import glob
import pathlib
import time
import logging
import json
import os
import hashlib
from typing import Optional
from .blockdevice import BlockDevice
from .exceptions import DiskError, SysCallError, UnknownFilesystemFormat
from .helpers import get_mount_info, get_filesystem_type
from .storage import storage
from ..output import log
from ..general import SysCommand

class Partition:
	def __init__(self, path: str, block_device: BlockDevice, part_id=None, size=-1, filesystem=None, mountpoint=None, encrypted=False, autodetect_filesystem=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.size = size  # TODO: Refresh?
		self._encrypted = None
		self.encrypted = encrypted
		self.allow_formatting = False

		if mountpoint:
			self.mount(mountpoint)

		mount_information = get_mount_info(self.path)

		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):
		if type(left_comparitor) == Partition:
			left_comparitor = left_comparitor.path
		else:
			left_comparitor = str(left_comparitor)
		return self.path < left_comparitor  # Not quite sure the order here is correct. But /dev/nvme0n1p1 comes before /dev/nvme0n1p5 so seems correct.

	def __repr__(self, *args, **kwargs):
		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.uuid}, parent={self.real_device}, fs={self.filesystem}{mount_repr})'
		else:
			return f'Partition(path={self.path}, size={self.size}, PARTUUID={self.uuid}, fs={self.filesystem}{mount_repr})'

	def __dump__(self):
		return {
			'type' : 'primary',
			'PARTUUID' : self.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):
		output = json.loads(SysCommand(f"lsblk --json -o+LOG-SEC {self.path}").decode('UTF-8'))

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

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

		# Get the bootable flag from the sfdisk output:
		# {
		#    "partitiontable": {
		#       "label":"dos",
		#       "id":"0xd202c10a",
		#       "device":"/dev/loop0",
		#       "unit":"sectors",
		#       "sectorsize":512,
		#       "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):
		lsblk = json.loads(SysCommand(f"lsblk --json -o+PTTYPE {self.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.
		"""

		lsblk = json.loads(SysCommand(f'lsblk -J -o+PARTUUID {self.path}').decode('UTF-8'))
		for partition in lsblk['blockdevices']:
			return partition.get('partuuid', None)
		return None

	@property
	def encrypted(self):
		return self._encrypted

	@encrypted.setter
	def encrypted(self, value: bool):

		self._encrypted = value

	@property
	def parent(self):
		return self.real_device

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

	def detect_inner_filesystem(self, password):
		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):
		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, **kwargs):
		"""
		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=None, path=None, log_formatting=True, options=[]):
		"""
		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

			mkfs = SysCommand(f"/usr/bin/mkfs.vfat {' '.join(options)} {path}").decode('UTF-8')
			if ('mkfs.fat' not in mkfs and 'mkfs.vfat' not in mkfs) or 'command not found' in mkfs:
				raise DiskError(f"Could not format {path} with {filesystem} because: {mkfs}")
			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 == '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, name, parent=None):
		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, fs=None, options=''):
		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

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

			try:
				if options:
					SysCommand(f"/usr/bin/mount -o {options} {self.path} {target}")
				else:
					SysCommand(f"/usr/bin/mount {self.path} {target}")
			except SysCallError as err:
				raise err

			self.mountpoint = target
			return True

	def unmount(self):
		try:
			SysCommand(f"/usr/bin/umount {self.path}")
		except SysCallError as err:
			exit_code = err.exit_code

			# 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 < exit_code < 8000:
				raise err

		self.mountpoint = None
		return True

	def umount(self):
		return self.unmount()

	def filesystem_supported(self):
		"""
		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 formatable as expected so the mkfs call exited with an error code
		except UnknownFilesystemFormat as err:
			raise err
		return True