'use strict';
(function(root){
  function describe(people, links, reference, target) {
    const byId = new Map(people.map(p=>[p.id,p]));
    if (!byId.has(reference) || !byId.has(target)) return '尚未关联';
    if (reference === target) return '本人';
    const edges=links.filter(e=>e.active), graph=new Map();
    function add(a,b,kind,lineage){if(!graph.has(a))graph.set(a,[]);graph.get(a).push({id:b,kind,lineage});}
    for(const e of edges){add(e.fromId,e.toId,e.kind==='parent'?'child':'spouse',e.lineage);add(e.toId,e.fromId,e.kind==='parent'?'parent':'spouse',e.lineage);}
    const queue=[{id:reference,path:[]}],seen=new Set([reference]);let path;
    for(let i=0;i<queue.length;i++){
      const node=queue[i];
      for(const next of graph.get(node.id)||[]){if(seen.has(next.id))continue;seen.add(next.id);const steps=[...node.path,next];if(next.id===target){path=steps;break;}queue.push({id:next.id,path:steps});}
      if(path)break;
    }
    if(!path)return '关系待补充';
    const gender=byId.get(target).gender, word=(m,f,u)=>gender==='male'?m:gender==='female'?f:u;
    const type=path.map(e=>e.kind),n=path.length;
    let result;
    if(type.every(k=>k==='child')){
      result=n===1?word('儿子','女儿','子女'):n===2?word('孙子','孙女','孙辈'):n===3?word('曾孙','曾孙女','曾孙辈'):n===4?word('玄孙','玄孙女','玄孙辈'):`第 ${n} 代后裔`;
      if(n===2 && byId.get(path[0].id)?.gender==='female')result=word('外孙','外孙女','外孙辈');
    }else if(type.every(k=>k==='parent')){
      result=n===1?word('爸爸','妈妈','父母'):n===2?(byId.get(path[0].id)?.gender==='female'?word('姥爷','姥姥','外祖辈'):byId.get(path[0].id)?.gender==='male'?word('爷爷','奶奶','祖辈'):'祖父母辈'):n===3?'曾祖辈':n===4?'高祖辈':`第 ${n} 代祖先`;
    }else if(n===1 && type[0]==='spouse') result='配偶';
    else if(n===2 && type.join('/')==='parent/child'){
      const a=byId.get(reference).birthDate,b=byId.get(target).birthDate;
      result=a&&b&&a!==b?(b<a?word('哥哥','姐姐','年长的手足'):word('弟弟','妹妹','年幼的手足')):word('兄弟（长幼待确认）','姐妹（长幼待确认）','手足（长幼待确认）');
    }else{
      result=path.map(e=>e.kind==='spouse'?'配偶':e.kind==='parent'?(byId.get(e.id)?.gender==='male'?'父亲':byId.get(e.id)?.gender==='female'?'母亲':'父母'):(byId.get(e.id)?.gender==='male'?'儿子':byId.get(e.id)?.gender==='female'?'女儿':'子女')).join(' → ');
    }
    return result+(path.some(e=>e.lineage==='adoptive'||e.lineage==='step')?'（含收养 / 继亲关系）':'');
  }
  const api={describe}; if(typeof module!=='undefined'&&module.exports)module.exports=api;else root.ZhaoKinship=api;
})(typeof window!=='undefined'?window:globalThis);