/**
* 多会话状态管理
* 支持同时管理多个 Excalidraw 图表会话
*/
export interface Session {
id: string
elements: ExcalidrawElement[]
appState: AppState
version: number
lastUpdated: Date
}
export interface ExcalidrawElement {
id: string
type: string
x?: number
y?: number
width?: number
height?: number
angle?: number
strokeColor?: string
backgroundColor?: string
fillStyle?: string
strokeWidth?: number
strokeStyle?: string
roundness?: { type: number; value?: number } | null
roughness?: number
opacity?: number
seed?: number
version?: number
versionNonce?: number
index?: string | null
isDeleted?: boolean
groupIds?: string[]
frameId?: string | null
boundElements?: BoundElement[] | null
updated?: number
link?: string | null
locked?: boolean
customData?: Record<string, any>
// skeleton / convert 相关属性
label?: {
text: string
fontSize?: number
fontFamily?: number
strokeColor?: string
textAlign?: 'left' | 'center' | 'right'
verticalAlign?: 'top' | 'middle' | 'bottom'
}
start?:
| { id: string }
| {
type: 'rectangle' | 'ellipse' | 'diamond' | 'text'
id?: string
text?: string
width?: number
height?: number
}
end?:
| { id: string }
| {
type: 'rectangle' | 'ellipse' | 'diamond' | 'text'
id?: string
text?: string
width?: number
height?: number
}
// 文本特有属性
text?: string
fontSize?: number
fontFamily?: number
textAlign?: string
verticalAlign?: string
containerId?: string | null
originalText?: string
autoResize?: boolean
lineHeight?: number
// 线条/箭头
points?: [number, number][]
lastCommittedPoint?: [number, number] | null
startBinding?: { elementId: string; focus: number; gap: number } | null
endBinding?: { elementId: string; focus: number; gap: number } | null
startArrowhead?: string | null
endArrowhead?: string | null
elbowed?: boolean
// 自由绘制
pressures?: number[]
simulatePressure?: boolean
// 图片
fileId?: string | null
status?: 'pending' | 'saved' | 'error'
scale?: [number, number]
crop?: {
x: number
y: number
width: number
height: number
naturalWidth: number
naturalHeight: number
} | null
// Frame / Magicframe
name?: string | null
}
export interface BoundElement {
id: string
type: string
}
export interface AppState {
viewBackgroundColor: string
currentItemStrokeColor: string
currentItemBackgroundColor: string
currentItemFillStyle: string
currentItemStrokeWidth: number
currentItemRoughness: number
zoom: { value: number }
[key: string]: any
}
// 多会话存储
const sessions = new Map<string, Session>()
// 默认会话 ID（向后兼容）
const DEFAULT_SESSION_ID = 'default'
// 会话过期时间（1小时）
const SESSION_TTL = 60 * 60 * 1000
/**
* 创建默认的 AppState
*/
function createDefaultAppState(): AppState {
return {
viewBackgroundColor: '#ffffff',
currentItemStrokeColor: '#1e1e1e',
currentItemBackgroundColor: 'transparent',
currentItemFillStyle: 'solid',
currentItemStrokeWidth: 2,
currentItemRoughness: 1,
zoom: { value: 1 },
}
}
/**
* 验证 sessionId 格式
* 防止恶意输入
*/
function isValidSessionId(sessionId: string): boolean {
return /^[a-zA-Z0-9_-]{1,64}$/.test(sessionId)
}
/**
* 创建新会话
*/
export function createSession(sessionId?: string): Session {
const id = sessionId || `mcp-${crypto.randomUUID().slice(0, 8)}`
if (!isValidSessionId(id)) {
throw new Error(
`Invalid session ID: ${id}. Must be alphanumeric with hyphens/underscores, max 64 chars.`,
)
}
const session: Session = {
id,
elements: [],
appState: createDefaultAppState(),
version: 0,
lastUpdated: new Date(),
}
sessions.set(id, session)
return session
}
/**
* 获取会话
* 如果会话不存在且 autoCreate 为 true，则自动创建
*/
export function getSession(sessionId?: string, autoCreate = true): Session {
const id = sessionId || DEFAULT_SESSION_ID
let session = sessions.get(id)
if (!session && autoCreate) {
session = createSession(id)
}
if (!session) {
throw new Error(`Session not found: ${id}`)
}
return session
}
/**
* 检查会话是否存在
*/
export function hasSession(sessionId: string): boolean {
return sessions.has(sessionId)
}
/**
* 更新会话
*/
export function updateSession(session: Session): void {
session.lastUpdated = new Date()
sessions.set(session.id, session)
}
/**
* 删除会话
*/
export function deleteSession(sessionId: string): boolean {
return sessions.delete(sessionId)
}
/**
* 清空所有会话
*/
export function clearAllSessions(): void {
sessions.clear()
}
/**
* 获取所有会话列表
*/
export function listSessions(): Array<{ id: string; elementCount: number; lastUpdated: Date }> {
return Array.from(sessions.values()).map((s) => ({
id: s.id,
elementCount: s.elements.length,
lastUpdated: s.lastUpdated,
}))
}
/**
* 清理过期会话
*/
export function cleanupExpiredSessions(): number {
const now = Date.now()
let cleaned = 0
for (const [id, session] of sessions) {
// 不清理默认会话
if (id === DEFAULT_SESSION_ID) continue
if (now - session.lastUpdated.getTime() > SESSION_TTL) {
sessions.delete(id)
cleaned++
}
}
return cleaned
}
// 定期清理过期会话（每5分钟）
setInterval(cleanupExpiredSessions, 5 * 60 * 1000)
// ============================================================
// 向后兼容的旧 API（使用默认会话）
// ============================================================
/**
* @deprecated 使用 getSession(sessionId) 代替
*/
export function getCurrentSession(): Session {
return getSession(DEFAULT_SESSION_ID)
}
/**
* @deprecated 使用 clearAllSessions() 或 deleteSession(id) 代替
*/
export function clearSession(): void {
deleteSession(DEFAULT_SESSION_ID)
}
