extends Node2D
## Title screen: the big core with turning rings and bouncing balls, the player's progress,
## what unlocks next, and a music toggle.

const BALL_SCENE := preload("res://scenes/ball.tscn")
const BALLS := 6
const RING_SPEEDS := [12.0, -8.0] # degrees per second, one per decorative ring
## Kinds sprinkled into the decorative rings, as a taste of what is coming.
const SHOWCASE := [
	Block.Kind.INDESTRUCTIBLE, Block.Kind.WATER, Block.Kind.ICE, Block.Kind.TNT,
	Block.Kind.RUBBER, Block.Kind.MOSS,
]

var _level := 0
var _rings: Array[Node2D] = []

@onready var core: Core = $Core


func _ready() -> void:
	var screen := get_viewport_rect().size
	core.position = Vector2(screen.x / 2.0, screen.y * 0.28)
	_add_rings()
	for i in BALLS:
		var ball: Ball = BALL_SCENE.instantiate()
		ball.position = Vector2(screen.x / 2.0, screen.y - Params.BALL_RADIUS * 2.0)
		$Balls.add_child(ball)
		ball.throw()

	var progress := Progress.load_level()
	_level = progress[0]
	$UI/Info/Level.text = "Level %d" % _level
	$UI/Info/Totals/Count.text = str(Progress.total_stars())
	var best := Progress.best_score()
	$UI/Info/Best.text = "Best score %d" % best if best > 0 else ""
	$UI/Play.text = "Play" if _level == 0 else "Continue"
	$UI/Next.text = _next_unlock(_level)
	if _level != 0:
		$UI/Decay.text = Params.MSG_LEVEL_BACK % [_level, progress[1]]
	$UI/Play.pressed.connect(_on_play_pressed)
	$UI/Levels.pressed.connect(func() -> void: get_tree().change_scene_to_file("res://scenes/levels.tscn"))
	$UI/MusicToggle.pressed.connect(_on_music_toggled)
	_show_music_state()
	Music.play("menu")


func _physics_process(delta: float) -> void:
	for i in _rings.size():
		_rings[i].rotation_degrees += RING_SPEEDS[i] * delta


## Two thin rings of segments around the core, mostly normal with a few special kinds.
## They are only decoration: no collisions.
func _add_rings() -> void:
	var inner := core.radius + 6.0
	for r in RING_SPEEDS.size():
		var ring := Node2D.new()
		ring.position = core.position
		var segments := 12 + r * 4
		var step := TAU / segments
		for i in segments:
			var kind: Block.Kind = SHOWCASE[(i + r * 3) % SHOWCASE.size()] if i % 3 == 0 else Block.Kind.NORMAL
			var block := Block.new(inner + r * 30.0, inner + r * 30.0 + 26.0, i * step, (i + 1) * step, kind)
			block.collision_layer = 0
			block.set_physics_process(false)
			ring.add_child(block)
		add_child(ring)
		move_child(ring, core.get_index())
		_rings.append(ring)


## "Next: Fireball at level 12" for the next power or segment to unlock after [param level].
static func _next_unlock(level: int) -> String:
	var best_level := -1
	var best_name := ""
	for info: Dictionary in PowerUp.KINDS.values() + Block.KINDS.values():
		var unlock: int = info.unlock
		if unlock > level and (best_level < 0 or unlock < best_level):
			best_level = unlock
			best_name = info.name
	if best_level < 0:
		return "Everything unlocked. How far can you go?"
	return "Next: %s at level %d" % [best_name, best_level]


func _on_play_pressed() -> void:
	Progress.current_level = _level
	get_tree().change_scene_to_file("res://scenes/game.tscn")


func _on_music_toggled() -> void:
	Music.set_enabled(not Progress.music_on())
	_show_music_state()


func _show_music_state() -> void:
	$UI/MusicToggle.text = "Music: %s" % ("on" if Progress.music_on() else "off")