feat：实现聊天系统核心功能

- 添加 SocketIOClient.gd 实现 Socket.IO 协议封装
- 添加 WebSocketManager.gd 管理连接生命周期和自动重连
- 添加 ChatManager.gd 实现聊天业务逻辑与会话管理
  - 支持当前会话缓存（最多 100 条消息）
  - 支持历史消息按需加载（每次 100 条）
  - 每次登录/重连自动重置会话缓存
  - 客户端频率限制（10 条/分钟）
  - Token 管理与认证
- 添加 ChatMessage.gd/tscn 消息气泡 UI 组件
- 添加 ChatUI.gd/tscn 聊天界面
- 在 EventNames.gd 添加 7 个聊天事件常量
- 在 AuthManager.gd 添加 game_token 管理方法
- 添加完整的单元测试（128 个测试用例）
  - test_socketio_client.gd (42 个测试)
  - test_websocket_manager.gd (38 个测试)
  - test_chat_manager.gd (48 个测试)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

scenes/prefabs/ui/ChatMessage.gd

@@ -0,0 +1,167 @@
+extends Panel
+
+# ============================================================================
+# ChatMessage.gd - 聊天消息气泡组件
+# ============================================================================
+# 显示单条聊天消息的 UI 组件
+#
+# 核心职责:
+# - 显示消息发送者、内容、时间戳
+# - 区分自己和他人的消息样式
+# - 自动格式化时间戳
+#
+# 使用方式:
+#   var message := chat_message_scene.instantiate()
+#   message.set_message("PlayerName", "Hello!", timestamp, false)
+#
+# 注意事项:
+# - 使用 @onready 缓存节点引用
+# - 最大宽度限制为 400 像素
+# ============================================================================
+
+class_name ChatMessage
+
+# ============================================================================
+# 导出参数
+# ============================================================================
+
+# 最大宽度（像素）
+@export var max_width: int = 400
+
+# ============================================================================
+# 节点引用
+# ============================================================================
+
+# 用户名标签
+@onready var username_label: Label = %UsernameLabel
+
+# 时间戳标签
+@onready var timestamp_label: Label = %TimestampLabel
+
+# 内容标签
+@onready var content_label: RichTextLabel = %ContentLabel
+
+# 用户信息容器
+@onready var user_info_container: HBoxContainer = %UserInfoContainer
+
+# ============================================================================
+# 成员变量
+# ============================================================================
+
+# 是否为自己发送的消息
+var _is_self: bool = false
+
+# ============================================================================
+# 生命周期方法
+# ============================================================================
+
+# 准备就绪
+func _ready() -> void:
+	# 应用最大宽度限制
+	custom_minimum_size.x = min(max_width, get_parent().size.x)
+
+# ============================================================================
+# 公共 API
+# ============================================================================
+
+# 设置消息内容
+#
+# 参数:
+#   from_user: String - 发送者用户名
+#   content: String - 消息内容
+#   timestamp: float - Unix 时间戳
+#   is_self: bool - 是否为自己发送的消息（默认 false）
+#
+# 使用示例:
+#   message.set_message("Alice", "Hello!", 1703500800.0, false)
+func set_message(from_user: String, content: String, timestamp: float, is_self: bool = false) -> void:
+	_is_self = is_self
+
+	# 设置用户名
+	username_label.text = from_user
+
+	# 设置内容
+	content_label.text = content
+
+	# 设置时间戳
+	timestamp_label.text = _format_timestamp(timestamp)
+
+	# 应用样式
+	_apply_style()
+
+# ============================================================================
+# 内部方法 - 样式处理
+# ============================================================================
+
+# 应用样式（自己和他人的消息不同）
+func _apply_style() -> void:
+	if _is_self:
+		# 自己的消息：右侧对齐，蓝色背景
+		size_flags_horizontal = Control.SIZE_SHRINK_END
+		user_info_container.alignment = BoxContainer.ALIGNMENT_END
+
+		# 设置面板样式
+		add_theme_stylebox_override("panel", _get_self_style())
+
+		# 设置文字颜色
+		username_label.add_theme_color_override("font_color", Color.WHITE)
+		timestamp_label.add_theme_color_override("font_color", Color(0.7, 0.7, 0.7))
+	else:
+		# 他人的消息：左侧对齐，灰色背景
+		size_flags_horizontal = Control.SIZE_SHRINK_BEGIN
+		user_info_container.alignment = BoxContainer.ALIGNMENT_BEGIN
+
+		# 设置面板样式
+		add_theme_stylebox_override("panel", _get_other_style())
+
+		# 设置文字颜色
+		username_label.add_theme_color_override("font_color", Color(0.2, 0.4, 0.8))
+		timestamp_label.add_theme_color_override("font_color", Color(0.5, 0.5, 0.5))
+
+# 获取自己消息的样式
+func _get_self_style() -> StyleBoxFlat:
+	var style := StyleBoxFlat.new()
+	style.bg_color = Color(0.2, 0.6, 1.0, 0.3)
+	style.corner_radius_top_left = 10
+	style.corner_radius_top_right = 10
+	style.corner_radius_bottom_left = 10
+	style.corner_radius_bottom_right = 2
+	style.content_margin_left = 10
+	style.content_margin_right = 10
+	style.content_margin_top = 8
+	style.content_margin_bottom = 8
+	return style
+
+# 获取他人消息的样式
+func _get_other_style() -> StyleBoxFlat:
+	var style := StyleBoxFlat.new()
+	style.bg_color = Color(0.9, 0.9, 0.9, 0.5)
+	style.corner_radius_top_left = 10
+	style.corner_radius_top_right = 10
+	style.corner_radius_bottom_left = 2
+	style.corner_radius_bottom_right = 10
+	style.content_margin_left = 10
+	style.content_margin_right = 10
+	style.content_margin_top = 8
+	style.content_margin_bottom = 8
+	return style
+
+# ============================================================================
+# 内部方法 - 工具函数
+# ============================================================================
+
+# 格式化时间戳
+#
+# 参数:
+#   timestamp: float - Unix 时间戳
+#
+# 返回值:
+#   String - 格式化的时间字符串
+func _format_timestamp(timestamp: float) -> String:
+	if timestamp == 0:
+		return ""
+
+	var datetime := Time.get_datetime_dict_from_unix_time(timestamp)
+
+	# 格式化为 HH:MM
+	return "%02d:%02d" % [datetime.hour, datetime.minute]

scenes/prefabs/ui/ChatMessage.gd.uid

@@ -0,0 +1 @@
+uid://djqrgj3h0lif7

scenes/prefabs/ui/ChatMessage.tscn

@@ -0,0 +1,45 @@
+[gd_scene load_steps=2 format=3 uid="uid://dqx8k3n8yqjvu"]
+
+[ext_resource type="Script" path="res://scenes/prefabs/ui/ChatMessage.gd" id="1"]
+
+[node name="ChatMessage" type="Panel"]
+offset_right = 400.0
+offset_bottom = 100.0
+size_flags_horizontal = 3
+script = ExtResource("1")
+
+[node name="VBoxContainer" type="VBoxContainer" parent="."]
+layout_mode = 1
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+theme_override_constants/separation = 4
+
+[node name="UserInfoContainer" type="HBoxContainer" parent="VBoxContainer"]
+unique_name_in_owner = true
+layout_mode = 2
+theme_override_constants/separation = 8
+
+[node name="UsernameLabel" type="Label" parent="VBoxContainer/UserInfoContainer"]
+unique_name_in_owner = true
+layout_mode = 2
+theme_override_colors/font_color = Color(0.2, 0.4, 0.8, 1)
+theme_override_font_sizes/font_size = 14
+text = "Username"
+
+[node name="TimestampLabel" type="Label" parent="VBoxContainer/UserInfoContainer"]
+unique_name_in_owner = true
+layout_mode = 2
+theme_override_colors/font_color = Color(0.5, 0.5, 0.5, 1)
+theme_override_font_sizes/font_size = 12
+text = "12:34"
+
+[node name="ContentLabel" type="RichTextLabel" parent="VBoxContainer"]
+unique_name_in_owner = true
+layout_mode = 2
+size_flags_vertical = 3
+bbcode_enabled = true
+text = "Message content here"
+fit_content = true

scenes/ui/ChatUI.gd

@@ -0,0 +1,371 @@
+extends Control
+
+# ============================================================================
+# ChatUI.gd - 聊天界面控制器（Enter 显示/隐藏版本）
+# ============================================================================
+# 聊天系统的用户界面控制器
+#
+# 核心职责:
+# - 显示聊天消息历史
+# - 处理用户输入
+# - 显示连接状态
+# - Enter 显示/隐藏 + 点击外部取消输入状态 + 5秒自动隐藏
+# - 只有按 Enter 才会取消倒计时
+# - Call Down: 通过 EventSystem 订阅聊天事件
+#
+# 使用方式:
+#   var chat_ui := preload("res://scenes/ui/ChatUI.tscn").instantiate()
+#   add_child(chat_ui)
+#
+# 注意事项:
+# - 遵循 "Signal Up, Call Down" 架构
+# - 使用 @onready 缓存节点引用
+# - 所有 UI 操作通过 ChatManager
+# ============================================================================
+
+# ============================================================================
+# 节点引用
+# ============================================================================
+
+# 聊天面板
+@onready var chat_panel: Panel = %ChatPanel
+
+# 聊天历史容器
+@onready var chat_history: ScrollContainer = %ChatHistory
+
+# 消息列表
+@onready var message_list: VBoxContainer = %MessageList
+
+# 聊天输入框
+@onready var chat_input: LineEdit = %ChatInput
+
+# 发送按钮
+@onready var send_button: Button = %SendButton
+
+# 状态标签
+@onready var status_label: Label = %StatusLabel
+
+# ============================================================================
+# 预加载资源
+# ============================================================================
+
+# 聊天消息场景
+@onready var chat_message_scene: PackedScene = preload("res://scenes/prefabs/ui/ChatMessage.tscn")
+
+# ============================================================================
+# 成员变量
+# ============================================================================
+
+# 是否显示聊天框
+var _is_chat_visible: bool = false
+
+# 隐藏计时器
+var _hide_timer: Timer = null
+
+# 是否在输入中（输入时不隐藏）
+var _is_typing: bool = false
+
+# 当前用户名
+var _current_username: String = ""
+
+# ============================================================================
+# 生命周期方法
+# ============================================================================
+
+# 准备就绪
+func _ready() -> void:
+	print("ChatUI 初始化完成")
+
+	# 初始隐藏聊天框
+	hide_chat()
+
+	# 创建隐藏计时器
+	_create_hide_timer()
+
+	# 设置初始状态
+	_update_connection_status(false)
+
+	# 订阅事件（Call Down via EventSystem）
+	_subscribe_to_events()
+
+	# 连接 UI 信号
+	_connect_ui_signals()
+
+# 清理
+func _exit_tree() -> void:
+	# 取消事件订阅
+	if EventSystem:
+		EventSystem.disconnect_event(EventNames.CHAT_MESSAGE_RECEIVED, _on_chat_message_received, self)
+		EventSystem.disconnect_event(EventNames.CHAT_ERROR_OCCURRED, _on_chat_error, self)
+		EventSystem.disconnect_event(EventNames.CHAT_CONNECTION_STATE_CHANGED, _on_connection_state_changed, self)
+		EventSystem.disconnect_event(EventNames.CHAT_LOGIN_SUCCESS, _on_login_success, self)
+
+	# 清理计时器
+	if _hide_timer:
+		_hide_timer.queue_free()
+
+# ============================================================================
+# 输入处理
+# ============================================================================
+
+# 处理全局输入
+func _input(event: InputEvent) -> void:
+	# 检查是否按下 Enter 键
+	if event.is_action_pressed("ui_text_submit") or event.is_key_pressed(KEY_ENTER):
+		_handle_enter_pressed()
+
+# 处理 Enter 键按下
+func _handle_enter_pressed() -> void:
+	# 如果聊天框未显示，显示它
+	if not _is_chat_visible:
+		show_chat()
+		chat_input.grab_focus()
+		return
+
+	# 如果聊天框已显示且输入框有焦点，发送消息
+	if chat_input.has_focus():
+		# 发送消息
+		_on_send_button_pressed()
+		return
+
+	# 如果聊天框已显示但输入框无焦点，重新聚焦（取消倒计时）
+	chat_input.grab_focus()
+	print("🔄 重新聚焦输入框，取消隐藏倒计时")
+
+# 处理 GUI 输入（鼠标点击）
+func _gui_input(event: InputEvent) -> void:
+	# 检查鼠标点击
+	if event is InputEventMouseButton and event.pressed:
+		if event.button_index == MOUSE_BUTTON_LEFT:
+			_handle_click_outside()
+
+# 处理点击聊天框外部区域
+func _handle_click_outside() -> void:
+	# 检查点击是否在聊天面板外部
+	if not chat_panel.get_global_rect().has_point(get_global_mouse_position()):
+		# 释放输入框焦点（取消输入状态）
+		if chat_input.has_focus():
+			chat_input.release_focus()
+			print("🖱️ 点击外部，取消输入状态")
+
+# ============================================================================
+# 显示/隐藏逻辑
+# ============================================================================
+
+# 显示聊天框
+func show_chat() -> void:
+	if _is_chat_visible:
+		return
+
+	_is_chat_visible = true
+	chat_panel.show()
+	print("👁️ 聊天框已显示")
+
+	# 停止隐藏计时器
+	_stop_hide_timer()
+
+# 隐藏聊天框
+func hide_chat() -> void:
+	if not _is_chat_visible:
+		return
+
+	_is_chat_visible = false
+	chat_panel.hide()
+	print("🚫 聊天框已隐藏")
+
+	# 停止隐藏计时器
+	_stop_hide_timer()
+
+# 创建隐藏计时器
+func _create_hide_timer() -> void:
+	_hide_timer = Timer.new()
+	_hide_timer.wait_time = 5.0  # 5 秒
+	_hide_timer.one_shot = true
+	_hide_timer.timeout.connect(_on_hide_timeout)
+	add_child(_hide_timer)
+
+# 开始隐藏倒计时
+func _start_hide_timer() -> void:
+	if _is_typing:
+		return  # 输入时不隐藏
+
+	_stop_hide_timer()  # 先停止之前的计时器
+	_hide_timer.start()
+	print("⏱️ 开始 5 秒倒计时...")
+
+# 停止隐藏倒计时
+func _stop_hide_timer() -> void:
+	if _hide_timer:
+		_hide_timer.stop()
+
+# 隐藏计时器超时
+func _on_hide_timeout() -> void:
+	hide_chat()
+
+# ============================================================================
+# UI 事件处理
+# ============================================================================
+
+# 连接 UI 信号
+func _connect_ui_signals() -> void:
+	# 发送按钮点击
+	send_button.pressed.connect(_on_send_button_pressed)
+
+	# 输入框回车
+	chat_input.text_submitted.connect(_on_chat_input_submitted)
+
+	# 输入框焦点变化
+	chat_input.focus_entered.connect(_on_input_focus_entered)
+	chat_input.focus_exited.connect(_on_input_focus_exited)
+
+# 输入框获得焦点
+func _on_input_focus_entered() -> void:
+	_is_typing = true
+	_stop_hide_timer()  # 停止隐藏计时器
+	print("✍️ 开始输入")
+
+# 输入框失去焦点
+func _on_input_focus_exited() -> void:
+	_is_typing = false
+	# 开始 5 秒倒计时
+	if not _is_chat_visible:
+		return
+	_start_hide_timer()
+	print("🚫 停止输入，开始 5 秒隐藏倒计时")
+
+# 发送按钮点击处理
+func _on_send_button_pressed() -> void:
+	var content: String = chat_input.text.strip_edges()
+
+	if content.is_empty():
+		return
+
+	# 发送消息
+	ChatManager.send_chat_message(content, "local")
+
+	# 清空输入框
+	chat_input.clear()
+
+	# 重新聚焦输入框
+	chat_input.grab_focus()
+
+# 聊天输入提交（回车键）处理
+func _on_chat_input_submitted(text: String) -> void:
+	_on_send_button_pressed()
+
+# ============================================================================
+# 事件订阅（Call Down）
+# ============================================================================
+
+# 订阅事件
+func _subscribe_to_events() -> void:
+	# 订阅聊天消息接收事件
+	EventSystem.connect_event(EventNames.CHAT_MESSAGE_RECEIVED, _on_chat_message_received, self)
+
+	# 订阅聊天错误事件
+	EventSystem.connect_event(EventNames.CHAT_ERROR_OCCURRED, _on_chat_error, self)
+
+	# 订阅连接状态变化事件
+	EventSystem.connect_event(EventNames.CHAT_CONNECTION_STATE_CHANGED, _on_connection_state_changed, self)
+
+	# 订阅登录成功事件
+	EventSystem.connect_event(EventNames.CHAT_LOGIN_SUCCESS, _on_login_success, self)
+
+# ============================================================================
+# 事件处理器
+# ============================================================================
+
+# 处理接收到的聊天消息
+func _on_chat_message_received(data: Dictionary) -> void:
+	var from_user: String = data.get("from_user", "")
+	var content: String = data.get("content", "")
+	var timestamp: float = data.get("timestamp", 0.0)
+
+	# 添加到消息历史
+	add_message_to_history(from_user, content, timestamp, false)
+
+# 处理聊天错误
+func _on_chat_error(data: Dictionary) -> void:
+	var error_code: String = data.get("error_code", "")
+	var message: String = data.get("message", "")
+
+	print("❌ ChatUI 错误: [", error_code, "] ", message)
+
+	# 显示错误消息（临时显示在状态栏）
+	status_label.text = "❌ " + message
+	status_label.modulate = Color.RED
+
+	# 3秒后恢复状态
+	var timer := get_tree().create_timer(3.0)
+	timer.timeout.connect(func():
+		_update_connection_status(ChatManager.is_connected())
+	)
+
+# 处理连接状态变化
+func _on_connection_state_changed(data: Dictionary) -> void:
+	var state: WebSocketManager.ConnectionState = data.get("state", WebSocketManager.ConnectionState.DISCONNECTED)
+
+	match state:
+		WebSocketManager.ConnectionState.CONNECTED:
+			_update_connection_status(true)
+		_:
+			_update_connection_status(false)
+
+# 处理登录成功
+func _on_login_success(data: Dictionary) -> void:
+	_current_username = data.get("username", "")
+	print("✅ ChatUI: 登录成功，用户名: ", _current_username)
+
+# ============================================================================
+# 公共 API - 消息管理
+# ============================================================================
+
+# 添加消息到历史
+#
+# 参数:
+#   from_user: String - 发送者用户名
+#   content: String - 消息内容
+#   timestamp: float - 时间戳
+#   is_self: bool - 是否为自己发送的消息（默认 false）
+func add_message_to_history(from_user: String, content: String, timestamp: float, is_self: bool) -> void:
+	# 如果聊天框隐藏，自动显示
+	if not _is_chat_visible:
+		show_chat()
+
+	# 创建消息节点
+	var message_node: ChatMessage = chat_message_scene.instantiate()
+
+	# 设置消息内容
+	message_node.set_message(from_user, content, timestamp, is_self)
+
+	# 添加到列表
+	message_list.add_child(message_node)
+
+	# 自动滚动到底部
+	call_deferred("_scroll_to_bottom")
+
+# ============================================================================
+# 内部方法 - UI 更新
+# ============================================================================
+
+# 更新连接状态显示
+func _update_connection_status(connected: bool) -> void:
+	if connected:
+		status_label.text = "● 已连接"
+		status_label.modulate = Color.GREEN
+		chat_input.editable = true
+		send_button.disabled = false
+	else:
+		status_label.text = "○ 未连接"
+		status_label.modulate = Color.GRAY
+		chat_input.editable = false
+		send_button.disabled = true
+
+# 滚动到底部
+func _scroll_to_bottom() -> void:
+	# 等待一帧，确保 UI 更新完成
+	await get_tree().process_frame
+
+	# 滚动到底部
+	if is_instance_valid(chat_history):
+		chat_history.scroll_vertical = chat_history.get_v_scroll_bar().max_value

scenes/ui/ChatUI.gd.uid

@@ -0,0 +1 @@
+uid://pibdlvhb12q8

scenes/ui/ChatUI.tscn

@@ -0,0 +1,77 @@
+[gd_scene load_steps=2 format=3 uid="uid://bv7k2m9n4xj8q"]
+
+[ext_resource type="Script" path="res://scenes/ui/ChatUI.gd" id="1"]
+
+[node name="ChatUI" type="Control"]
+layout_mode = 3
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+mouse_filter = 2
+script = ExtResource("1")
+
+[node name="ChatPanel" type="Panel" parent="."]
+unique_name_in_owner = true
+layout_mode = 1
+anchors_preset = 3
+anchor_left = 1.0
+anchor_top = 1.0
+anchor_right = 1.0
+anchor_bottom = 1.0
+offset_left = -450.0
+offset_top = -400.0
+grow_horizontal = 0
+grow_vertical = 0
+
+[node name="VBoxContainer" type="VBoxContainer" parent="ChatPanel"]
+layout_mode = 1
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+theme_override_constants/separation = 8
+offset_left = 10.0
+offset_top = 10.0
+offset_right = -10.0
+offset_bottom = -10.0
+
+[node name="HeaderContainer" type="HBoxContainer" parent="ChatPanel/VBoxContainer"]
+layout_mode = 2
+
+[node name="StatusLabel" type="Label" parent="ChatPanel/VBoxContainer/HeaderContainer"]
+unique_name_in_owner = true
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_colors/font_color = Color(0.5, 0.5, 0.5, 1)
+theme_override_font_sizes/font_size = 12
+text = "○ 未连接"
+
+[node name="ChatHistory" type="ScrollContainer" parent="ChatPanel/VBoxContainer"]
+unique_name_in_owner = true
+layout_mode = 2
+size_flags_vertical = 3
+
+[node name="MessageList" type="VBoxContainer" parent="ChatPanel/VBoxContainer/ChatHistory"]
+unique_name_in_owner = true
+layout_mode = 2
+size_flags_horizontal = 3
+size_flags_vertical = 3
+theme_override_constants/separation = 8
+
+[node name="InputContainer" type="HBoxContainer" parent="ChatPanel/VBoxContainer"]
+layout_mode = 2
+theme_override_constants/separation = 8
+
+[node name="ChatInput" type="LineEdit" parent="ChatPanel/VBoxContainer/InputContainer"]
+unique_name_in_owner = true
+layout_mode = 2
+size_flags_horizontal = 3
+placeholder_text = "输入消息..."
+
+[node name="SendButton" type="Button" parent="ChatPanel/VBoxContainer/InputContainer"]
+unique_name_in_owner = true
+layout_mode = 2
+text = "发送"