#!/usr/bin/python2.4
import os, sys, re, urllib, libxml2, libxslt

#
# globals
#
cscUri = "http://csclub.uwaterloo.ca/xsltproc"

#
# csc:encode-for-uri
#
def cscEncodeForUri(ctx, str):
    if type(str) == type([]):
        str = libxml2.xmlNode(str[0]).getContent()
    print urllib.quote(str)
    return urllib.quote(str)

#
# csc:term
#
def cscTerm(ctx, str):
    if type(str) == type([]):
        str = libxml2.xmlNode(str[0]).getContent()

    try:
        # YYYY-MM-DD
        (year, month, day) = re.findall("^([0-9]+)-([0-9]+)-([0-9]+)$", str)[0]
        month = int(month)
        if month >= 1 and month <= 4:
            return "Winter " + year
        elif month >= 5 and month <= 8:
            return "Spring " + year
        elif month >= 9 and month <= 12:
            return "Fall " + year
        else:
            print "Invalid month '" + month + "'"
    except:
        print "Invalid term '" + str + "'"

#
# csc:email
#
def cscEmail(ctx, str):
    return "_EMAIL_TODO_"

#
# main
#

# check argv
if len(sys.argv) < 4:
    print "Usage: xsltproc.py input-file style-sheet output-file [params...]"
    sys.exit(1)
inFile = sys.argv[1]
xsltFile = sys.argv[2]
outFile = sys.argv[3]
rawParams = sys.argv[4:]

# check params
params = {}
for p in rawParams:
    p = p.split("=")
    if len(p) == 1:
        print "Missing value for parameter " + p[0]
        sys.exit(1)
    params[p[0]] = "'" + p[1] + "'"

try:
    # register extensions
    libxslt.registerExtModuleFunction("encode-for-uri", cscUri, cscEncodeForUri)
    libxslt.registerExtModuleFunction("term", cscUri, cscTerm)
    libxslt.registerExtModuleFunction("email", cscUri, cscEmail)

    # parse xml/xslt and apply style-sheet
    style = libxslt.parseStylesheetFile(xsltFile)
    doc = libxml2.parseFile(inFile)
    res = style.applyStylesheet(doc, params)
    style.saveResultToFilename(outFile, res, 0)

except:
    print "Unexpected error:", sys.exc_info()[0]
    sys.exit(1)