#!/usr/bin/python

'''
rstiki - a minimalist wiki, using reStructuredText_ syntax via docutils_,
inspired by pwyky_.

+-------------------------------+------------------+
| Method + URL                  |    Action        |  
+-------------------------------+------------------+
| GET /rst-wiki/FooBar          | normal rendering |
| GET /rst-wiki/FooBar?edit     | edit form        |
| POST /rst-wiki/FooBar         | edit submission  |
+-------------------------------+------------------+

.. _docutils: http://docutils.sourceforge.net/docs/index.html
.. _reStructuredText: http://docutils.sourceforge.net/docs/user/rst/cheatsheet.txt
.. _pwyky: http://infomesh.net/pwyky/

@author Josh Sled <jsled@asynchronous.org>
@since 2007-02-03
@license GNU GPL version 2.
'''

import cgi
import cgitb
import docutils.core
import os
import os.path
import textwrap


class Response (object):
    def __init__(self, **kwargs):
        kwargs.setdefault('response_code', '200')
        kwargs.setdefault('content_type', 'text/html')
        kwargs.setdefault('content', '')
        kwargs.setdefault('headers', [])
        self._response_code = kwargs['response_code']
        self._content_type = kwargs['content_type']
        self._headers = kwargs['headers']
        self._content = kwargs['content']

    def _set_content_type(self, content_type):
        self._content_type = content_type

    def _set_content(self, content):
        self._content = content

    content_type = property(lambda s: s._content_type, _set_content_type)
    content = property(lambda s: s._content, _set_content)
    response_code = property(lambda s: s._response_code)
    headers = property(lambda s: s._headers)


def get_node_name(request_uri = None):
    if not request_uri: request_uri = os.environ.get('REDIRECT_URL')
    if not request_uri: return 'index'
    rel_path = '/'.join(request_uri.split('/')[2:])
    return rel_path


def edit_fetch(form):
    node_name = get_node_name()
    node_content = ''
    if os.path.exists(node_name):
        node_file = file(node_name, 'r')
        node_content = node_file.read(-1)
        node_file.close()
    r = Response()
    r.content = common_header() + textwrap.dedent('''
    <form method="POST">
      <input type="hidden" name="edit"/>
      <textarea name="content">%s</textarea><br />
      <input type="submit" name="Submit"/>
      syntax <a href="http://docutils.sourceforge.net/docs/user/rst/quickref.html">quickref</a>
      - <a href="http://docutils.sourceforge.net/docs/user/rst/cheatsheet.txt">cheatsheet</a>
    </form>
    ''' % (cgi.escape(node_content))) + common_footer()
    return r
    

def render(form):
    node_name = get_node_name()
    if not os.path.exists(node_name):
        r = Response(content=common_header() + '<p>[%s] does not exist; <a href="?edit">create it</a>?</p>' % (node_name) + common_footer())
        return r
    node_file = file(node_name, 'r')
    node_content = node_file.read(-1)
    node_file.close()
    # http://docutils.sourceforge.net/docs/howto/security.html
    heightened_security_settings = {'file_insertion_enabled': 0,
                                    'raw_enabled': 0}
    # http://docutils.sourceforge.net/docs/api/publisher.html
    parts = docutils.core.publish_parts(source=node_content, writer_name='html',
                                        settings_overrides=heightened_security_settings)
    r = Response(content=common_header(parts['title']) + parts['html_body'] + common_footer())
    return r


def edit_submit(form):
    node_name = get_node_name()
    node_file = file(node_name, 'w+')
    node_file.write(form['content'].value)
    node_file.close()
    return render(form)
    # fixme, this should really be a redirect... something like:
    #path = os.environ.get('REQUEST_URI')
    #rel_url = path.split('?')[0]
    #new_url = 'http://%s%s' % (os.environ.get('HTTP_HOST'), rel_url)
    #return Response(response_code='201',
    #                headers=[('Location',new_url)],
    #                content= common_header('created!') + '<p><a href="%(url)s">%(url)s</a> created.</p>' % {'url':rel_url} + common_footer())


def dispatch():
    form = cgi.FieldStorage(keep_blank_values=True)
    fn = render
    if form.has_key('edit'):
        if os.environ.get('REQUEST_METHOD') == 'POST':
            fn = edit_submit
        else:
            fn = edit_fetch
    return fn(form)


def common_header(title=None):
    if not title: title = '(unknown)'
    title = 'rstiki > %s' % (title)
    return textwrap.dedent('''
    <html>
      <head>
        <title>%s</title>
        <style type="text/css">
        BODY { background-color: white; }
        TABLE { border-width: 1; }
        TEXTAREA { width: 90%%; height: 90%%; border: solid thin black; }
        </style>
      </head>
      <body>
''' % (cgi.escape(title)))


def common_footer():
    return textwrap.dedent('''
        <hr />
        <a href="?edit">[Edit]</a><br />
      </body>
    </html>''')


def check_install():
    if os.path.exists('.htaccess'):
        return None
    htaccess = file('.htaccess', 'w+')
    htaccess.write(textwrap.dedent('''
# cribbed from pwyky...
DirectoryIndex index.cgi
Options -MultiViews
RewriteEngine on
RewriteRule ^([A-Za-z0-9-]+)$ index.cgi [L]
'''))
    htaccess.close()
    return Response(content=common_header('install') + textwrap.dedent('''
    <h1>rstiki installed</h1>
    <p>rstiki has been installed.  You should <a href="./?edit">edit the first page</a>.</p>
    ''') + common_footer())


def main():
    rtn = check_install()
    if rtn: return rtn
    return dispatch()


def print_response(resp):
    print 'Status: %s' % (resp.response_code)
    print 'Content-Type: ' + resp.content_type
    if resp.headers:
        for name,value in resp.headers:
            print '%s: %s' % (name,value)
    if resp.content:
        print ''
        print resp.content


if __name__ == '__main__':
    # cgi.test()
    cgitb.enable()
    resp = main()
    print_response(resp)