extends Node2D
## One level: the core and its rings, the paddle, the balls and the falling power-ups.

const BALL_SCENE := preload("res://scenes/ball.tscn")
const POWER_UP_SCENE := preload("res://scenes/power_up.tscn")
const SUN_BURST_SCENE := preload("res://scenes/sun_burst.tscn")

const SHIELD_HEIGHT := 6.0 # px above the bottom edge
const DEBRIS_PIECES := 10

var level := 0
## Set once the level is won or lost; stops power-up drops and collision handling.
var over := false
## When a ball last touched anything (seconds). Long gaps make triple balls more likely.
var last_touch := 0.0
var screen := Vector2.ZERO
## Balls the shield will still save.
var shield := 0:
	set(value):
		shield = value
		queue_redraw()
var _started := 0.0
var score := 0
## Segments broken in a row since a ball last touched the paddle.
var combo := 0
## Screen shake amount, 0 to 1; decays over time.
var _trauma := 0.0

@onready var blocks: Blocks = $Blocks
@onready var paddle: Paddle = $Paddle
@onready var balls: Node2D = $Balls
@onready var power_ups: Node2D = $PowerUps
@onready var alerts: Control = $HUD/Alerts
@onready var end_menu: Control = $HUD/EndMenu
@onready var end_message: Label = $HUD/EndMenu/Message
@onready var end_button: Button = $HUD/EndMenu/Button
@onready var end_stars: Stars = $HUD/EndMenu/Stars
@onready var end_score: Label = $HUD/EndMenu/Score
@onready var score_label: Label = $HUD/Score
@onready var combo_label: Label = $HUD/Combo
@onready var camera: Camera2D = $Camera


func _ready() -> void:
	screen = get_viewport_rect().size
	level = Progress.current_level
	last_touch = _now()
	_started = _now()
	$HUD/Level.text = "Level %d" % level

	paddle.position = Vector2(screen.x / 2.0, screen.y - Params.PADDLE_ALTITUDE - Params.PADDLE_HEIGHT / 2.0)
	# The rings sit centred on screen; when there are many, the core moves up so they keep
	# their thickness and still leave PADDLE_CLEARANCE above the paddle.
	var lowest_ring_edge := paddle.position.y - Params.PADDLE_HEIGHT / 2.0 - Params.PADDLE_CLEARANCE
	var natural_radius := Params.CORE_RADIUS + Params.ring_count(level) * Params.RING_SIZE
	var core_y := clampf(lowest_ring_edge - natural_radius, screen.y * Params.HIGHEST_CORE, screen.y / 2.0)
	blocks.position = Vector2(screen.x / 2.0, core_y)
	blocks.build(level, lowest_ring_edge - core_y)
	paddle.released.connect(_release_caught_balls)
	blocks.segment_broken.connect(_on_segment_broken)
	blocks.exploded.connect(func(_at: Vector2) -> void: _shake(0.5))
	end_button.pressed.connect(_restart)
	_update_score()
	Music.play("game")

	_drop_power_up()
	_drop_triple_balls()
	_add_and_throw_ball()


func _on_ball_hit(ball: Ball, other: Node) -> void:
	last_touch = _now()
	if over:
		return
	if other is Block:
		var block := other as Block
		match block.strike(ball):
			Block.Hit.BROKE, Block.Hit.DAMAGED:
				$Sounds/Pipe.play()
			Block.Hit.BLOCKED:
				$Sounds/Metal.play()
		if ball.bomb:
			ball.bomb = false
			blocks.explode(ball.global_position, Params.BOMB_RADIUS)
			$Sounds/Bomb.play()
	elif other is Core:
		_win()
	elif other is Paddle:
		combo = 0
		_update_score()
		if paddle.catch_time > 0.0:
			ball.stick_to(paddle, Params.CATCH_HOLD_SECONDS)
		elif ball.velocity.y < 0.0:
			ball.aim_from(paddle)
	elif other.is_in_group("bottom"):
		if shield > 0:
			shield -= 1
			_alert(Params.MSG_SHIELD_USED)
			$Sounds/Metal.play()
		else:
			_lose_ball(ball)


func _on_power_up_collected(kind: PowerUp.Kind) -> void:
	if over:
		return
	var live := _live_balls()
	match kind:
		PowerUp.Kind.TRIPLE_BALLS:
			_alert(Params.MSG_TRIPLE_BALLS)
			for i in 3 - live.size():
				_add_and_throw_ball()
		PowerUp.Kind.PADDLE:
			if randf() < 0.5:
				_alert(Params.MSG_DOUBLE_PADDLE)
				paddle.double_size()
			else:
				_alert(Params.MSG_HALF_PADDLE)
				paddle.half_size()
		PowerUp.Kind.SUPERBALL:
			if blocks.has_unbreakable() and not live.is_empty():
				_alert(Params.MSG_SUPER_BALL)
				live[0].superball = true
		PowerUp.Kind.SLOW:
			_alert(Params.MSG_SLOW)
			for ball: Ball in live:
				ball.set_time_scale(Params.SLOW_SCALE, Params.SLOW_SECONDS)
		PowerUp.Kind.RUSH:
			_alert(Params.MSG_RUSH)
			for ball: Ball in live:
				ball.set_time_scale(Params.RUSH_SCALE, Params.RUSH_SECONDS)
		PowerUp.Kind.CATCH:
			_alert(Params.MSG_CATCH)
			paddle.set_catch(Params.CATCH_SECONDS)
		PowerUp.Kind.SHIELD:
			_alert(Params.MSG_SHIELD)
			shield = Params.SHIELD_CHARGES
		PowerUp.Kind.BIG_BALL:
			_alert(Params.MSG_BIG_BALL)
			for ball: Ball in live:
				ball.set_big(Params.BIG_BALL_SECONDS)
		PowerUp.Kind.FIREBALL:
			_alert(Params.MSG_FIREBALL)
			for ball: Ball in live:
				ball.set_fire(Params.FIREBALL_SECONDS)
		PowerUp.Kind.LASER:
			_alert(Params.MSG_LASER)
			paddle.set_laser(Params.LASER_SECONDS)
		PowerUp.Kind.FREEZE:
			_alert(Params.MSG_FREEZE)
			blocks.freeze(Params.FREEZE_SECONDS)
		PowerUp.Kind.BOMB:
			_alert(Params.MSG_BOMB)
			if not live.is_empty():
				live[0].bomb = true
		PowerUp.Kind.HOMING:
			_alert(Params.MSG_HOMING)
			for ball: Ball in live:
				ball.set_homing(Params.HOMING_SECONDS)


func _release_caught_balls() -> void:
	for ball: Ball in _live_balls():
		if ball.is_stuck_to(paddle):
			ball.release()


## Score, combo and debris for every segment that breaks, however it broke.
func _on_segment_broken(block: Block) -> void:
	if over:
		return
	combo += 1
	var points := Params.POINTS_PER_BREAK * _multiplier()
	score += points
	_update_score()
	var at := block.center()
	_debris(at, block.color)
	_popup(at, "+%d" % points, Params.COLOR_ORANGE if _multiplier() > 1 else Color.WHITE)
	_shake(0.12)


func _multiplier() -> int:
	return mini(Params.MAX_COMBO, 1 + combo / Params.BREAKS_PER_COMBO_STEP)


func _update_score() -> void:
	score_label.text = str(score)
	combo_label.text = "x%d combo" % _multiplier() if _multiplier() > 1 else ""


func _lose_ball(ball: Ball) -> void:
	$Sounds/Bomb.play()
	_burst(ball.global_position)
	_shake(0.6)
	ball.queue_free()
	if _live_balls().is_empty():
		over = true
		_clear_play_field()
		end_message.text = Params.MSG_OVER
		end_message.show()
		end_stars.hide()
		end_score.text = "Score %d" % score
		end_button.text = Params.MSG_RESTART
		end_menu.show()


func _win() -> void:
	over = true
	$Sounds/Win.play()
	_shake(0.8)
	var seconds := _now() - _started
	var par := Params.par_seconds(level)
	var stars := 3 if seconds <= par else (2 if seconds <= 2.0 * par else 1)
	_clear_play_field()
	await blocks.core.explode()
	Progress.save_stars(level, stars)
	var best := Progress.save_best_score(score)
	end_message.text = Params.MSG_LEVEL_DONE % level
	end_message.show()
	end_stars.show()
	end_stars.reveal(stars)
	end_score.text = ("New best! " if best else "") + "Score %d" % score
	level += 1
	Progress.save_level(level)
	end_button.text = Params.MSG_NEXT_LEVEL
	end_menu.show()


## Restarts at the current level (the next one after a win).
func _restart() -> void:
	Progress.current_level = level
	get_tree().reload_current_scene()


func _clear_play_field() -> void:
	for node in balls.get_children() + power_ups.get_children():
		node.queue_free()
	paddle.queue_free()
	shield = 0


func _add_and_throw_ball() -> void:
	if paddle.is_queued_for_deletion():
		return
	var ball: Ball = BALL_SCENE.instantiate()
	ball.position = paddle.position + Vector2(0, -Params.PADDLE_HEIGHT / 2.0 - Params.BALL_RADIUS - 1.0)
	ball.target = blocks.core
	ball.max_speed = Params.max_ball_speed(level)
	ball.hit.connect(_on_ball_hit)
	balls.add_child(ball)
	ball.throw(Params.launch_speed(level))


func _live_balls() -> Array:
	return balls.get_children().filter(func(ball: Node) -> bool: return not ball.is_queued_for_deletion())


# Power-up drops. Each one rolls its chance, then reschedules itself.

func _drop_power_up() -> void:
	if over:
		return
	if randf() < Params.power_up_chance(level):
		var kind := _pick_power_up()
		if kind >= 0:
			_spawn_power_up(kind as PowerUp.Kind)
	_schedule(_drop_power_up)


## Weighted pick among the power-ups that can drop right now; -1 if none can.
func _pick_power_up() -> int:
	var kinds: Array[int] = []
	var weights: Array[float] = []
	for kind: int in PowerUp.KINDS:
		var w := PowerUp.weight(kind as PowerUp.Kind, level)
		# A super ball only helps while something unbreakable is left.
		if kind == PowerUp.Kind.SUPERBALL and not blocks.has_unbreakable():
			w = 0.0
		if w > 0.0:
			kinds.append(kind)
			weights.append(w)
	var roll: float = randf() * weights.reduce(func(sum: float, w: float) -> float: return sum + w, 0.0)
	for i in kinds.size():
		roll -= weights[i]
		if roll <= 0.0:
			return kinds[i]
	return -1


func _drop_triple_balls() -> void:
	if over:
		return
	var idle := _now() - last_touch
	if randf() < idle * Params.DROP_TRIPLE_BALL:
		last_touch = _now()
		if _live_balls().size() < 3:
			_spawn_power_up(PowerUp.Kind.TRIPLE_BALLS)
	_schedule(_drop_triple_balls)


func _schedule(callback: Callable) -> void:
	var interval := Params.POWER_UP_INTERVAL
	var delay := interval + randf_range(-1.0, 1.0) * interval / 4.0
	get_tree().create_timer(delay).timeout.connect(callback)


func _spawn_power_up(kind: PowerUp.Kind) -> void:
	var power_up: PowerUp = POWER_UP_SCENE.instantiate()
	power_up.kind = kind
	power_up.position = Vector2(randf_range(PowerUp.RADIUS, screen.x - PowerUp.RADIUS), PowerUp.RADIUS + 1.0)
	# Collected inside a physics callback, where bodies can't be added or resized
	# (triple balls, paddle size, big ball): apply it once physics is done.
	power_up.collected.connect(_on_power_up_collected, CONNECT_DEFERRED)
	power_ups.add_child(power_up)


func _alert(text: String) -> void:
	var label := Label.new()
	label.text = text
	label.add_theme_font_size_override("font_size", 40)
	label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	label.vertical_alignment = VERTICAL_ALIGNMENT_CENTER
	label.autowrap_mode = TextServer.AUTOWRAP_WORD_SMART
	label.mouse_filter = Control.MOUSE_FILTER_IGNORE
	alerts.add_child(label)
	label.set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)
	var tween := label.create_tween()
	tween.tween_property(label, "modulate:a", 0.0, 3.0)
	tween.tween_callback(label.queue_free)


## Chips flying off a broken segment, in its colour.
func _debris(at: Vector2, color: Color) -> void:
	var debris := CPUParticles2D.new()
	debris.position = at
	debris.one_shot = true
	debris.amount = DEBRIS_PIECES
	debris.lifetime = 0.6
	debris.explosiveness = 1.0
	debris.spread = 180.0
	debris.gravity = Vector2(0, 600)
	debris.initial_velocity_min = 60.0
	debris.initial_velocity_max = 180.0
	debris.scale_amount_min = 3.0
	debris.scale_amount_max = 5.0
	debris.color = color
	var fade := Gradient.new()
	fade.set_color(0, Color.WHITE)
	fade.set_color(1, Color(1, 1, 1, 0))
	debris.color_ramp = fade
	debris.finished.connect(debris.queue_free)
	add_child(debris)
	debris.emitting = true


## Points floating up from where a segment broke.
func _popup(at: Vector2, text: String, color: Color) -> void:
	var label := Label.new()
	label.text = text
	label.add_theme_font_size_override("font_size", 22)
	label.add_theme_color_override("font_color", color)
	label.position = at - Vector2(20, 14)
	label.z_index = 5
	add_child(label)
	var tween := label.create_tween().set_parallel()
	tween.tween_property(label, "position:y", label.position.y - 40.0, 0.7)
	tween.tween_property(label, "modulate:a", 0.0, 0.7).set_delay(0.2)
	tween.chain().tween_callback(label.queue_free)


func _shake(amount: float) -> void:
	_trauma = minf(1.0, _trauma + amount)


func _process(delta: float) -> void:
	_trauma = maxf(0.0, _trauma - Params.SHAKE_DECAY * delta)
	var strength := _trauma * _trauma * Params.SHAKE_MAX
	camera.offset = Vector2(randf_range(-1, 1), randf_range(-1, 1)) * strength


func _burst(at: Vector2) -> void:
	var burst: CPUParticles2D = SUN_BURST_SCENE.instantiate()
	burst.position = at
	add_child(burst)


func _draw() -> void:
	if shield > 0:
		var y := screen.y - SHIELD_HEIGHT
		draw_line(Vector2(0, y), Vector2(screen.x, y), Color("#f4f4f0"), 4.0, true)


func _now() -> float:
	return Time.get_ticks_msec() / 1000.0