extends Node2D

const COMET_SPAWNER = preload("res://scenes/comet_spawner.tscn")

@export var level : int = 1

var save_file := "user://highscore.dat"

var viewport_size : Vector2
var score : int = 0
var high_score : int
var points_per_comet := 300

func _ready() -> void:
	high_score = load_score()
	new_level(level)
	viewport_size = get_viewport_rect().size
	$Background/Stars.emission_rect_extents = viewport_size

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

func new_level(current_level : int) -> void:
	var comet_spawner := COMET_SPAWNER.instantiate()
	comet_spawner.comet_count *= current_level
	comet_spawner.comet_shot.connect(increase_score)
	comet_spawner.screen_cleared.connect(level_finished)
	self.add_child(comet_spawner)

func level_finished() -> void:
	level += 1
	new_level(level)

func game_over() -> void:
	# Wait 1 second before showing the game over screen for "dramatic" effect
	await get_tree().create_timer(1.0).timeout
	$UI/GameOverScreen.visible = true
	if score > high_score:
		save_score()

func _on_invader_spawner_shot() -> void:
	# This is not the most modular way to do this.
	score += 500

func increase_score(comet_size : int) -> void:
	# We add one since comet_size starts count at 0
	comet_size += 1
	score += int(points_per_comet / comet_size)

func update_ui()-> void:
	# Label strings must be all caps for font to render proper
	$UI/Score.text = "SCORE: " + str(score)
	$UI/Level.text = "LEVEL: " + str(level)
	$UI/HighScore.text = "HIGH SCORE:\n" + str(high_score)

func save_score() -> void:
	var file := FileAccess.open(save_file, FileAccess.WRITE)
	file.store_var(score)

func load_score() -> int:
	if FileAccess.file_exists(save_file):
		var file := FileAccess.open(save_file, FileAccess.READ)
		return file.get_var(score)
	else:
		return 0