import CryptoBox
import WebInterfaceDataset
import re
import Plugins
from CryptoBoxExceptions import *
import cherrypy
import types
import os

try:
	import neo_cgi, neo_util, neo_cs
except ImportError:
	errorMsg = "Could not import clearsilver module. Try 'apt-get install python-clearsilver'."
	self.log.error(errorMsg)
	sys.stderr.write(errorMsg)
	raise ImportError, errorMsg



class PluginIconHandler:

	def __init__(self, plugins):
		for plugin in plugins.getPlugins():
			if not plugin: continue
			plname = plugin.getName()
			## expose the getIcon function of this plugin
			setattr(self, plname, plugin.getIcon)



class WebInterfaceSites:
	'''
	'''

	## this template is used under strange circumstances
	defaultTemplate = "empty"


	def __init__(self):
		import logging
		self.cbox = CryptoBox.CryptoBoxProps()
		self.log = logging.getLogger("CryptoBox")
		self.prefs = self.cbox.prefs
		self.__resetDataset()


	def __resetDataset(self):
		"""this method has to be called at the beginning of every "site" action
			important: only at the beginning of an action (to not loose information)
			important: for _every_ "site" action (cherrypy is stateful)
		also take care for the plugins, as they also contain datasets
		"""
		self.__loadPlugins()
		self.dataset = WebInterfaceDataset.WebInterfaceDataset(self.cbox, self.prefs, self.pluginList.getPlugins())
		## publish plugin icons
		self.icons = PluginIconHandler(self.pluginList)
		self.icons.exposed = True
		## check, if a configuration partition has become available
		self.cbox.prefs.preparePartition()


	def __loadPlugins(self):
		self.pluginList = Plugins.PluginManager(self.cbox, self.prefs["Locations"]["PluginDir"])
		for plugin in self.pluginList.getPlugins():
			if not plugin: continue
			plname = plugin.getName()
			if plugin.isEnabled():
				self.cbox.log.info("Plugin '%s' loaded" % plname)
				## this should be the "easiest" way to expose all plugins as URLs
				setattr(self, plname, self.return_plugin_action(plugin))
				setattr(getattr(self, plname), "exposed", True)
				# TODO: check, if this really works - for now the "stream_response" feature seems to be broken
				#setattr(getattr(self, plname), "stream_respones", True)
			else:
				self.cbox.log.info("Plugin '%s' is disabled" % plname)
				## remove the plugin, if it was active before
				setattr(self, plname, None)


	## this is a function decorator to check authentication
	## it has to be defined before any page definition requiring authentification
	def __requestAuth(self=None):
		def check_credentials(site):
			def _inner_wrapper(self, *args, **kargs):
				import base64
				## define a "non-allowed" function
				user, password = None, None
				try:
					resp = cherrypy.request.headers["Authorization"][6:]	# ignore "Basic "
					(user, password) = base64.b64decode(resp).split(":",1)
				except KeyError:
					## no "authorization" header was sent
					pass
				except TypeError:
					## invalid base64 string
					pass
				except AttributeError:
					## no cherrypy response header defined
					pass
				authDict = self.cbox.prefs.userDB["admins"]
				if user in authDict.keys():
					if self.cbox.prefs.userDB.getDigest(password) == authDict[user]:
						## ok: return the choosen page
						self.cbox.log.info("access granted for: %s" % user)
						return site(self, *args, **kargs)
					else:
						self.cbox.log.info("wrong password supplied for: %s" % user)
				else:
					self.cbox.log.info("unknown user: %s" % str(user))
				## wrong credentials: return "access denied"
				cherrypy.response.headers["WWW-Authenticate"] = '''Basic realm="CryptoBox"'''
				cherrypy.response.status = 401
				return self.__render("access_denied")
			return _inner_wrapper
		return check_credentials
	

	######################################################################
	## put real sites down here and don't forget to expose them at the end


	@cherrypy.expose
	def index(self, weblang=""):
		self.__resetDataset()
		self.__setWebLang(weblang)
		self.__checkEnvironment()
		## do not forget the language!
		param_dict = {"weblang":weblang}
		## render "disks" plugin by default
		return self.return_plugin_action(self.pluginList.getPlugin("disks"))(**param_dict)
	

	def return_plugin_action(self, plugin):
		def handler(self, **args):
			self.__resetDataset()
			self.__checkEnvironment()
			args_orig = dict(args)
			## set web interface language
			try:
				self.__setWebLang(args["weblang"])
				del args["weblang"]
			except KeyError:
				self.__setWebLang("")
			## we always read the "device" setting - otherwise volume-plugin links
			## would not work easily (see "volume_props" linking to "format_fs")
			## it will get ignored for non-volume plugins
			try:
				plugin.device = None
				if self.__setDevice(args["device"]):
					plugin.device = args["device"]
				del args["device"]
			except KeyError:
				pass
			## check the device argument of volume plugins
			if "volume" in plugin.pluginCapabilities:
				## initialize the dataset of the selected device if necessary
				if plugin.device:
					self.dataset.setCurrentDiskState(plugin.device)
				else:
					## invalid (or missing) device setting
					return self.__render(self.defaultTemplate)
			## check if there is a "redirect" setting - this will override the return
			## value of the doAction function (e.g. useful for umount-before-format)
			try:
				if args["redirect"]:
					override_nextTemplate = { "plugin":args["redirect"] }
					if "volume" in plugin.pluginCapabilities:
						override_nextTemplate["values"] = {"device":plugin.device}
					del args["redirect"]
			except KeyError:
				override_nextTemplate = None
			## call the plugin handler
			nextTemplate = plugin.doAction(**args)
			## for 'volume' plugins: reread the dataset of the current disk
			## additionally: set the default template for plugins
			if "volume" in plugin.pluginCapabilities:
				## maybe the state of the current volume was changed?
				self.dataset.setCurrentDiskState(plugin.device)
				if not nextTemplate: nextTemplate = { "plugin":"volume_mount", "values":{"device":plugin.device}}
			else:
				## maybe a non-volume plugin changed some plugin settings (e.g. plugin_manager)
				self.dataset.setPluginData()
				## update the container hdf-dataset (maybe a plugin changed the state of a container)
				self.dataset.setContainersState()
				## default page for non-volume plugins is the disk selection
				if not nextTemplate: nextTemplate = { "plugin":"disks", "values":{} }
			## was a redirect requested?
			if override_nextTemplate:
				nextTemplate = override_nextTemplate
			## if another plugins was choosen for 'nextTemplate', then do it!
			if isinstance(nextTemplate, types.DictType) \
					and "plugin" in nextTemplate.keys() \
					and "values" in nextTemplate.keys() \
					and self.pluginList.getPlugin(nextTemplate["plugin"]):
				valueDict = dict(nextTemplate["values"])
				## force the current weblang attribute - otherwise it gets lost
				valueDict["weblang"] = self.dataset["Settings.Language"]
				new_plugin = self.pluginList.getPlugin(nextTemplate["plugin"])
				return self.return_plugin_action(new_plugin)(**valueDict)
			## save the currently active plugin name
			self.dataset["Data.ActivePlugin"] = plugin.getName()
			return self.__render(nextTemplate, plugin)
		## apply authentication?
		if plugin.isAuthRequired():
			return lambda **args: self.__requestAuth()(handler)(self, **args)
		else:
			return lambda **args: handler(self, **args)

				
	## test authentication
	@cherrypy.expose
	@__requestAuth
	def test(self, weblang=""):
		self.__resetDataset()
		self.__setWebLang(weblang)
		self.__checkEnvironment()
		return "test passed"
	

	@cherrypy.expose
	def test_stream(self):
		"""just for testing purposes - to check if the "stream_response" feature
		actually works - for now (September 02006) it does not seem to be ok"""
		import time
		yield "<html><head><title>neu</title></head><body><p><ul>"
		for a in range(10):
			yield "<li>yes: %d - %s</li>" % (a, str(time.time()))
			time.sleep(1)
		yield "</ul></p></html>"



	##################### input checker ##########################

	def __checkEnvironment(self):
		"""here we should place all interesting checks to inform the user of problems

		examples are: non-https, readonly-config, ...
		"""
		## TODO: maybe add an option "mount"?
		if self.cbox.prefs.requiresPartition() and not self.cbox.prefs.getActivePartition():
			self.dataset["Data.EnvironmentWarning"] = "ReadOnlyConfig"
		# TODO: turn this on soon (add "not") - for now it is annoying
		if self.__checkHTTPS():
			self.dataset["Data.EnvironmentWarning"] = "NoSSL"


	def __checkHTTPS(self):
		## check the request scheme
		if cherrypy.request.scheme == "https": return True
		## check an environment setting - this is quite common behind proxies
		try:
			if os.environ["HTTPS"]: return True
		except KeyError:
			pass
		## check http header TODO (check pound for the name)
		try:
			if cherrypy.request.headers["TODO"]: return True
		except KeyError:
			pass
		## the connection seems to be unencrypted
		return False


	def __setWebLang(self, value):
		guess = value
		availLangs = self.cbox.getAvailableLanguages()
		## no language specified: check browser language
		if not guess:
			guess = self.__getPreferredBrowserLanguage(availLangs)
		## no preferred language or invalid language?
		if not guess \
				or not guess in availLangs \
				or re.search(u'\W', guess):
			## warn only for invalid languages
			if not guess is None:
				self.cbox.log.info("invalid language choosen: %s" % guess)
			guess = self.prefs["WebSettings"]["Language"]
		## maybe the language is still not valid
		if not guess in availLangs:
			self.log.warn("the configured language is invalid: %s" % guess)
			guess = "en"
		## maybe there is no english dataset???
		if not guess in availLangs:
			self.log.warn("couldn't find the english dataset")
			guess = availLangs[0]
		self.dataset["Settings.Language"] = guess
		## we only have to save it, if it was specified correctly and explicitly
		if value == guess:
			self.dataset["Settings.LinkAttrs.weblang"] = guess


	def __getPreferredBrowserLanguage(self, availLangs):
		"""guess the preferred language of the user (as sent by the browser)
		take the first language, that is part of 'availLangs'
		"""
		try:
			pref_lang_header = cherrypy.request.headers["Accept-Language"]
		except KeyError:
			## no language header was specified
			return None
		## this could be a typical 'Accept-Language' header:
		##	de-de,de;q=0.8,en-us;q=0.5,en;q=0.3
		regex = re.compile(u"\w+(-\w+)?(;q=[\d\.]+)?$")
		pref_langs = [e.split(";",1)[0]
			for e in pref_lang_header.split(",")
			if regex.match(e)]
		## is one of these preferred languages available?
		for lang in pref_langs:
			if lang in availLangs: return lang
		## we try to be nice: also look for "de" if "de-de" was specified ...
		for lang in pref_langs:
			## use only the first part of the language
			short_lang = lang.split("-",1)[0]
			if short_lang in availLangs: return short_lang
		## we give up
		return None


	def __setDevice(self, device):
		if device and re.match(u'[\w /\-]+$', device) and self.cbox.getContainer(device):
			self.log.debug("select device: %s" % device)
			return True
		else:
			self.log.warn("invalid device: %s" % device)
			self.dataset["Data.Warning"] = "InvalidDevice"
			return False
	

	def __checkVolumeName(self, name):
		if name and re.match(u'[\w \-]+$', name):
			return True
		else:
			return False


	def __getLanguageValue(self, value):
		hdf = self.__getLanguageData(self.dataset["Settings.Language"])
		return hdf.getValue(value, "")


	def __getLanguageData(self, web_lang="en"):
		default_lang = "en"
		conf_lang = self.prefs["WebSettings"]["Language"]
		hdf = neo_util.HDF()
		langDir = os.path.abspath(self.prefs["Locations"]["LangDir"])
		langFiles = []
		## first: read default language (en)
		if (default_lang != conf_lang) and (default_lang != web_lang):
			langFiles.append(os.path.join(langDir, default_lang + ".hdf"))
		## second: read language as defined in the config file
		if (conf_lang != web_lang):
			langFiles.append(os.path.join(langDir, conf_lang + ".hdf"))
		## third: read language as configured via web interface
		langFiles.append(os.path.join(langDir, web_lang + ".hdf"))
		for langFile in langFiles:
			if os.access(langFile, os.R_OK):
				hdf.readFile(langFile)
			else:
				log.warn("Couldn't read language file: %s" % langFile)
		return hdf

	
	def __render(self, renderInfo, plugin=None):
		'''renders from clearsilver templates and returns the resulting html
		'''
		## is renderInfo a string (filename of the template) or a dictionary?
		if type(renderInfo) == types.DictType:
			template = renderInfo["template"]
			if renderInfo.has_key("generator"):
				generator = renderInfo["generator"]
			else:
				generator = False
		else:
			(template, generator) = (renderInfo, None)

		## load the language data
		hdf = neo_util.HDF()
		hdf.copy("Lang", self.__getLanguageData(self.dataset["Settings.Language"]))

		## first: assume, that the template file is in the global template directory
		self.dataset["Settings.TemplateFile"] = os.path.abspath(os.path.join(self.prefs["Locations"]["TemplateDir"], template + ".cs"))

		if plugin:
			## check, if the plugin provides the template file -> overriding
			plugin_cs_file = plugin.getTemplateFileName(template)
			if plugin_cs_file:
				self.dataset["Settings.TemplateFile"] = plugin_cs_file

			## add the current state of the plugins to the hdf dataset
			self.dataset["Data.Status.Plugins.%s" % plugin.getName()] = plugin.getStatus()
			## load the language data
			pl_lang = plugin.getLanguageData(self.dataset["Settings.Language"])
			if pl_lang:
				hdf.copy("Lang.Plugins.%s" % plugin.getName(), pl_lang)
			## load the dataset of the plugin
			plugin.loadDataSet(hdf)

		self.log.info("rendering site: " + template)

		cs_path = os.path.abspath(os.path.join(self.prefs["Locations"]["TemplateDir"], "main.cs"))
		if not os.access(cs_path, os.R_OK):
			log.error("Couldn't read clearsilver file: %s" % cs_path)
			yield "Couldn't read clearsilver file: %s" % cs_path
			return

		self.log.debug(self.dataset)
		for key in self.dataset.keys():
			hdf.setValue(key,str(self.dataset[key]))
		cs = neo_cs.CS(hdf)
		cs.parseFile(cs_path)

		## is there a generator containing additional information?
		if generator is None:
			## all content in one flush
			yield cs.render()
		else:
			content_generate = generator()
			dummy_line = """<!-- CONTENT_DUMMY -->"""
			## now we do it linewise - checking for the content marker
			for line in cs.render().splitlines():
				if line.find(dummy_line) != -1:
					yield line.replace(dummy_line, content_generate.next())
				else:
					yield line + "\n"