extends SceneTree

# Headless test: run with
#   godot --headless -s res://tests/test_skill_menu.gd
# Forgejo #93, both halves of it.
#
#   A mouse could not drive the research menu at all. Input reaches the tree
#   through BuildController._unhandled_input as raw events (a Control that
#   eats them through the GUI system would swallow the drag - see
#   SkillTreeView's header), and the tree only ever read touch events. That
#   was invisible for as long as the project set emulate_touch_from_mouse,
#   which handed it a synthetic touch per click; with that setting gone, the
#   menu is inert under a mouse and there is no other way to research
#   anything on a desktop.
#
#   The panel also still had a hole in it. The buy button below the readout
#   went away in #83, and nothing moved into the space, so ~180px of empty
#   panel sat under the text while the tree canvas above it stayed cramped.
#
# Covers:
#   A. a left click selects a node, through the real routing in
#      BuildController rather than by calling the view directly
#   B. a second click on the SAME node researches it, which is #83's
#      confirm gesture reached with a mouse
#   C. holding the left button and moving scrolls the canvas, and moving
#      with no button held does NOT - a hovering pointer must not drag the
#      tree out from under the reader
#   D. the wheel scrolls, in both directions
#   E. the readout sits at the bottom of the panel and the tree canvas fills
#      everything above it, so neither the dead band nor the cramped tree
#      comes back

const GAP_TOLERANCE: float = 48.0

var game_state: Node
var scene: Node
var controller: Node
var skill_menu: Control
var tree_view: Control
var stage: int = 0
var elapsed: float = 0.0


func _initialize() -> void:
	game_state = root.get_node("GameState")
	game_state.buildings.clear()
	game_state.extractors.clear()
	game_state.reset_progression()
	game_state.reset_formation()
	game_state.rocks = 500

	scene = load("res://world/Main.tscn").instantiate()
	root.add_child(scene)
	controller = scene.get_node("BuildController")
	skill_menu = scene.get_node("UI/SkillMenu")
	tree_view = scene.get_node("UI/SkillMenu/Tree")


func _click(at: Vector2, pressed: bool) -> void:
	var event: InputEventMouseButton = InputEventMouseButton.new()
	event.button_index = MOUSE_BUTTON_LEFT
	event.pressed = pressed
	event.position = at
	# Through the controller, not straight into the view: the missing piece
	# was the ROUTING, so a test that called tree_view.handle_mouse_button()
	# itself would have passed against the reported bug.
	controller._unhandled_input(event)


func _wheel(button: int) -> void:
	var event: InputEventMouseButton = InputEventMouseButton.new()
	event.button_index = button
	event.pressed = true
	event.position = tree_view.global_position + tree_view.size * 0.5
	controller._unhandled_input(event)


func _move(relative: Vector2) -> void:
	var event: InputEventMouseMotion = InputEventMouseMotion.new()
	event.relative = relative
	event.position = tree_view.global_position + tree_view.size * 0.5
	controller._unhandled_input(event)


func _node_at(id: String) -> Vector2:
	return tree_view.global_position + tree_view.node_screen_pos(game_state.skill_node(id))


func _process(delta: float) -> bool:
	elapsed += delta
	if stage == 0:
		scene.get_node("AsteroidField").set_process(false)
		scene.get_node("EnemySpawner").set_process(false)
		scene.get_node("BuildingField").place(GameState.BUILDING_MOTHERSHIP, Vector2(400.0, 0.0))
		elapsed = 0.0
		stage = 1
		return false
	if stage != 1 or elapsed < 0.2:
		return false
	stage = 2

	var mothership: Node2D = null
	for building in scene.get_node("BuildingField").spawned:
		if is_instance_valid(building) and building.building_type == GameState.BUILDING_MOTHERSHIP:
			mothership = building
	controller.current_building = mothership
	controller._on_action_pressed()
	if not skill_menu.visible:
		return _fail("the mothership did not open the research menu")

	# --- A. a click selects --------------------------------------------
	var shipyards: Vector2 = _node_at("shipyards")
	_click(shipyards, true)
	if tree_view.selected_id != "shipyards":
		return _fail("a left click on a node selected \"%s\" instead of it" % tree_view.selected_id)
	_click(shipyards, false)
	print("a left click selects the node under it")

	# --- B. a second click researches ----------------------------------
	if game_state.is_unlocked("shipyards"):
		return _fail("shipyards was already researched, so the confirm proves nothing")
	_click(shipyards, true)
	_click(shipyards, false)
	if not game_state.is_unlocked("shipyards"):
		return _fail("a second click on the selected node did not research it")
	print("a second click on the same node researches it")

	# --- C. held drag scrolls, a bare hover does not --------------------
	# #219 removed the eight-deep doctrine lane and the tree now fits its own
	# view, so there is nothing left to scroll. What is under test here is the
	# INPUT rule - drag only while the button is held, wheel both ways - not
	# how tall the tree happens to be, so the view is shortened to give the
	# gesture something to move. Scrolled to the bottom first, the way the
	# menu opens when the content does overflow.
	var authored_height: float = tree_view.size.y
	tree_view.size.y = authored_height * 0.4
	tree_view.scroll_y = tree_view._max_scroll()
	if tree_view.scroll_y <= 0.0:
		return _fail("the tree still has nothing to scroll, so this proves nothing")

	var before: float = tree_view.scroll_y
	_move(Vector2(0.0, 120.0))
	if not is_equal_approx(tree_view.scroll_y, before):
		return _fail("the tree scrolled under a hovering pointer with no button held")
	_click(_node_at("shipyards"), true)
	_move(Vector2(0.0, 120.0))
	var dragged: float = tree_view.scroll_y
	if dragged >= before:
		return _fail("holding the button and moving did not scroll the tree (%f -> %f)" \
			% [before, dragged])
	_click(_node_at("shipyards"), false)
	_move(Vector2(0.0, 120.0))
	if not is_equal_approx(tree_view.scroll_y, dragged):
		return _fail("the tree kept scrolling after the button was released")
	print("drag scrolls only while the button is held: %.0f -> %.0f" % [before, dragged])

	# --- D. the wheel scrolls ------------------------------------------
	_wheel(MOUSE_BUTTON_WHEEL_UP)
	var wheeled: float = tree_view.scroll_y
	if wheeled >= dragged:
		return _fail("the wheel did not scroll the tree upward")
	_wheel(MOUSE_BUTTON_WHEEL_DOWN)
	if tree_view.scroll_y <= wheeled:
		return _fail("the wheel did not scroll back down")
	print("the wheel scrolls both ways")

	# --- E. the panel has no dead band at the bottom --------------------
	# Back to the authored height: section C shortened the view to have
	# something to scroll, and the layout below is about the real one.
	tree_view.size.y = authored_height
	tree_view.scroll_y = 0.0
	var detail: Control = scene.get_node("UI/SkillMenu/DetailLabel")
	var status: Control = scene.get_node("UI/SkillMenu/StatusLabel")
	var tree_bottom: float = tree_view.position.y + tree_view.size.y
	var readout_gap: float = detail.position.y - tree_bottom
	var floor_gap: float = skill_menu.size.y - (status.position.y + status.size.y)
	print("tree %.0fpx tall, %.0fpx to the readout, %.0fpx of panel below it" \
		% [tree_view.size.y, readout_gap, floor_gap])
	if tree_view.size.y <= 0.0:
		return _fail("the tree canvas has no height")
	if readout_gap < 0.0:
		return _fail("the tree canvas overlaps the readout below it")
	if readout_gap > GAP_TOLERANCE:
		return _fail("%.0fpx of unused panel between the tree and the readout" % readout_gap)
	if floor_gap > GAP_TOLERANCE:
		return _fail("%.0fpx of dead panel below the readout - the removed buy button's hole" \
			% floor_gap)

	print("TEST_SKILL_MENU: PASS")
	quit(0)
	return true


func _fail(message: String) -> bool:
	print("TEST_SKILL_MENU: FAIL (%s)" % message)
	quit(1)
	return true