import subprocess
import os
import logging
import CryptoBoxTools
import CryptoBoxPlugin

class partition(CryptoBoxPlugin.CryptoBoxPlugin):

	PartTypes = {
		"windows"	: ["0xC", "vfat"],
		"linux"	: ["L", "ext3"]}

	ConfigPartition = {
		"size"	: 5,	# size of configuration partition (if necessary) in MB
		"type"	: "L",
		"fs"	: "ext2"}


	def doAction(self, **args):
		## retrieve some values from 'args' - defaults are empty
		self.withConfigPartition = self.__isWithConfigPartition(args)
		self.device = self.__getSelectedDevice(args)
		self.deviceSize = self.__getAvailableDeviceSize(self.device)
		try:
			step = args["step"]
			del args["step"]
		except KeyError:
			step = "select_device"
		## no (or invalid) device was supplied
		if not self.device:
			step == "select_device"
		if step == "add_partition":
			return self.__actionAddPartition(args)
		if step == "del_partition":
			return self.__actionDelPartition(args)
		elif step == "finish":
			return self.__actionFinish(args)
		else:	# for "select_device" and for invalid targets
			return self.__actionSelectDevice(args)


	def getStatus(self):
		return "%s / %s / %s" % (self.device, self.deviceSize, self.withConfigPartition)


	def __getSelectedDevice(self, args):
		try:
			device = args["block_device"]
		except KeyError:
			return None
		if not self.__isDeviceValid(device):
			return None
		if self.__isDeviceBusy(device):
			self.hdf["Data.Warning"] = "Plugins.partition.DiskIsBusy"
			return None
		return device


	def __isDeviceValid(self, device):
		if not device:
			return False
		if not self.cbox.isDeviceAllowed(device):
			return False
		if not device in CryptoBoxTools.getParentBlockDevices():
			return False
		return True


	def __isDeviceBusy(self, device):
		"""check if the device (or one of its partitions) is mounted"""
		# TODO: the config partition is ignored, as it is not part of the container list - that is not good
		import re
		for c in self.cbox.getContainerList():
			if re.match(device + "\d*$", c.getDevice()):
				if c.isMounted(): return True
		return False


	def __actionSelectDevice(self, args):
		block_devices = [e
			for e in CryptoBoxTools.getParentBlockDevices()
			if self.cbox.isDeviceAllowed(e)]
		counter = 0
		for a in block_devices:
			self.hdf[self.hdf_prefix + "BlockDevices.%d" % counter] = a
			self.cbox.log.debug("found a suitable block device: %s" % a)
			counter += 1
		if self.withConfigPartition:
			self.hdf[self.hdf_prefix + "CreateConfigPartition"] = "1"
		## there is no disk available
		if not block_devices:
			self.hdf["Data.Warning"] = "Plugins.partition.NoDisksAvailable"
		return "select_device"


	def __actionAddPartition(self, args):
		self.hdf[self.hdf_prefix + "Device"] = self.device
		self.hdf[self.hdf_prefix + "Device.Size"] = self.deviceSize
		parts = self.__getPartitionsFromArgs(args)
		self.__setPartitionData(parts)
		return "set_partitions"


	def __actionDelPartition(self, args):
		try:
			part_num = int(args["del_num"])
		except (TypeError,KeyError):
			return self.__actionAddPartition(args)
		self.hdf[self.hdf_prefix + "Device"] = self.device
		self.hdf[self.hdf_prefix + "Device.Size"] = self.deviceSize
		parts = self.__getPartitionsFromArgs(args)
		## valid partition number to be deleted?
		if part_num < len(parts):
			del parts[part_num]
		else:
			return self.__actionAddPartition(args)
		self.__setPartitionData(parts)
		return "set_partitions"


	def __actionFinish(self, args):
		parts = self.__getPartitionsFromArgs(args)
		if parts:
			self.__setPartitionData(parts)
			if not self.__runFDisk(parts):
				self.hdf["Data.Warning"] = "Plugins.partition.PartitioningFailed"
				return self.__actionAddPartition(args)
			else:
				# TODO: will we use the "yield"-style? If yes, then remove these messages (success and warning)
				#if self.__formatPartitions(parts):
				#	self.hdf["Data.Success"] = "Plugins.partition.Partitioned"
				#else:
				#	self.hdf["Data.Warning"] = "Plugins.partition.FormattingFailed"
				"""
				tricky problem: if the device was partitioned, then a created config partition is still part of the containerlist, as the label is not checked again - very ugly!!! So we will call reReadContainerList after formatting the last partition - see below
				"""
				self.cbox.reReadContainerList()
				def result_generator():
					counter = 0
					## initialize the generator
					formatPart_gen = self.__formatPartitions(parts)
					while counter < len(parts):
						## first part: get the device name
						yield formatPart_gen.next()
						counter += 1
						## second part: do the real formatting of a partition
						result = formatPart_gen.next()
						## after the first partiton, we can reRead the containerList (as the possible config partition was already created)
						if self.withConfigPartition and (counter == 1):
							## important: reRead the containerList
							self.cbox.reReadContainerList()
						## return the result
						yield result
				return {
					"template": "show_format_progress",
					"generator": result_generator}
		else:
			return self.__actionAddPartition(args)


	def __setPartitionData(self, parts):
		availSize = self.deviceSize
		i = 0
		for part in parts:
			self.cbox.log.debug(part)
			self.hdf[self.hdf_prefix + "Parts.%d.Size" % i] = part["size"]
			self.hdf[self.hdf_prefix + "Parts.%d.Type" % i] = part["type"]
			availSize -= part["size"]
			i += 1
		self.hdf[self.hdf_prefix + "availSize"] = availSize
		if self.withConfigPartition:
			self.hdf[self.hdf_prefix + "CreateConfigPartition"] = "1"
		for t in self.PartTypes.keys():
			self.hdf[self.hdf_prefix + "Types.%s" % t] = t


	def __getPartitionsFromArgs(self, args):
		parts = []
		done = False
		availSize = self.deviceSize
		i = -1
		while not done:
			i += 1
			try:
				size = int(args["part%d_size" % i])
				partType = args["part%d_type" % i]
				if int(size) > availSize:
					self.hdf["Data.Warning"] = "Plugins.partition.PartitionTooBig"
					continue
				if int(size) < 10:
					self.hdf["Data.Warning"] = "Plugins.partition.PartitionTooSmall"
					continue
				if not partType in self.PartTypes.keys(): continue
				parts.append({"size":size, "type":partType})
				availSize -= size
			except TypeError:
				pass
			except KeyError:
				done = True
		return parts


	def __getAvailableDeviceSize(self, device):
		"""calculate the available size (MB) of the device
		also consider a (possible) configuration partition"""
		if not device: return 0
		rdev = os.stat(device).st_rdev
		minor = os.minor(rdev)
		major = os.major(rdev)
		for f in file("/proc/partitions"):
			try:
				elements = f.split()
				if len(elements) != 4: continue
				if (int(elements[0]) == major) and (int(elements[1]) == minor):
					deviceSize = int(elements[2])/1024
					if self.withConfigPartition:
						deviceSize -= self.ConfigPartition["size"]
					return deviceSize
			except ValueError:
				pass
		return 0


	def __isWithConfigPartition(self, args):
		try:
			if args["create_config_partition"]:
				createConfig = True
			else:
				createConfig = False
		except KeyError:
			createConfig = False
		return createConfig


	def __runFDisk(self, parts):
		## check if the device is completely filled (to avoid some empty last blocks)
		avail_size = self.deviceSize
		for d in parts: avail_size -= d["size"]
		isFilled = avail_size == 0
		proc = subprocess.Popen(
			shell = False,
			stdin = subprocess.PIPE,
			stdout = subprocess.PIPE,
			stderr = subprocess.PIPE,
			args = [
				self.cbox.prefs["Programs"]["super"],
				self.cbox.prefs["Programs"]["CryptoBoxRootActions"],
				"plugin",
				os.path.join(os.path.dirname(__file__), "root_action.py"),
				"partition",
				self.device])
		for line in self.__getSFDiskLayout(parts, isFilled):
			proc.stdin.write(line + "\n")
		(output, error) = proc.communicate()
		if proc.returncode != 0: self.cbox.log.debug("partitioning failed: %s" % error)
		return proc.returncode == 0


	def __getSFDiskLayout(self, paramParts, isFilled):
		parts = paramParts[:]
		## first a (possible) configuration partition - so it will be reusable
		if self.withConfigPartition:
			## fill the main table (including a config partition)
			yield ",%d,%s" % (self.ConfigPartition["size"], self.ConfigPartition["type"])
		## one primary partition
		yield ",%d,%s,*" % (parts[0]["size"], self.PartTypes[parts[0]["type"]][0])
		del parts[0]
		## no extended partition, if there is only one disk
		if not parts: return
		## an extended container for the rest
		yield ",,E"
		## an empty partition in main table
		yield ";"
		## maybe another empty partition if there is no config partition
		if not self.withConfigPartition: yield ";"
		while parts:
			if isFilled and (len(parts) == 1):
				yield ",,%s" % (self.PartTypes[parts[0]["type"]][0],)
			else:
				yield ",%d,%s" % (parts[0]["size"], self.PartTypes[parts[0]["type"]][0])
			del parts[0]


	def __formatPartitions(self, paramParts):
		import threading
		parts = paramParts[:]
		part_num = 1
		## maybe a config partition?
		if self.withConfigPartition:
			dev_name = self.device + str(part_num)
			self.cbox.log.info("formatting config partition (%s)" % dev_name)
			if self.__formatOnePartition(dev_name, self.ConfigPartition["fs"]):
				self.__setLabelOfPartition(dev_name, self.cbox.prefs["Main"]["ConfigVolumeLabel"])
			part_num += 1
		## the first data partition
		dev_name = self.device + str(part_num)
		partType = self.PartTypes[parts[0]["type"]][1]
		self.cbox.log.info("formatting partition (%s) as '%s'" % (dev_name, partType))
		yield dev_name
		if self.__formatOnePartition(dev_name, partType):
			yield "OK"
		else:
			yield "<b>Failed!</b>"
		del parts[0]
		## other data partitions
		part_num = 5
		while parts:
			dev_name = self.device + str(part_num)
			partType = self.PartTypes[parts[0]["type"]][1]
			self.cbox.log.info("formatting partition (%s) as '%s'" % (dev_name, partType))
			yield dev_name
			if self.__formatOnePartition(dev_name, partType):
				yield "OK"
			else:
				yield "<b>Failed!</b>"
			part_num += 1
			del parts[0]
		return


	def __formatOnePartition(self, dev_name, type):
		proc = subprocess.Popen(
			shell = False,
			args = [
				self.cbox.prefs["Programs"]["super"],
				self.cbox.prefs["Programs"]["CryptoBoxRootActions"],
				"plugin",
				os.path.join(os.path.dirname(__file__), "root_action.py"),
				"format",
				dev_name,
				type])
		(output, error) = proc.communicate()
		if proc.returncode != 0:
			self.cbox.log.warn("failed to create filesystem on %s: %s" % (dev_name, error))
			return False
		else:
			return True


	def __setLabelOfPartition(self, dev_name, label):
		proc = subprocess.Popen(
			shell = False,
			stdout = subprocess.PIPE,
			stderr = subprocess.PIPE,
			args = [
				self.cbox.prefs["Programs"]["super"],
				self.cbox.prefs["Programs"]["CryptoBoxRootActions"],
				"plugin",
				os.path.join(os.path.dirname(__file__), "root_action.py"),
				"label",
				dev_name,
				label])
		(output, error) = proc.communicate()
		if proc.returncode == 0:
			return True
		else:
			self.cbox.log.warn("failed to create filesystem on %s: %s" % (dev_name, error))
			return False