'use client';

import { useEffect, useState } from 'react';
import { useRouter } from 'next/navigation';
import { Inbox, RefreshCw } from 'lucide-react';
import { Permission } from '@pac/types';
import { Can } from '@/components/can';
import { plansApi } from '@/components/plans/plans-api';
import { PatientPickerRail } from '@/components/plans/patient-picker-rail';
import { IdentityCluster } from '@/components/identity-cluster';
import { isEmbedded } from '@/lib/embed';

/**
 * /plans — 工作台入口解析器(原列表页已弃用,组件保留在 plans-list-app.tsx 未挂载)。
 *
 * 进来直接落到详情工作台,选人规则(纯规则):
 *   ① 我的「进行中」第一个(优先续上手头工作)
 *   ② 没有 → 召回池优先级最高的一个(开新工作)
 *   ③ 都没有 → 空工作台:左栏照常(可自行调筛选找人)+ 右侧整体空态
 * 所有旧入口(/ 重定向、各处"返回召回池"链接)自动适配 —— 都会被本页弹回详情。
 */
export default function PlansEntryPage() {
  return (
    <Can perm={Permission.PLAN_VIEW_OWN}>
      <EntryResolver />
    </Can>
  );
}

function EntryResolver() {
  const router = useRouter();
  const [phase, setPhase] = useState<'resolving' | 'empty'>('resolving');

  useEffect(() => {
    let cancelled = false;
    (async () => {
      try {
        // ① 我的进行中(优先级最高的一个)
        const mine = await plansApi.list({ view: 'mine', status: 'assigned', sort: 'priority_desc', page: 1, pageSize: 1 });
        if (cancelled) return;
        if (mine.items[0]) {
          router.replace(`/plans/${mine.items[0].id}`);
          return;
        }
        // ② 召回池第一个
        const pool = await plansApi.list({ view: 'pool', sort: 'priority_desc', page: 1, pageSize: 1 });
        if (cancelled) return;
        if (pool.items[0]) {
          router.replace(`/plans/${pool.items[0].id}`);
          return;
        }
        setPhase('empty');
      } catch {
        if (!cancelled) setPhase('empty');
      }
    })();
    return () => {
      cancelled = true;
    };
  }, [router]);

  if (phase === 'resolving') {
    return (
      <div className="flex h-screen items-center justify-center gap-2 text-sm text-muted-foreground">
        <span className="h-4 w-4 animate-spin rounded-full border-2 border-brand-500 border-t-transparent" />
        正在进入召回工作台…
      </div>
    );
  }

  // ③ 空工作台:左栏可用(调筛选自己找人),右侧整体空态
  return (
    <div className="flex h-screen flex-col overflow-hidden bg-slate-50">
      {/* 空态 header —— 内容只有 PAC 品牌 + 用户三件套,无功能项;嵌入宿主时整体隐藏 */}
      {!isEmbedded() && (
        <header className="flex h-12 flex-none items-center gap-2 border-b border-slate-100 bg-white px-4">
          <span className="inline-flex h-7 w-7 items-center justify-center rounded-md bg-brand-600 text-[12px] font-bold text-white">
            PAC
          </span>
          <h1 className="text-[14px] font-semibold text-slate-900">召回工作台</h1>
          <div className="ml-auto flex items-center gap-2">
            <IdentityCluster />
          </div>
        </header>
      )}
      <div className="flex min-h-0 flex-1">
        <PatientPickerRail currentPlanId="" />
        <div className="flex min-w-0 flex-1 flex-col items-center justify-center gap-3 text-center">
          <span className="inline-flex h-14 w-14 items-center justify-center rounded-2xl bg-slate-100 text-slate-400">
            <Inbox className="h-7 w-7" />
          </span>
          <div className="text-[15px] font-medium text-slate-700">当前没有待跟进的召回任务</div>
          <p className="max-w-sm text-[12.5px] leading-relaxed text-slate-500">
            我的任务与召回池都是空的。可以在左侧调整筛选(视图 / 诊所 / 筛选标签)自行查找,
            或等召回引擎下次重算后刷新。
          </p>
          <button
            type="button"
            onClick={() => window.location.reload()}
            className="inline-flex items-center gap-1.5 rounded-md border border-slate-100 bg-white px-3 py-1.5 text-[12.5px] text-slate-600 hover:bg-slate-50"
          >
            <RefreshCw className="h-3.5 w-3.5" />
            刷新
          </button>
        </div>
      </div>
    </div>
  );
}
