extends Camera3D
class_name CameraManager

@export var global_effect_curve : Curve
var target:int
var target_character_pos:Vector2 = Vector2.ZERO
var target_pos:Vector2 = Vector2.ZERO
var target_pos_y:float
var target_pos_now:Vector2 = Vector2.ZERO
var level_size:Vector2
var offset:float = 5
var shake_offset_x:float
var camera_limit = Vector3(6.4,1.04,3.6) #x,up,z-downd
var camera_size = 7.2

var basic_size = Vector2(640,360)
var scale_y = cos(deg_to_rad(45.0)) * 2.0 #1.414
var sample_rate = 3.0
var stage_size = basic_size * sample_rate
var stage_scale = Vector2(1,scale_y) / sample_rate
var stage_offset_y = (scale_y - 1.0) * 0.5 / sample_rate * stage_size.y
var screen_pos_scale = Vector2(sample_rate,sample_rate/scale_y)
var screen_pos_offset = Vector2(0,-stage_offset_y)

var global_effect_list = []

class GlobalEffect:
	var effect_type : Enum.EGlobalEffect
	var life_time : float
	var life_time_now : float
	var value : float

func _ready():
	Global.camera_mgr = self
	SignalManager.character_create.connect(on_character_create)
	SignalManager.character_pos_changed.connect(on_character_pos_changed)
	SignalManager.character_hit_floor.connect(on_character_hit_floor)
	SignalManager.character_destroy.connect(on_character_destroy)
	SignalManager.level_size_change.connect(on_level_size_change)
	SignalManager.level_loading_end.connect(on_level_loading_end)
	
func _process(delta):
	update_global_effect(delta)
	update_camera_pos(delta)

func update_global_effect(delta):
	var remove_list = []
	for global_effect : GlobalEffect in global_effect_list:
		global_effect.life_time_now += delta
		global_effect.life_time_now = min(global_effect.life_time_now,global_effect.life_time)
		if global_effect.life_time_now == global_effect.life_time:
			remove_list.append(global_effect)
		var rate = global_effect.life_time_now/global_effect.life_time
		var value = global_effect_curve.sample(rate)*global_effect.value
		match global_effect.effect_type:
			Enum.EGlobalEffect.CameraSize:size = camera_size * (1 - 0.2*value);refresh_target_pos()
			Enum.EGlobalEffect.CameraShake: shake_offset_x = (sin(rate * PI * 10) - 0.5)*0.04*value
			Enum.EGlobalEffect.ColorShift:Global.view_mgr.set_post_processing("shift_strength",value)
			Enum.EGlobalEffect.Blur:Global.view_mgr.set_post_processing("blur_strength",value)
	for global_effect : GlobalEffect in remove_list:
		global_effect_list.erase(global_effect)

func update_camera_pos(delta):
	target_pos_lerp(0,delta,5)
	target_pos_lerp(1,delta,5)
	position.x = target_pos_now.x + shake_offset_x
	position.z = target_pos_now.y + target_pos_y + offset
	position.y = target_pos_y + offset

func target_pos_lerp(index:int,delta:float,delta_scale:float):
	var target_pos_real = target_pos
	var diff = abs(target_pos_now[index] - target_pos_real[index])
	if diff < Setting.pixel_size:
		target_pos_now[index] = Util.snap_float(target_pos_real[index])
	else:
		var weight_min = Setting.pixel_size / 2 / diff
		var weight = max(delta * delta_scale,weight_min)
		target_pos_now[index] = lerp(target_pos_now[index], target_pos_real[index], weight)

func on_character_create(id:int,type:int,pos:Vector3):
	if type == Enum.ECharacterType.Player:
		target = id
		on_character_pos_changed(id,pos)
		on_character_hit_floor(id,pos)
		on_level_loading_end()
	
func on_character_pos_changed(id:int,pos:Vector3):
	if id == target:
		target_character_pos.x = pos.x
		target_character_pos.y = pos.z
		refresh_target_pos()

func on_character_hit_floor(id:int,pos:Vector3):
	if id == target:
		target_pos_y = pos.y
		refresh_target_pos()

func refresh_target_pos():
	var pos = target_character_pos
	var camera_size_diff = (camera_size - size)/2.0
	var x_min = camera_limit.x - camera_size_diff
	var x_max = level_size.x - camera_limit.x + camera_size_diff
	var y_min = camera_limit.y - target_pos_y - camera_size_diff
	var y_max = level_size.y - camera_limit.z - target_pos_y + camera_size_diff
	target_pos.x = clamp(pos.x,x_min,x_max)
	target_pos.y = clamp(pos.y-target_pos_y,y_min,y_max)

func on_character_destroy(id:int):target = 0
func on_level_size_change(size:Vector2):level_size = size

func on_level_loading_end():
	target_pos_now.x = target_pos.x
	target_pos_now.y = target_pos.y

func get_screen_pos(pos:Vector3) -> Vector2:
	var ret = unproject_position(pos)
	ret.x /= screen_pos_scale.x
	ret.y /= screen_pos_scale.y
	ret.x += screen_pos_offset.x
	ret.y += screen_pos_offset.y
	return ret

func add_global_effect(effect_type:Enum.EGlobalEffect ,life_time:float ,value:float):
	for global_effect : GlobalEffect in global_effect_list:
		if global_effect.effect_type == effect_type:
			global_effect.life_time = life_time
			global_effect.life_time_now = 0
			global_effect.value = value
			return
	var global_effect = GlobalEffect.new()
	global_effect.effect_type = effect_type
	global_effect.life_time = life_time
	global_effect.life_time_now = 0
	global_effect.value = value
	global_effect_list.append(global_effect)

func effect(pause_time):
	if not pause_time:
		return
	var basic_pause_time = 0.3
	var effect_time = pause_time * 2
	var rate = pause_time/basic_pause_time
	add_global_effect(Enum.EGlobalEffect.CameraShake,effect_time,0.8 * rate)
	add_global_effect(Enum.EGlobalEffect.CameraSize,effect_time,0.4 * rate)
	add_global_effect(Enum.EGlobalEffect.ColorShift,effect_time,0.8 * rate)
	add_global_effect(Enum.EGlobalEffect.Blur,effect_time,0.8 * rate)


func effect_normal():
	add_global_effect(Enum.EGlobalEffect.CameraShake,0.2,0.2)
	add_global_effect(Enum.EGlobalEffect.CameraSize,0.2,0.02)
	add_global_effect(Enum.EGlobalEffect.ColorShift,0.2,0.2)
	add_global_effect(Enum.EGlobalEffect.Blur,0.2,0.1)
	
func effect_mid():
	add_global_effect(Enum.EGlobalEffect.CameraShake,0.3,0.4)
	add_global_effect(Enum.EGlobalEffect.CameraSize,0.3,0.2)
	add_global_effect(Enum.EGlobalEffect.ColorShift,0.3,0.4)
	add_global_effect(Enum.EGlobalEffect.Blur,0.3,0.4)
	
func effect_strong():
	add_global_effect(Enum.EGlobalEffect.CameraShake,0.4,0.8)
	add_global_effect(Enum.EGlobalEffect.CameraSize,0.4,0.4)
	add_global_effect(Enum.EGlobalEffect.ColorShift,0.4,0.8)
	add_global_effect(Enum.EGlobalEffect.Blur,0.4,0.8)