extends Node2D

## Fog overlay controller — manages ColorRect + shader uniforms for D-059 fog.
## Reads textures from FogState autoload, positions rect to cover viewport.
## Architecture: docs/architecture/fog-shader-spec.md

signal fog_noise_ready
var _noise_ready: bool = false

var _fog_rect: ColorRect
var _shader_mat: ShaderMaterial

const TILE_SIZE := float(Constants.TILE_SIZE)


func _ready() -> void:
	# Create the fog overlay ColorRect — transparent fallback so a shader failure
	# doesn't paint solid white over the entire world (z:900 covers everything).
	_fog_rect = ColorRect.new()
	_fog_rect.name = "FogRect"
	_fog_rect.color = Color.TRANSPARENT
	add_child(_fog_rect)

	# Load shader and create material
	var shader := load("res://shaders/fog.gdshader") as Shader
	if shader == null:
		push_error("FogShader: failed to load res://shaders/fog.gdshader — fog disabled")
		return
	_shader_mat = ShaderMaterial.new()
	_shader_mat.shader = shader
	_fog_rect.material = _shader_mat

	# Create seamless noise texture for fog animation
	var noise := FastNoiseLite.new()
	noise.seed = 42
	noise.noise_type = FastNoiseLite.TYPE_PERLIN
	noise.frequency = 0.03
	var noise_tex := NoiseTexture2D.new()
	noise_tex.noise = noise
	noise_tex.width = 256
	noise_tex.height = 256
	noise_tex.seamless = true
	noise_tex.changed.connect(func(): _noise_ready = true; fog_noise_ready.emit())
	_shader_mat.set_shader_parameter("noise_tex", noise_tex)
	_shader_mat.set_shader_parameter("tile_size", TILE_SIZE)

	print("FogShader: Initialized (D-059 3-state)")


func update_fog() -> void:
	if _shader_mat == null:
		return  # Shader failed to load — fog disabled

	# 1. Update FogState textures from GameState
	FogState.update_from_state()

	# 2. Position ColorRect to cover the current viewport.
	# Use the camera's actual position (not player position) so the fog rect
	# tracks the smoothed camera and never desynchronizes during smooth pan.
	var vp_size := get_viewport().get_visible_rect().size
	var cam := get_viewport().get_camera_2d()
	var zoom := cam.zoom if cam else Vector2(2.0, 2.0)
	var camera_pos := cam.global_position if cam else GameState.player_position * TILE_SIZE
	var half_view := vp_size / (2.0 * zoom)
	_fog_rect.position = camera_pos - half_view
	_fog_rect.size = vp_size / zoom

	# 3. Update shader uniforms
	_shader_mat.set_shader_parameter("visibility_tex", FogState.visibility_texture)
	_shader_mat.set_shader_parameter("exploration_tex", FogState.exploration_texture)
	_shader_mat.set_shader_parameter("zone_tint_tex", FogState.zone_tint_texture)
	_shader_mat.set_shader_parameter("rect_pos", _fog_rect.position)
	_shader_mat.set_shader_parameter("rect_sz", _fog_rect.size)
	_shader_mat.set_shader_parameter("map_offset", Vector2(FogState.map_bounds.position))
	_shader_mat.set_shader_parameter("map_size", Vector2(FogState.map_bounds.size))
	var t: float = FogState.override_time if FogState.override_time >= 0.0 else Time.get_ticks_msec() / 1000.0
	_shader_mat.set_shader_parameter("time", t)
	_shader_mat.set_shader_parameter("debug_exploration", FogState.debug_exploration)