import glob
import pathlib
import time
import logging
import json
import os
import hashlib
from typing import Optional, Dict, Any, List, Union

from .blockdevice import BlockDevice
from .helpers import get_mount_info, get_filesystem_type, convert_size_to_gb, split_bind_name
from ..storage import storage
from ..exceptions import DiskError, SysCallError, UnknownFilesystemFormat
from ..output import log
from ..general import SysCommand


class Partition:
	def __init__(self,
		path: str,
		block_device: BlockDevice,
		part_id :Optional[str] = None,
		filesystem :Optional[str] = None,
		mountpoint :Optional[str] = None,
		encrypted :bool = False,
		autodetect_filesystem :bool = True):

		if not part_id:
			part_id = os.path.basename(path)

		self.block_device = block_device
		self.path = path
		self.part_id = part_id
		self.mountpoint = mountpoint
		self.target_mountpoint = mountpoint
		self.filesystem = filesystem
		self._encrypted = None
		self.encrypted = encrypted
		self.allow_formatting = False

		if mountpoint:
			self.mount(mountpoint)

		try:
			mount_information = get_mount_info(self.path)
		except DiskError:
			mount_information = {}

		if self.mountpoint != mount_information.get('target', None) and mountpoint:
			raise DiskError(f"{self} was given a mountpoint but the actual mountpoint differs: {mount_information.get('target', None)}")

		if target := mount_information.get('target', None):
			self.mountpoint = target

		if not self.filesystem and autodetect_filesystem:
			if fstype := mount_information.get('fstype', get_filesystem_type(path)):
				self.filesystem = fstype

		if self.filesystem == 'crypto_LUKS':
			self.encrypted = True

	def __lt__(self, left_comparitor :BlockDevice) -> bool:
		if type(left_comparitor) == Partition:
			left_comparitor = left_comparitor.path
		else:
			left_comparitor = str(left_comparitor)

		# The goal is to check if /dev/nvme0n1p1 comes before /dev/nvme0n1p5
		return self.path < left_comparitor

	def __repr__(self, *args :str, **kwargs :str) -> str:
		mount_repr = ''
		if self.mountpoint:
			mount_repr = f", mounted={self.mountpoint}"
		elif self.target_mountpoint:
			mount_repr = f", rel_mountpoint={self.target_mountpoint}"

		if self._encrypted:
			return f'Partition(path={self.path}, size={self.size}, PARTUUID={self._safe_uuid}, parent={self.real_device}, fs={self.filesystem}{mount_repr})'
		else:
			return f'Partition(path={self.path}, size={self.size}, PARTUUID={self._safe_uuid}, fs={self.filesystem}{mount_repr})'

	def __dump__(self) -> Dict[str, Any]:
		return {
			'type': 'primary',
			'PARTUUID': self._safe_uuid,
			'wipe': self.allow_formatting,
			'boot': self.boot,
			'ESP': self.boot,
			'mountpoint': self.target_mountpoint,
			'encrypted': self._encrypted,
			'start': self.start,
			'size': self.end,
			'filesystem': {
				'format': get_filesystem_type(self.path)
			}
		}

	@property
	def sector_size(self) -> Optional[int]:
		output = json.loads(SysCommand(f"lsblk --json -o+LOG-SEC {self.device_path}").decode('UTF-8'))

		for device in output['blockdevices']:
			return device.get('log-sec', None)

	@property
	def start(self) -> Optional[str]:
		output = json.loads(SysCommand(f"sfdisk --json {self.block_device.path}").decode('UTF-8'))

		for partition in output.get('partitiontable', {}).get('partitions', []):
			if partition['node'] == self.path:
				return partition['start']  # * self.sector_size

	@property
	def end(self) -> Optional[str]:
		# TODO: Verify that the logic holds up, that 'size' is the size without 'start' added to it.
		output = json.loads(SysCommand(f"sfdisk --json {self.block_device.path}").decode('UTF-8'))

		for partition in output.get('partitiontable', {}).get('partitions', []):
			if partition['node'] == self.path:
				return partition['size']  # * self.sector_size

	@property
	def size(self) -> Optional[float]:
		for i in range(storage['DISK_RETRY_ATTEMPTS']):
			self.partprobe()

			if (handle := SysCommand(f"lsblk --json -b -o+SIZE {self.device_path}")).exit_code == 0:
				lsblk = json.loads(handle.decode('UTF-8'))

				for device in lsblk['blockdevices']:
					return convert_size_to_gb(device['size'])

			time.sleep(storage['DISK_TIMEOUTS'])

	@property
	def boot(self) -> bool:
		output = json.loads(SysCommand(f"sfdisk --json {self.block_device.path}").decode('UTF-8'))

		# Get the bootable flag from the sfdisk output:
		# {
		#    "partitiontable": {
		#       "device":"/dev/loop0",
		#       "partitions": [
		#          {"node":"/dev/loop0p1", "start":2048, "size":10483712, "type":"83", "bootable":true}
		#       ]
		#    }
		# }

		for partition in output.get('partitiontable', {}).get('partitions', []):
			if partition['node'] == self.path:
				return partition.get('bootable', False)

		return False

	@property
	def partition_type(self) -> Optional[str]:
		lsblk = json.loads(SysCommand(f"lsblk --json -o+PTTYPE {self.device_path}").decode('UTF-8'))

		for device in lsblk['blockdevices']:
			return device['pttype']

	@property
	def uuid(self) -> Optional[str]:
		"""
		Returns the PARTUUID as returned by lsblk.
		This is more reliable than relying on /dev/disk/by-partuuid as
		it doesn't seam to be able to detect md raid partitions.
		For bind mounts all the subvolumes share the same uuid
		"""
		for i in range(storage['DISK_RETRY_ATTEMPTS']):
			self.partprobe()

			partuuid = self._safe_uuid
			if partuuid:
				return partuuid

			time.sleep(storage['DISK_TIMEOUTS'])

		raise DiskError(f"Could not get PARTUUID for {self.path} using 'blkid -s PARTUUID -o value {self.path}'")

	@property
	def _safe_uuid(self) -> Optional[str]:
		"""
		A near copy of self.uuid but without any delays.
		This function should only be used where uuid is not crucial.
		For instance when you want to get a __repr__ of the class.
		"""
		self.partprobe()
		return SysCommand(f'blkid -s PARTUUID -o value {self.device_path}').decode('UTF-8').strip()

	@property
	def encrypted(self) -> Union[bool, None]:
		return self._encrypted

	@encrypted.setter
	def encrypted(self, value: bool) -> None:
		self._encrypted = value

	@property
	def parent(self) -> str:
		return self.real_device

	@property
	def real_device(self) -> str:
		for blockdevice in json.loads(SysCommand('lsblk -J').decode('UTF-8'))['blockdevices']:
			if parent := self.find_parent_of(blockdevice, os.path.basename(self.device_path)):
				return f"/dev/{parent}"
		# 	raise DiskError(f'Could not find appropriate parent for encrypted partition {self}')
		return self.path

	@property
	def device_path(self) -> str:
		""" for bind mounts returns the phisical path of the partition
		"""
		device_path, bind_name = split_bind_name(self.path)
		return device_path

	@property
	def bind_name(self) -> str:
		""" for bind mounts returns the bind name (subvolume path).
		Returns none if this property does not exist
		"""
		device_path, bind_name = split_bind_name(self.path)
		return bind_name

	def partprobe(self) -> bool:
		if SysCommand(f'bash -c "partprobe"').exit_code == 0:
			time.sleep(1)
			return True
		return False

	def detect_inner_filesystem(self, password :str) -> Optional[str]:
		log(f'Trying to detect inner filesystem format on {self} (This might take a while)', level=logging.INFO)
		from ..luks import luks2

		try:
			with luks2(self, storage.get('ENC_IDENTIFIER', 'ai') + 'loop', password, auto_unmount=True) as unlocked_device:
				return unlocked_device.filesystem
		except SysCallError:
			return None

	def has_content(self) -> bool:
		fs_type = get_filesystem_type(self.path)
		if not fs_type or "swap" in fs_type:
			return False

		temporary_mountpoint = '/tmp/' + hashlib.md5(bytes(f"{time.time()}", 'UTF-8') + os.urandom(12)).hexdigest()
		temporary_path = pathlib.Path(temporary_mountpoint)

		temporary_path.mkdir(parents=True, exist_ok=True)
		if (handle := SysCommand(f'/usr/bin/mount {self.path} {temporary_mountpoint}')).exit_code != 0:
			raise DiskError(f'Could not mount and check for content on {self.path} because: {b"".join(handle)}')

		files = len(glob.glob(f"{temporary_mountpoint}/*"))
		iterations = 0
		while SysCommand(f"/usr/bin/umount -R {temporary_mountpoint}").exit_code != 0 and (iterations := iterations + 1) < 10:
			time.sleep(1)

		temporary_path.rmdir()

		return True if files > 0 else False

	def encrypt(self, *args :str, **kwargs :str) -> str:
		"""
		A wrapper function for luks2() instances and the .encrypt() method of that instance.
		"""
		from ..luks import luks2

		handle = luks2(self, None, None)
		return handle.encrypt(self, *args, **kwargs)

	def format(self, filesystem :Optional[str] = None, path :Optional[str] = None, log_formatting :bool = True, options :List[str] = []) -> bool:
		"""
		Format can be given an overriding path, for instance /dev/null to test
		the formatting functionality and in essence the support for the given filesystem.
		"""
		if filesystem is None:
			filesystem = self.filesystem

		if path is None:
			path = self.path

		# To avoid "unable to open /dev/x: No such file or directory"
		start_wait = time.time()
		while pathlib.Path(path).exists() is False and time.time() - start_wait < 10:
			time.sleep(0.025)

		if log_formatting:
			log(f'Formatting {path} -> {filesystem}', level=logging.INFO)

		if filesystem == 'btrfs':
			options = ['-f'] + options

			if 'UUID:' not in (mkfs := SysCommand(f"/usr/bin/mkfs.btrfs {' '.join(options)} {path}").decode('UTF-8')):
				raise DiskError(f'Could not format {path} with {filesystem} because: {mkfs}')
			self.filesystem = filesystem

		elif filesystem == 'fat32':
			options = ['-F32'] + options

			if (handle := SysCommand(f"/usr/bin/mkfs.vfat {' '.join(options)} {path}")).exit_code != 0:
				raise DiskError(f"Could not format {path} with {filesystem} because: {handle.decode('UTF-8')}")
			self.filesystem = filesystem

		elif filesystem == 'ext4':
			options = ['-F'] + options

			if (handle := SysCommand(f"/usr/bin/mkfs.ext4 {' '.join(options)} {path}")).exit_code != 0:
				raise DiskError(f"Could not format {path} with {filesystem} because: {handle.decode('UTF-8')}")
			self.filesystem = filesystem

		elif filesystem == 'ext2':
			options = ['-F'] + options

			if (handle := SysCommand(f"/usr/bin/mkfs.ext2 {' '.join(options)} {path}")).exit_code != 0:
				raise DiskError(f'Could not format {path} with {filesystem} because: {b"".join(handle)}')
			self.filesystem = 'ext2'

		elif filesystem == 'xfs':
			options = ['-f'] + options

			if (handle := SysCommand(f"/usr/bin/mkfs.xfs {' '.join(options)} {path}")).exit_code != 0:
				raise DiskError(f"Could not format {path} with {filesystem} because: {handle.decode('UTF-8')}")
			self.filesystem = filesystem

		elif filesystem == 'f2fs':
			options = ['-f'] + options

			if (handle := SysCommand(f"/usr/bin/mkfs.f2fs {' '.join(options)} {path}")).exit_code != 0:
				raise DiskError(f"Could not format {path} with {filesystem} because: {handle.decode('UTF-8')}")
			self.filesystem = filesystem

		elif filesystem == 'ntfs':
			options = ['-f'] + options

			if (handle := SysCommand(f"/usr/bin/mkfs.ntfs -Q {' '.join(options)} {path}")).exit_code != 0:
				raise DiskError(f"Could not format {path} with {filesystem} because: {handle.decode('UTF-8')}")
			self.filesystem = filesystem

		elif filesystem == 'crypto_LUKS':
			# 	from ..luks import luks2
			# 	encrypted_partition = luks2(self, None, None)
			# 	encrypted_partition.format(path)
			self.filesystem = filesystem

		else:
			raise UnknownFilesystemFormat(f"Fileformat '{filesystem}' is not yet implemented.")

		if get_filesystem_type(path) == 'crypto_LUKS' or get_filesystem_type(self.real_device) == 'crypto_LUKS':
			self.encrypted = True
		else:
			self.encrypted = False

		return True

	def find_parent_of(self, data :Dict[str, Any], name :str, parent :Optional[str] = None) -> Optional[str]:
		if data['name'] == name:
			return parent
		elif 'children' in data:
			for child in data['children']:
				if parent := self.find_parent_of(child, name, parent=data['name']):
					return parent

	def mount(self, target :str, fs :Optional[str] = None, options :str = '') -> bool:
		if not self.mountpoint:
			log(f'Mounting {self} to {target}', level=logging.INFO)
			if not fs:
				if not self.filesystem:
					raise DiskError(f'Need to format (or define) the filesystem on {self} before mounting.')
				fs = self.filesystem

			fs_type = get_mount_fs_type(fs)

			pathlib.Path(target).mkdir(parents=True, exist_ok=True)

			if self.bind_name:
				device_path = self.device_path
				# TODO options should be better be a list than a string
				if options:
					options = f"{options},subvol={self.bind_name}"
				else:
					options = f"subvol={self.bind_name}"
			else:
				device_path = self.path
			try:
				if options:
					mnt_handle = SysCommand(f"/usr/bin/mount -t {fs_type} -o {options} {device_path} {target}")
				else:
					mnt_handle = SysCommand(f"/usr/bin/mount -t {fs_type} {device_path} {target}")

				# TODO: Should be redundant to check for exit_code
				if mnt_handle.exit_code != 0:
					raise DiskError(f"Could not mount {self.path} to {target} using options {options}")
			except SysCallError as err:
				raise err

			self.mountpoint = target
			return True

		return False

	def unmount(self) -> bool:
		worker = SysCommand(f"/usr/bin/umount {self.path}")
			
		# Without to much research, it seams that low error codes are errors.
		# And above 8k is indicators such as "/dev/x not mounted.".
		# So anything in between 0 and 8k are errors (?).
		if 0 < worker.exit_code < 8000:
			raise SysCallError(f"Could not unmount {self.path} properly: {worker}", exit_code=worker.exit_code)

		self.mountpoint = None
		return True

	def umount(self) -> bool:
		return self.unmount()

	def filesystem_supported(self) -> bool:
		"""
		The support for a filesystem (this partition) is tested by calling
		partition.format() with a path set to '/dev/null' which returns two exceptions:
			1. SysCallError saying that /dev/null is not formattable - but the filesystem is supported
			2. UnknownFilesystemFormat that indicates that we don't support the given filesystem type
		"""
		try:
			self.format(self.filesystem, '/dev/null', log_formatting=False, allow_formatting=True)
		except (SysCallError, DiskError):
			pass  # We supported it, but /dev/null is not formattable as expected so the mkfs call exited with an error code
		except UnknownFilesystemFormat as err:
			raise err
		return True


def get_mount_fs_type(fs :str) -> str:
	if fs == 'ntfs':
		return 'ntfs3'  # Needed to use the Paragon R/W NTFS driver
	elif fs == 'fat32':
		return 'vfat'  # This is the actual type used for fat32 mounting
	return fs