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
# - 打开 NPC 对话框并广播 NPC 对话事件
#
# 依赖: EventSystem, EventNames, ChatUI
# 作者: Codex
# 创建时间: 2026-03-10
# ============================================================================

signal interaction_happened(text: String)

const NPC_TALKED_EVENT: String = "npc_talked"
const NPC_COLLISION_LAYER: int = 2
const NPC_COLLISION_MASK: int = 1
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 = 16
const NAMEPLATE_VISUAL_HEIGHT: int = 15
const NAMEPLATE_VISUAL_MIN_WIDTH: int = 64
const NAMEPLATE_VISUAL_MAX_WIDTH: int = 100
const NAMEPLATE_FONT_ZH: FontFile = preload("res://assets/fonts/fusion-pixel-12px/fusion-pixel-12px-proportional-zh_hans.ttf.woff2")
const NAMEPLATE_FONT_LATIN: FontFile = preload("res://assets/fonts/fusion-pixel-12px/fusion-pixel-12px-proportional-latin.ttf.woff2")

@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

@onready var animation_player: AnimationPlayer = $AnimationPlayer

var _nameplate: Label
var _nicknameFont: FontFile

func _ready() -> void:
	# 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()

	# NPC 单独占用交互层；玩家的物理掩码同时包含地图层和 NPC 层。
	collision_layer = NPC_COLLISION_LAYER
	collision_mask = NPC_COLLISION_MASK

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

# 处理玩家交互，打开统一对话框并向全局事件系统广播。
func interact() -> void:
	var chatUi := get_tree().root.find_child("ChatUI", true, false)
	if chatUi != null and chatUi.has_method("show_npc_dialogue"):
		chatUi.call("show_npc_dialogue", npcName, 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)

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(0.09, 0.25, 0.31, 1.0))
	_nameplate.add_theme_color_override("font_outline_color", Color(1.0, 0.965, 0.88, 0.98))
	_nameplate.add_theme_constant_override("outline_size", 3)
	_nameplate.add_theme_font_override("font", _get_nickname_font())
	_nameplate.add_theme_font_size_override("font_size", NAMEPLATE_FONT_SIZE)
	_nameplate.add_theme_stylebox_override("normal", StyleBoxEmpty.new())

func _nameplate_visual_width(displayName: String) -> int:
	var measuredWidth := _get_nickname_font().get_string_size(displayName, HORIZONTAL_ALIGNMENT_LEFT, -1, NAMEPLATE_FONT_SIZE).x
	var visualWidth := ceili(measuredWidth * NAMEPLATE_RENDER_SCALE + 20.0)
	return clampi(visualWidth, NAMEPLATE_VISUAL_MIN_WIDTH, NAMEPLATE_VISUAL_MAX_WIDTH)

func _get_nickname_font() -> FontFile:
	if _nicknameFont == null:
		_nicknameFont = NAMEPLATE_FONT_ZH.duplicate() as FontFile
		_nicknameFont.fallbacks = [NAMEPLATE_FONT_LATIN]
	return _nicknameFont