import { NFError } from "../error";
import { NFEventBus } from "../eventbus";
import { INFWaitState, NFNodeCfg, NFNodeType, NFWaitKind } from "../types";
import { NFNode } from "./node";

/**
 * 等待节点：定时 / 消息 / 信号。
 *
 * 到达后挂起，由流程实例的 `message`、`signal` 或 `resumeWaits` 唤醒后续顺序流。
 */
export class NFWaitNode extends NFNode{
    waitKind:string;
    delay?:number;
    dueTime?:number;
    messageName?:string;
    signalName?:string;

    /**
     * 创建等待节点。
     *
     * @param cfg - 需含 `waitKind`；消息 / 信号还须 `messageName` / `signalName`
     * @param process - 所属流程
     * @throws `1101` 当消息名或信号名缺失
     */
    constructor(cfg:NFNodeCfg,process){
        super(cfg,process);
        this.type = NFNodeType.WAIT;
        this.waitKind = (cfg.waitKind || NFWaitKind.TIMER) as string;
        this.delay = cfg.delay;
        this.dueTime = cfg.dueTime;
        this.messageName = cfg.messageName;
        this.signalName = cfg.signalName;

        if(this.waitKind === NFWaitKind.MESSAGE && !this.messageName){
            throw new NFError("1101",[this.name || this.id]);
        }
        if(this.waitKind === NFWaitKind.SIGNAL && !this.signalName){
            throw new NFError("1101",[this.name || this.id]);
        }
    }

    /**
     * 登记等待态后挂起，不推进出口。
     */
    async run(){
        await super.run();
        const state:INFWaitState = {
            kind: this.waitKind,
            nodeId: this.id
        };
        if(this.waitKind === NFWaitKind.TIMER){
            state.dueTime = this.dueTime != null
                ? this.dueTime
                : (Date.now() + (this.delay || 0));
        }else if(this.waitKind === NFWaitKind.MESSAGE){
            state.messageName = this.messageName;
        }else if(this.waitKind === NFWaitKind.SIGNAL){
            state.signalName = this.signalName;
        }
        await this.process.addWait(state);
        await NFEventBus.emit('node.leave',{ process:this.process, node:this, waiting:true });
        // 挂起，不推进出口
    }

    /**
     * 被唤醒后移除等待态并继续出口顺序流。
     */
    async resume(){
        await this.process.removeWait(this.id);
        const seq = this.process.nodeManager.getSequenceNode(this.id);
        if(seq){
            await seq.run();
        }
    }
}