from flup.server.fcgi_fork import WSGIServer
from os import getpid
 
from pam import authenticate
from cgi import FieldStorage
from base64 import b64decode
 
from markdown import markdown
from nstore import FileStore
import sys
import re
 
LISTEN_PORT = 9609
INSTALL_DIR = '/home/synack/src/nikiwiki'
PID_FILE = '/var/run/nikiwiki.pid'
 
def render(template, app, **kwargs):
	vars = {
		'STATIC_URL': 'http://static.example.com/niki',
		'SITE_NAME': 'nikiwiki',
		'SITE_MOTTO': 'everybody can edit, nobody can talk',
		'CONTENT_TYPE': 'text/html',
	}
	vars.update(kwargs)
 
	app.header('Content-type', vars['CONTENT_TYPE'])
	return template % vars
 
def valid_auth(environ):
	auth = environ.get('HTTP_AUTHORIZATION', None)
	if auth:
		auth = b64decode(auth[6:])
		username, password = auth.split(':')
		return authenticate(username, password)
	else:
		return False
 
class WikiPage(object):
	def __init__(self):
		self.app = None
		self.data = FileStore('%s/data/' % INSTALL_DIR)
 
	def GET(self, pagename='Main_Page'):
		pagename = pagename.rstrip('/')
		try:
			content = self.data[pagename]
		except KeyError:
			try:
				entries = []
				for line in self.data[pagename + '/.index'].split('\n'):
					entry = line.split(',', 1)
					if len(entry) == 2:
						entries.append(entry)
				entries.sort(key=lambda x: x[1], reverse=True)
				latest = entries[:5]
				content = ''
				for slug, timestamp in latest:
					content += self.data[pagename + '/' + slug]
					content += '\n***\n' 
				content += '#### Older posts\n\n'
				for slug, timestamp in entries:
					content += '[%s](%s/%s)  \n' % (slug, pagename, slug)
			except KeyError:
				content = self.data['Not_Found']
 
		yield render(self.data['templates/wiki.html'], self.app,
			title=pagename,
			raw_content=content,
			content=markdown(content))
		return
 
	def POST(self, pagename=None):
		if not valid_auth(self.app.environ):
			self.app.status = '401 Unauthorized'
			self.app.header('WWW-Authenticate', 'Basic realm="Restricted"')
			yield 'Unauthorized'
			return
		if not pagename:
			self.app.status = '400 Bad Request'
			yield 'Bad request'
			return
		try:
			content = self.app.get_content()['content'].value
			self.data[pagename] = content
			yield markdown(content)
		except:
			self.app.status = '500 Internal Server Error'
			yield 'Unable to write content to data store\n'
 
	def PUT(self, pagename):
		self.POST(pagename)
 
	def DELETE(self, pagename):
		if not valid_auth(self.app.environ):
			self.app.status = '401 Unauthorized'
			self.app.header('WWW-Authenticate', 'Basic realm=Restricted')
			return
		del self.data[pagename]
		return
 
class WSGIApp(object):
	def __init__(self, urls=None):
		self.load_urls(urls)
 
	def __call__(self, environ, start_response):
		self.environ = environ
		self.start_response = start_response
		self.headers = []
		self.status = '200 OK'
		return self.handle_request()
 
	def handle_request(self):
		for url in self.urls:
			match = url.match(self.environ['PATH_INFO'])
			if match:
				groupdict = match.groupdict()
				if not groupdict:
					groupdict = {}
				handler = self.urls[url]()
				handler.app = self
				if hasattr(handler, self.environ['REQUEST_METHOD']):
					method = getattr(handler, self.environ['REQUEST_METHOD'])
 
					response = method(**groupdict)
					response = [x.encode('ascii', 'ignore') for x in response]
					self.header('Content-Length', str(sum([len(x) for x in response])))
					self.start_response(self.status, self.headers)
					return response
 
	def header(self, name, value):
		self.headers.append((name, value))
 
	def get_content(self):
		input = self.environ['wsgi.input']
		form = FieldStorage(fp=input, environ=self.environ, keep_blank_values=True)
		return form
 
	def load_urls(self, urls):
		self.urls = {}
		for url in urls:
			handler = urls[url]
			url = re.compile(url)
			self.urls[url] = handler
 
urls = {
	'/':					WikiPage,
	'/(?P<pagename>.+)':	WikiPage,
}
 
def main():
	server = WSGIServer(WSGIApp(urls), bindAddress=('0.0.0.0', LISTEN_PORT)).run()
 
if __name__ == '__main__':
	# Create a PID file
	fd = open(PID_FILE, 'w')
	fd.write(str(getpid()))
	fd.close()
 
	main()