#!/usr/bin/python
import cgi, os, os.path, time, re, xml.sax.saxutils

lockFileName = "files/todolock"
fileName = "files/todos.xml"

while(os.path.exists(lockFileName)):
    time.sleep(.25)

lockFileHandle = open(lockFileName, "w")
lockFileHandle.write("locked")
lockFileHandle.close()

form = cgi.FieldStorage()
#name = form['title'].value
#nextAction = form['nextAction'].value
name = form.getfirst("title")
nextAction = form.getfirst("nextAction")
category = form.getfirst("category")

oldFile = open(fileName, 'r')
oldFileLines = oldFile.readlines()
oldFile.close()

usedIDs = []
categoryStartre = re.compile(r'^<category type="%s">' % category)
categoryEndre = re.compile(r'^</category>')
todoIDre = re.compile(r'^<todo todoID="(\d+)"')
for line in oldFileLines:
    todoIDmatch = todoIDre.match(line)
    if (todoIDmatch):
        usedIDs.append(int(todoIDmatch.group(1)))

id = 1
while (id in usedIDs):
    id = id + 1

# Find the category, if it exists.
lineNumber = 0
foundCategory = False
todoLineToInsert = '<todo todoID="%d" title=%s nextAction=%s/>\n' % (id, xml.sax.saxutils.quoteattr(name), xml.sax.saxutils.quoteattr(nextAction))
for line in oldFileLines:
    if (foundCategory and categoryEndre.match(line)):
        oldFileLines.insert(lineNumber, todoLineToInsert)
        break
    if (categoryStartre.match(line)):
        foundCategory = True
    lineNumber = lineNumber + 1
if (not foundCategory):
    # Need to add the new category.
    oldFileLines.insert(len(oldFileLines)-1, '<category type="%s">\n' % category)
    oldFileLines.insert(len(oldFileLines)-1, todoLineToInsert)
    oldFileLines.insert(len(oldFileLines)-1, '</category>\n')
newFile = open(fileName, 'w')
for line in oldFileLines:
    newFile.write(line)
newFile.close()

os.remove(lockFileName)

print "Content-type: text/plain\n\n"
print "done."