#
#  This file is part of Documancer (http://documancer.sf.net)
#
#  Copyright (C) 2002-2005 Vaclav Slavik
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License version 2 as
#  published by the Free Software Foundation.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
#  $Id: __init__.py,v 1.13 2005/01/30 19:46:30 vaclavslavik Exp $
#
#  Interface that providers must implement
#

import sys

# --------------------------------------------------------------------------
# Provider interface:
# --------------------------------------------------------------------------

class DocumentationProvider:
    def getID(self):
        """Returns unique id of the provider"""
        raise NotImplementedError
    
    def getName(self):
        """Returns human-readable string identifying the provider"""
        raise NotImplementedError

    def getDescription(self):
        """Returns human-readable description of the provider in HTML."""
        raise NotImplementedError

    def initForBook(self, book):
        """Runs book-specific initialization of the provider. For example,
           cache objects may be added here. The default implementation
           adds fulltext index object."""
        import indexer, cache
        cache.get(book).addObject(indexer.FulltextCacheObject(book, deps=[]))

    def serve(self, book, url):
        """Returns tuple (data_string,mime_type_string)"""
        raise NotImplementedError

    def getURLForIndexing(self, book):
        """Returns URL where the indexer should start"""
        raise NotImplementedError

    def getHomeURL(self, book):
        """Return URL where the browser should go if "Home" is pressed."""
        raise NotImplementedError

    def getContents(self, book):
        """Returns tree structure with book's contents, or None if not
           supported."""
        return None

    def getConfigurationDialog(self, parent):
        """Returns wxPython wxPanel object that can be used to configure
           the provider. This wxPanel must have 
             - SetData function (accepting book.attr dictionary)
             - GetData that return the dict
           It must call UpdateBook method of object given as argument to
           its SetDialog method after any change)."""
        raise NotImplementedError
   
    def shutdown(self):
        """Called when Documancer exits to clean up the provider, if needed."""
        pass


# --------------------------------------------------------------------------
# book-keeping code:
# --------------------------------------------------------------------------

providers = {}
providersNameToId = {}

def register(provider):
    global providers
    id = provider.getID()
    providers[id] = provider
    providersNameToId[provider.getName()] = id


def shutdown():
    """Shuts down all providers."""
    for p in providers.values():
        p.shutdown()


# --------------------------------------------------------------------------
# import all available providers on startup:
# --------------------------------------------------------------------------

import os, os.path, imp
from utils import getDocumancerHome

providers_path = os.path.join(getDocumancerHome(), 'providers')

for module in os.listdir(providers_path):
    fn = os.path.join(providers_path, module)
    if (not os.path.isdir(fn) or
        not os.path.isfile(os.path.join(fn, 'provider.py'))):
        continue

    try:
        exec 'import %s.provider' % module
    except ImportError:
        pass