import tkinter.filedialog as file_dia
import os.path as path

import config

"""
NOTE STANDARD FORMATTING
empty newlines separate notes for different splits

It is also possible to set your own split separator in the settings menu

lines that start and end with [ ] are ignored for notes.
these can be used for titles. 
(ex. [Split1] is not included in notes)

all other lines of text are added as notes
"""


def get_note_lines(file_path):
	"""
	Reads file at given path and returns 
	a list containing all rows of text in given file.
	Returns false if file can not be read.
	"""

	# check so file isn't too big
	if path.getsize(file_path) > config.MAX_FILE_SIZE:
		return False

	try:
		notes_file = open(file_path, "r")
	except:
		return False

	# read file line per line
	f_lines = []
	keep_reading = True
	while keep_reading:

		try:
			cur_line = notes_file.readline()
		except:
			return False

		if cur_line:
			f_lines.append(cur_line)
		else:
			keep_reading = False

	return f_lines


def decode_notes(note_lines, separator):
	"""
	Takes a list containing strings.
	Encodes given strings according to the note formatting.
	Returns the list containing the notes for every split. 
	"""

	#Check if newline is being used as separator

	if separator == config.NEWLINE_CONSTANT:
		separator = "" # left after stripping newline

	def is_title(line):
		if not line:
			return False

		return (line[0] == "[") and (line[-1] == "]")

	def is_separator(line):
		return (line == separator)

	def is_newline(s):
		return (s == "\n")

	def remove_new_line(line):
		if (len(line) >= 1) and (is_newline(line[-1])):
			return line[:-1]
		else:
			return line

	note_list = []
	cur_notes = ""

	for line in note_lines:
		line = remove_new_line(line)

		if is_separator(line):
			if cur_notes:
				note_list.append(cur_notes)
				cur_notes = ""
		else:
			if not is_title(line):
				cur_notes += line + "\n"  # newline

	if cur_notes:
		note_list.append(cur_notes)

	return note_list


def get_notes(file_path, separator):
	"""
	Takes a path to a file and returns a list with the notes 
	in the file encoded according to the note fromatting.
	
	Returns False if file is empty.
	"""
	note_lines = get_note_lines(file_path)

	if not note_lines:
		return False

	note_list = decode_notes(note_lines, separator)

	return note_list


def select_file():
	"""
	Opens a file select window.
	Returns False upon no file selection.
	Otherwise returns absolute path to selected file.
	"""

	file = file_dia.askopenfilename(filetypes=config.TEXT_FILES)

	if file:
		return file
	else:
		return False


def file_exists(file):
	"""Checks if given path leads to an existing file."""
	return path.isfile(file)