# Copyright (c) 2021, Leroy Hopson (MIT License).
#
# This file contains snippets of code derived from Godot's editor_node.cpp file.
# These snippets are copyright of their authors and released under the MIT license:
# - Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur (MIT License).
# - Copyright (c) 2014-2021 Godot Engine contributors (MIT License).
tool
extends Control

const EditorTerminal := preload("./editor_terminal.tscn")
const TerminalSettings := preload("./settings/terminal_settings.gd")

const SETTINGS_FILE_PATH := "res://.gdxterm/settings.tres"

enum TerminalPopupMenuOptions {
	NEW_TERMINAL = 0,
	COPY = 2,
	PASTE = 3,
	SELECT_ALL = 4,
	CLEAR = 6,
	KILL_TERMINAL = 7,
}

# Has access to the EditorSettings singleton so it can dynamically generate the
# terminal color scheme based on editor theme settings.
var editor_plugin: EditorPlugin
var editor_interface: EditorInterface

onready var editor_settings: EditorSettings = editor_interface.get_editor_settings()
onready var tabs: Tabs = $VBoxContainer/TabbarContainer/Tabs
onready var tabbar_container: HBoxContainer = $VBoxContainer/TabbarContainer
onready var add_button: ToolButton = $VBoxContainer/TabbarContainer/Tabs/AddButton
onready var tab_container: TabContainer = $VBoxContainer/TabContainer
onready var terminal_popup_menu: PopupMenu = $VBoxContainer/TerminalPopupMenu
onready var ready := true

var _theme := Theme.new()
var _settings: TerminalSettings
var _tab_container_min_size


func _ready():
	tab_container.add_stylebox_override("panel", get_stylebox("Background", "EditorStyles"))
	_update_settings()


func _load_or_create_settings() -> void:
	var dir := Directory.new()

	if not dir.dir_exists(SETTINGS_FILE_PATH.get_base_dir()):
		dir.make_dir(SETTINGS_FILE_PATH.get_base_dir())

	if not dir.file_exists(SETTINGS_FILE_PATH):
		var settings := TerminalSettings.new()
		ResourceSaver.save(SETTINGS_FILE_PATH, settings)

	_settings = load(SETTINGS_FILE_PATH)


func _update_settings() -> void:
	_load_or_create_settings()

	var editor_scale: float = editor_interface.get_editor_scale()
	rect_min_size = Vector2(0, tabbar_container.rect_size.y + 182) * editor_scale

	tabs.tab_close_display_policy = Tabs.CLOSE_BUTTON_SHOW_ALWAYS

	_update_terminal_tabs()


func _update_terminal_tabs():
	# Wait a couple of frames to allow everything to resize before updating.
	yield(get_tree(), "idle_frame")
	yield(get_tree(), "idle_frame")

	if tabs.get_offset_buttons_visible():
		# Move add button to fixed position on the tabbar.
		if add_button.get_parent() == tabs:
			add_button.rect_position = Vector2.ZERO
			tabs.remove_child(add_button)
			tabbar_container.add_child(add_button)
			tabbar_container.move_child(add_button, 0)
	else:
		# Move add button after last tab.
		if add_button.get_parent() == tabbar_container:
			tabbar_container.remove_child(add_button)
			tabs.add_child(add_button)
		var last_tab := Rect2()
		if tabs.get_tab_count() > 0:
			last_tab = tabs.get_tab_rect(tabs.get_tab_count() - 1)
		add_button.rect_position = Vector2(
			last_tab.position.x + last_tab.size.x + 3, last_tab.position.y
		)

	# Make sure we still own the button, so it gets saved with our scene.
	add_button.owner = self


func _on_AddButton_pressed():
	var shell = OS.get_environment("SHELL") if OS.has_environment("SHELL") else "sh"
	var terminal := EditorTerminal.instance()
	tabs.add_tab(shell.get_file())
	terminal.editor_settings = editor_settings
	terminal.set_anchors_preset(PRESET_WIDE)
	terminal.connect("gui_input", self, "_on_TabContainer_gui_input")
	tab_container.add_child(terminal)
	terminal.pty.fork(shell)
	terminal.grab_focus()
	tabs.current_tab = tabs.get_tab_count() - 1
	tab_container.current_tab = tabs.current_tab
	_update_terminal_tabs()


func _on_Tabs_tab_changed(tab_index):
	tab_container.current_tab = tab_index
	tab_container.get_child(tab_index).grab_focus()


func _on_Tabs_tab_close(tab_index):
	tabs.remove_tab(tab_index)
	tab_container.get_child(tab_index).queue_free()
	_update_terminal_tabs()


func _notification(what):
	if not ready:
		return

	match what:
		EditorSettings.NOTIFICATION_EDITOR_SETTINGS_CHANGED:
			_update_settings()
			_update_terminal_tabs()
		NOTIFICATION_RESIZED:
			_update_terminal_tabs()
		NOTIFICATION_WM_FOCUS_IN:
			_update_terminal_tabs()


func _input(event: InputEvent) -> void:
	if not _settings or not event.is_pressed():
		return

	if _settings.new_terminal_shortcut and _settings.new_terminal_shortcut.shortcut:
		if event.shortcut_match(_settings.new_terminal_shortcut.shortcut):
			editor_plugin.make_bottom_panel_item_visible(self)
			_on_AddButton_pressed()


func _on_TabContainer_gui_input(event):
	if event is InputEventMouseButton and event.button_index == BUTTON_RIGHT:
		terminal_popup_menu.rect_position = event.global_position
		terminal_popup_menu.popup()


func _on_TerminalPopupMenu_id_pressed(id):
	match id:
		TerminalPopupMenuOptions.NEW_TERMINAL:
			_on_AddButton_pressed()

	if tabs.get_tab_count() > 0:
		var terminal = tab_container.get_child(tab_container.current_tab)
		match id:
			TerminalPopupMenuOptions.PASTE:
				for i in OS.clipboard.length():
					var event = InputEventKey.new()
					event.unicode = ord(OS.clipboard[i])
					event.pressed = true
					terminal._gui_input(event)
			TerminalPopupMenuOptions.CLEAR:
				terminal.clear()
			TerminalPopupMenuOptions.KILL_TERMINAL:
				_on_Tabs_tab_close(tabs.current_tab)