# -*- coding: utf-8 -*-
# Copyright © 2005 Lateef Alabi-Oki
#
# This file is part of Scribes.
#
# Scribes 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 2 of the License, or
# (at your option) any later version.
#
# Scribes 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 Scribes; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

"""
This module implements functions that indent line(s) in a gtksourceview
buffer.

@author: Lateef Alabi-Oki
@organization: The Scribes Project
@copyright: Copyright © 2005 Lateef Alabi-Oki
@license: GNU GPLv2 or Later
@contact: mystilleef@gmail.com
"""

def indent(sourceview):
	"""
	Indent line(s) in a text buffer.

	@param sourceview: A container for the text buffer.
	@type textbuffer: A gtksourceview.SoureView object.
	"""
	sourceview.set_property("editable", False)
	sourcebuffer = sourceview.get_property("buffer")
	cursor_iterator = sourcebuffer.get_iter_at_mark(sourcebuffer.get_insert())
	lines_indented = []
	line_number = cursor_iterator.get_line()
	try:
		begin_selection, end_selection = sourcebuffer.get_selection_bounds()
		if begin_selection.get_line() == end_selection.get_line():
			sourcebuffer.begin_user_action()
			indent_line(sourceview, begin_selection.get_line())
			sourcebuffer.end_user_action()
			lines_indented.append(line_number)
		else:
			use_response = False
			begining_line = begin_selection.get_line()
			end_line = end_selection.get_line()
			if end_line - begining_line > 1000:
				use_response = True
			from SCRIBES.utils import response
			sourcebuffer.begin_user_action()
			for line in range(begining_line, end_line+1):
				if use_response:
					response()
				indent_line(sourceview, line)
				lines_indented.append(line)
			sourcebuffer.end_user_action()
	except ValueError:
		sourcebuffer.begin_user_action()
		indent_line(sourceview, line_number)
		sourcebuffer.end_user_action()
		lines_indented.append(line_number)
	sourceview.set_property("editable", True)
	return lines_indented

def indent_line(sourceview, line_number):
	"""
	Indent a line in the a text buffer.

	This indentation algorithm is based on tab stops. That is a line is indented
	to the nearest tab stop. During the indentation process all spaces are
	converted to tab characters. If spaces is used for indentation, then all tab
	characters are converted to spaces.

	@param sourceview: The container of the text buffer.
	@type sourceview: A gtksourceview.SoureView object.

	@param line_number: A line in the text buffer.
	@type line_number: An Integer object.
	"""
	sourcebuffer = sourceview.get_property("buffer")
	use_spaces = sourceview.get_property("insert-spaces-instead-of-tabs")
	tab_width = sourceview.get_property("tabs-width")
	begin_position = sourcebuffer.get_iter_at_line(line_number)
	transition_position = begin_position.copy()
	space_list = []
	tab_list = []
	while True:
		if transition_position.get_char() in (" "):
			space_list.append(" ")
		elif transition_position.get_char() in ("\t"):
			tab_list.append("\t")
		else:
			break
		transition_position.forward_char()
	if transition_position.equal(begin_position):
		if use_spaces:
			sourcebuffer.insert(begin_position, " " * tab_width)
		else:
			sourcebuffer.insert(begin_position, "\t")
		return
	number_of_spaces = len(space_list)
	number_of_tabs = len(tab_list)
	if use_spaces:
		new_spaces = []
		if number_of_spaces:
			if 0 < number_of_spaces < tab_width:
				new_spaces.append(" " * tab_width)
			else:
				if number_of_spaces % tab_width:
					new_spaces.append(" " * tab_width)
					tab_stops = number_of_spaces / tab_width
					if tab_stops:
						new_spaces.append(" " * (tab_stops * tab_width))
				else:
					space_list.append(" " * tab_width)
					new_spaces = space_list
		else:
			new_spaces.append(" " * tab_width)
		if number_of_tabs:
			new_spaces.append(" " * (number_of_tabs * tab_width))
		string = "".join(new_spaces)
	else:
		if not number_of_spaces:
			tab_list.append("\t")
		else:
			if 0 < number_of_spaces < tab_width:
				tab_list.append("\t")
			else:
				if number_of_spaces % tab_width:
					tab_list.append("\t")
				tab_stops = number_of_spaces / tab_width
				if tab_stops:
					tab_list.append("\t" * tab_stops)
		string = "".join(tab_list)
	sourcebuffer.delete(begin_position, transition_position)
	begin_position = sourcebuffer.get_iter_at_line(line_number)
	sourcebuffer.insert(begin_position, string)
	return