/**
 * 工作台外壳 —— 自原型 `(proto)/page.tsx` 平移(README《前端 UI · 原型 1:1 平移》)。
 *
 * 左轨 = 品牌 → **工作台五要素**(任务 / 审批 / 消息 / 纪要 / 汇报)→ 轨底身份;
 * 任务四区 = 左栏列表区 / 中上标题区 / 中下工作区 / 右栏对话区。
 *
 * **前端零过程状态**:数据全部来自服务端投影,刷新即从投影重建(§9.2)。
 */
import { useRef, useState } from 'react';
import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
import type { Session, TaskCard, TaskDetail, WorkOrderReply } from '@contracts';
import {
  listApprovalsForMeRoute,
  listMessagesRoute,
  listTasksRoute,
  logoutRoute,
  replyWorkOrderRoute,
  sessionRoute,
  taskDetailRoute,
} from '@contracts';
import { TaskChat, TaskList, ViewRegion } from '@features/desk-task';
import { ApprovalDesk } from '@features/desk-approval';
import { MessageDesk } from '@features/desk-message';
import { MinuteDesk } from '@features/desk-minute';
import { ReportDesk } from '@features/desk-report';
import { Ico } from '@web-shared/Ico.tsx';
import { call } from '@web-shared/typed-fetch.ts';
import { useChatWidth } from '@web-shared/useChatWidth.ts';
import { EmptyState } from '@web-shared/desk/module-kit.tsx';
import { queryKeys } from './query.ts';

type ModuleKey = 'tasks' | 'approvals' | 'messages' | 'minutes' | 'report';

const NAV_MODULES: ReadonlyArray<{ key: ModuleKey; label: string; icon: string }> = [
  { key: 'tasks', label: '任务', icon: 'list-checks' },
  { key: 'approvals', label: '审批', icon: 'file-check' },
  { key: 'messages', label: '消息', icon: 'messages-square' },
  { key: 'minutes', label: '纪要', icon: 'notebook-pen' },
  { key: 'report', label: '汇报', icon: 'bar-chart' },
];

export function AppShell() {
  const queryClient = useQueryClient();
  const [module, setModule] = useState<ModuleKey>('tasks');
  const [taskId, setTaskId] = useState('');
  const [collapsed, setCollapsed] = useState(false);
  /*
   * 工单填报值 —— **壳层持有**,工作区与对话区共用同一份。
   *
   * 验收工单是「AI 已填好、可编辑」,而**裁决在对话区的验收单上**(PRD 口径):
   * 编辑与裁决是同一件事的两半,却分在两个区里做。缓冲只活在工作区里,
   * 人在报告上改的值就到不了裁决那一刻 —— 验收回传的 `values` 恒空,修订永远落不下来。
   *
   * 换任务即清空:填报值是**过程状态**,不跨单。
   */
  const [orderValues, setOrderValues] = useState<Record<string, string>>({});
  /*
   * 对话区点「打开工单」→ 视图区跳转定位(PRD:locate)。
   * `seq` 每点递增:同一张卡点两次也要再跳一次 —— 人就是想回到它。
   */
  const [locate, setLocate] = useState<{ seq: number; orderId?: string; tab?: 'comms' } | null>(null);
  const locateSeq = useRef(0);
  const split = useChatWidth();


  const session = useQuery({
    queryKey: queryKeys.session,
    queryFn: () => call<Session>(sessionRoute),
  });

  const tasks = useQuery({
    queryKey: queryKeys.tasks,
    queryFn: () => call<{ tasks: TaskCard[] }>(listTasksRoute),
  });

  // 角标常驻:责任面要一眼看见「什么在等我」,不能等切过去才知道
  const messages = useQuery({
    queryKey: queryKeys.messages,
    queryFn: () => call<{ messages: Array<{ id: string; read: boolean }> }>(listMessagesRoute),
  });
  const approvals = useQuery({
    queryKey: queryKeys.approvals,
    queryFn: () => call<{ approvals: Array<{ state: string }> }>(listApprovalsForMeRoute),
  });

  const list = tasks.data?.tasks ?? [];
  const active = list.filter((t) => t.terminal === undefined);
  const current = taskId !== '' ? taskId : (active[0]?.id ?? list[0]?.id ?? '');

  const detail = useQuery({
    queryKey: queryKeys.task(current),
    queryFn: () => call<TaskDetail>(taskDetailRoute, { params: { taskId: current } }),
    enabled: current !== '',
  });




  /** 登出后**整体清空缓存**:上一个人的任务、审批、消息不能留在下一个人眼前 */
  const logout = useMutation({
    mutationFn: () => call<{ ok: boolean }>(logoutRoute),
    onSuccess: () => {
      queryClient.clear();
      // 整页导航:SSE 连接、组件状态、路由位置一并归零 —— 登出不留残影
      window.location.assign('/');
    },
  });

  const me = session.data?.staff.name ?? '—';

  /**
   * 工单回传 —— 视图区与对话区同一条口。
   * 回传后按键失效、画面由服务端重投影:前端不自行推演卡与工单的状态(§9.2)。
   */
  const replyOrder = useMutation({
    mutationFn: (reply: WorkOrderReply) => call(replyWorkOrderRoute, { body: { reply } }),
    onSuccess: () => {
      void queryClient.invalidateQueries({ queryKey: ['desk'] });
    },
  });

  return (
    <div className="app-shell">
      <div className="app-body">
        <nav className="app-nav">
          <div className="app-nav-mark" title="JCAI 智能协同工作台">
            <Ico name="bot" s={20} />
          </div>
          <span className="jc-rail-brand">JCAI</span>
          {NAV_MODULES.map((m) => {
            const badge =
              m.key === 'tasks'
                ? active.length
                : m.key === 'approvals'
                  ? (approvals.data?.approvals ?? []).filter((a) => a.state === 'pending').length
                  : m.key === 'messages'
                    ? (messages.data?.messages ?? []).filter((x) => !x.read).length
                    : undefined;
            return (
              <button
                key={m.key}
                className={module === m.key ? 'active' : ''}
                onClick={() => setModule(m.key)}
                aria-current={module === m.key ? 'page' : undefined}
              >
                <span className="app-nav-icon-wrap">
                  <Ico name={m.icon} s={20} />
                  {badge !== undefined && badge > 0 ? <span className="app-nav-badge">{badge}</span> : null}
                </span>
                <span>{m.label}</span>
              </button>
            );
          })}
          <div className="jc-rail-foot">
            {/* 轨底只报身份,不再兼职登出入口 —— 退出登录挪到顶栏,免得点头像误触登出 */}
            <div className="jc-nav-user" title={`${me}(本工作台所有者)`}>
              <span className="jc-nav-ava">{me.slice(0, 1)}</span>
              <span className="jc-nav-name">{me}</span>
            </div>
          </div>
        </nav>

        <div className="app-main">
          <header className="jc-topbar">
            <span className="jc-topbar-title">{NAV_MODULES.find((m) => m.key === module)?.label ?? ''}</span>
            <div className="jc-topbar-user">
              <span className="jc-topbar-name">{me}</span>
              <button
                type="button"
                className="jc-topbar-logout"
                disabled={logout.isPending}
                onClick={() => logout.mutate()}
              >
                <Ico name="log-out" s={14} />
                退出登录
              </button>
            </div>
          </header>

          <div className="app-main-body">
          {module === 'tasks' ? (
          <div className={'workspace' + (collapsed ? ' jc-side-collapsed' : '')} style={split.style}>
            {collapsed && (
              <button
                type="button"
                className="jc-wl-expand"
                title="展开列表区"
                aria-label="展开列表区"
                onClick={() => setCollapsed(false)}
              >
                <Ico name="chevron-right" s={12} />
              </button>
            )}
            <TaskList
              tasks={list}
              selectedId={current}
              collapsed={collapsed}
              onPick={(id) => {
                // 换任务即清空填报缓冲与定位:它们是**过程状态**,不跨单
                setOrderValues({});
                setLocate(null);
                setTaskId(id);
              }}
              onCollapse={() => setCollapsed(true)}
            />
            {/*
              手上没任务时,三栏也得**站得住**:中栏与对话区各给自己的空态。
              少一栏会让整个工位看着像坏了 —— 空态是常态,不是缺页。
            */}
            {detail.data !== undefined ? (
              <ViewRegion
                key={current}
                detail={detail.data}
                onReplyOrder={(reply) => replyOrder.mutate(reply)}
                values={orderValues}
                onField={(k, v) => setOrderValues((old) => ({ ...old, [k]: v }))}
                locate={locate}
              />
            ) : (
              /*
               * **手上没任务时,中栏也得是一张卡**。
               *
               * 其余四个模块(审批 / 消息 / 纪要 / 汇报)的空态都挂 `jc-panel-card`,
               * 只有任务这一栏是裸的 `execution-panel` —— 而那个类在工作区里被显式
               * 去边框去底色(视图区不再有外层卡)。于是同一套工作台上,四个模块的空态
               * 是白卡片,任务这一栏却是画布上飘着的一段文字,看着像没渲染出来。
               */
              <main className="execution-panel jc-panel-card">
                {tasks.isLoading ? (
                  <div className="jc-list-empty">
                    <Ico name="list-checks" s={18} />
                    载入中…
                  </div>
                ) : (
                  <EmptyState
                    ico="list-checks"
                    tone="brand"
                    title="手上没有任务"
                    desc="流程走到你负责的活动时,任务会连同办这件事要用的全部上下文一起送到这里 —— 待处理的事、往来记录、产出的文件都在一屏之内。"
                    hint="有新任务时左侧列表会亮角标"
                  />
                )}
              </main>
            )}
            <i
              className="jc-vsplit"
              title="拖拽调整对话区宽度 · 双击复位"
              onPointerDown={split.onSplitDown}
              onDoubleClick={split.onSplitReset}
            />
            <section className="session-chat">
              {detail.data !== undefined ? (
                <TaskChat
                  key={current}
                  detail={detail.data}
                  onLocate={(orderId) => {
                    locateSeq.current += 1;
                    setLocate({ seq: locateSeq.current, orderId });
                  }}
                  onOpenComms={() => {
                    locateSeq.current += 1;
                    setLocate({ seq: locateSeq.current, tab: 'comms' });
                  }}
                  orderValues={orderValues}
                  onField={(k, v) => setOrderValues((old) => ({ ...old, [k]: v }))}
                />
              ) : (
                <div className="jc-tch">
                  <header className="jc-tch-head">
                    <span className="jc-tch-mark">
                      <Ico name="bot" s={15} />
                    </span>
                    <b className="jc-tch-name">任务助理</b>
                    <em className="jc-tch-tag">Agent</em>
                    <span className="jc-tch-desc">开一单即可对话</span>
                  </header>
                  <div className="jc-tch-scroll">
                    <EmptyState
                      ico="messages-square"
                      tone="brand"
                      title="还没有可对话的任务"
                      desc="每一单任务都有自己的对话:AI 有结论、要派工、或者要你拿个主意,都在那一单里说 —— 所以得先有一单在手。"
                    />
                  </div>
                  <div className="copilot-composer session-composer">
                    <div className="composer-row">
                      <textarea rows={2} disabled placeholder="选中一单任务后就能在这里交代" />
                      <button className="copilot-send" disabled>
                        <Ico name="send" s={14} /> 发送
                      </button>
                    </div>
                  </div>
                </div>
              )}
            </section>
          </div>
        ) : module === 'approvals' ? (
          <ApprovalDesk />
        ) : module === 'messages' ? (
          <MessageDesk />
        ) : module === 'minutes' ? (
          <MinuteDesk />
        ) : (
          <ReportDesk />
        )}
          </div>
        </div>
      </div>
    </div>
  );
}