-110117-sim_HDR_4rlks_c10.unw
    Outputs:
        atr : dict, Attributes dictionary
    """
    # 1. Read basic metadata file
    basic_rsc_file = fname+'.rsc'
    if not os.path.isfile(basic_rsc_file) and fname.endswith('_snap_connect.byt'):
        unw_rsc_file = '{}.unw.rsc'.format(fname.split('_snap_connect.byt')[0])
        copyCmd = 'cp {} {}'.format(unw_rsc_file, basic_rsc_file)
        print(copyCmd)
        os.system(copyCmd)
    basic_dict = readfile.read_roipac_rsc(basic_rsc_file)

    # return if baseline attributes are already there.
    if 'P_BASELINE_TOP_HDR' in basic_dict.keys():
        return basic_rsc_file

    atr = {}
    atr['PROCESSOR'] = 'roipac'
    atr['FILE_TYPE'] = os.path.splitext(fname)[1]

    # 2. Read baseline metadata file
    date1, date2 = basic_dict['DATE12'].split('-')
    baseline_rsc_file = os.path.dirname(fname)+'/'+date1+'_'+date2+'_baseline.rsc'
    baseline_dict = readfile.read_roipac_rsc(baseline_rsc_file)

    # 3. Merge
    atr.update(basic_dict)
    atr.update(baseline_dict)

    # Write to rsc file
    basic_rsc_file = fname+'.rsc'
    try:
        atr_orig = readfile.read_roipac_rsc(basic_rsc_file)
    except:
        atr_orig = dict()
    if not set(atr.items()).issubset(set(atr_orig.items())):
        atr_out = {**atr_orig, **atr}
        print('merging {} into {} '.format(os.path.basename(baseline_rsc_file),
                                           os.path.basename(basic_rsc_file)))
        writefile.write_roipac_rsc(atr_out, out_file=basic_rsc_file)
    return basic_rsc_file


def prepare_metadata(inps):
    inps.file = ut.get_file_list(inps.file, abspath=True)

    # Check input file type
    ext = os.path.splitext(inps.file[0])[1]
    if ext not in ['.unw', '.cor', '.int', '.byt']:
        return

    # check outfile and parallel option
    if inps.parallel:
        (num_cores,
         inps.parallel,
         Parallel,
         delayed) = ut.check_parallel(len(inps.file), print_msg=False)
    if len(inps.file) == 1:
        extract_metadata(inps.file[0])
    elif inps.parallel:
        Parallel(n_jobs=num_cores)(delayed(extract_metadata)(fname) for fname in inps.file)
    else:
        for fname in inps.file:
            extract_metadata(fname)
    return


##################################################################################################
def main(iargs=None):
    inps = cmd_line_parse(iargs)
    prepare_metadata(inps)
    return


###################################################################################################
if __name__ == '__main__':
    main()