from __future__ import print_function
import tuned.admin
from tuned.utils.commands import commands
from tuned.profiles import Locator as profiles_locator
from .exceptions import TunedAdminDBusException
from tuned.exceptions import TunedException
import tuned.consts as consts
from tuned.utils.profile_recommender import ProfileRecommender
import os
import sys
import errno
import time
import threading
import logging

class Admin(object):
	def __init__(self, dbus = True, debug = False, asynco = False,
			timeout = consts.ADMIN_TIMEOUT,
			log_level = logging.ERROR):
		self._dbus = dbus
		self._debug = debug
		self._async = asynco
		self._timeout = timeout
		self._cmd = commands(debug)
		self._profiles_locator = profiles_locator(consts.LOAD_DIRECTORIES)
		self._daemon_action_finished = threading.Event()
		self._daemon_action_profile = ""
		self._daemon_action_result = True
		self._daemon_action_errstr = ""
		self._controller = None
		self._log_token = None
		self._log_level = log_level
		self._profile_recommender = ProfileRecommender()
		if self._dbus:
			self._controller = tuned.admin.DBusController(consts.DBUS_BUS, consts.DBUS_INTERFACE, consts.DBUS_OBJECT, debug)
			try:
				self._controller.set_signal_handler(consts.DBUS_SIGNAL_PROFILE_CHANGED, self._signal_profile_changed_cb)
			except TunedAdminDBusException as e:
				self._error(e)
				self._dbus = False

	def _error(self, message):
		print(message, file=sys.stderr)

	def _signal_profile_changed_cb(self, profile_name, result, errstr):
		# ignore successive signals if the signal is not yet processed
		if not self._daemon_action_finished.is_set():
			self._daemon_action_profile = profile_name
			self._daemon_action_result = result
			self._daemon_action_errstr = errstr
			self._daemon_action_finished.set()

	def _tuned_is_running(self):
		try:
			os.kill(int(self._cmd.read_file(consts.PID_FILE)), 0)
		except OSError as e:
			return e.errno == errno.EPERM
		except (ValueError, IOError) as e:
			return False
		return True

	# run the action specified by the action_name with args
	def action(self, action_name, *args, **kwargs):
		if action_name is None or action_name == "":
			return False
		action = None
		action_dbus = None
		res = False
		try:
			action_dbus = getattr(self, "_action_dbus_" + action_name)
		except AttributeError as e:
			self._dbus = False
		try:
			action = getattr(self, "_action_" + action_name)
		except AttributeError as e:
			if not self._dbus:
				self._error(str(e) + ", action '%s' is not implemented" % action_name)
				return False
		if self._dbus:
			try:
				self._controller.set_on_exit_action(
						self._log_capture_finish)
				self._controller.set_action(action_dbus, *args, **kwargs)
				res = self._controller.run()
			except TunedAdminDBusException as e:
				self._error(e)
				self._dbus = False

		if not self._dbus:
			res = action(*args, **kwargs)
		return res

	def _print_profiles(self, profile_names):
		print("Available profiles:")
		for profile in profile_names:
			if profile[1] is not None and profile[1] != "":
				print(self._cmd.align_str("- %s" % profile[0], 30, "- %s" % profile[1]))
			else:
				print("- %s" % profile[0])

	def _action_dbus_list_profiles(self):
		try:
			profile_names = self._controller.profiles2()
		except TunedAdminDBusException as e:
			# fallback to older API
			profile_names = [(profile, "") for profile in self._controller.profiles()]
		self._print_profiles(profile_names)
		self._action_dbus_active()
		return self._controller.exit(True)

	def _action_list_profiles(self):
		self._print_profiles(self._profiles_locator.get_known_names_summary())
		self._action_active()
		return True

	def _dbus_get_active_profile(self):
		profile_name = self._controller.active_profile()
		if profile_name == "":
			profile_name = None
		self._controller.exit(True)
		return profile_name

	def _get_active_profile(self):
		profile_name, manual = self._cmd.get_active_profile()
		return profile_name

	def _get_profile_mode(self):
		(profile, manual) = self._cmd.get_active_profile()
		if manual is None:
			manual = profile is not None
		return consts.ACTIVE_PROFILE_MANUAL if manual else consts.ACTIVE_PROFILE_AUTO

	def _print_profile_info(self, profile, profile_info):
		if profile_info[0] == True:
			print("Profile name:")
			print(profile_info[1])
			print()
			print("Profile summary:")
			print(profile_info[2])
			print()
			print("Profile description:")
			print(profile_info[3])
			return True
		else:
			print("Unable to get information about profile '%s'" % profile)
			return False

	def _action_dbus_profile_info(self, profile = ""):
		if profile == "":
			profile = self._dbus_get_active_profile()
		return self._controller.exit(self._print_profile_info(profile, self._controller.profile_info(profile)))

	def _action_profile_info(self, profile = ""):
		if profile == "":
			try:
				profile = self._get_active_profile()
				if profile is None:
					print("No current active profile.")
					return False
			except TunedException as e:
				self._error(str(e))
				return False
		return self._print_profile_info(profile, self._profiles_locator.get_profile_attrs(profile, [consts.PROFILE_ATTR_SUMMARY, consts.PROFILE_ATTR_DESCRIPTION], ["", ""]))

	def _print_profile_name(self, profile_name):
		if profile_name is None:
			print("No current active profile.")
			return False
		else:
			print("Current active profile: %s" % profile_name)
		return True

	def _action_dbus_active(self):
		return self._controller.exit(self._print_profile_name(self._dbus_get_active_profile()))

	def _action_active(self):
		try:
			profile_name = self._get_active_profile()
		except TunedException as e:
			self._error(str(e))
			return False
		if profile_name is not None and not self._tuned_is_running():
			print("It seems that tuned daemon is not running, preset profile is not activated.")
			print("Preset profile: %s" % profile_name)
			return True
		return self._print_profile_name(profile_name)

	def _print_profile_mode(self, mode):
		print("Profile selection mode: " + mode)

	def _action_dbus_profile_mode(self):
		mode, error = self._controller.profile_mode()
		self._print_profile_mode(mode)
		if error != "":
			self._error(error)
			return self._controller.exit(False)
		return self._controller.exit(True)

	def _action_profile_mode(self):
		try:
			mode = self._get_profile_mode()
			self._print_profile_mode(mode)
			return True
		except TunedException as e:
			self._error(str(e))
			return False

	def _profile_print_status(self, ret, msg):
		if ret:
			if not self._controller.is_running() and not self._controller.start():
				self._error("Cannot enable the tuning.")
				ret = False
		else:
			self._error(msg)
		return ret

	def _action_dbus_wait_profile(self, profile_name):
		if time.time() >= self._timestamp + self._timeout:
			print("Operation timed out after waiting %d seconds(s), you may try to increase timeout by using --timeout command line option or using --async." % self._timeout)
			return self._controller.exit(False)
		if self._daemon_action_finished.isSet():
			if self._daemon_action_profile == profile_name:
				if not self._daemon_action_result:
					print("Error changing profile: %s" % self._daemon_action_errstr)
					return self._controller.exit(False)
				return self._controller.exit(True)
		return False

	def _log_capture_finish(self):
		if self._log_token is None or self._log_token == "":
			return
		try:
			log_msgs = self._controller.log_capture_finish(
					self._log_token)
			self._log_token = None
			print(log_msgs, end = "", file = sys.stderr)
			sys.stderr.flush()
		except TunedAdminDBusException as e:
			self._error("Error: Failed to stop log capture. Restart the Tuned daemon to prevent a memory leak.")

	def _action_dbus_profile(self, profiles):
		if len(profiles) == 0:
			return self._action_dbus_list()
		profile_name = " ".join(profiles)
		if profile_name == "":
			return self._controller.exit(False)
		self._daemon_action_finished.clear()
		if not self._async and self._log_level is not None:
			# 25 seconds default DBus timeout + 5 secs safety margin
			timeout = self._timeout + 25 + 5
			self._log_token = self._controller.log_capture_start(
					self._log_level, timeout)
		(ret, msg) = self._controller.switch_profile(profile_name)
		if self._async or not ret:
			return self._controller.exit(self._profile_print_status(ret, msg))
		else:
			self._timestamp = time.time()
			self._controller.set_action(self._action_dbus_wait_profile, profile_name)
		return self._profile_print_status(ret, msg)

	def _restart_tuned(self):
		print("Trying to (re)start tuned...")
		(ret, msg) = self._cmd.execute(["service", "tuned", "restart"])
		if ret == 0:
			print("Tuned (re)started, changes applied.")
		else:
			print("Tuned (re)start failed, you need to (re)start tuned by hand for changes to apply.")

	def _set_profile(self, profile_name, manual):
		if profile_name in self._profiles_locator.get_known_names():
			try:
				self._cmd.save_active_profile(profile_name, manual)
				self._restart_tuned()
				return True
			except TunedException as e:
				self._error(str(e))
				self._error("Unable to switch profile.")
				return False
		else:
			self._error("Requested profile '%s' doesn't exist." % profile_name)
			return False

	def _action_profile(self, profiles):
		if len(profiles) == 0:
			return self._action_list_profiles()
		profile_name = " ".join(profiles)
		if profile_name == "":
			return False
		return self._set_profile(profile_name, True)

	def _action_dbus_auto_profile(self):
		profile_name = self._controller.recommend_profile()
		self._daemon_action_finished.clear()
		if not self._async and self._log_level is not None:
			# 25 seconds default DBus timeout + 5 secs safety margin
			timeout = self._timeout + 25 + 5
			self._log_token = self._controller.log_capture_start(
					self._log_level, timeout)
		(ret, msg) = self._controller.auto_profile()
		if self._async or not ret:
			return self._controller.exit(self._profile_print_status(ret, msg))
		else:
			self._timestamp = time.time()
			self._controller.set_action(self._action_dbus_wait_profile, profile_name)
		return self._profile_print_status(ret, msg)

	def _action_auto_profile(self):
		profile_name = self._profile_recommender.recommend()
		return self._set_profile(profile_name, False)

	def _action_dbus_recommend_profile(self):
		print(self._controller.recommend_profile())
		return self._controller.exit(True)

	def _action_recommend_profile(self):
		print(self._profile_recommender.recommend())
		return True

	def _action_dbus_verify_profile(self, ignore_missing):
		if ignore_missing:
			ret = self._controller.verify_profile_ignore_missing()
		else:
			ret = self._controller.verify_profile()
		if ret:
			print("Verfication succeeded, current system settings match the preset profile.")
		else:
			print("Verification failed, current system settings differ from the preset profile.")
			print("You can mostly fix this by restarting the Tuned daemon, e.g.:")
			print("  systemctl restart tuned")
			print("or")
			print("  service tuned restart")
			print("Sometimes (if some plugins like bootloader are used) a reboot may be required.")
		print("See tuned log file ('%s') for details." % consts.LOG_FILE)
		return self._controller.exit(ret)

	def _action_verify_profile(self, ignore_missing):
		print("Not supported in no_daemon mode.")
		return False

	def _action_dbus_off(self):
		# 25 seconds default DBus timeout + 5 secs safety margin
		timeout = 25 + 5
		self._log_token = self._controller.log_capture_start(
				self._log_level, timeout)
		ret = self._controller.off()
		if not ret:
			self._error("Cannot disable active profile.")
		return self._controller.exit(ret)

	def _action_off(self):
		print("Not supported in no_daemon mode.")
		return False

	def _action_dbus_list(self, list_choice="profiles", verbose=False):
		"""Print accessible profiles or plugins got from tuned dbus api

		Keyword arguments:
		list_choice -- argument from command line deciding what will be listed
		verbose -- if True then list plugin's config options and their hints
			if possible. Functional only with plugin listing, with profiles
			this argument is omitted
		"""
		if list_choice == "profiles":
			return self._action_dbus_list_profiles()
		elif list_choice == "plugins":
			return self._action_dbus_list_plugins(verbose=verbose)

	def _action_list(self, list_choice="profiles", verbose=False):
		"""Print accessible profiles or plugins with no daemon mode

		Keyword arguments:
		list_choice -- argument from command line deciding what will be listed
		verbose -- Plugins cannot be listed in this mode, so verbose argument
			is here only because argparse module always supplies verbose
			option and if verbose was not here it would result in error
		"""
		if list_choice == "profiles":
			return self._action_list_profiles()
		elif list_choice == "plugins":
			return self._action_list_plugins(verbose=verbose)

	def _action_dbus_list_plugins(self, verbose=False):
		"""Print accessible plugins

		Keyword arguments:
		verbose -- if is set to True then parameters and hints are printed
		"""
		plugins = self._controller.get_plugins()
		for plugin in plugins.keys():
			print(plugin)
			if not verbose or len(plugins[plugin]) == 0:
				continue
			hints = self._controller.get_plugin_hints(plugin)
			for parameter in plugins[plugin]:
				print("\t%s" %(parameter))
				hint = hints.get(parameter, None)
				if hint:
					print("\t\t%s" %(hint))
		return self._controller.exit(True)

	def _action_list_plugins(self, verbose=False):
		print("Not supported in no_daemon mode.")
		return False