import hashlib
import json
import logging
import os
import pty
import shlex
import sys
import time
from datetime import datetime, date
from select import epoll, EPOLLIN, EPOLLHUP
from typing import Union

from .exceptions import *
from .output import log


def gen_uid(entropy_length=256):
	return hashlib.sha512(os.urandom(entropy_length)).hexdigest()

def multisplit(s, splitters):
	s = [s,]
	for key in splitters:
		ns = []
		for obj in s:
			x = obj.split(key)
			for index, part in enumerate(x):
				if len(part):
					ns.append(part)
				if index < len(x)-1:
					ns.append(key)
		s = ns
	return s

def locate_binary(name):
	for PATH in os.environ['PATH'].split(':'):
		for root, folders, files in os.walk(PATH):
			for file in files:
				if file == name:
					return os.path.join(root, file)
			break # Don't recurse

class JSON_Encoder:
	def _encode(obj):
		if isinstance(obj, dict):
			## We'll need to iterate not just the value that default() usually gets passed
			## But also iterate manually over each key: value pair in order to trap the keys.

			copy = {}
			for key, val in list(obj.items()):
				if isinstance(val, dict):
					val = json.loads(json.dumps(val, cls=JSON)) # This, is a EXTREMELY ugly hack..
                                                            # But it's the only quick way I can think of to
                                                            # trigger a encoding of sub-dictionaries.
				else:
					val = JSON_Encoder._encode(val)

				if type(key) == str and key[0] == '!':
					copy[JSON_Encoder._encode(key)] = '******'
				else:
					copy[JSON_Encoder._encode(key)] = val
			return copy
		elif hasattr(obj, 'json'):
			return obj.json()
		elif hasattr(obj, '__dump__'):
			return obj.__dump__()
		elif isinstance(obj, (datetime, date)):
			return obj.isoformat()
		elif isinstance(obj, (list, set, tuple)):
			r = []
			for item in obj:
				r.append(json.loads(json.dumps(item, cls=JSON)))
			return r
		else:
			return obj

class JSON(json.JSONEncoder, json.JSONDecoder):
	def _encode(self, obj):
		return JSON_Encoder._encode(obj)

	def encode(self, obj):
		return super(JSON, self).encode(self._encode(obj))

class sys_command():#Thread):
	"""
	Stolen from archinstall_gui
	"""
	def __init__(self, cmd, callback=None, start_callback=None, peak_output=False, environment_vars={}, *args, **kwargs):
		kwargs.setdefault("worker_id", gen_uid())
		kwargs.setdefault("emulate", False)
		kwargs.setdefault("suppress_errors", False)

		self.log = kwargs.get('log', log)

		if kwargs['emulate']:
			self.log(f"Starting command '{cmd}' in emulation mode.", level=logging.DEBUG)

		if type(cmd) is list:
			# if we get a list of arguments
			self.raw_cmd = shlex.join(cmd)
			self.cmd = cmd
		else:
			# else consider it a single shell string
			# this should only be used if really necessary
			self.raw_cmd = cmd
			try:
				self.cmd = shlex.split(cmd)
			except Exception as e:
				raise ValueError(f'Incorrect string to split: {cmd}\n{e}')

		self.args = args
		self.kwargs = kwargs
		self.peak_output = peak_output
		self.environment_vars = environment_vars

		self.kwargs.setdefault("worker", None)
		self.callback = callback
		self.pid = None
		self.exit_code = None
		self.started = time.time()
		self.ended = None
		self.worker_id = kwargs['worker_id']
		self.trace_log = b''
		self.status = 'starting'

		user_catalogue = os.path.expanduser('~')

		if (workdir := kwargs.get('workdir', None)):
			self.cwd = workdir
			self.exec_dir = workdir
		else:
			self.cwd = f"{user_catalogue}/.cache/archinstall/workers/{kwargs['worker_id']}/"
			self.exec_dir = f'{self.cwd}/{os.path.basename(self.cmd[0])}_workingdir'

		if not self.cmd[0][0] == '/':
			# "which" doesn't work as it's a builtin to bash.
			# It used to work, but for whatever reason it doesn't anymore. So back to square one..

			#self.log('Worker command is not executed with absolute path, trying to find: {}'.format(self.cmd[0]), origin='spawn', level=5)
			#self.log('This is the binary {} for {}'.format(o.decode('UTF-8'), self.cmd[0]), origin='spawn', level=5)
			self.cmd[0] = locate_binary(self.cmd[0])

		if not os.path.isdir(self.exec_dir):
			os.makedirs(self.exec_dir)

		if start_callback:
			start_callback(self, *args, **kwargs)
		self.run()

	def __iter__(self, *args, **kwargs):
		for line in self.trace_log.split(b'\n'):
			yield line

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

	def decode(self, fmt='UTF-8'):
		return self.trace_log.decode(fmt)

	def dump(self):
		return {
			'status': self.status,
			'worker_id': self.worker_id,
			'worker_result': self.trace_log.decode('UTF-8'),
			'started': self.started,
			'ended': self.ended,
			'started_pprint': '{}-{}-{} {}:{}:{}'.format(*time.localtime(self.started)),
			'ended_pprint': '{}-{}-{} {}:{}:{}'.format(*time.localtime(self.ended)) if self.ended else None,
			'exit_code': self.exit_code
		}

	def peak(self, output : Union[str, bytes]) -> bool:
		if type(output) == bytes:
			try:
				output = output.decode('UTF-8')
			except UnicodeDecodeError:
				return False
		output = output.strip('\r\n ')
		if len(output) <= 0:
			return False

		if self.peak_output:
			from .user_interaction import get_terminal_width

			# Move back to the beginning of the terminal
			sys.stdout.flush()
			sys.stdout.write("\033[%dG" % 0)
			sys.stdout.flush()

			# Clear the line
			sys.stdout.write(" " * get_terminal_width())
			sys.stdout.flush()

			# Move back to the beginning again
			sys.stdout.flush()
			sys.stdout.write("\033[%dG" % 0)
			sys.stdout.flush()

			# And print the new output we're peaking on:
			sys.stdout.write(output)
			sys.stdout.flush()
		return True

	def run(self):
		self.status = 'running'
		old_dir = os.getcwd()
		os.chdir(self.exec_dir)
		self.pid, child_fd = pty.fork()
		if not self.pid: # Child process
			# Replace child process with our main process
			if not self.kwargs['emulate']:
				try:
					os.execve(self.cmd[0], self.cmd, {**os.environ, **self.environment_vars})
				except FileNotFoundError:
					self.status = 'done'
					self.log(f"{self.cmd[0]} does not exist.", level=logging.DEBUG)
					self.exit_code = 1
					return False

		os.chdir(old_dir)

		poller = epoll()
		poller.register(child_fd, EPOLLIN | EPOLLHUP)

		if 'events' in self.kwargs and 'debug' in self.kwargs:
			self.log(f'[D] Using triggers for command: {self.cmd}', level=logging.DEBUG)
			self.log(json.dumps(self.kwargs['events']), level=logging.DEBUG)

		alive = True
		last_trigger_pos = 0
		while alive and not self.kwargs['emulate']:
			for fileno, event in poller.poll(0.1):
				try:
					output = os.read(child_fd, 8192)
					self.peak(output)
					self.trace_log += output
				except OSError:
					alive = False
					break

				if 'debug' in self.kwargs and self.kwargs['debug'] and len(output):
					self.log(self.cmd, 'gave:', output.decode('UTF-8'), level=logging.DEBUG)

				if 'on_output' in self.kwargs:
					self.kwargs['on_output'](self.kwargs['worker'], output)

				lower = output.lower()
				broke = False
				if 'events' in self.kwargs:
					for trigger in list(self.kwargs['events']):
						if type(trigger) != bytes:
							original = trigger
							trigger = bytes(original, 'UTF-8')
							self.kwargs['events'][trigger] = self.kwargs['events'][original]
							del(self.kwargs['events'][original])
						if type(self.kwargs['events'][trigger]) != bytes:
							self.kwargs['events'][trigger] = bytes(self.kwargs['events'][trigger], 'UTF-8')

						if trigger.lower() in self.trace_log[last_trigger_pos:].lower():
							trigger_pos = self.trace_log[last_trigger_pos:].lower().find(trigger.lower())

							if 'debug' in self.kwargs and self.kwargs['debug']:
								self.log(f"Writing to subprocess {self.cmd[0]}: {self.kwargs['events'][trigger].decode('UTF-8')}", level=logging.DEBUG)
								self.log(f"Writing to subprocess {self.cmd[0]}: {self.kwargs['events'][trigger].decode('UTF-8')}", level=logging.DEBUG)

							last_trigger_pos = trigger_pos
							os.write(child_fd, self.kwargs['events'][trigger])
							del(self.kwargs['events'][trigger])
							broke = True
							break

					if broke:
						continue

					## Adding a exit trigger:
					if len(self.kwargs['events']) == 0:
						if 'debug' in self.kwargs and self.kwargs['debug']:
							self.log(f"Waiting for last command {self.cmd[0]} to finish.", level=logging.DEBUG)

						if bytes(f']$'.lower(), 'UTF-8') in self.trace_log[0-len(f']$')-5:].lower():
							if 'debug' in self.kwargs and self.kwargs['debug']:
								self.log(f"{self.cmd[0]} has finished.", level=logging.DEBUG)
							alive = False
							break

		self.status = 'done'

		if 'debug' in self.kwargs and self.kwargs['debug']:
			self.log(f"{self.cmd[0]} waiting for exit code.", level=logging.DEBUG)

		if not self.kwargs['emulate']:
			try:
				self.exit_code = os.waitpid(self.pid, 0)[1]
			except ChildProcessError:
				try:
					self.exit_code = os.waitpid(child_fd, 0)[1]
				except ChildProcessError:
					self.exit_code = 1
		else:
			self.exit_code = 0

		if 'debug' in self.kwargs and self.kwargs['debug']:
			self.log(f"{self.cmd[0]} got exit code: {self.exit_code}", level=logging.DEBUG)

		if 'ignore_errors' in self.kwargs:
			self.exit_code = 0

		if self.exit_code != 0 and not self.kwargs['suppress_errors']:
			#self.log(self.trace_log.decode('UTF-8'), level=logging.DEBUG)
			#self.log(f"'{self.raw_cmd}' did not exit gracefully, exit code {self.exit_code}.", level=logging.ERROR)
			raise SysCallError(message=f"{self.trace_log.decode('UTF-8')}\n'{self.raw_cmd}' did not exit gracefully (trace log above), exit code: {self.exit_code}", exit_code=self.exit_code)

		self.ended = time.time()
		with open(f'{self.cwd}/trace.log', 'wb') as fh:
			fh.write(self.trace_log)

		try:
			os.close(child_fd)
		except:
			pass


def prerequisite_check():
	if not os.path.isdir("/sys/firmware/efi"):
		raise RequirementError("Archinstall only supports machines in UEFI mode.")

	return True

def reboot():
	o = b''.join(sys_command("/usr/bin/reboot"))