#!/usr/bin/python
# Program mref.py converts typical .tex file into BibTex format
# with MR links by reference to MR database using MREF
# Written by Bartlomiej Siudeja
# Based on script mrefh.py by Jim Pitman  pitman@stat.berkeley.edu 10/10/03.
# Uses standard input and standard output.
# e.g. on unix system, save program in a file mrefh.py then  do
#           chmod +x mref.py
# then starting from a file refs.bbl to create refs.html usage is
#           cat refs.tex | mrefh.py > refs.bib
import urllib,string,sys,re

flag = r'\bibitem'

def mref(texstring):
	m=re.search("\{([\w\-]*)\}",texstring)
	texstring=re.sub("(\W*)bibitem(\s*)\{([\w\-]*)\}","",texstring)
	front = r'http://www.ams.org/mathscinet-mref?ref='
	back =  r'&mref-submit=Search&dataType=bibtex'  
	address = '%s%s%s' % (front,urllib.quote_plus(texstring),back)
	infile = urllib.urlopen(address)
	while 1:
		line = infile.readline()
		if string.find(line,'No Unique Match Found') >=0 :
			if m:
				print '\n@article {'+m.group(1)+',\n TITLE = {'+texstring+'}\n}'
				sys.stderr.write('\n!! No Match for: '+m.group(1)+' !!\n')
			else:
				print '\n@article {!!!,\n TITLE = {'+texstring+'}\n}'
				sys.stderr.write('\n!! No Match for: '+texstring+' !!\n')
			break
		if not line : break
		if string.find(line,'Matched') >= 0: 
			break
	
	while 1:
		if string.find(line,'No Unique Match Found') >=0 :
			break
		line = infile.readline()
		if string.find(line,'@')>=0:
			m2=re.search("\@(\w*)\s*\{(\w*)",line)
			if m: 
				if m2:
					if string.find(m2.group(1),'preamble')<0:
						line='@'+m2.group(1)+'{'+m.group(1)+',\n'
				else:
					line='@article{'+m.group(1)+',\n'
			else:
				sys.stderr.write('!! Error in: '+texstring+' !!\n')
			line=re.sub("<tr>(.*)<pre>","",line)
		if not line : break
		if string.find(line,'}</pre></td></tr>') >= 0: 
			if m2: 
				if string.find(m2.group(1),'preamble')<0:
					print '       URL = {http://www.ams.org/mathscinet-getitem?mr='+m2.group(2)+'}\n}',
				else:
					print '}',
			else:
				print '       URL = {}\n}',
				if m:
					sys.stderr.write('!! Error in: '+m.group(1)+' !!\n')
				else:
					sys.stderr.write('!! Error in: '+texstring+' !!\n')
			break
 		print line,

f = sys.stdin

currentstring = ''
addline = 0

while 1:
	line = f.readline()
	if not line : 
		mref(currentstring)
		break
	if string.find(line,flag) >= 0: 
		addline = 1
		mref(currentstring)
		currentstring = line
	elif addline == 1:
		currentstring = currentstring + line