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

import os,sys,string,numpy
from optparse import OptionParser, OptionGroup, Option, SUPPRESS_HELP

# -----------------------------
class extendedOption(Option):
# -----------------------------
# used for definition of new option parser action 'extend', which enables to take multiple option arguments
# taken from online tutorial http://docs.python.org/library/optparse.html
    
    ACTIONS = Option.ACTIONS + ("extend",)
    STORE_ACTIONS = Option.STORE_ACTIONS + ("extend",)
    TYPED_ACTIONS = Option.TYPED_ACTIONS + ("extend",)
    ALWAYS_TYPED_ACTIONS = Option.ALWAYS_TYPED_ACTIONS + ("extend",)

    def take_action(self, action, dest, opt, value, values, parser):
        if action == "extend":
            lvalue = value.split(",")
            values.ensure_value(dest, []).extend(lvalue)
        else:
            Option.take_action(self, action, dest, opt, value, values, parser)



def outStdout(cmd,locals):
  if cmd[0:3] == '(!)':
    exec(cmd[3:])
  elif cmd[0:3] == '(?)':
    cmd = eval(cmd[3:])
    print cmd
  else:
    print cmd
  return

def outFile(cmd,locals):
  if cmd[0:3] == '(!)':
    exec(cmd[3:])
  elif cmd[0:3] == '(?)':
    cmd = eval(cmd[3:])
    locals['filepointer'].write(cmd+'\n')
  else:
    locals['filepointer'].write(cmd+'\n')
  return


def output(cmds,locals,dest):
  for cmd in cmds:
    if isinstance(cmd,list):
      output(cmd,locals,dest)
    else:
      {\
      'File': outFile,\
      'Stdout': outStdout,\
      }[dest](str(cmd),locals)
  return


# +++++++++++++++++++++++++++++++++++++++++++++++++++
def vtk_writeASCII_mesh(dim,res,data):
# +++++++++++++++++++++++++++++++++++++++++++++++++++
  """ function writes data array defined on a rectilinear grid """
  N  = res[0]*res[1]*res[2]
  
  cmds = [\
          '# vtk DataFile Version 3.1',
          'powered by $Id$',
          'ASCII',
          'DATASET RECTILINEAR_GRID',
          'DIMENSIONS %i %i %i'%(res[0]+1,res[1]+1,res[2]+1),
          'X_COORDINATES %i float'%(res[0]+1),
          ' '.join(map(str,[i*dim[0]/res[0] for i in range(res[0]+1)])),
          'Y_COORDINATES %i float'%(res[1]+1),
          ' '.join(map(str,[i*dim[1]/res[1] for i in range(res[1]+1)])),
          'Z_COORDINATES %i float'%(res[2]+1),
          ' '.join(map(str,[i*dim[2]/res[2] for i in range(res[2]+1)])),
          'CELL_DATA %i'%N,
         ]
  
  for datatype in data:
    for item in data[datatype]:
      cmds += [\
               '%s %s float'%(datatype.upper()+{True:'',False:'S'}[datatype.lower().endswith('s')],item),
               'LOOKUP_TABLE default',
               [[['\t'.join(map(str,data[datatype][item][:,j,k]))] for j in range(res[1])] for k in range(res[2])]
              ]

  return cmds


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

mapping = {
        'resolution': {'a':0,'b':1,'c':2},
        'dimension':  {'x':0,'y':1,'z':2},
          }

parser = OptionParser(option_class=extendedOption, usage='%prog geomfile[s]', description = """
Produce VTK point file from geom data

""" + string.replace('$Id$','\n','\\n')
)

(options, args) = parser.parse_args()

for filename in args:
  if not os.path.exists(filename):
    continue

  print filename
  file = open(filename)
  
  res = [0,0,0]
  resolutionData = file.readline().split()
  if resolutionData[0].lower() != 'resolution':
    sys.stderr.write('no resolution info found...\n')
    continue
  else:
    for i in range(1,6,2):
      if resolutionData[i] not in mapping['resolution']:
        sys.stderr.write('corrupt resolution info...\n')
        continue
      else:
        res[mapping['resolution'][resolutionData[i]]] = int(resolutionData[i+1])
        N = res[0]*res[1]*res[2]
      
  dim = [0.0,0.0,0.0]
  dimensionData = file.readline().split()
  if dimensionData[0].lower() != 'dimension':
    sys.stderr.write('no dimension info found...\n')
    continue
  else:
    for i in range(1,6,2):
      if dimensionData[i] not in mapping['dimension']:
        sys.stderr.write('corrupt dimension info...\n')
        continue
      else:
        dim[mapping['dimension'][dimensionData[i]]] = float(dimensionData[i+1])

  print 'dimension',dim
  
  file.readline()                        # skip homogenization

  data = {'scalar':{'texture':numpy.zeros(N,'i').reshape(res[2],res[1],res[0]).T}}
  for k in range(res[2]):
    for j in range(res[1]):
      for i in range(res[0]):
        data['scalar']['texture'][i,j,k] = int(file.readline().split()[0])

  out = {}
  out['mesh'] = vtk_writeASCII_mesh(dim,res,data)
  
  for what in out.keys():
    (head,tail) = os.path.split(filename)
    vtk = open(os.path.join(head,'%s_'%what+os.path.splitext(tail)[0]+'.vtk'), 'w')
    output(out[what],{'filepointer':vtk},'File')
    vtk.close()