import glob, re, os, json
from collections import OrderedDict
from helpers.general import sys_command
from exceptions import *

ROOT_DIR_PATTERN = re.compile('^.*?/devices')
GPT = 0b00000001

class BlockDevice():
	def __init__(self, path, info):
		self.path = path
		self.info = info

	@property
	def device(self):
		"""
		Returns the actual device-endpoint of the BlockDevice.
		If it's a loop-back-device it returns the back-file,
		If it's a ATA-drive it returns the /dev/X device
		And if it's a crypto-device it returns the parent device
		"""
		if not 'type' in self.info: raise DiskError(f'Could not locate backplane info for "{self.path}"')

		if self.info['type'] == 'loop':
			for drive in json.loads(b''.join(sys_command(f'losetup --json', hide_from_log=True)).decode('UTF_8'))['loopdevices']:
				if not drive['name'] == self.path: continue

				return drive['back-file']
		elif self.info['type'] == 'disk':
			return self.path
		elif self.info['type'] == 'crypt':
			if not 'pkname' in self.info: raise DiskError(f'A crypt device ({self.path}) without a parent kernel device name.')
			return f"/dev/{self.info['pkname']}"

	@property
	def partitions(self):
		o = b''.join(sys_command(f'partprobe {self.path}'))

		parts = OrderedDict()
		#o = b''.join(sys_command('/usr/bin/lsblk -o name -J -b {dev}'.format(dev=dev)))
		o = b''.join(sys_command(f'/usr/bin/lsblk -J {self.path}'))
		if b'not a block device' in o:
			raise DiskError(f'Can not read partitions off something that isn\'t a block device: {self.path}')

		if not o[:1] == b'{':
			raise DiskError(f'Error getting JSON output from:', f'/usr/bin/lsblk -J {self.path}')

		r = json.loads(o.decode('UTF-8'))
		if len(r['blockdevices']) and 'children' in r['blockdevices'][0]:
			root_path = f"/dev/{r['blockdevices'][0]['name']}"
			for part in r['blockdevices'][0]['children']:
				part_id = part['name'][len(os.path.basename(self.path)):]
				parts[part_id] = {
					'size' : part['size'],
					'id' : part_id,
					'path' : root_path + part_id
				}

		return {k: parts[k] for k in sorted(parts)}

	@property
	def partition(self):
		all_partitions = self.partitions
		return [all_partitions[k] for k in all_partitions]

	def __repr__(self, *args, **kwargs):
		return f"BlockDevice({self.device})"

	def __getitem__(self, key, *args, **kwargs):
		if not key in self.info:
			raise KeyError(f'{self} does not contain information: "{key}"')
		return self.info[key]

class luks2():
	def __init__(self, filesystem):
		self.filesystem = filesystem

	def __enter__(self):
		return self

	def __exit__(self, *args, **kwargs):
		# TODO: https://stackoverflow.com/questions/28157929/how-to-safely-handle-an-exception-inside-a-context-manager
		if len(args):
			raise args[1]
		return True

	def encrypt(self, partition, password, key_size=512, hash_type='sha512', iter_time=10000, key_file=None):
		if not key_file: key_file = f'/tmp/{os.path.basename(self.filesystem.blockdevice.device)}.disk_pw' #TODO: Make disk-pw-file randomly unique?
		if type(password) != bytes: password = bytes(password, 'UTF-8')

		with open(key_file, 'wb') as fh:
			fh.write(password)

		o = b''.join(sys_command(f'/usr/bin/cryptsetup -q -v --type luks2 --pbkdf argon2i --hash {hash_type} --key-size {key_size} --iter-time {iter_time} --key-file {os.path.abspath(key_file)} --use-urandom luksFormat {partition["path"]}'))
		if not b'Command successful.' in o:
			raise DiskError(f'Could not encrypt volume "{partition["path"]}": {o}')
	
		return key_file

	def mount(self, partition, mountpoint, key_file):
		"""
		Mounts a lukts2 compatible partition to a certain mountpoint.
		Keyfile must be specified as there's no way to interact with the pw-prompt atm.

		:param mountpoint: The name without absolute path, for instance "luksdev" will point to /dev/mapper/luksdev
		:type mountpoint: str
		"""
		if '/' in mountpoint: os.path.basename(mountpoint) # TODO: Raise exception instead?
		sys_command(f'/usr/bin/cryptsetup open {partition["path"]} {mountpoint} --key-file {os.path.abspath(key_file)} --type luks2')
		return os.path.islink(f'/dev/mapper/{mountpoint}')

	def close(self, mountpoint):
		sys_command(f'cryptsetup close /dev/mapper/{mountpoint}')
		return os.path.islink(f'/dev/mapper/{mountpoint}') is False
		
class Filesystem():
	# TODO:
	#   When instance of a HDD is selected, check all usages and gracefully unmount them
	#   as well as close any crypto handles.
	def __init__(self, blockdevice, mode=GPT):
		self.blockdevice = blockdevice
		self.mode = mode

	def __enter__(self, *args, **kwargs):
		if self.mode == GPT:
			if sys_command(f'/usr/bin/parted -s {self.blockdevice.device} mklabel gpt',).exit_code == 0:
				return self
			else:
				raise DiskError(f'Problem setting the partition format to GPT:', f'/usr/bin/parted -s {self.blockdevice.device} mklabel gpt')
		else:
			raise DiskError(f'Unknown mode selected to format in: {self.mode}')

	def __exit__(self, *args, **kwargs):
		b''.join(sys_command(f'sync'))

	def raw_parted(self, string:str):
		x = sys_command(f'/usr/bin/parted -s {string}')
		o = b''.join(x)
		return x

	def parted(self, string:str):
		"""
		Performs a parted execution of the given string

		:param string: A raw string passed to /usr/bin/parted -s <string>
		:type string: str
		"""
		return self.raw_parted(string).exit_code

	def use_entire_disk(self, prep_mode=None):
		self.add_partition('primary', start='1MiB', end='513MiB', format='fat32')
		self.set_name(0, 'EFI')
		self.set(0, 'boot on')
		self.set(0, 'esp on') # TODO: Redundant, as in GPT mode it's an alias for "boot on"? https://www.gnu.org/software/parted/manual/html_node/set.html
		if prep_mode == 'luks2':
			self.add_partition('primary', start='513MiB', end='100%')
		else:
			self.add_partition('primary', start='1MiB', end='513MiB', format='ext4')

	def add_partition(self, type, start, end, format=None):
		if format:
			return self.parted(f'{self.blockdevice.device} mkpart {type} {format} {start} {end}') == 0
		else:
			return self.parted(f'{self.blockdevice.device} mkpart {type} {start} {end}') == 0

	def set_name(self, partition:int, name:str):
		return self.parted(f'{self.blockdevice.device} name {partition+1} "{name}"') == 0

	def set(self, partition:int, string:str):
		return self.parted(f'{self.blockdevice.device} set {partition+1} {string}') == 0

def device_state(name, *args, **kwargs):
	# Based out of: https://askubuntu.com/questions/528690/how-to-get-list-of-all-non-removable-disk-device-names-ssd-hdd-and-sata-ide-onl/528709#528709
	if os.path.isfile('/sys/block/{}/device/block/{}/removable'.format(name, name)):
		with open('/sys/block/{}/device/block/{}/removable'.format(name, name)) as f:
			if f.read(1) == '1':
				return

	path = ROOT_DIR_PATTERN.sub('', os.readlink('/sys/block/{}'.format(name)))
	hotplug_buses = ("usb", "ieee1394", "mmc", "pcmcia", "firewire")
	for bus in hotplug_buses:
		if os.path.exists('/sys/bus/{}'.format(bus)):
			for device_bus in os.listdir('/sys/bus/{}/devices'.format(bus)):
				device_link = ROOT_DIR_PATTERN.sub('', os.readlink('/sys/bus/{}/devices/{}'.format(bus, device_bus)))
				if re.search(device_link, path):
					return
	return True

# lsblk --json -l -n -o path
def all_disks(*args, **kwargs):
	if not 'partitions' in kwargs: kwargs['partitions'] = False
	drives = OrderedDict()
	#for drive in json.loads(sys_command(f'losetup --json', *args, **lkwargs, hide_from_log=True)).decode('UTF_8')['loopdevices']:
	for drive in json.loads(b''.join(sys_command(f'lsblk --json -l -n -o path,size,type,mountpoint,label,pkname', *args, **kwargs, hide_from_log=True)).decode('UTF_8'))['blockdevices']:
		if not kwargs['partitions'] and drive['type'] == 'part': continue

		drives[drive['path']] = BlockDevice(drive['path'], drive)
	return drives