#!/usr/bin/env python
def usage():
  print ''' %s filename[.sly extension optional]
	splits filename into separate files.  The first two bytes are
the field separator.  The next line begins the list of target files
terminated by a field separator at the beginning of a line.  The first
data (comment) field immediately follows.  If it is not empty, it is
written to all files.  Then fields are written in turn to particular
files.  For safety's sake, sly will not write files if run on a bare
header.  A line which ends with a \"%%\" will continue to the same file.
Empty fields become blank lines, except comments.  Example:

!! test.sly  This line is not written....
dummy.ly   !! target.ly  !! tpt.ly
!!!!  m1 !! notes to target.ly !! notes to tpt.ly
!! m2 !! target notes !! tpt notes
comment !! m3 !! target notes !! tpt notes %%
more tpt notes !!!! m4

(c)2004 David Raleigh Arnold, under GNU. 20040410''' % (sys.argv[0])
  sys.exit()
                                                                   
def inputfile():
  '''Get file from argument. Supply .sly ending, test
    existence of file, and open it for reading. '''
  if not len(sys.argv) == 2:
    print "One argument, a file name with \".sly\" extension, is required."
    usage()
  arg = sys.argv[1]
  if os.path.isfile(arg + '.sly'):
    infile = open(arg + '.sly')
  elif os.path.isfile(arg):
    infile = open(arg)
  else:
    print "File " + arg + " or " + arg + ".sly does not exist."
    usage()
  return infile

import string, os, sys
try:
  file = inputfile() # which is open
  comment = file.readline()
  print comment,  
  fsep = comment[:2]
  ''' Put whole file in memory. '''
  lines = []
  for line in file:
    line = line.strip()
    lines.append(line)
  lines = '\n'.join(lines)
  all = lines.split('\n' + fsep, 1)
  head, data = all[0], all[1]
  if len(data.split('\n'))<2 and len(data.split(fsep))<2:
    print "Bare header.  Nothing written."
    usage()
  
  ''' Process head, get names into list '''
  filelist = fsep.join(head.split('\n')) # sub fsep for newline
  filelist = filelist.split(fsep)
  names = []
  print "Writing files:"
  for filename in filelist:
    name = filename.strip()
    print '\t\t' + name
    target = open(name, 'w')
    names.append(target) # "names" is list of opened target files
  print '''
    Data written to first file, with field numbers, except that comment fields
    (which start at "0") were not written if they were empty:''' 
 
  ''' Process data...'''
  data = data.split('\n') # arrange data in lines
  data = fsep.join(data).rstrip() # rstrip & make newline new field
  data = data.split('%' + fsep) # split at lily comment if at end of field
  data = '%\n'.join(data) # join so now fields can have multiple lines
  data = data.split(fsep)
  count = 0 # start number of fields at one 1st comment gets mod zero 
  volte = len(names)+1 # constant: number of targets 
  for field in data:    
    opnum = 0 # index sts at 0, but 2nd iter=1st file.
    for target in names:      
      if (count % volte)==0: # write to all files
        if opnum==0:
          print count, field
        if field.strip()!='': # but only if comment exists.       
          target.write(field + '\n')                   
      if (count % volte)==opnum+1: # zero pass is comment        
        names[opnum].write(field + '\n')
        if opnum==0:
          print count, "field 1:", field
        else:
          print count,
      opnum = opnum + 1 # index next target file                   
    count = count + 1 # next field
except:
  pass
  #print "main-errors: ", sys.exc_type, sys.exc_value