#!/usr/bin/env python
# -*- coding: UTF-8 no BOM -*-

import os,re,sys,math,string
from collections import defaultdict
from optparse import OptionParser
import damask

scriptID = '$Id$'
scriptName = scriptID.split()[1]

def determinant(m):
  return  +m[0]*m[4]*m[8] \
          +m[1]*m[5]*m[6] \
          +m[2]*m[3]*m[7] \
          -m[2]*m[4]*m[6] \
          -m[1]*m[3]*m[8] \
          -m[0]*m[5]*m[7]

# --------------------------------------------------------------------
#                                MAIN
# --------------------------------------------------------------------

parser = OptionParser(option_class=damask.extendableOption, usage='%prog options [file[s]]', description = """
Add column(s) containing determinant of requested tensor column(s).

""", version=string.replace(scriptID,'\n','\\n')
)

parser.add_option('-t','--tensor',      dest='tensor', action='extend', type='string', metavar='<string LIST>',
                                        help='heading of columns containing tensor field values')
parser.set_defaults(tensor = [])

(options,filenames) = parser.parse_args()

if len(options.tensor) == 0:
  parser.error('no data column specified...')

datainfo = {                                                                                        # list of requested labels per datatype
             'tensor':     {'len':9,
                            'label':[]},
           }

datainfo['tensor']['label'] += options.tensor

# ------------------------------------------ setup file handles -----------------------------------
files = []
if filenames == []:
  files.append({'name':'STDIN', 'input':sys.stdin, 'output':sys.stdout, 'croak':sys.stderr})
else:
  for name in filenames:
    if os.path.exists(name):
      files.append({'name':name, 'input':open(name), 'output':open(name+'_tmp','w'), 'croak':sys.stderr})

#--- loop over input files ------------------------------------------------------------------------
for file in files:
  if file['name'] != 'STDIN': file['croak'].write('\033[1m'+scriptName+'\033[0m: '+file['name']+'\n')
  else: file['croak'].write('\033[1m'+scriptName+'\033[0m\n')

  table = damask.ASCIItable(file['input'],file['output'],False)                                     # make unbuffered ASCII_table
  table.head_read()                                                                                 # read ASCII header info
  table.info_append(string.replace(scriptID,'\n','\\n') + '\t' + ' '.join(sys.argv[1:]))

  active = []
  column = defaultdict(dict)

  for label in datainfo['tensor']['label']:
    key = '1_%s'%label
    if key not in table.labels:
      file['croak'].write('column %s not found...\n'%key)
    else:
      active.append(label)
      column[label] = table.labels.index(key)                                                       # remember columns of requested data

# ------------------------------------------ assemble header --------------------------------------- 
  for label in active:
    table.labels_append('det(%s)'%label)                                                            # extend ASCII header with new labels
  table.head_write()

# ------------------------------------------ process data ---------------------------------------  
  outputAlive = True
  while outputAlive and table.data_read():                                                          # read next data line of ASCII table
    for label in active:
      table.data_append(determinant(map(float,table.data[column[label]:
                                                         column[label]+datainfo['tensor']['len']])))
    outputAlive = table.data_write()                                                                # output processed line

# ------------------------------------------ output result ---------------------------------------  
  outputAlive and table.output_flush()                                                              # just in case of buffered ASCII table

  file['input'].close()                                                                             # close input ASCII table (works for stdin)
  file['output'].close()                                                                            # close output ASCII table (works for stdout)
  if file['name'] != 'STDIN':
    os.rename(file['name']+'_tmp',file['name'])                                                     # overwrite old one with tmp new