extends Node2D

@export_group("Visual Settings")
@export var STARRY_SKY_LAYER: PackedScene
@export var Star_Count: int = 2000: set = set_star_count

@export var Background_Image_Size: Vector2 = Vector2(1080, 1920): 
        set = set_Background_Image_Size
@export var Background_Layers: Array [StarrySkyLayer]

var Stars_by_Layers: Dictionary = {}

const BACKGROUND_COLOR: Color = Color.BLACK

const X_SCROLL_RANGE: Vector2 = Vector2(3, 10)
const Y_SCROLL_RANGE: Vector2 = Vector2(1, 5)
const SCALE_FACTOR = 1

const STAR_COLOR_DISTRIBUTION = [
        [700, '#8FA8FFFF', 0 ],
        [1700, '#8FA8FFD8', 0 ],
        [3400, '#8FA8FFA0', 0 ],
        [6000, '#A0B5FFFF', 0 ],
        [9900, '#A0B5FFD0', 0 ],
        [16400, '#A0B5FF90', 0 ],
        [17300, '#B0C5FFFF', 0 ],
        [18600, '#B0C5FFC8', 0 ],
        [20800, '#B0C5FF88', 0 ],
        [26000, '#D0DBFFFF', 0 ],
        [33800, '#D0DBFFC0', 0 ],
        [46800, '#D0DBFF80', 0 ],
        [57200, '#F8F7FFE0', 1 ],
        [72900, '#F8F7FFA8', 1 ],
        [99000, '#F8F7FF70', 1 ],
        [114700, '#FFF4EAD0', 1 ],
        [138200, '#FFF4EA98', 1 ],
        [177400, '#FFF4EA60', 1 ],
        [180000, '#FFD280F0', 1 ],
        [183000, '#FFD280B8', 1 ],
        [189000, '#FFD28078', 1 ],
        [191000, '#FFA64DF8', 1 ],
        [194000, '#FFA64DC0', 1 ],
        [199000, '#FFA64D80', 1 ],
        [225000, '#FFE4B5C0', 2 ],
        [264000, '#FFE4B588', 2 ],
        [309000, '#FFE4B550', 2 ],
        [364000, '#FFCC99A0', 2 ],
        [441000, '#FFCC9968', 2 ],
        [604000, '#FFCC9940', 2 ],
        [658000, '#FFB36690', 2 ],
        [753000, '#FFB3665C', 2 ],
        [893000, '#FFB36630', 2 ],
        [914000, '#E8F4FF80', 2 ],
        [946000, '#E8F4FF50', 2 ],
        [1_000_000, '#E8F4FF28', 2 ],    
    ]

func _ready() -> void:
    initiate_layers()
    randomize_parallax()
    generate_layers()

func _process(delta: float) -> void:
    if randi_range(0, 1000) == 0:
        randomize_parallax()

func _draw() -> void:
    draw_rect(Rect2(Vector2.ZERO, Background_Image_Size), BACKGROUND_COLOR)

func generate_layers():
    var max_rnd_seed = STAR_COLOR_DISTRIBUTION[-1][0]
            
    for ind1 in range(Star_Count):
        var star_coords = Vector2(randi_range(0, Background_Image_Size.x), 
                                    randi_range(0, Background_Image_Size.y))
        var rnd_seed = randi_range(0, max_rnd_seed)
        for item:Array in STAR_COLOR_DISTRIBUTION:
            var item_seed = item[0]
            if rnd_seed <= item_seed:
                var star_color = Color.html(item[1])
                var star_layer = item[2]
                Background_Layers[star_layer].Stars.append({
                    "coords": star_coords, 
                    "color": star_color,
                    })
                break

func initiate_layers():
    var layer_count = 0
    for item:Array in STAR_COLOR_DISTRIBUTION:
        if item[2] > layer_count:
            layer_count = item[2]
    for ind1 in range(layer_count + 1):
        var new_star_layer:StarrySkyLayer = STARRY_SKY_LAYER.instantiate()
        add_child(new_star_layer)
        new_star_layer.Background_Image_Size = Background_Image_Size
        #new_star_layer.autoscroll = (ind1 + 1) * DEFAULT_AUTOSCROL 
        Background_Layers.append(new_star_layer)

func randomize_parallax():
    var x_offset = 0
    var y_offset = 0
    if _random_sign() == 1:
        x_offset = _random_offset(X_SCROLL_RANGE) * _random_sign()
    else:
        y_offset = _random_offset(Y_SCROLL_RANGE) * _random_sign()

    var scale_factor = 1
    for layer in Background_Layers:
        layer.autoscroll = Vector2(x_offset, y_offset) * scale_factor
        scale_factor += SCALE_FACTOR

#region Random offset

func _random_offset(rng: Vector2i) -> int:
    return randi_range(rng.x, rng.y)

func _random_sign() -> int:
    return [1, -1].pick_random()            

#endregion

#region Сеттеры для автоматического обновления
func set_Background_Image_Size(value: Vector2):
    Background_Image_Size = value
    queue_redraw()

func set_star_count(value: int):
    Star_Count = value
    queue_redraw()

#endregion