from CryptoBoxLogger import CryptoBoxLogger
try:
	import subprocess
except:
	print "Couldn't import 'subprocess'. You need a python version >= 2.4"
import os
import re

"""exceptions:
	VolumeIsActive
	NameActivelyUsed
	InvalidName
	InvalidPassword
	InvalidType
	CreateError
	MountError
	ChangePasswordError
	"""

class CryptoBoxContainer:

	Types = {
		"unused":0,
		"plain":1,
		"luks":2,
		"swap":3}
	

	__fsTypes = {
		"plain":["ext3", "ext2", "vfat", "reiser"],
		"swap":["swap"]}
	"TODO: mehr Dateisystemtypen? / 'reiser' pruefen"

	__dmDir = "/dev/mapper"


	def __init__(self, device, cbox):
		self.device = device
		self.cbox = cbox
		self.debugMessage = self.cbox.debugMessage
		self.Progs = self.cbox.cbxPrefs["Programs"]
		self.__resetObject()


	def getName(self):
		return self.name


	def setName(self, new_name):
		"TODO: den Test-Code pruefen"
		if new_name == self.name: return
		if self.isMounted():
			raise "VolumeIsActive", "the container must be inactive during renaming"
		if not re.search(r'^[a-zA-Z0-9_\.\- ]+$', new_name):
			raise "InvalidName", "the supplied new name contains illegal characters"
		"check for active partitions with the same name"
		prev_name_owner = self.cbox.getContainerList(filterName=new_name)
		if prev_name_owner:
			for a in prev_name_owner:
				if a.isMounted():
					raise "NameActivelyUsed", "the supplied new name is already in use for an active partition"
		self.cbox.setNameForUUID(self.uuid, new_name)
		self.name = new_name


	def getDevice(self):
		return self.device


	def getType(self):
		return self.type


	def isMounted(self):
		return os.path.ismount(self.__getMountPoint())


	def create(self, type, password=None):
		if type == self.Types["luks"]:
			self.__createLuks(password)
			self.__resetObject()
			return
		if type == self.Types["plain"]:
			self.__createPlain()
			self.__resetObject()
			return
		raise "InvalidType", "invalid container type (%d) supplied" % (type, )


	def changePassword(self, oldpw, newpw):
		if self.type != self.Types["luks"]:
			raise "InvalidType", \
				"changing of password is possible only for luks containers"
		if not oldpw:
			raise "InvalidPassword", "no old password supplied for password change"
		if not newpw:
			raise "InvalidPassword", "no new password supplied for password change"
		"return if new and old passwords are the same"
		if oldpw == newpw: return
		if self.isMounted():
			raise "VolumeIsActive", "this container is currently active"
		devnull = None
		try:
			devnull = open(os.devnull, "w")
		except IOError:
			self.debugMessage(
				CryptoBoxLogger.DebugLevels["warn"],
				"Could not open %s" % (os.devnull, ))
		"remove any potential open luks mapping"
		self.__umountLuks()
		"create the luks header"
		proc = subprocess.Popen(
			shell = False,
			stdin = subprocess.PIPE,
			stdout = subprocess.PIPE,
			stderr = subprocess.PIPE,
			args = [
				self.Progs["cryptsetup"],
				"--batch-mode",
				"luksAddKey",
				self.device])
		proc.stdin.write("%s\n%s" % (oldpw, newpw))
		(output, errout) = proc.communicate()
		if proc.returncode != 0:
			errorMsg = "Could not add a new luks key: %s - %s" % (output.strip(), errout.strip(), )
			self.debugMessage(CryptoBoxLogger.DebugLevels["error"], errorMsg)
			raise "ChangePasswordError", errorMsg
		keys_found = re.search(r'key slot (\d{1,3}) unlocked', output).groups()
		if keys_found:
			keyslot = int(keys_found[0])
		else:
			raise "ChangePasswordError", "could not get the old key slot"
		"remove the old key"
		proc = subprocess.Popen(
			shell = False,
			stdin = None,
			stdout = devnull,
			stderr = subprocess.PIPE,
			args = [
				self.Progs["cryptsetup"],
				"--batch-mode",
				"luksDelKey",
				self.device,
				"%d" % (keyslot, )])
		proc.wait()
		if proc.returncode != 0:
			errorMsg = "Could not remove the old luks key: %s" % (proc.stderr.read().strip(), )
			self.debugMessage(CryptoBoxLogger.DebugLevels["error"], errorMsg)
			raise "ChangePasswordError", errorMsg
		


	" ****************** internal stuff ********************* "

	def __resetObject(self):
		"""	recheck the information about this container
			this is especially useful after changing the type via 'create'	"""
		self.uuid = self.__getUUID()
		self.type = self.__getTypeOfPartition()
		self.name = self.__getNameOfContainer()
		if self.type == self.Types["luks"]:
			self.mount = self.__mountLuks
			self.umount = self.__umountLuks
		if self.type == self.Types["plain"]:
			self.mount = self.__mountPlain
			self.umount = self.__umountPlain


	def __getNameOfContainer(self):
		"retrieve the name of the container by querying the database"
		def_name = self.cbox.getNameForUUID(self.uuid)
		if def_name: return def_name
		"there is no name defined for this uuid - we will propose a good one"
		prefix = self.cbox.cbxPrefs["Main"]["DefaultVolumePrefix"]
		unused_found = False
		counter = 1
		while not unused_found:
			guess = prefix + str(counter)
			if self.cbox.getUUIDForName(guess):
				counter += 1
			else:
				unused_found = True
		self.cbox.setNameForUUID(self.uuid, guess)
		return guess


	def __getUUID(self):
		"""return UUID for luks partitions, ext2/3 and vfat filesystems"""
		devnull = None
		try:
			devnull = open(os.devnull, "w")
		except IOError:
			self.debugMessage(
				CryptoBoxLogger.DebugLevels["warn"],
				"Could not open %s" % (os.devnull, ))
		proc = subprocess.Popen(
			shell=False,
			stdin=None,
			stdout=subprocess.PIPE,
			stderr=devnull,
			args=[self.Progs["blkid"],
				"-s", "UUID",
				"-o", "value",
				"-c", os.devnull,
				"-w", os.devnull,
				self.device])
		proc.wait()
		result = proc.stdout.read().strip()
		if proc.returncode != 0:
			self.debugMessage(
				CryptoBoxLogger.DebugLevels["warn"],
				"retrieving of partition type via 'blkid' failed: %s" % (proc.stderr.read().strip(), ))
			return None
		devnull.close()
		if result: return result
		return self.device.replace(os.path.sep, "_")


	def __getTypeOfPartition(self):
		"retrieve the type of the given partition (see CryptoBoxContainer.Types)"
		if self.__isLuksPartition(): return self.Types["luks"]
		typeOfPartition = self.__getTypeIdOfPartition()
		if typeOfPartition in self.__fsTypes["plain"]:
			return self.Types["plain"]
		if typeOfPartition in self.__fsTypes["swap"]:
			return self.Types["swap"]
		return self.Types["unused"]


	def __getTypeIdOfPartition(self):
		"returns the type of the partition (see 'man blkid')"
		devnull = None
		try:
			devnull = open(os.devnull, "w")
		except IOError:
			self.debugMessage(
				CryptoBoxLogger.DebugLevels["warn"],
				"Could not open %s" % (os.devnull, ))
		proc = subprocess.Popen(
			shell=False,
			stdin=None,
			stdout=subprocess.PIPE,
			stderr=subprocess.PIPE,
			args=[self.Progs["blkid"],
				"-s", "TYPE",
				"-o", "value",
				"-c", os.devnull,
				"-w", os.devnull,
				self.device])
		proc.wait()
		output = proc.stdout.read().strip()
		if proc.returncode != 0:
			self.debugMessage(
				CryptoBoxLogger.DebugLevels["warn"],
				"retrieving of partition type via 'blkid' failed: %s" % (proc.stderr.read().strip(), ))
			return None
		devnull.close()
		return output


	def __isLuksPartition(self):
		"check if the given device is a luks partition"
		devnull = None
		try:
			devnull = open(os.devnull, "w")
		except IOError:
			self.debugMessage(
				CryptoBoxLogger.DebugLevels["warn"],
				"Could not open %s" % (os.devnull, ))
		proc = subprocess.Popen(
			shell = False,
			stdin = None,
			stdout = devnull,
			stderr = devnull,
			args = [
				self.Progs["cryptsetup"],
				"--batch-mode",
				"isLuks",
				self.device])
		proc.wait()
		devnull.close()
		return proc.returncode == 0


	def __getMountPoint(self):
		"return the name of the mountpoint of this volume"
		return os.path.join(self.cbox.cbxPrefs["System"]["MountParentDir"], self.name)


	def __mountLuks(self, password):
		"mount a luks partition"
		if not password:
			raise "InvalidPassword", "no password supplied for luksOpen"
		if self.isMounted(): raise "VolumeIsActive", "this container is already active"
		self.__umountLuks()
		try:
			devnull = open(os.devnull, "w")
		except IOError:
			self.debugMessage(
				CryptoBoxLogger.DebugLevels["warn"],
				"Could not open %s" % (os.devnull, ))
		self.__cleanMountDirs()
		if not os.path.exists(self.__getMountPoint()):
			os.mkdir(self.__getMountPoint())
		if not os.path.exists(self.__getMountPoint()):
			errorMsg = "Could not create mountpoint (%s)" % (self.__getMountPoint(), )
			self.debugMessage("error", errorMsg)
			raise "MountError", errorMsg
		proc = subprocess.Popen(
			shell = False,
			stdin = subprocess.PIPE,
			stdout = devnull,
			stderr = subprocess.PIPE,
			args = [
				self.Progs["cryptsetup"],
				"luksOpen",
				"--batch-mode",
				self.device,
				self.name])
		proc.stdin.write(password)
		(output, errout) = proc.communicate()
		if proc.returncode != 0:
			errorMsg = "Could not open the luks mapping: %s" % (errout.strip(), )
			self.debugMessage(CryptoBoxLogger.DebugLevels["warn"], errorMsg)
			raise "MountError", errorMsg
		proc = subprocess.Popen(
			shell = False,
			stdin = None,
			stdout = devnull,
			stderr = subprocess.PIPE,
			args = [
				self.Progs["mount"],
				os.path.join(self.__dmDir, self.name),
				self.__getMountPoint()])
		proc.wait()
		if proc.returncode != 0:
			errorMsg = "Could not mount the filesystem: %s" % (proc.stderr.read().strip(), )
			self.debugMessage(CryptoBoxLogger.DebugLevels["warn"], errorMsg)
			raise "MountError", errorMsg
		devnull.close()


	def __umountLuks(self):
		"umount a luks partition"
		devnull = None
		try:
			devnull = open(os.devnull, "w")
		except IOError:
			self.debugMessage(
				CryptoBoxLogger.DebugLevels["warn"],
				"Could not open %s" % (os.devnull, ))
		if self.isMounted():
			proc = subprocess.Popen(
				shell = False,
				stdin = None,
				stdout = devnull,
				stderr = subprocess.PIPE,
				args = [self.Progs["umount"], "-l", self.__getMountPoint()])
			proc.wait()
			if proc.returncode != 0:
				errorMsg = "Could not umount the filesystem: %s" % (proc.stderr.read().strip(), )
				self.debugMessage(CryptoBoxLogger.DebugLevels["warn"], errorMsg)
				raise "MountError", errorMsg
		if os.path.exists(os.path.join(self.__dmDir, self.name)):
			proc = subprocess.Popen(
				shell = False,
				stdin = None,
				stdout = devnull,
				stderr = subprocess.PIPE,
				args = [
					self.Progs["cryptsetup"],
					"--batch-mode",
					"luksClose",
					self.name])
			proc.wait()
			if proc.returncode != 0:
				errorMsg = "Could not remove the luks mapping: %s" % (proc.stderr.read().strip(), )
				self.debugMessage(CryptoBoxLogger.DebugLevels["warn"], errorMsg)
				raise "MountError", errorMsg
		devnull.close()


	def __mountPlain(self):
		"mount a plaintext partition"
		if self.isMounted(): raise "VolumeIsActive", "this container is already active"
		devnull = None
		try:
			devnull = open(os.devnull, "w")
		except IOError:
			self.debugMessage(
				CryptoBoxLogger.DebugLevels["warn"],
				"Could not open %s" % (os.devnull, ))
		self.__cleanMountDirs()
		if not os.path.exists(self.__getMountPoint()):
			os.mkdir(self.__getMountPoint())
		if not os.path.exists(self.__getMountPoint()):
			errorMsg = "Could not create mountpoint (%s)" % (self.__getMountPoint(), )
			self.debugMessage("error", errorMsg)
			raise "MountError", errorMsg
		proc = subprocess.Popen(
			shell = False,
			stdin = None,
			stdout = devnull,
			stderr = subprocess.PIPE,
			args = [
				self.Progs["mount"],
				self.device,
				self.__getMountPoint()])
		proc.wait()
		if proc.returncode != 0:
			errorMsg = "Could not mount the filesystem: %s" % (proc.stderr.read().strip(), )
			self.debugMessage(CryptoBoxLogger.DebugLevels["warn"], errorMsg)
			raise "MountError", errorMsg
		devnull.close()


	def __umountPlain(self):
		"umount a plaintext partition"
		devnull = None
		try:
			devnull = open(os.devnull, "w")
		except IOError:
			self.debugMessage(
				CryptoBoxLogger.DebugLevels["warn"],
				"Could not open %s" % (os.devnull, ))
		if self.isMounted():
			proc = subprocess.Popen(
				shell = False,
				stdin = None,
				stdout = devnull,
				stderr = subprocess.PIPE,
				args = [
					self.Progs["umount"],
					"-l",
					self.__getMountPoint()])
			proc.wait()
			if proc.returncode != 0:
				errorMsg = "Could not umount the filesystem: %s" % (proc.stderr.read().strip(), )
				self.debugMessage(CryptoBoxLogger.DebugLevels["warn"], errorMsg)
				raise "MountError", errorMsg
		devnull.close()
	

	def __createPlain(self):
		"make a plaintext partition"
		if self.isMounted():
			raise "VolumeIsActive", \
				"deactivate the partition before filesystem initialization"
		devnull = None
		try:
			devnull = open(os.devnull, "w")
		except IOError:
			self.debugMessage(
				CryptoBoxLogger.DebugLevels["warn"],
				"Could not open %s" % (os.devnull, ))
		proc = subprocess.Popen(
			shell = False,
			stdin = None,
			stdout = devnull,
			stderr = subprocess.PIPE,
			args = [
				self.Progs["mkfs-data"],
				self.device])
		proc.wait()
		if proc.returncode != 0:
			errorMsg = "Could not create the filesystem: %s" % (proc.stderr.read().strip(), )
			self.debugMessage(CryptoBoxLogger.DebugLevels["error"], errorMsg)
			raise "CreateError", errorMsg
		devnull.close()


	def __createLuks(self, password):
		"make a luks partition"
		if not password:
			raise "InvalidPassword", "no password supplied for new luks mapping"
		if self.isMounted():
			raise "VolumeIsActive", \
				"deactivate the partition before filesystem initialization"
		devnull = None
		try:
			devnull = open(os.devnull, "w")
		except IOError:
			self.debugMessage(
				CryptoBoxLogger.DebugLevels["warn"],
				"Could not open %s" % (os.devnull, ))
		"remove any potential open luks mapping"
		self.__umountLuks()
		"create the luks header"
		proc = subprocess.Popen(
			shell = False,
			stdin = subprocess.PIPE,
			stdout = devnull,
			stderr = subprocess.PIPE,
			args = [
				self.Progs["cryptsetup"],
				"--batch-mode",
				"--cipher", self.cbox.cbxPrefs["System"]["DefaultCipher"],
				"--iter-time", "2000",
				"luksFormat",
				self.device])
		proc.stdin.write(password)
		(output, errout) = proc.communicate()
		if proc.returncode != 0:
			errorMsg = "Could not create the luks header: %s" % (errout.strip(), )
			self.debugMessage("error", errorMsg)
			raise "CreateError", errorMsg
		"open the luks container for mkfs"
		proc = subprocess.Popen(
			shell = False,
			stdin = subprocess.PIPE,
			stdout = devnull,
			stderr = subprocess.PIPE,
			args = [
				self.Progs["cryptsetup"],
				"--batch-mode",
				"luksOpen",
				self.device,
				self.name])
		proc.stdin.write(password)
		(output, errout) = proc.communicate()
		if proc.returncode != 0:
			errorMsg = "Could not open the new luks mapping: %s" % (errout.strip(), )
			self.debugMessage(CryptoBoxLogger.DebugLevels["error"], errorMsg)
			raise "CreateError", errorMsg
		"make the filesystem"
		proc = subprocess.Popen(
			shell = False,
			stdin = None,
			stdout = devnull,
			stderr = subprocess.PIPE,
			args = [
				self.Progs["mkfs-data"],
				os.path.join(self.__dmDir, self.name)])
		proc.wait()
		"remove the mapping - for every exit status"
		self.__umountLuks()
		if proc.returncode != 0:
			errorMsg = "Could not create the filesystem: %s" % (proc.stderr.read().strip(), )
			self.debugMessage(CryptoBoxLogger.DebugLevels["error"], errorMsg)
			"remove the luks mapping"
			raise "CreateError", errorMsg
		devnull.close()


	def __cleanMountDirs(self):
		"""	remove all unnecessary subdirs of the mount parent directory
			this should be called for every (u)mount	"""
		subdirs = os.listdir(self.cbox.cbxPrefs["System"]["MountParentDir"])
		for dir in subdirs:
			abs_dir = os.path.join(self.cbox.cbxPrefs["System"]["MountParentDir"], dir)
			if (not os.path.islink(abs_dir)) and os.path.isdir(abs_dir) and (not os.path.ismount(abs_dir)): os.rmdir(abs_dir)