extends Control
## The tutorial's guide panel and marker (docs/TUTORIAL_DESIGN.md §1): what to
## do now, top right under the clock, with a progress count; a tick when a
## step's done; a pale glowing post where to go, and an arrow with the
## distance when it's off-screen. H hides the panel. Drawn from the Guide
## autoload; hidden when no tutorial is running.

const UITheme = preload("res://scripts/ui/theme.gd")

var player: Node3D
var _box: PanelContainer
var _chapter: Label
var _title: Label
var _text: Label
var _progress: Label
var _tick: Label
var _arrow: Label
var _marker: Node3D
var _hidden := false

func setup(p: Node3D) -> void:
	player = p
	set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)
	mouse_filter = Control.MOUSE_FILTER_IGNORE
	_box = UITheme.panel()
	_box.set_anchors_and_offsets_preset(Control.PRESET_TOP_RIGHT)
	_box.grow_horizontal = Control.GROW_DIRECTION_BEGIN
	_box.offset_right = -22
	_box.offset_top = 48
	_box.custom_minimum_size = Vector2(340, 0)
	_box.mouse_filter = Control.MOUSE_FILTER_IGNORE
	add_child(_box)
	var v := VBoxContainer.new()
	v.add_theme_constant_override("separation", 4)
	v.custom_minimum_size = Vector2(320, 0)
	_box.add_child(v)
	_chapter = UITheme.label("", 13, UITheme.TEXT_DIM)
	v.add_child(_chapter)
	_title = UITheme.label("", 19)
	v.add_child(_title)
	_text = UITheme.label("", 15, UITheme.TEXT_DIM)
	_text.autowrap_mode = TextServer.AUTOWRAP_WORD_SMART
	_text.custom_minimum_size = Vector2(320, 0)
	v.add_child(_text)
	_progress = UITheme.label("", 15, Color(0.95, 0.82, 0.5))
	v.add_child(_progress)
	_tick = UITheme.label("", 22, Color(0.55, 0.9, 0.45))
	_tick.set_anchors_and_offsets_preset(Control.PRESET_CENTER_TOP)
	_tick.offset_top = 90
	_tick.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	_tick.modulate.a = 0.0
	add_child(_tick)
	_arrow = UITheme.label("", 20, Color(0.75, 0.95, 1.0))
	_arrow.visible = false
	add_child(_arrow)
	Guide.step_started.connect(func(_i, _s): _redraw())
	Guide.progressed.connect(_redraw)
	Guide.step_done.connect(_on_done)
	Guide.started.connect(_redraw)
	Guide.finished.connect(_on_finished)
	_redraw()

func _unhandled_input(event: InputEvent) -> void:
	if Guide.active and event is InputEventKey and event.pressed and not event.echo and event.keycode == KEY_H:
		_hidden = not _hidden
		_redraw()

func _redraw() -> void:
	var s: Dictionary = Guide.current()
	visible = Guide.active
	_box.visible = Guide.active and not _hidden and not s.is_empty()
	if s.is_empty():
		return
	_chapter.text = "%s  ·  step %d of %d   (H hides)" % [Guide.chapter_title(s), Guide.index + 1, Guide.steps.size()]
	_title.text = String(s.title)
	# The hermit's words, in quotes, with his name.
	_text.text = ("%s: \"%s\"" % [Guide.guide_name, String(s.text)]) if not Guide.guide_name.is_empty() else String(s.text)
	_progress.text = Guide.progress_text()

func _on_done(_i: int, s: Dictionary) -> void:
	_tick.text = "✓  " + String(s.title)
	var tw := create_tween()
	_tick.modulate.a = 1.0
	tw.tween_interval(1.4)
	tw.tween_property(_tick, "modulate:a", 0.0, 0.6)

func _on_finished() -> void:
	_box.visible = false
	_tick.text = "✓  Chapter done. More of the tutorial is on its way."
	_tick.modulate.a = 1.0
	var tw := create_tween()
	tw.tween_interval(3.0)
	tw.tween_property(_tick, "modulate:a", 0.0, 1.0)

func _process(_delta: float) -> void:
	_update_marker()

## The glowing post at the target, and the arrow at the screen edge.
func _update_marker() -> void:
	var at: Vector3 = Guide.marker_position() if Guide.active else Vector3.INF
	if _marker != null and (not is_instance_valid(_marker) or _marker.get_parent() != Guide.world):
		if is_instance_valid(_marker):
			_marker.queue_free()
		_marker = null   # (its world went: a reload, or back to the title)
	if _marker == null and Guide.active and Guide.world != null:
		_marker = make_marker()
		Guide.world.add_child(_marker)
	if _marker == null:
		_arrow.visible = false
		return
	_marker.visible = at != Vector3.INF
	if at == Vector3.INF:
		_arrow.visible = false
		return
	_marker.global_position = at
	var cam := get_viewport().get_camera_3d()
	if cam == null or _hidden:
		_arrow.visible = false
		return
	var vis := not cam.is_position_behind(at)
	var sp := cam.unproject_position(at + Vector3(0, 1.0, 0))
	var r := get_viewport_rect()
	if vis and r.grow(-40).has_point(sp):
		_arrow.visible = false
		return
	# Off-screen: an arrow at the edge, pointing the way, with the distance.
	var c := r.size * 0.5
	var dir := (sp - c) * (-1.0 if not vis else 1.0)
	if dir.length() < 1.0:
		dir = Vector2(0, -1)
	dir = dir.normalized()
	var edge := c + dir * (minf(c.x, c.y) - 70.0)
	edge = edge.clamp(Vector2(40, 40), r.size - Vector2(140, 60))
	var arrows := ["→", "↘", "↓", "↙", "←", "↖", "↑", "↗"]
	var k := wrapi(roundi(atan2(dir.y, dir.x) / (PI / 4.0)), 0, 8)
	var who: Node3D = Guide.world.player if Guide.world != null else player
	_arrow.text = "%s %d m" % [arrows[k], roundi(who.global_position.distance_to(at))]
	_arrow.position = edge
	_arrow.visible = true

## A pale, glowing post with a ring at its foot.
static func make_marker() -> Node3D:
	var root := Node3D.new()
	root.name = "GuideMarker"
	var m := StandardMaterial3D.new()
	m.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
	m.transparency = BaseMaterial3D.TRANSPARENCY_ALPHA
	m.blend_mode = BaseMaterial3D.BLEND_MODE_ADD
	m.albedo_color = Color(0.55, 0.85, 1.0, 0.35)
	m.cull_mode = BaseMaterial3D.CULL_DISABLED
	var beam := MeshInstance3D.new()
	var cyl := CylinderMesh.new()
	cyl.top_radius = 0.06
	cyl.bottom_radius = 0.14
	cyl.height = 5.0
	cyl.material = m
	beam.mesh = cyl
	beam.position = Vector3(0, 2.6, 0)
	beam.cast_shadow = GeometryInstance3D.SHADOW_CASTING_SETTING_OFF
	root.add_child(beam)
	var ring := MeshInstance3D.new()
	var torus := TorusMesh.new()
	torus.inner_radius = 0.55
	torus.outer_radius = 0.7
	torus.material = m
	ring.mesh = torus
	ring.position = Vector3(0, 0.05, 0)
	ring.cast_shadow = GeometryInstance3D.SHADOW_CASTING_SETTING_OFF
	root.add_child(ring)
	if DisplayServer.get_name() != "headless":
		var l := OmniLight3D.new()
		l.light_color = Color(0.55, 0.85, 1.0)
		l.light_energy = 0.6
		l.omni_range = 4.0
		l.position = Vector3(0, 1.0, 0)
		root.add_child(l)
	return root