class_name StickyNotePanel
extends Panel

var minimum_size:Vector2 = Vector2(400, 100):
	set(size):
		minimum_size = size
		custom_minimum_size = size
var attached_sticky_note: StickyNote
var ancor_position: Vector2

func _init(cstm_minimum_size: Vector2 = minimum_size, note_position: Vector2 = Vector2(105, 57)) -> void:
	minimum_size = cstm_minimum_size
	ancor_position = note_position
	mouse_filter = MOUSE_FILTER_PASS 
	self_modulate = Color(1, 1, 1, 0)

func _ready():
	custom_minimum_size = Vector2(custom_minimum_size.x, 0)

var is_attatching: bool = false
func attatch_sticky_note(attatchment: StickyNote, custom_owner: Node, tween:bool = true, re_parent:bool = true):
	is_attatching = true
	attatchment.on_board = false
	attached_sticky_note = attatchment
	attatchment.attached_to = null
	if tween:
		await get_tree().process_frame
		var height_tween: Tween = create_tween()
		height_tween.tween_property(self, "custom_minimum_size", minimum_size, 0.1)
		var target_post := get_global_transform().origin+ancor_position
		for panel: StickyNotePanel in get_parent().get_children():
			if panel.attached_sticky_note == attatchment and panel.get_index() < get_index():
				target_post = get_global_transform().origin+ancor_position - Vector2(0, minimum_size.y)
		attatchment.tween_transform_to(Transform2D(0, target_post))
		await attatchment.transform_tween_finished
		await get_tree().process_frame
		attatchment.reparent(self)
		attatchment.position = ancor_position
	else:
		custom_minimum_size = minimum_size
		if re_parent:
			attatchment.reparent(self)
		else:
			add_child(attatchment)
		attatchment.position = ancor_position
	is_attatching = false
	attatchment.owner = custom_owner
	attatchment.attached_to = self
	attatchment.current_handle = custom_owner
	

var is_gapped: bool = false
func create_gap():
	var self_id = get_parent().get_children().find(self)
	var next_id = min(self_id + 1, get_parent().get_child_count() - 1)
	var previous_id = max(self_id - 1, 0)
	
	if not (is_gapped or get_parent().get_child(next_id).attached_sticky_note.is_dragged or get_parent().get_child(previous_id).attached_sticky_note.is_dragged) and owner.current_context == CardBoard.DRAG:
		is_gapped = true
		var height_tween: Tween = create_tween()
		height_tween.tween_property(self, "custom_minimum_size", minimum_size*Vector2(1.0, 1.8), 0.1)
		
	get_parent().get_child(next_id).collapse_gap()
	if not get_parent().get_children().find(self) == 0: get_parent().get_child(previous_id).collapse_gap()

func collapse_gap():
	if is_gapped:
		is_gapped = false
		var height_tween: Tween = create_tween()
		height_tween.tween_property(self, "custom_minimum_size", minimum_size, 0.1)

func reclaim_sticky_note() -> bool:
	if is_empty() and attached_sticky_note.attached_to != Card:
		is_attatching = true
		attached_sticky_note.on_board = false
		attached_sticky_note.tween_transform_to(Transform2D(0, get_screen_position() + ancor_position))
		await attached_sticky_note.transform_tween_finished
		await get_tree().process_frame
		attached_sticky_note.reparent(self)
		attached_sticky_note.attached_to = self
		attached_sticky_note.owner = self.owner
		is_attatching = false
		return true
	return false

var invalid: bool = false
func clear_if_empty():
	if !is_empty(): return
	invalid = true
	if attached_sticky_note.attached_to == self: attached_sticky_note.attached_to = null
	var height_tween: Tween = create_tween()
	height_tween.tween_property(self, "custom_minimum_size", Vector2.ZERO, 0.3)
	await height_tween.finished
	owner.on_sticky_panel_cleared(get_parent().get_children().find(self))
	self.queue_free()

func replace_sticky_note_with(new_sticky_note: StickyNote):
	if is_empty():
		attached_sticky_note = new_sticky_note

func is_empty() -> bool:
	return get_child_count() == 0 and not is_attatching


# === DROP TARGET PATTERN IMPLEMENTATION ===

## Checks if this panel can accept the given draggable
func can_accept_drop(draggable: Draggable) -> bool:
	return draggable is StickyNote and is_empty()

## Handles dropping a sticky note onto this panel
func handle_drop(draggable: StickyNote) -> int:
	if not can_accept_drop(draggable):
		return Draggable.DropResult.REJECTED
	
	# Attach sticky to this panel
	attatch_sticky_note(draggable, owner, true, true)
	
	# Clean up other empty panels
	for panel in get_parent().get_children():
		if panel is StickyNotePanel and panel != self:
			panel.clear_if_empty()
	
	return Draggable.DropResult.ACCEPTED