extends CharacterBody2D
class_name NPCController

# ============================================================================
# 文件名: NPCController.gd
# 作用: 通用 NPC 控制器，负责角色待机表现与交互对话
#
# 主要功能:
# - 播放 NPC 待机动画
# - 响应玩家射线交互
# - 触发聊天气泡与 NPC 对话事件
#
# 依赖: EventSystem, EventNames, ChatBubble
# 作者: Codex
# 创建时间: 2026-03-10
# ============================================================================

signal interaction_happened(text: String)

const CHAT_BUBBLE_SCENE: PackedScene = preload("res://scenes/ui/ChatBubble.tscn")
const CHAT_BUBBLE_LAYER_NAME: String = "WorldChatBubbleLayer"
const CHAT_BUBBLE_TARGET_OFFSET: Vector2 = Vector2(0, -84)
const NPC_TALKED_EVENT: String = "npc_talked"
const WORLD_SORT_Z_OFFSET: int = 2048
const WORLD_TEXT_THEME = preload("res://assets/ui/world_text_theme.tres")
const NAMEPLATE_RENDER_SCALE: float = 0.5
const NAMEPLATE_FONT_SIZE: int = 24
const NAMEPLATE_VISUAL_HEIGHT: int = 22
const NAMEPLATE_VISUAL_MIN_WIDTH: int = 76
const NAMEPLATE_VISUAL_MAX_WIDTH: int = 118
const NAMEPLATE_VISUAL_CHAR_WIDTH: int = 12

@export var npcName: String = "NPC"
@export_multiline var dialogue: String = "欢迎来到WhaleTown，我是镇长范鲸晶"
@export var showNameplate: bool = false
@export var nameplateOffsetY: float = -112.0
@export var interactionDistance: float = 150.0

@onready var animation_player: AnimationPlayer = $AnimationPlayer

var _nameplate: Label

func _ready() -> void:
	if get_node_or_null("CafeCompanionTarget") == null:
		var interactable: InteractableComponent = InteractableComponent.new()
		interactable.interaction_id = "npc:%s" % str(get_path())
		interactable.interaction_title = "与 %s 交谈" % npcName
		interactable.interaction_priority = 40
		interactable.interaction_distance = interactionDistance
		interactable.activation_method = &"interact"
		add_child(interactable)
	# 播放场景里配置好的待机动画，让不同 NPC 可以复用同一个控制器。
	if animation_player.has_animation("idle"):
		animation_player.play("idle")
	_update_nameplate()
	_update_world_sort_z()

	# 保持 NPC 可被玩家射线与角色碰撞识别。
	collision_layer = 3
	collision_mask = 3

func _physics_process(_delta: float) -> void:
	_update_world_sort_z()

# 处理玩家交互，展示气泡并向全局事件系统广播。
func interact() -> void:
	show_bubble(dialogue)
	var eventSystem: Node = get_node_or_null("/root/EventSystem")
	if eventSystem != null:
		eventSystem.call("emit_event", NPC_TALKED_EVENT, {
			"npc": self,
			"npc_name": npcName,
			"dialogue": dialogue
		})
		interaction_happened.emit(dialogue)

# 在 NPC 头顶生成一次性聊天气泡。
#
# 参数:
#   text: String - 要展示的对话内容
func show_bubble(text: String) -> void:
	var bubble: Control = CHAT_BUBBLE_SCENE.instantiate() as Control
	if bubble == null:
		return
	var bubbleLayer: CanvasLayer = _get_chat_bubble_layer()
	bubbleLayer.add_child(bubble)
	if bubble.has_method("set_text"):
		bubble.call("set_text", text, self, CHAT_BUBBLE_TARGET_OFFSET)

func _get_chat_bubble_layer() -> CanvasLayer:
	var root: Window = get_tree().root
	var layer: CanvasLayer = root.get_node_or_null(CHAT_BUBBLE_LAYER_NAME) as CanvasLayer
	if layer != null:
		return layer

	layer = CanvasLayer.new()
	layer.name = CHAT_BUBBLE_LAYER_NAME
	layer.layer = 20
	root.add_child(layer)
	return layer

func _update_world_sort_z() -> void:
	z_index = WORLD_SORT_Z_OFFSET + int(round(global_position.y))

func _update_nameplate() -> void:
	if not showNameplate:
		if is_instance_valid(_nameplate):
			_nameplate.visible = false
		return
	if not is_instance_valid(_nameplate):
		_nameplate = Label.new()
		_nameplate.name = "Nameplate"
		add_child(_nameplate)

	var displayName := npcName.strip_edges()
	if displayName.is_empty():
		displayName = "NPC"
	var visualWidth := _nameplate_visual_width(displayName)
	var renderWidth := ceili(float(visualWidth) / NAMEPLATE_RENDER_SCALE)
	var renderHeight := ceili(float(NAMEPLATE_VISUAL_HEIGHT) / NAMEPLATE_RENDER_SCALE)

	_nameplate.theme = WORLD_TEXT_THEME
	_nameplate.text = displayName
	_nameplate.visible = true
	_nameplate.z_index = 30
	_nameplate.scale = Vector2.ONE * NAMEPLATE_RENDER_SCALE
	_nameplate.position = Vector2(float(visualWidth) * -0.5, nameplateOffsetY)
	_nameplate.custom_minimum_size = Vector2(renderWidth, renderHeight)
	_nameplate.size = _nameplate.custom_minimum_size
	_nameplate.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	_nameplate.vertical_alignment = VERTICAL_ALIGNMENT_CENTER
	_nameplate.clip_text = true
	_nameplate.text_overrun_behavior = TextServer.OVERRUN_TRIM_ELLIPSIS
	_nameplate.mouse_filter = Control.MOUSE_FILTER_IGNORE
	_nameplate.add_theme_color_override("font_color", Color(0.12, 0.20, 0.24, 1.0))
	_nameplate.add_theme_color_override("font_shadow_color", Color(1.0, 1.0, 1.0, 0.85))
	_nameplate.add_theme_constant_override("shadow_offset_x", 0)
	_nameplate.add_theme_constant_override("shadow_offset_y", 1)
	_nameplate.add_theme_font_size_override("font_size", NAMEPLATE_FONT_SIZE)
	_nameplate.add_theme_stylebox_override("normal", _create_nameplate_style())

func _nameplate_visual_width(displayName: String) -> int:
	var estimatedWidth := displayName.length() * NAMEPLATE_VISUAL_CHAR_WIDTH + 28
	return clampi(estimatedWidth, NAMEPLATE_VISUAL_MIN_WIDTH, NAMEPLATE_VISUAL_MAX_WIDTH)

func _create_nameplate_style() -> StyleBoxFlat:
	var style := StyleBoxFlat.new()
	style.bg_color = Color(1.0, 0.988, 0.955, 0.96)
	style.border_color = Color(0.18, 0.34, 0.38, 0.92)
	style.border_width_left = 2
	style.border_width_top = 2
	style.border_width_right = 2
	style.border_width_bottom = 2
	style.corner_radius_top_left = 12
	style.corner_radius_top_right = 12
	style.corner_radius_bottom_left = 12
	style.corner_radius_bottom_right = 12
	style.content_margin_left = 12
	style.content_margin_top = 4
	style.content_margin_right = 12
	style.content_margin_bottom = 4
	style.shadow_color = Color(0.05, 0.08, 0.09, 0.18)
	style.shadow_size = 4
	style.shadow_offset = Vector2(0, 2)
	return style