# (c) 2023-present Eroax
# (c) 2023-present Yagich
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
extends VBoxContainer
class_name VariableViewer

const REMOVE_ICON = preload("res://graph_node_renderer/textures/remove-icon.svg")

@onready var new_variable_button: Button = %NewVariableButton
@onready var variable_tree: Tree = %VariableTree
@onready var types_popup: PopupMenu = %TypesPopup

var root: TreeItem
var _old_name: String

signal top_field_edited(old_name: String, new_name: String, new_value: Variant)
signal top_field_removed(field_name: String)


func _ready() -> void:
	variable_tree.set_column_title(0, "Name")
	variable_tree.set_column_title(1, "Value")
	variable_tree.set_column_title(2, "Type")
	variable_tree.set_column_expand(1, true)
	variable_tree.set_column_expand_ratio(0, 15)
	variable_tree.set_column_expand_ratio(1, 70)
	variable_tree.set_column_expand_ratio(2, 15)
	root = variable_tree.create_item()
	rebuild_variable_tree()
	
	variable_tree.item_activated.connect(edit_item)
	variable_tree.item_edited.connect(commit_item_change)
	
	variable_tree.nothing_selected.connect(
		func():
			var item := variable_tree.get_edited()
			if item == null:
				item = variable_tree.get_selected()
			
			if item != null:
				commit_item_change(item)
				item.deselect(variable_tree.get_selected_column())
	)
	
	variable_tree.button_clicked.connect(_on_variable_tree_button_clicked)
	
	for i in DeckType.Types.size() - 1:
		types_popup.add_radio_check_item(DeckType.type_str(i))
	
	types_popup.id_pressed.connect(_on_types_popup_id_pressed)
	
	new_variable_button.pressed.connect(_on_new_variable_button_pressed)
	
	disable_new_button()


func commit_item_change(item: TreeItem = variable_tree.get_edited()) -> void:
	var new_name := item.get_text(0)
	var new_value
	var type: DeckType.Types = item.get_metadata(2)
	
	match type:
		DeckType.Types.STRING:
			new_value = item.get_text(1)
		DeckType.Types.BOOL:
			new_value = item.is_checked(1)
		DeckType.Types.NUMERIC:
			new_value = item.get_range(1)
		_:
			new_value = item.get_meta(&"value")
	
	if not item.has_meta(&"container"):
		top_field_edited.emit(_old_name, new_name, new_value)
	else:
		var container = item.get_meta(&"container")
		
		# array
		if item.get_meta(&"indexed", false):
			var index := item.get_index()
			(container as Array)[index] = new_value
		# dictionary
		else:
			var key := new_name
			(container as Dictionary).erase(_old_name)
			(container as Dictionary)[key] = new_value
	
	set_item_value(item, new_value)


func edit_item() -> void:
	var column := variable_tree.get_selected_column()
	var item := variable_tree.get_selected()
	
	# do nothing if this is an array and user is trying to edit index
	# (TODO: proper reordering)
	if column == 0 and item.get_meta(&"indexed"):
		return

	if column < 2:
		var value = item.get_meta(&"value")
		if column == 1 and (value is Array or value is Dictionary):
			item.collapsed = not item.collapsed
			return
		_old_name = item.get_text(0)
		
		variable_tree.edit_selected(true)
	elif column == 2:
		var pos := get_global_mouse_position()
		var r := Rect2i(Vector2i(pos), Vector2i(0, 100))

		for i in types_popup.get_item_count():
			types_popup.set_item_checked(i, false)

		types_popup.set_item_checked(item.get_metadata(2), true)
		types_popup.popup(r)


func rebuild_variable_tree(data: Dictionary = {}) -> void:
	#variable_tree.clear() # godot will raw dog a nullptr later if we clear the whole tree
	for i in root.get_children():
		i.free()
	
	for i in data:
		add_item(i, data[i])


func add_item(item_name: String, item_value: Variant, parent: TreeItem = root, container: Variant = null, indexed: bool = false) -> TreeItem:
	# the container parameter is -1 instead of null because Object#get_meta() logs an error
	# if the default parameter is null
	var item := variable_tree.create_item(parent)
	item.set_text(0, item_name)

	# TODO: proper null handling
	var value_type := typeof(item_value)
	var type: DeckType.Types
	if value_type == TYPE_NIL:
		type = DeckType.Types.STRING
		item_value = "<nothing>"
	else:
		type = DeckType.INVERSE_GODOT_TYPES_MAP[typeof(item_value)]
	item.set_meta(&"container", container)
	item.set_meta(&"indexed", indexed)
	
	set_item_value(item, item_value)

	item.set_text(2, DeckType.type_str(type))
	item.set_metadata(2, type)
	if item_value is Dictionary:
		for i in item_value:
			add_item(i, item_value[i], item, item_value)
	if item_value is Array:
		for i in (item_value as Array).size():
			add_item(str(i), item_value[i], item, item_value, true)
	#item.collapsed = true
	item.add_button(2, REMOVE_ICON)

	return item


func set_item_value(item: TreeItem, value: Variant) -> void:
	item.set_meta(&"value", value)
	var type: DeckType.Types = DeckType.INVERSE_GODOT_TYPES_MAP[typeof(value)]
	match type:
		DeckType.Types.NUMERIC:
			item.set_cell_mode(1, TreeItem.CELL_MODE_RANGE)
			item.set_range_config(1, -9999, 9999, 0.0001)
			item.set_range(1, value)
		DeckType.Types.BOOL:
			item.set_cell_mode(1, TreeItem.CELL_MODE_CHECK)
			item.set_checked(1, value)
		_:
			item.set_cell_mode(1, TreeItem.CELL_MODE_STRING)
			item.set_text(1, str(value))

	if item.has_meta(&"container"):
		var container = item.get_meta(&"container")
		if container is Array:
			var index := item.get_index()
			container[index] = value
		else:
			var key := item.get_text(0)
			container[key] = value

	if item.get_parent() != root:
		refresh_item_value(item.get_parent())


func refresh_item_value(item: TreeItem) -> void:
	var value = item.get_meta(&"value")
	var type: DeckType.Types = DeckType.INVERSE_GODOT_TYPES_MAP[typeof(value)]
	match type:
		DeckType.Types.NUMERIC:
			item.set_cell_mode(1, TreeItem.CELL_MODE_RANGE)
			item.set_range_config(1, -9999, 9999, 0.0001)
			item.set_range(1, value)
		DeckType.Types.BOOL:
			item.set_cell_mode(1, TreeItem.CELL_MODE_CHECK)
			item.set_checked(1, value)
		_:
			item.set_cell_mode(1, TreeItem.CELL_MODE_STRING)
			item.set_text(1, str(value))


func _on_variable_tree_button_clicked(item: TreeItem, _column: int, _id: int, mouse_button_index: int) -> void:
	if mouse_button_index != MOUSE_BUTTON_LEFT:
		return
	
	# we only have a delete button for now, so assume it is what's clicked
	
	if not item.has_meta(&"container"):
		var key := item.get_text(0)
		top_field_removed.emit(key)
		item.free()
	else:
		var container = item.get_meta(&"container")
		var parent := item.get_parent()
		# array
		if item.get_meta(&"indexed", false):
			var index := item.get_index()
			(container as Array).remove_at(index)
			item.free()
			
			# go through the array and reset the index strings
			for i in (container as Array).size():
				parent.get_child(i).set_text(0, str(i))
			
		# dictionary
		else:
			(container as Dictionary).erase(item.get_text(0))
			item.free()
		
		refresh_item_value(parent)


func _on_types_popup_id_pressed(id: int) -> void:
	var current_item := variable_tree.get_selected()
	
	if current_item.get_metadata(2) == id:
		return

	current_item.set_metadata(2, id)

	var new_value: Variant
	match id as DeckType.Types:
		DeckType.Types.BOOL, DeckType.Types.STRING, DeckType.Types.NUMERIC:
			# simple types that can generally be converted between each other
			var target_type: Variant.Type = DeckType.GODOT_TYPES_MAP[id]
			new_value = type_convert(current_item.get_meta(&"value"), target_type)
		DeckType.Types.ARRAY:
			new_value = []
			for i in current_item.get_children():
				i.free()
		DeckType.Types.DICTIONARY:
			new_value = {}
			for i in current_item.get_children():
				i.free()
	
	set_item_value(current_item, new_value)

	current_item.set_text(2, DeckType.type_str(id))

	if not current_item.has_meta(&"container"):
		var field_name := current_item.get_text(0)
		top_field_edited.emit(field_name, field_name, new_value)


func _on_new_variable_button_pressed() -> void:
	var selected := variable_tree.get_selected()
	# TODO: UX impr. - if selected is part of a container, add to that container instead
	# (but if selected is a container, prioritize adding to that)
	if selected == null or not (selected.get_meta(&"value") is Array or selected.get_meta(&"value") is Dictionary):
		# top field
		var var_name := "new_variable%s" % variable_tree.get_root().get_child_count()
		var new_item := add_item(var_name, "")
		top_field_edited.emit(var_name, var_name, "")
		new_item.select(0)
	else:
		var container = selected.get_meta(&"value")
		if container is Dictionary:
			var var_name := "new_key%s" % (container as Dictionary).size()
			var new_item := add_item(var_name, "", selected, container)
			new_item.select(0)
			container[var_name] = ""
		else:
			var index := (container as Array).size()
			(container as Array).append("")
			var new_item := add_item(str(index), "", selected, container, true)
			new_item.select(0)
		refresh_item_value(selected)


func enable_new_button() -> void:
	new_variable_button.disabled = false
	new_variable_button.tooltip_text = ""


func disable_new_button() -> void:
	new_variable_button.disabled = true
	new_variable_button.tooltip_text = "There is no deck open, so you can not create a new variable.\nOpen a deck first."