#!/usr/bin/python
"""A Little Wiki Script Thing."""

import sys, re, os, cgi

def quoteHTML(s): 
   s = s.replace('&', '&')
   s = s.replace('<', '&lt;')
   return s

r_wikiname = re.compile(r'(^|[^A-Za-z0-9?])(([A-Z][a-z]+){2,})')

def wikiLinkify(s): 
   def htmlify(m): 
      return '%s<a href="./%s">%s</a>' % (m.group(1), m.group(2), m.group(2))
   return r_wikiname.sub(htmlify, s)

def wikiParse(s): 
   s = quoteHTML(s) # must quote HTML first...
   return wikiLinkify(s)

def get(wn): 
   if os.path.exists(wn + '.txt'): 
      s = wikiParse(open(wn + '.txt').read())
      return s + '<p>(<a href="./%s.edit">edit me</a>)</p>' % wn
   else: return '<a href="./%s.edit">Create me</a>' % wn

def edit(wn): 
   if os.path.exists(wn + '.txt'): 
      s = quoteHTML(open(wn + '.txt').read())
   else: s = ''
   return '''
     <form action="./%s.txt" method="POST">
        <div>
          <textarea rows="7" cols="80" name="text">%s</textarea>
        </div>
        <div><input type="submit" /></div>
     </form>
''' % (wn, s)

def post(wn): 
   form = cgi.parse_qs(sys.stdin.read())
   form = dict([(item[0], ''.join(item[1])) for item in form.items()])
   s = form.get('text') or ''
   open('%s.txt' % wn, 'w').write(s)
   return 'Wrote %s bytes to <a href="./%s">%s</a>' % (len(s), wn, wn)

def main(env=None): 
   if env is None: 
      env = os.environ

   method = env.get('REQUEST_METHOD')
   if method not in ('GET', 'POST'): 
      raise "UnsupportedMethodError", "Unsupported method: %s" % method
   
   wn = env.get('PATH_INFO') or 'HomePage'
   wn = wn.split('/').pop()

   if wn.endswith('.edit'): 
      action = 'edit'
      wn = wn[:-5]
   elif wn.endswith('.txt'): 
      action = 'get'
      wn = wn[:-4] # @@ disallow using the .txt files? unless POSTing?
                   # but then that messes up making new files. argh!
   else: action = 'get'

   if not re.compile(r'^[A-Za-z0-9-]+$').match(wn): 
      raise "ScriptError", "Invalid filename: %s" % wn

   print "Content-Type: text/html; charset=utf-8"
   print 
   if method == 'POST': 
      print post(wn)
   elif action == 'edit': 
      print edit(wn)
   else: print get(wn)

if __name__=="__main__": 
   try: main()
   except: cgi.print_exception()