import getpass, pathlib, os, shutil, re
import sys, time, signal
from .exceptions import *
from .profiles import Profile
from .locale_helpers import search_keyboard_layout
from .output import log, LOG_LEVELS
from .storage import storage
from .networking import list_interfaces
from .general import sys_command
from .hardware import AVAILABLE_GFX_DRIVERS, hasUEFI

## TODO: Some inconsistencies between the selection processes.
##       Some return the keys from the options, some the values?

def get_terminal_height():
	return shutil.get_terminal_size().lines

def get_terminal_width():
	return shutil.get_terminal_size().columns

def get_longest_option(options):
	return max([len(x) for x in options])

def check_for_correct_username(username):
	if re.match(r'^[a-z_][a-z0-9_-]*\$?$', username) and len(username) <= 32:
		return True
	log(
		"The username you entered is invalid. Try again",
		level=LOG_LEVELS.Warning,
		fg='red'
	)
	return False

def do_countdown():
	SIG_TRIGGER = False
	def kill_handler(sig, frame):
		print()
		exit(0)

	def sig_handler(sig, frame):
		global SIG_TRIGGER
		SIG_TRIGGER = True
		signal.signal(signal.SIGINT, kill_handler)

	original_sigint_handler = signal.getsignal(signal.SIGINT)
	signal.signal(signal.SIGINT, sig_handler)

	for i in range(5, 0, -1):
		print(f"{i}", end='')

		for x in range(4):
			sys.stdout.flush()
			time.sleep(0.25)
			print(".", end='')

		if SIG_TRIGGER:
			abort = input('\nDo you really want to abort (y/n)? ')
			if abort.strip() != 'n':
				exit(0)

			if SIG_TRIGGER is False:
				sys.stdin.read()
			SIG_TRIGGER = False
			signal.signal(signal.SIGINT, sig_handler)
	print()
	signal.signal(signal.SIGINT, original_sigint_handler)
	return True

def get_password(prompt="Enter a password: "):
	while (passwd := getpass.getpass(prompt)):
		passwd_verification = getpass.getpass(prompt='And one more time for verification: ')
		if passwd != passwd_verification:
			log(' * Passwords did not match * ', fg='red')
			continue

		if len(passwd.strip()) <= 0:
			break

		return passwd
	return None

def print_large_list(options, padding=5, margin_bottom=0, separator=': '):
	highest_index_number_length = len(str(len(options)))
	longest_line = highest_index_number_length + len(separator) + get_longest_option(options) + padding
	max_num_of_columns = get_terminal_width() // longest_line
	max_options_in_cells = max_num_of_columns * (get_terminal_height()-margin_bottom)

	if (len(options) > max_options_in_cells):
		for index, option in enumerate(options):
			print(f"{index}: {option}")
	else:
		for row in range(0, (get_terminal_height()-margin_bottom)):
			for column in range(row, len(options), (get_terminal_height()-margin_bottom)):
				spaces = " "*(longest_line - len(options[column]))
				print(f"{str(column): >{highest_index_number_length}}{separator}{options[column]}", end = spaces)
			print()

def ask_for_superuser_account(prompt='Create a required super-user with sudo privileges: ', forced=False):
	while 1:
		new_user = input(prompt).strip(' ')

		if not new_user and forced:
			# TODO: make this text more generic?
			#       It's only used to create the first sudo user when root is disabled in guided.py
			log(' * Since root is disabled, you need to create a least one (super) user!', fg='red')
			continue
		elif not new_user and not forced:
			raise UserError("No superuser was created.")
		elif not check_for_correct_username(new_user):
			continue

		password = get_password(prompt=f'Password for user {new_user}: ')
		return {new_user: {"!password" : password}}

def ask_for_additional_users(prompt='Any additional users to install (leave blank for no users): '):
	users = {}
	super_users = {}

	while 1:
		new_user = input(prompt).strip(' ')
		if not new_user:
			break
		if not check_for_correct_username(new_user):
			continue
		password = get_password(prompt=f'Password for user {new_user}: ')
		
		if input("Should this user be a sudo (super) user (y/N): ").strip(' ').lower() in ('y', 'yes'):
			super_users[new_user] = {"!password" : password}
		else:
			users[new_user] = {"!password" : password}

	return users, super_users

def ask_for_a_timezone():
	timezone = input('Enter a valid timezone (examples: Europe/Stockholm, US/Eastern) or press enter to use UTC: ').strip()
	if timezone == '':
		timezone = 'UTC'
	if (pathlib.Path("/usr")/"share"/"zoneinfo"/timezone).exists():
		return timezone
	else:
		log(
			f"Time zone {timezone} does not exist, continuing with system default.",
			level=LOG_LEVELS.Warning,
			fg='red'
		)

def ask_for_bootloader() -> str:
	bootloader = "systemd-bootctl"
	if hasUEFI()==False:
		bootloader="grub-install"
	else:
		bootloader_choice = input("Would you like to use GRUB as a bootloader instead of systemd-boot? [y/N] ").lower()
		if bootloader_choice == "y":
			bootloader="grub-install"
	return bootloader

def ask_for_audio_selection():
	audio = "pulseaudio" # Default for most desktop environments
	pipewire_choice = input("Would you like to install pipewire instead of pulseaudio as the default audio server? [Y/n] ").lower()
	if pipewire_choice in ("y", ""):
		audio = "pipewire"

	return audio

def ask_to_configure_network():
	# Optionally configure one network interface.
	#while 1:
	# {MAC: Ifname}
	interfaces = {'ISO-CONFIG' : 'Copy ISO network configuration to installation','NetworkManager':'Use NetworkManager to control and manage your internet connection', **list_interfaces()}

	nic = generic_select(interfaces.values(), "Select one network interface to configure (leave blank to skip): ")
	if nic and nic != 'Copy ISO network configuration to installation':
		if nic == 'Use NetworkManager to control and manage your internet connection':
			return {'nic': nic,'NetworkManager':True}
		mode = generic_select(['DHCP (auto detect)', 'IP (static)'], f"Select which mode to configure for {nic}: ")
		if mode == 'IP (static)':
			while 1:
				ip = input(f"Enter the IP and subnet for {nic} (example: 192.168.0.5/24): ").strip()
				if ip:
					break
				else:
					log(
						"You need to enter a valid IP in IP-config mode.",
						level=LOG_LEVELS.Warning,
						fg='red'
					)

			if not len(gateway := input('Enter your gateway (router) IP address or leave blank for none: ').strip()):
				gateway = None

			dns = None
			if len(dns_input := input('Enter your DNS servers (space separated, blank for none): ').strip()):
				dns = dns_input.split(' ')

			return {'nic': nic, 'dhcp': False, 'ip': ip, 'gateway' : gateway, 'dns' : dns}
		else:
			return {'nic': nic}
	elif nic:
		return nic

	return {}

def ask_for_disk_layout():
	options = {
		'keep-existing' : 'Keep existing partition layout and select which ones to use where.',
		'format-all' : 'Format entire drive and setup a basic partition scheme.',
		'abort' : 'Abort the installation.'
	}

	value = generic_select(options.values(), "Found partitions on the selected drive, (select by number) what you want to do: ")
	return next((key for key, val in options.items() if val == value), None)

def ask_for_main_filesystem_format():
	options = {
		'btrfs' : 'btrfs',
		'ext4' : 'ext4',
		'xfs' : 'xfs',
		'f2fs' : 'f2fs'
	}

	value = generic_select(options.values(), "Select which filesystem your main partition should use (by number or name): ")
	return next((key for key, val in options.items() if val == value), None)

def generic_select(options, input_text="Select one of the above by index or absolute value: ", sort=True):
	"""
	A generic select function that does not output anything
	other than the options and their indexes. As an example:

	generic_select(["first", "second", "third option"])
	1: first
	2: second
	3: third option
	"""

	if type(options) == dict: options = list(options)
	if sort: options = sorted(list(options))
	if len(options) <= 0: raise RequirementError('generic_select() requires at least one option to operate.')

	for index, option in enumerate(options):
		print(f"{index}: {option}")

	selected_option = input(input_text)
	if len(selected_option.strip()) <= 0:
		return None
	elif selected_option.isdigit():
		selected_option = int(selected_option)
		if selected_option > len(options):
			raise RequirementError(f'Selected option "{selected_option}" is out of range')
		selected_option = options[selected_option]
	elif selected_option in options:
		pass # We gave a correct absolute value
	else:
		raise RequirementError(f'Selected option "{selected_option}" does not exist in available options: {options}')
	
	return selected_option

def select_disk(dict_o_disks):
	"""
	Asks the user to select a harddrive from the `dict_o_disks` selection.
	Usually this is combined with :ref:`archinstall.list_drives`.

	:param dict_o_disks: A `dict` where keys are the drive-name, value should be a dict containing drive information.
	:type dict_o_disks: dict

	:return: The name/path (the dictionary key) of the selected drive
	:rtype: str
	"""
	drives = sorted(list(dict_o_disks.keys()))
	if len(drives) >= 1:
		for index, drive in enumerate(drives):
			print(f"{index}: {drive} ({dict_o_disks[drive]['size'], dict_o_disks[drive].device, dict_o_disks[drive]['label']})")
		drive = input('Select one of the above disks (by number or full path) or write /mnt to skip partitioning: ')
		if drive.strip() == '/mnt':
			return None
		elif drive.isdigit():
			drive = int(drive)
			if drive >= len(drives):
				raise DiskError(f'Selected option "{drive}" is out of range')
			drive = dict_o_disks[drives[drive]]
		elif drive in dict_o_disks:
			drive = dict_o_disks[drive]
		else:
			raise DiskError(f'Selected drive does not exist: "{drive}"')
		return drive

	raise DiskError('select_disk() requires a non-empty dictionary of disks to select from.')

def select_profile(options):
	"""
	Asks the user to select a profile from the `options` dictionary parameter.
	Usually this is combined with :ref:`archinstall.list_profiles`.

	:param options: A `dict` where keys are the profile name, value should be a dict containing profile information.
	:type options: dict

	:return: The name/dictionary key of the selected profile
	:rtype: str
	"""
	profiles = sorted(list(options))

	if len(profiles) >= 1:
		for index, profile in enumerate(profiles):
			print(f"{index}: {profile}")

		print(' -- The above list is a set of pre-programmed profiles. --')
		print(' -- They might make it easier to install things like desktop environments. --')
		print(' -- (Leave blank and hit enter to skip this step and continue) --')
		selected_profile = input('Enter a pre-programmed profile name if you want to install one: ')

		if len(selected_profile.strip()) <= 0:
			return None
			
		if selected_profile.isdigit() and (pos := int(selected_profile)) <= len(profiles)-1:
			selected_profile = profiles[pos]
		elif selected_profile in options:
			selected_profile = options[options.index(selected_profile)]
		else:
			RequirementError("Selected profile does not exist.")

		return Profile(None, selected_profile)

	raise RequirementError("Selecting profiles require a least one profile to be given as an option.")

def select_language(options, show_only_country_codes=True):
	"""
	Asks the user to select a language from the `options` dictionary parameter.
	Usually this is combined with :ref:`archinstall.list_keyboard_languages`.

	:param options: A `dict` where keys are the language name, value should be a dict containing language information.
	:type options: dict

	:param show_only_country_codes: Filters out languages that are not len(lang) == 2. This to limit the number of results from stuff like dvorak and x-latin1 alternatives.
	:type show_only_country_codes: bool

	:return: The language/dictionary key of the selected language
	:rtype: str
	"""
	DEFAULT_KEYBOARD_LANGUAGE = 'us'
	
	if show_only_country_codes:
		languages = sorted([language for language in list(options) if len(language) == 2])
	else:
		languages = sorted(list(options))

	if len(languages) >= 1:
		for index, language in enumerate(languages):
			print(f"{index}: {language}")

		print(' -- You can enter ? or help to search for more languages, or skip to use US layout --')
		selected_language = input('Select one of the above keyboard languages (by number or full name): ')
		
		if len(selected_language.strip()) == 0:
			return DEFAULT_KEYBOARD_LANGUAGE
		elif selected_language.lower() in ('?', 'help'):
			while True:
				filter_string = input('Search for layout containing (example: "sv-"): ')
				new_options = list(search_keyboard_layout(filter_string))

				if len(new_options) <= 0:
					log(f"Search string '{filter_string}' yielded no results, please try another search or Ctrl+D to abort.", fg='yellow')
					continue

				return select_language(new_options, show_only_country_codes=False)

		elif selected_language.isdigit() and (pos := int(selected_language)) <= len(languages)-1:
			selected_language = languages[pos]
			return selected_language
		# I'm leaving "options" on purpose here.
		# Since languages possibly contains a filtered version of
		# all possible language layouts, and we might want to write
		# for instance sv-latin1 (if we know that exists) without having to
		# go through the search step.
		elif selected_language in options:
			selected_language = options[options.index(selected_language)]
			return selected_language
		else:
			raise RequirementError("Selected language does not exist.")

	raise RequirementError("Selecting languages require a least one language to be given as an option.")

def select_mirror_regions(mirrors, show_top_mirrors=True):
	"""
	Asks the user to select a mirror or region from the `mirrors` dictionary parameter.
	Usually this is combined with :ref:`archinstall.list_mirrors`.

	:param mirrors: A `dict` where keys are the mirror region name, value should be a dict containing mirror information.
	:type mirrors: dict

	:param show_top_mirrors: Will limit the list to the top 10 fastest mirrors based on rank-mirror *(Currently not implemented but will be)*.
	:type show_top_mirrors: bool

	:return: The dictionary information about a mirror/region.
	:rtype: dict
	"""

	# TODO: Support multiple options and country codes, SE,UK for instance.
	regions = sorted(list(mirrors.keys()))
	selected_mirrors = {}

	if len(regions) >= 1:
		print_large_list(regions, margin_bottom=4)

		print(' -- You can skip this step by leaving the option blank --')
		selected_mirror = input('Select one of the above regions to download packages from (by number or full name): ')
		if len(selected_mirror.strip()) == 0:
			# Returning back empty options which can be both used to
			# do "if x:" logic as well as do `x.get('mirror', {}).get('sub', None)` chaining
			return {}

		elif selected_mirror.isdigit() and int(selected_mirror) <= len(regions)-1:
			# I'm leaving "mirrors" on purpose here.
			# Since region possibly contains a known region of
			# all possible regions, and we might want to write
			# for instance Sweden (if we know that exists) without having to
			# go through the search step.
			region = regions[int(selected_mirror)]
			selected_mirrors[region] = mirrors[region]
		elif selected_mirror in mirrors:
			selected_mirrors[selected_mirror] = mirrors[selected_mirror]
		else:
			raise RequirementError("Selected region does not exist.")

		return selected_mirrors

	raise RequirementError("Selecting mirror region require a least one region to be given as an option.")

def select_driver(options=AVAILABLE_GFX_DRIVERS):
	"""
	Some what convoluted function, which's job is simple.
	Select a graphics driver from a pre-defined set of popular options.

	(The template xorg is for beginner users, not advanced, and should
	there for appeal to the general public first and edge cases later)
	"""
	if len(options) >= 1:
		lspci = sys_command(f'/usr/bin/lspci')
		for line in lspci.trace_log.split(b'\r\n'):
			if b' vga ' in line.lower():
				if b'nvidia' in line.lower():
					print(' ** nvidia card detected, suggested driver: nvidia **')
				elif b'amd' in line.lower():
					print(' ** AMD card detected, suggested driver: AMD / ATI **')

		selected_driver = generic_select(options, input_text="Select your graphics card driver: ", sort=True)
		initial_option = selected_driver

		if type(options[initial_option]) == dict:
			driver_options = sorted(options[initial_option].keys())

			selected_driver_package_group = generic_select(driver_options, input_text=f"Which driver-type do you want for {initial_option}: ")
			if selected_driver_package_group in options[initial_option].keys():
				print(options[initial_option][selected_driver_package_group])
				selected_driver = options[initial_option][selected_driver_package_group]
			else:
				raise RequirementError(f"Selected driver-type does not exist for {initial_option}.")

			return selected_driver_package_group

		return selected_driver

	raise RequirementError("Selecting drivers require a least one profile to be given as an option.")