62 lines
1.7 KiB
TypeScript
62 lines
1.7 KiB
TypeScript
import type { SessionState } from "../types";
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/** 合法状态迁移表 */
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const TRANSITIONS: Record<SessionState, SessionState[]> = {
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idle: ["connecting", "disconnected"],
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connecting: ["auth_pending", "error", "disconnected"],
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auth_pending: ["connected", "error", "disconnected"],
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connected: ["reconnecting", "disconnected", "error"],
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reconnecting: ["connected", "error", "disconnected"],
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disconnected: ["connecting", "idle"],
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error: ["connecting", "disconnected"],
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};
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export function canTransition(from: SessionState, to: SessionState): boolean {
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return (TRANSITIONS[from] ?? []).includes(to);
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}
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export function assertTransition(from: SessionState, to: SessionState): void {
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if (!canTransition(from, to)) {
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throw new Error(`非法状态跳转: ${from} → ${to}`);
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}
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}
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/**
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* SessionMachine — 会话生命周期状态机。
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* 纯状态逻辑，无任何副作用，零 DOM 依赖。
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*/
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export class SessionMachine {
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private _state: SessionState = "idle";
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private listeners = new Set<(state: SessionState) => void>();
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get state(): SessionState {
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return this._state;
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}
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transition(to: SessionState): void {
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assertTransition(this._state, to);
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this._state = to;
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for (const fn of this.listeners) {
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fn(this._state);
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}
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}
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tryTransition(to: SessionState): boolean {
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if (!canTransition(this._state, to)) return false;
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this.transition(to);
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return true;
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}
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onChange(fn: (state: SessionState) => void): () => void {
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this.listeners.add(fn);
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return () => this.listeners.delete(fn);
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}
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reset(): void {
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this._state = "idle";
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for (const fn of this.listeners) {
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fn(this._state);
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}
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}
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}
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