#!/usr/bin/env python

# Copyright (c) 2009 Fergus Gallagher <fergus.gallagher@citeulike.org>
# All rights reserved.
#
# This code is derived from software contributed to CiteULike.org
# by
#    Diwaker Gupta
#    Kristinn B. Gylfason <citeulike@askur.org>
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. All advertising materials mentioning features or use of this software
#    must display the following acknowledgement:
#        This product includes software developed by
#		 CiteULike <http://www.citeulike.org> and its
#		 contributors.
# 4. Neither the name of CiteULike nor the names of its
#    contributors may be used to endorse or promote products derived
#    from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY CITEULIKE.ORG AND CONTRIBUTORS
# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#
import re, sys, urllib, urllib2, cookielib, codecs

DOI_URL_SEP ='%2F'
DOI_SEP ='/'

# regexp for document object identifiers (DOI)
DOI_REGEXP = r"""/		# begin at slash
		(10\.\S*?)/	# valid DOI prefixes start with '10.'
		([^/?]+)		# DOI suffixes can be anything
		\s*"""		# terminate at end of line (strip witesp.)
DOI_REGEXP_FLAGS = re.IGNORECASE | re.VERBOSE

# error messages
ERR_STR_PREFIX = 'status\terr\t'
ERR_STR_FETCH = 'Unable to fetch the bibliographic data: '
ERR_STR_TRY_AGAIN = 'The server may be down.  Please try later.'
ERR_STR_NO_DOI = 'No document object identifier found in the URL: '
ERR_STR_REPORT = 'Please report the error to plugins@citeulike.org.'


def process(serverRoot, linkoutType=None):
	CITATION_SERVER_ROOT = 'http://%s/action/downloadCitation' % serverRoot

	sys.stdout = codecs.getwriter('utf-8')(sys.stdout)

	# read url from std input
	url = sys.stdin.readline()
	# get rid of the newline at the end
	url = url.strip()

	# 'unparse' url to remove %HH escapes which confuse the DOI parser below
	url = urllib2.unquote(url)

	# parse the DOI from the url and exit gracefully if not found
	doi_match  = re.search(DOI_REGEXP, url, DOI_REGEXP_FLAGS)
	if not doi_match:
		print ERR_STR_PREFIX + ERR_STR_NO_DOI + url + '.  ' + ERR_STR_REPORT
		return

	doi_prefix = doi_match.group(1)
	doi_suffix = doi_match.group(2)
	url_doi = doi_prefix + DOI_URL_SEP + doi_suffix
	doi = doi_prefix + DOI_SEP + doi_suffix

	# fetch the BibTeX entry for the DOI and exit gracefully in case of trouble
	cj = cookielib.CookieJar()
	opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj))
	post_data = urllib.urlencode( { "doi" : doi,
					"include" : "abs",
					"format" : "refman",
					"direct" : "on",
					"submit" : "Download references"} )
	try:
		# Cookie me...
		opener.open("http://%s/action/showCitFormats?doi=%s" % (serverRoot, url_doi))
		# ... and fetch the bibtex record
		f = opener.open(CITATION_SERVER_ROOT, post_data)
	except:
		print ERR_STR_PREFIX + ERR_STR_FETCH + CITATION_SERVER_ROOT + '.  ' + ERR_STR_TRY_AGAIN
		return

	bibtex_entry = f.read().strip()

	# get rid of the session id in the url
	url_pat = re.compile(r';jsessionid.*$',re.MULTILINE)
	bibtex_entry = re.sub(url_pat,'',bibtex_entry)

	# print the results
	print "begin_tsv"
	if linkoutType:
		print "linkout\t%s\t\t%s\t\t" % (linkoutType,doi)
	print "linkout\tDOI\t\t%s\t\t" % (doi)
	print "type\tJOUR"
	print "doi\t" + doi
	print "end_tsv"
	print "begin_ris"
	print bibtex_entry.decode("utf-8")
	print "end_ris"
	print "status\tok"