local Luan = require "luan:Luan.luan"
local error = Luan.error
local String = require "luan:String.luan"
local to_number = String.to_number 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 new_menu_bar = require("luan:swing/Menu_bar.luan").new or error()
local Menu = require "luan:swing/Menu.luan"
local new_menu = Menu.new or error()
local separator = Menu.separator 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 function action_listener(fn)
	return function(_)
		fn()
	end
end

local function add_menu_bar(window)
	local document = window.text_area.document
	local revert = new_menu_item{
		text = "Revert"
		enabled = window.has_file
		action_listener = action_listener(window.revert)
	}
	local undo = new_menu_item{
		text = "Undo"
		accelerator = "meta Z"
		action_listener = action_listener(document.undo)
	}
	local redo = new_menu_item{
		text = "Redo"
		accelerator = "meta shift Z"
		action_listener = action_listener(document.redo)
	}
	local function update_undo_redo()
		undo.set_enabled(document.can_undo())
		redo.set_enabled(document.can_redo())
	end
	window.update_undo_redo = update_undo_redo  -- dont gc
	update_undo_redo()
	document.add_undo_listener(update_undo_redo)

	local find_menu_item = new_check_box_menu_item{
		text = "Find and Replace"
		accelerator = "meta F"
		action_listener = function(event)
			window.show_find_panel(event.source.state)
		end
	}
	window.find_menu_item = find_menu_item

	local menu_bar = new_menu_bar{
		menus = {
			new_menu{
				text = "File"
				menu_items = {
					new_menu_item{
						text = "New File"
						accelerator = "meta N"
						action_listener = action_listener(window.new)
					}
					new_menu_item{
						text = "Open..."
						accelerator = "meta O"
						action_listener = action_listener(window.open)
					}
					new_menu_item{
						text = "Save"
						accelerator = "meta S"
						action_listener = function(_)
							if window.save() then
								revert.set_enabled(true)
							end
						end
					}
					revert
				}
			}
			new_menu{
				text = "Edit"
				menu_items = {
					undo
					redo
					separator
					new_menu_item{
						text = "Cut"
						accelerator = "meta X"
						action_listener = action_listener(window.text_area.cut)
					}
					new_menu_item{
						text = "Copy"
						accelerator = "meta C"
						action_listener = action_listener(window.text_area.copy)
					}
					new_menu_item{
						text = "Paste"
						accelerator = "meta V"
						action_listener = action_listener(window.text_area.paste)
					}
					separator
					new_menu_item{
						text = "Indent"
						accelerator = "meta CLOSE_BRACKET"
						action_listener = action_listener(window.indent)
					}
					new_menu_item{
						text = "Unindent"
						accelerator = "meta OPEN_BRACKET"
						action_listener = action_listener(window.unindent)
					}
					separator
					new_menu_item{
						text = "Select All"
						accelerator = "meta A"
						action_listener = action_listener(window.text_area.select_all)
					}
				}
			}
			new_menu{
				text = "Find"
				menu_items = {
					find_menu_item
					new_menu_item{
						text = "Find Case Insensitive"
						action_listener = window.find_case_insensitive
					}
					new_menu_item{
						text = "Convert Leading Tabs to Spaces"
						action_listener = window.tabs_to_spaces
					}
					new_menu_item{
						text = "Convert Leading Spaces to Tabs"
						action_listener = window.spaces_to_tabs
					}
				}
			}
			new_menu{
				text = "View"
				menu_items = {
					new_check_box_menu_item{
						text = "Word Wrap"
						state = window.text_area.line_wrap
						action_listener = function(event)
							window.text_area.line_wrap = event.source.state
						end
					}
					new_check_box_menu_item{
						text = "Show Whitespace"
						action_listener = function(event)
							window.text_area.show_whitespace(event.source.state)
						end
					}
					new_menu_item{
						text = "Show Cursor Column"
						action_listener = function(_)
							show_message_dialog( window.frame, "Cursor Column: "..window.cursor_column() )
						end
					}
					new_menu_item{
						text = "Goto Line"
						accelerator = "meta G"
						action_listener = function(_)
							local input = show_input_dialog( window.frame, "Goto line" )
							local line = input and to_number(input)
							if line ~= nil then
								window.goto(line)
							end
						end
					}
				}
			}
		}
	}
	window.frame.set_menu_bar(menu_bar)
end

return add_menu_bar