import { NFNode } from "./node";
import { NFNodeCfg, NFNodeType } from "../types";
import { NFSequenceNode } from "./sequencenode";
import { NFProcess } from "../process";
import { NFError } from "../error";

/**
 * 排他网关（XOR）
 * - 分叉：按顺序取第一条条件为真的出口；若皆不满足则走 default / 无条件出口
 * - 汇聚：任一入边到达即通过（不同步等待）
 */
export class NFExclusiveNode extends NFNode{
    /**
     * 出口顺序流
     */
    outSequences:NFSequenceNode[];
    
    /**
     * @param cfg - 节点配置
     * @param process - 所属流程
     */
    constructor(cfg:NFNodeCfg,process:NFProcess){
        super(cfg,process);
        this.type = NFNodeType.EXCLUSIVE;
    }
    
    /**
     * 按条件选一条出口执行。
     *
     * @throws `1101` 当无匹配出口且无默认 / 无条件流
     */
    async run() {
        await super.run();

        let selected:NFSequenceNode = null;
        let defaultSeq:NFSequenceNode = null;

        for(let seq of this.outSequences){
            if(seq.isDefaultFlow()){
                defaultSeq = defaultSeq || seq;
                continue;
            }
            if(seq.match()){
                selected = seq;
                break;
            }
        }

        // 无匹配时：显式 default > 无条件出口
        if(!selected){
            selected = defaultSeq || this.outSequences.find(s=>!s.expr && !s.isDefaultFlow());
        }

        if(!selected){
            throw new NFError("1101",[this.name || this.id]);
        }

        await selected.run(true);
    }

    /**
     * 绑定出口顺序流。
     *
     * @throws `1101` 当没有出口
     */
    init(){
        this.outSequences = this.process.nodeManager.getSequenceNodes(this.id);
        if(!this.outSequences || this.outSequences.length === 0){
            throw new NFError("1101",[this.name || this.id]);
        }
    }
}