"""Miscellaneous class and functions used in utils script."""

"""
This program is free software: you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program. If not, see <https://www.gnu.org/licenses/>.
"""

__author__ = "Théo de la Hogue"
__credits__ = []
__copyright__ = "Copyright 2023, Ecole Nationale de l'Aviation Civile (ENAC)"
__license__ = "GPLv3"

import os
import pathlib
import time
import csv
import types
import traceback

from argaze import DataFeatures

import numpy
import cv2

def print_progress_bar (iteration:int, total:int, prefix:str = '', suffix:str = '', decimals:int = 1, length:int = 100, fill:str = '█', printEnd:str = "\r"):
	"""
	Print iterations progress.  
	Call in a loop to create terminal progress bar.  

	Parameters:
		iteration: current iteration  
		total: total iterations  
		prefix: string to print before progress bar
		suffix: string to print after progress bar
		decimals: positive number of decimals in percent complete  
		length: character length of bar  
		fill: bar fill character  
		printEnd: end character (e.g. \\r, \\r\\n)
	"""
	percent = ("{0:." + str(decimals) + "f}").format(100 * (iteration / float(total)))
	filledLength = int(length * iteration // total)
	bar = fill * filledLength + '-' * (length - filledLength)
	print(f'\r{prefix} |{bar}| {percent}% {suffix}', end = printEnd)

	# Print New Line on Complete
	if iteration == total: 
		print()

def import_from_test_package(module: str) -> types.ModuleType:
	"""
	Import module from ArGaze test package.

	Parameters:
		module: module name <Module> into ArGaze package

	Returns:
		module named <Module>Test
	"""

	import argaze
	import importlib.util
	import sys
	import os

	source_directory = os.path.dirname(os.path.dirname(os.path.abspath(argaze.__file__)))
	module_directory = os.path.join(source_directory, 'argaze.test', f'{module}.py')

	spec = importlib.util.spec_from_file_location(f'{module}Test', module_directory)
	TestModule = importlib.util.module_from_spec(spec)
	sys.modules[f'{module}Test'] = TestModule
	spec.loader.exec_module(TestModule)

	return TestModule

class TimeProbe():
	"""
	Assess temporal performance.
	"""

	def __init__(self):

		self.start()

	def start(self):
		"""
		Start chronometer.
		"""

		# noinspection PyAttributeOutsideInit
		self.__last_time = time.perf_counter()
		# noinspection PyAttributeOutsideInit
		self.__lap_counter = 0
		# noinspection PyAttributeOutsideInit
		self.__elapsed_time = 0

	def lap(self) -> tuple[float, int, float]:
		"""
		Get lap info.

		Returns:
			last lap time (millisecond)
			number of laps
			total elapsed time (millisecond)
		"""

		lap_time = time.perf_counter() - self.__last_time

		# noinspection PyAttributeOutsideInit
		self.__last_time = time.perf_counter()
		self.__lap_counter += 1
		self.__elapsed_time += lap_time

		return lap_time * 1e3, self.__lap_counter, self.__elapsed_time * 1e3

	def end(self) -> tuple[float, int]:
		"""
		Stop chronometer

		Returns:
			elapsed time (millisecond)
		"""

		self.__elapsed_time += time.perf_counter() - self.__last_time

		return self.__elapsed_time * 1e3, self.__lap_counter

	def restart(self):
		"""
		Restart chronometer.
		"""
		
		self.start()

def tuple_to_string(t: tuple, separator: str = ", ") -> str:
	"""Convert tuple elements into quoted strings separated by a separator string."""

	return separator.join(f'\"{e}\"' for e in t)

def PrintCallStack(method):
	"""Define a decorator to print call stack until the decorated method."""

	def wrapper(self, *args, **kwargs):
		"""Wrap method to print call stack before its call.

		Parameters:
			self:
			args: method arguments.
			kwargs: extra arguments.
		"""
		print(f'Call stack until method \'{method.__name__}\':', )
		
		traceback.print_stack()

		return method(self, *args, **kwargs)

	return wrapper

class FileWriter(DataFeatures.PipelineStepObject):
	"""Write data into a file line by line."""

	# noinspection PyMissingConstructor
	@DataFeatures.PipelineStepInit
	def __init__(self, **kwargs):
		
		# Init private attributes
		self.__path = None
		self.__separator = ','
		self.__header = None

	@property
	def path(self) -> str:
		"""File path where to write data."""
		return self.__path

	@path.setter
	def path(self, path: str):

		self.__path = pathlib.Path(path)

	@property
	def separator(self) -> str:
		"""String used to separate elements during tuple to string conversion."""
		return self.__separator

	@separator.setter
	def separator(self, separator: str):

		self.__separator = separator

	@property
	def header(self) -> str|tuple:
		"""String or tuple to write first."""
		return self.__header

	@header.setter
	def header(self, header: str|tuple):

		self.__header = header

	@DataFeatures.PipelineStepEnter
	def __enter__(self):
		"""Check that folder structure exist and open file then, write header line."""

		if not os.path.exists(self.__path.parent.absolute()):

			os.makedirs(self.__path.parent.absolute())

		# Open file
		self.__file = open(self.__path, 'w', encoding='utf-8', buffering=1)

		# Write header if required
		if self.__header is not None:

			# Format list or tuple element into quoted strings
			if not isinstance(self.__header, str):

				self.__header = tuple_to_string(self.__header, self.__separator)

			print(self.__header, file=self.__file, flush=True)

	@DataFeatures.PipelineStepExit
	def __exit__(self, exception_type, exception_value, exception_traceback):
		"""Close file."""
		self.__file.close()

	def write(self, data: str|tuple):
		"""Write data as a new line into file. 

		!!! note
			Tuple elements are converted into quoted strings separated by separator string.
		"""

		# Format list or tuple element into quoted strings
		if not isinstance(data, str):

			data = tuple_to_string(data, self.__separator)

		# Write into file
		print(data, file=self.__file, flush=True)

class FileReader(DataFeatures.PipelineStepObject):
	"""Read data from a file line by line."""

	# noinspection PyMissingConstructor
	@DataFeatures.PipelineStepInit
	def __init__(self, **kwargs):
		
		# Init private attributes
		self.__path = None
		self.__separator = ','

	@property
	def path(self) -> str:
		"""File path where to read data."""
		return self.__path

	@path.setter
	def path(self, path: str):

		self.__path = pathlib.Path(path)

	@property
	def separator(self) -> str:
		"""String used to separate elements during string to tuple conversion."""
		return self.__separator

	@separator.setter
	def separator(self, separator: str):

		self.__separator = separator

	@DataFeatures.PipelineStepEnter
	def __enter__(self):

		# Open file
		self.__file = csv.reader(open(self.__path), delimiter= self.__separator)

	@DataFeatures.PipelineStepExit
	def __exit__(self, exception_type, exception_value, exception_traceback):
		
		pass

	def read(self) -> str|tuple:
		"""Read next data from file. 

		!!! note
			Quoted strings separated by separator string are converted into tuple elements.
		"""

		try:

			return next(self.__file)

		except Exception:

			raise EOFError

class VideoWriter(DataFeatures.PipelineStepObject, DataFeatures.SharedObject):
	"""Open ffmpeg application as sub-process.
		FFmpeg input PIPE: RAW images in BGR color format
		FFmpeg output MP4 file encoded with HEVC codec.

		Arguments list:
			-y				   Overwrite output file without asking
			-s {width}x{height}  Input resolution width x height (1344x756)
			-pixel_format bgr24  Input frame color format is BGR with 8 bits per color component
			-f rawvideo		  Input format: raw video
			-r {fps}			 Frame rate: fps
			-i pipe:			 ffmpeg input is a PIPE
			-vcodec libx265	  Video codec: H.265 (HEVC)
			-pix_fmt yuv420p	 Output video color space YUV420 (saving space compared to YUV444)
			-crf 24			  Constant quality encoding (lower value for higher quality and larger output file).
			{output_filename}	Output file name: output_filename (output.mp4)
	"""

	@DataFeatures.PipelineStepInit
	def __init__(self, **kwargs):

		# Init parent classes
		DataFeatures.SharedObject.__init__(self)
		
		# Init private attributes
		self.__path = None
		self.__width = 320
		self.__height = 240
		self.__fps = 25

	@property
	def path(self) -> str:
		"""File path where to write images."""
		return self.__path

	@path.setter
	def path(self, path: str):

		self.__path = pathlib.Path(path)

	@property
	def width(self) -> int:
		"""Video horizontal resolution."""
		return self.__width

	@width.setter
	def width(self, width: int):

		self.__width = width

	@property
	def height(self) -> int:
		"""Video vertical resolution."""
		return self.__height

	@height.setter
	def height(self, height: int):

		self.__height = height

	@property
	def fps(self) -> int:
		"""frame per second."""
		return self.__fps
	
	@fps.setter
	def fps(self, fps: int):

		self.__fps = fps

	@DataFeatures.PipelineStepEnter
	def __enter__(self):
		"""Check that folder structure exist then, open ffmpeg subprocess."""

		# Use lock feature
		with self._lock:
		
			import subprocess as sp
			import shlex

			if not os.path.exists(self.__path.parent.absolute()):
				
				os.makedirs(self.__path.parent.absolute())

			self.__process = sp.Popen(shlex.split(f'ffmpeg -hide_banner -loglevel error -y -s {self.__width}x{self.__height} -pixel_format bgr24 -f rawvideo -r {self.__fps} -i pipe: -vcodec libx265 -x265-params log-level=error -pix_fmt yuv420p -crf 24 {self.__path.as_posix()}'), stdin=sp.PIPE)
		
	@DataFeatures.PipelineStepExit
	def __exit__(self, exception_type, exception_value, exception_traceback):

		# Use lock feature
		with self._lock:

			# Close and flush stdin
			self.__process.stdin.close()

			# Wait for sub-process to finish
			self.__process.wait()

			# Terminate the sub-process
			# Note: We don't have to terminate the sub-process (after process.wait(), the sub-process is supposed to be closed).
			self.__process.terminate() 

	def write(self, image: numpy.array):
		"""Write raw video frame to input stream of ffmpeg sub-process."""

		# Use lock feature
		with self._lock:

			# Check if subprocess still alive
			if self.__process.poll() is None:

				# Resize image to adapt to video resolution
				output = cv2.resize(image, dsize=(self.__width, self.__height), interpolation=cv2.INTER_LINEAR)

				self.__process.stdin.write(output.tobytes())