#!/usr/bin/env python

# Renumber a mma song file. Just take any lines
# which start with a number and do those sequenially.

import sys, os


def error(m):
    """ Abort on error with message. """
    print m
    sys.exit(1)

def usage():
    """ Print usage message and exit. """

    print "Mma-renum, (c) Bob van der Poel"
    print "Re-numbers a mma song file and"
    print "  cleans up chord tabbing."
    print "Overwrites existing file!"
    print
    sys.exit(1)



##########################

if len(sys.argv[1:]) != 1:
    print "mma-rnum: requires 1 filename argument."
    usage()
    
filename = sys.argv[1]

if filename[0] == '-':
    usage()

try:
    inpath = open(filename, 'r')
except:
    error("Can't access the file '%s'" % filename)

tempfile = "%s.%s.tmp" % (filename, os.getpid())
try:
    outpath = open( tempfile, 'w')
except:
    error("Can't open scratchfile '%s', error '%s'" % (tempfile, sys.exc_info()[0]) )
    
linenum = 1

for l in inpath:
    l=l.rstrip()
    
    try:
        x = int(l.split()[0])
    except:
        x = None

    if x != None: 
        otherstuff = ''           # break off non-chord items
        cmt = ''
        if l.count('//'):
            l, cmt=l.split('//', 1)

        for i,a in enumerate(l):
            if a in('{[*'):
                otherstuff=l[i:]
                l=l[:i]
                l=l.strip()
                break
        newl=['%-5s' % linenum]

        linenum += 1              # the global line number

        for a in l.split()[1:]:   # do each chord item
            newl.append(" %6s" % a)

        if otherstuff:            # join on non-chord stuff
            newl.append("    ")
            newl.append(otherstuff)

        if cmt:
            newl.append("   //")
            newl.append(cmt)

        newl=''.join(newl)

    else:
        newl = l

    outpath.write(newl + "\n")
    
inpath.close()
outpath.close()

try:
    os.remove(filename)
except:
    error("Cannot delete '%s', new file '%s' remains" % (filename, tempfile) )
    
try:
    os.rename(tempfile, filename)
except:
    error("Cannot rename '%s' to '%s'." (tempfile, filename) )