# -*- coding: utf-8 -*-

# ####################################################################
#  Copyright (C) 2005-2009 by the FIFE team
#  http://www.fifengine.de
#  This file is part of FIFE.
#
#  FIFE is free software; you can redistribute it and/or
#  modify it under the terms of the GNU Lesser General Public
#  License as published by the Free Software Foundation; either
#  version 2.1 of the License, or (at your option) any later version.
#
#  This library 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
#  Lesser General Public License for more details.
#
#  You should have received a copy of the GNU Lesser General Public
#  License along with this library; if not, write to the
#  Free Software Foundation, Inc.,
#  51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
# ####################################################################

import os, sys, traceback

class PluginManager:
	""" Currently, pluginmanager iterates through the plugin directory
	adding the plugins if they are set to True in settings.xml. If a plugin
	isn't set in settings.xml it assumes it is not to be loaded, and saves it
	as False in settings.xml.
	
	If a plugin fails to load due to exceptions, they are caught and a line
	of the error is printed to console.
	"""
	def __init__(self, settings, addPluginDir, *args, **kwargs):
		"""
		@param addPluginDir - directory that is scanned for plugins additionally to
						   the default pluginDir
		"""
		self._settings = settings
		
		self._pluginDir = "plugins"
		self._plugins = []

		dirs = [self._pluginDir]
		if addPluginDir is not None:
			dirs.append(addPluginDir)
		
		files = []
		for d in dirs:
			for f in os.listdir(d):
				path = os.path.join(d, f)
				if os.path.isfile(path) and os.path.splitext(f)[1] == ".py" and f != "__init__.py":
					files.append((d,os.path.splitext(f)[0]))
				
		for d,f in files:
			importPlugin = self._settings.get("Plugins", f, False)
			if importPlugin:
				try:
					print "Importing plugin:", f
					plugin = None

					if d == "plugins":
						# default plugins dir needs special treating
						plugin = __import__(d+"."+f)
						plugin = eval("plugin."+f+"."+f+"()")
					else:
						plugin = __import__(f)
						plugin = eval("plugin."+f+"()")

					if isinstance(plugin, Plugin) is False:
						print f+" is not an instance of Plugin!"
					else:
						plugin.enable()
						self._plugins.append(plugin)
				except BaseException, error:
					print "Invalid plugin:", f
					traceback.print_exc()
			else:
				print "Not importing plugin:", f
				
			self._settings.set("Plugins", f, importPlugin)
			
		self._settings.saveSettings()

	def stop(self):
		""" stop signal from editor on app shutdown """
		for plugin in self._plugins:
			plugin.disable()
		
class Plugin(object):
	""" The base class for all plugins. All plugins should implement these functions. 
	
	@type	default_settings:	dict
	@ivar	default_settings:	mapping with (generic) default settings, used as fallback
								and to create the entries in settings.xml if they are not present
	@note:	plugins should provide their own default settings by overwriting this ivar
	
	@type	settings:	dict
	@ivar	settings:	current settings, simple item - value mapping (e.g. docking : True)
	@note:	plugins shouldn't touch that ivar
	
	@type	eds:	fife_settings
	@ivar	eds:	editor settings module (fife extension)
	@note:	plugins have to provide the settings module by overwriting this ivar
	"""
	def __init__(self):
		self.default_settings = {}
		self.settings = {}
		self.eds = None
	
	def enable(self):
		raise NotImplementedError, "Plugin has not implemented the enable() function!"

	def disable(self):
		raise NotImplementedError, "Plugin has not implemented the disable() function!"

	def isEnabled(self):
		raise NotImplementedError, "Plugin has not implemented the isEnabled() function!"

	def getName(self):
		raise NotImplementedError, "Plugin has not implemented the getName() function!"
		
	def update_settings(self):
		""" read the settings for this plugin from the editor's settings file 
		
		@note:	
			- in order to use stored settings, a plugin has to call this method
			  on init
			- default settings have to be provided by the plugin, otherwise
			  we don't do anything here
		"""
		if self.eds is None: return
		if not self.default_settings: return
		if 'module' not in self.default_settings: return
		if 'items' not in self.default_settings: return
		
		module = self.default_settings['module']

		for name, default_value in self.default_settings['items'].iteritems():
			value = self.eds.get(module, name, default_value)
			self.settings[name] = value

	#--- These are not so important ---#
	def getAuthor(self):
		return "Unknown"
		
	def getDescription(self):
		return ""

	def getLicense(self):
		return ""
		
	def getVersion(self):
		return "0.1"