local Luan = require "luan:Luan.luan"
local error = Luan.error
local ipairs = Luan.ipairs or error()
local stringify = Luan.stringify or error()
local String = require "luan:String.luan"
local sub_string = String.sub or error()
local replace = String.replace or error()
local starts_with = String.starts_with or error()
local to_number = String.to_number or error()
local Io = require "luan:Io.luan"
local print = Io.print or error()
local new_file = Io.schemes.file or error()
local Math = require "luan:Math.luan"
local min = Math.min or error()
local Swing = require "luan:swing/Swing.luan"
local new_frame = require("luan:swing/Frame.luan").new or error()
local new_label = require("luan:swing/Label.luan").new or error()
local new_text_area = require("luan:swing/Text_area.luan").new or error()
local new_scroll_pane = require("luan:swing/Scroll_pane.luan").new or error()
local new_text_area_line_numbers = require("luan:swing/TextAreaLineNumbers.luan").new or error()
local new_menu_bar = require("luan:swing/Menu_bar.luan").new or error()
local new_menu = require("luan:swing/Menu.luan").new or error()
local new_menu_item = require("luan:swing/Menu_item.luan").new or error()
local new_check_box_menu_item = require("luan:swing/Check_box_menu_item.luan").new or error()
local int_to_color = require("luan:swing/Color.luan").int_to_color or error()
local create_empty_border = require("luan:swing/Border.luan").create_empty_border or error()
local Option_pane = require "luan:swing/Option_pane.luan"
local show_message_dialog = Option_pane.show_message_dialog or error()
local show_input_dialog = Option_pane.show_input_dialog or error()
local Logging = require "luan:logging/Logging.luan"
local logger = Logging.logger "editor"


local new_window

local function make_menu_bar(window)
	local menu_bar = new_menu_bar()
	do
		local file_menu = new_menu()
		file_menu.text = "File"
		do
			local new_file = new_menu_item()
			new_file.text = "New File"
			new_file.accelerator = "meta N"
			new_file.add_action_listener(new_window)
			file_menu.add(new_file)
		end
		do
			local open = new_menu_item()
			open.text = "Open..."
			open.accelerator = "meta O"
			open.add_action_listener(window.open)
			file_menu.add(open)
		end
		local revert
		do
			local save = new_menu_item()
			save.text = "Save"
			save.accelerator = "meta S"
			save.add_action_listener(function()
				if window.save() then
					revert.set_enabled(true)
				end
			end)
			file_menu.add(save)
		end
		do
			revert = new_menu_item()
			revert.text = "Revert"
			revert.set_enabled(window.has_file)
			revert.add_action_listener(window.revert)
			file_menu.add(revert)
		end
		menu_bar.add(file_menu)
	end
	do
		local edit_menu = new_menu()
		edit_menu.text = "Edit"
		local document = window.text_area.document
		local undo, redo
		do
			undo = new_menu_item()
			undo.text = "Undo"
			undo.accelerator = "meta Z"
			undo.add_action_listener(document.undo)
			edit_menu.add(undo)
		end
		do
			redo = new_menu_item()
			redo.text = "Redo"
			redo.accelerator = "meta shift Z"
			redo.add_action_listener(document.redo)
			edit_menu.add(redo)
		end
		local function update_undo_redo()
			undo.set_enabled(document.can_undo())
			redo.set_enabled(document.can_redo())
		end
		edit_menu.dont_gc(update_undo_redo)
		update_undo_redo()
		document.add_undo_listener(update_undo_redo)
		edit_menu.add_separator()
		do
			local cut = new_menu_item()
			cut.text = "Cut"
			cut.accelerator = "meta X"
			cut.add_action_listener(window.text_area.cut)
			edit_menu.add(cut)
		end
		do
			local copy = new_menu_item()
			copy.text = "Copy"
			copy.accelerator = "meta C"
			copy.add_action_listener(window.text_area.copy)
			edit_menu.add(copy)
		end
		do
			local paste = new_menu_item()
			paste.text = "Paste"
			paste.accelerator = "meta V"
			paste.add_action_listener(window.text_area.paste)
			edit_menu.add(paste)
		end
		edit_menu.add_separator()
		do
			local indent = new_menu_item()
			indent.text = "Indent"
			indent.accelerator = "meta CLOSE_BRACKET"
			indent.add_action_listener(window.indent)
			edit_menu.add(indent)
		end
		do
			local unindent = new_menu_item()
			unindent.text = "Unindent"
			unindent.accelerator = "meta OPEN_BRACKET"
			unindent.add_action_listener(window.unindent)
			edit_menu.add(unindent)
		end
		edit_menu.add_separator()
		do
			local select_all = new_menu_item()
			select_all.text = "Select All"
			select_all.accelerator = "meta A"
			select_all.add_action_listener(window.text_area.select_all)
			edit_menu.add(select_all)
		end
		menu_bar.add(edit_menu)
	end
	do
		local view_menu = new_menu()
		view_menu.text = "View"
		do
			local word_wrap = new_check_box_menu_item()
			word_wrap.text = "Word Wrap"
			word_wrap.state = window.text_area.line_wrap
			word_wrap.add_action_listener(function()
				window.text_area.line_wrap = word_wrap.state
			end)
			view_menu.add(word_wrap)
		end
		do
			local show_whitespace = new_check_box_menu_item()
			show_whitespace.text = "Show Whitespace"
			show_whitespace.add_action_listener(function()
				window.text_area.show_whitespace(show_whitespace.state)
			end)
			view_menu.add(show_whitespace)
		end
		do
			local show_column = new_menu_item()
			show_column.text = "Show Cursor Column"
			show_column.add_action_listener(function()
				show_message_dialog( window.frame, "Cursor Column: "..window.cursor_column() )
			end)
			view_menu.add(show_column)
		end
		do
			local goto = new_menu_item()
			goto.text = "Goto Line"
			goto.accelerator = "meta G"
			goto.add_action_listener(function()
				local input = show_input_dialog( window.frame, "Cursor Column: "..window.cursor_column() )
				--logger.info("input "..input)
				local line = input and to_number(input)
				if line ~= nil then
					window.goto(line)
				end
			end)
			view_menu.add(goto)
		end
		menu_bar.add(view_menu)
	end
	return menu_bar
end

local n_windows = 0
local documents = {}

function new_window(file)
	local window = {}
	window.has_file = file~=nil and file.is_file()
	local frame = new_frame()
	window.frame = frame
	local title = file and file.canonical().to_string() or "new"
	frame.add_close_listener(function()
		n_windows = n_windows - 1
		if n_windows == 0 then
			Luan.exit()
		end
	end)
	local text_area = new_text_area()
	window.text_area = text_area
	if file ~= nil then
		local document = documents[title]
		if document == nil then
			documents[title] = text_area.document
		else
			text_area.document = document
		end
		if file.is_file() then
			text_area.text = file.read_text()
		end
	end
	local function set_title()
		local s = title
		if not text_area.document.is_unedited() then
			s = s.." *"
		end
		frame.title = s
	end
	set_title()
	text_area.dont_gc(set_title)
	text_area.document.add_undo_listener(set_title)
	text_area.rows = 10
	text_area.columns = 20
	text_area.wrap_style_word = true
	text_area.line_wrap = true
	text_area.tab_size = 4
	text_area.set_font{ family="Monospaced", size=13 }
	text_area.set_selection(0)
	--print(text_area.line_count)
	local scroll_pane = new_scroll_pane(text_area)
	local line_numbers = new_text_area_line_numbers(text_area)
	line_numbers.foreground_color = int_to_color(0x888888)
	line_numbers.border = create_empty_border(0,8,0,8)
	scroll_pane.set_row_header_view(line_numbers)
	frame.add(scroll_pane)
	function window.open()
		local file_chooser = frame.file_chooser_load()
		if file ~= nil then
			file_chooser.directory = file.parent()
		end
		file_chooser.visible = true
		local new_file = file_chooser.file
		if new_file ~= nil then
			new_window(new_file)
		end
	end
	function window.save()
		if file == nil then
			local file_chooser = frame.file_chooser_save()
			file_chooser.visible = true
			file = file_chooser.file
			if file == nil then
				return false
			end
			title = file.canonical().to_string()
			frame.title = title
			documents[title] = text_area.document
		end
		file.write_text(text_area.text)
		text_area.document.set_unedited()
		return true
	end
	function window.revert()
		local selection = text_area.get_selection()
		local text = file.read_text()
		text_area.text = text
		text_area.set_selection(min(selection,#text+1))
		text_area.document.set_unedited()
	end
	local function selection_lines()
		local start_seletion, end_selection = text_area.get_selection()
		local end_ = end_selection == start_seletion and end_selection or end_selection - 1
		local start_line = text_area.get_line_from_position(start_seletion)
		local end_line = text_area.get_line_from_position(end_)
		local start_pos = text_area.get_line_start_position(start_line)
		local end_pos = text_area.get_line_end_position(end_line)
		local text = text_area.text
		text = sub_string(text,start_pos,end_pos-2)
		return {
			text = text
			start_pos = start_pos
			length = #text
			lines = end_line - start_line + 1
			start_seletion = start_seletion
			end_selection = end_selection
		}
	end
	function window.indent()
		local r = selection_lines()
		local text = r.text
		local start_pos = r.start_pos
		text = "\t"..replace(text,"\n","\n\t")
		text_area.replace(start_pos,r.length,text)
		--logger.info(stringify{text_area.get_selection()})
		text_area.set_selection( r.start_seletion+1, r.end_selection+r.lines )
	end
	function window.unindent()
		local r = selection_lines()
		local text = r.text
		text = "\n"..text
		local start_seletion = r.start_seletion
		if starts_with(text,"\n\t") then
			start_seletion = start_seletion - 1
		end
		local len1 = #text
		text = replace(text,"\n\t","\n")
		local len2 = #text
		local end_selection = r.end_selection - (len1 - len2)
		text = sub_string(text,2)
		text_area.replace(r.start_pos,r.length,text)
		text_area.set_selection(start_seletion,end_selection)
	end
	function window.cursor_column()
		local cursor_pos = text_area.get_selection()
		local line = text_area.get_line_from_position(cursor_pos)
		local start_line_pos = text_area.get_line_start_position(line)
		return cursor_pos - start_line_pos + 1
	end
	function window.goto(line)
		local pos = text_area.get_line_start_position(line)
		text_area.set_selection(pos)
	end
	local menu_bar = make_menu_bar(window)
	frame.set_menu_bar(menu_bar)
	frame.pack()
	frame.visible = true
	text_area.request_focus_in_window()
	n_windows = n_windows + 1
end

Swing.run(function()
	local args = Luan.arg
	if #args == 0 then
		new_window()
	else
		for _, arg in ipairs(args) do
			local file = new_file(arg)
			new_window(file)
		end
	end
end)