#!/usr/bin/python
"""
cgiutil.py - Utilities for CGI Scripts
License: GPL 2; share and enjoy!
Author: Sean B. Palmer, inamidst.com
"""

import sys, os, re, cgi, urllib, itertools, robotparser

r_title = re.compile(r'<title>([^<]+)</title>')
method = os.environ.get('REQUEST_METHOD')
form = cgi.FieldStorage()
form.__call__ = lambda s: form[s].value
bufsize = 2048

# @@ doctypes

def serve(status, body, mime=None, charset=None, raw=None): 
   # @@ doc, and import the status codes if they'll work
   mime = mime or 'text/html'
   charset = charset or 'utf-8'
   sys.stdout.write("Status: %s\r\n" % status)
   sys.stdout.write("Content-Type: %s; charset=%s\r\n\r\n" % (mime, charset))
   if raw: sys.stdout.write(body)
   else: 
      body = str(body)
      if not body.endswith('\n') or body.endswith('\r'): 
         body += '\n'
      sys.stdout.write(body)
   sys.exit()

def escape(html): 
   return cgi.escape(html)

def unescape(html): 
   html = html.replace('&lt;', '<')
   html = html.replace('&gt;', '>')
   html = html.replace('&amp;', '&')
   return html

def all(seq, pred=bool): 
   """Returns True if pred(x) is True for every element in the iterable."""
   return False not in itertools.imap(pred, seq)

def any(seq, pred=bool):
   """Returns True if pred(x) is True at least one element in the iterable."""
   return True in itertools.imap(pred, seq)

class RobotsTxt(object): 
   """A better robots.txt parser, using robotparser.

      Example: 
         rp = RobotsTxt(fn='/web/mysite.tld/robots.txt')
         if rp.fetchable('/somepath'): 
            print "/somepath is fetchable"
   """
   def __init__(self, uri=None, fn=None): 
      if uri and fn: 
         raise "ArgumentError", "Can only pass uri or fn, not both."
      elif not (uri or fn): 
         raise "ArgumentError", "Must pass one of uri or fn."

      self.rp = robotparser.RobotFileParser()
      if uri: self.rp.set_url(uri)
      else: 
         if os.path.isfile(fn): 
            self.rp.set_url(fn)
         else: raise IOError, "Not found: %s" % fn
      self.rp.read() # @@ this reads borked files too

   def fetchable(self, path, ua=None): 
      if ua is None: ua = '*'
      return self.rp.can_fetch(ua, path)

def getTitle(fn): 
   # Modified from the version in bookmarks.cgi
   # @@ support URIs too
   if not fn.endswith('.html'): 
      return None
   try: f = open(fn)
   except: return None
   else: 
      html = ''
      while 1: 
         s = f.read(bufsize)
         if not s: break
         html += s
         m = r_title.search(html)
         if m: 
            f.close()
            return unescape(m.group(1))
   f.close()
   return None

def trim(s): 
   while s.startswith('\n') or s.startswith('\r'): 
      s = s[1:]
   if s.endswith('\n'): s = s[:-1]

   i = 0
   for char in s: 
      if char == ' ': i += 1
      else: break

   result = ''
   for line in s.splitlines(): 
      if line.startswith(' ' * i): 
         result += line[i:] + '\n'
      else: result += line + '\n'

   return result

def test(): 
   pass

def main(): 
   pass
   # if running as a CGI: test()
   # else: print __doc__

if __name__=="__main__": 
   main()