/**
 * 消息要素 —— 自 `~/coding/JCAI_PRD/workbench/_components/ModuleWorkspace.tsx`
 * 的 `MessagesModule` / `MessageDetail` 平移;mock 数据换成服务端投影。
 *
 * 「消息是**信息**,不产生责任」:系统通知 + 他人任务发来的人类工具卡。
 * 跨任务卡**就地作答** —— 作答权限只及卡面与决策包,**不开放任务对话流**;
 * 任务要素永远只装「我负责的任务」,跨人卡是一次性的解答请求,不是责任转移。
 */
import { useState } from 'react';
import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
import type { FormField, ListMessagesOutput, SystemMessageView } from '@contracts';
import { answerMessageRoute, listMessagesRoute, markMessageReadRoute } from '@contracts';
import { Ico } from '@web-shared/Ico.tsx';
import ScrollArea from '@web-shared/ScrollArea.tsx';
import { call } from '@web-shared/typed-fetch.ts';
import { Chip, DocPanel, Hero, ListEmpty, NoteBand, Section, SidebarHead } from '@web-shared/desk/module-kit.tsx';

const KIND_META: Readonly<Record<string, { icon: string; grad: readonly [string, string]; kicker: string }>> = {
  notice: { icon: 'bell', grad: ['#7f3bf5', '#5b21cf'], kicker: '系统 · 通知' },
  elicitation: { icon: 'messages-square', grad: ['#3370ff', '#245bdb'], kicker: '跨任务征答' },
  'dead-letter': { icon: 'alert-triangle', grad: ['#ff8800', '#de7802'], kicker: '死信回执' },
  unowned: { icon: 'help-circle', grad: ['#f14ba9', '#c92d86'], kicker: '无主入站 · 待认领' },
};
const metaOf = (kind: string) => KIND_META[kind] ?? KIND_META['notice']!;

export function MessageDesk() {
  const queryClient = useQueryClient();
  const [selId, setSelId] = useState<string | undefined>(undefined);
  const [filter, setFilter] = useState<'unread' | 'all'>('unread');

  const q = useQuery({ queryKey: ['messages'], queryFn: () => call<ListMessagesOutput>(listMessagesRoute) });
  const messages = q.data?.messages ?? [];
  const unread = messages.filter((m) => !m.read);
  const visible = filter === 'unread' ? unread : messages;
  const sel = messages.find((m) => m.id === selId) ?? visible[0];

  const markRead = useMutation({
    mutationFn: (messageId: string) => call(markMessageReadRoute, { params: { messageId } }),
    onSuccess: () => void queryClient.invalidateQueries({ queryKey: ['messages'] }),
  });

  const pick = (m: SystemMessageView) => {
    setSelId(m.id);
    if (!m.read) markRead.mutate(m.id);
  };

  return (
    <div className="workspace">
      <aside className="task-sidebar">
        <SidebarHead icon="messages-square" title="消息" sub={`与我相关 · ${unread.length} 条未读`} />
        <div className="jc-flt-wrap" aria-label="消息筛选">
          <div className="jc-flt" role="tablist" aria-label="按状态">
            <button className={filter === 'unread' ? 'active' : ''} onClick={() => setFilter('unread')}>
              <span>未读</span>
              <strong>{unread.length}</strong>
            </button>
            <button className={filter === 'all' ? 'active' : ''} onClick={() => setFilter('all')}>
              <span>全部</span>
              <strong>{messages.length}</strong>
            </button>
          </div>
        </div>
        <ScrollArea className="jc-sa--fill" vpClassName="task-list">
          {visible.map((m) => {
            const meta = metaOf(m.kind);
            const pending = m.card !== undefined && !m.card.answered;
            return (
              <button
                key={m.id}
                className={'jc-mcard' + (m.id === sel?.id ? ' selected' : '')}
                onClick={() => pick(m)}
              >
                <span className="jc-mcard-ico" style={{ background: `linear-gradient(140deg, ${meta.grad[0]}, ${meta.grad[1]})` }}>
                  <Ico name={meta.icon} s={15} />
                </span>
                <span className="jc-mcard-body">
                  <span className="jc-mcard-top">
                    <em>{meta.kicker}</em>
                    {pending ? (
                      <Chip tone="todo" label="待作答" pulse />
                    ) : (
                      <Chip tone={m.read ? 'done' : 'brand'} label={m.read ? '已读' : '未读'} pulse={!m.read} />
                    )}
                  </span>
                  <strong className="jc-mcard-title jc-clamp2">{m.title}</strong>
                  <span className="jc-mcard-foot">
                    <time className="jc-mono">{m.at.slice(5, 16).replace('T', ' ')}</time>
                  </span>
                </span>
              </button>
            );
          })}
          {visible.length === 0 && <ListEmpty icon="circle-check">没有{filter === 'unread' ? '未读' : ''}消息</ListEmpty>}
        </ScrollArea>
      </aside>

      {sel === undefined ? (
        <main className="execution-panel jc-panel-card">
          <ListEmpty icon="messages-square">选一条消息</ListEmpty>
        </main>
      ) : (
        <DocPanel scrollKey={sel.id}>
          <Hero
            grad={metaOf(sel.kind).grad}
            icon={metaOf(sel.kind).icon}
            kicker={metaOf(sel.kind).kicker}
            title={sel.title}
            meta={<time className="jc-mono">{sel.at.slice(0, 16).replace('T', ' ')}</time>}
            chip={<Chip tone={sel.read ? 'done' : 'brand'} label={sel.read ? '已读' : '未读'} />}
          />

          <Section icon="file-text" title="正文">
            <div className="jc-summary">{sel.body}</div>
          </Section>

          {sel.card !== undefined && (
            <Section icon="messages-square" title="就地作答" extra={`来源任务 ${sel.card.sourceTaskId.slice(0, 8)}`}>
              {sel.card.rejectedReason !== undefined && (
                <NoteBand>被驳回重答:{sel.card.rejectedReason}(原卡已闭合,这是新的一条)</NoteBand>
              )}
              {sel.card.answered ? (
                <div className="jc-mod-donehint">
                  <Ico name="circle-check" s={15} />
                  已作答 · 回传已写回来源任务并留痕
                </div>
              ) : (
                <ElicitationForm
                  ask={sel.card.ask}
                  fields={sel.card.fields}
                  onAnswer={(answer) =>
                    call(answerMessageRoute, { params: { messageId: sel.id }, body: { answer } }).then(() => {
                      void queryClient.invalidateQueries({ queryKey: ['messages'] });
                    })
                  }
                />
              )}
              <NoteBand>
                跨人卡是<b>一次性的解答请求,不是责任转移</b>:作答权限只及卡面与决策包,
                不开放任务对话流;它不占你的任务清单。
              </NoteBand>
            </Section>
          )}
        </DocPanel>
      )}
    </div>
  );
}

/**
 * 卡面表单:字段由 `@contracts/card.ts` 的 schema 驱动渲染,与后端回传校验同 schema(§9.2)。
 */
function ElicitationForm({
  ask,
  fields,
  onAnswer,
}: {
  ask: string;
  fields: readonly FormField[];
  onAnswer: (answer: Record<string, unknown>) => Promise<unknown>;
}) {
  const [values, setValues] = useState<Record<string, string>>({});
  const [busy, setBusy] = useState(false);
  const [error, setError] = useState<string | undefined>(undefined);

  // 必填未回填不得提交 —— 与后端回传校验同一条规矩
  const missing = fields.filter((f) => f.required === true && (values[f.key] ?? '').trim() === '');

  return (
    <>
      {ask !== '' && <p className="jc-ask">{ask}</p>}
      {fields.map((f) => (
        <div key={f.key} className="jc-field">
          <em>
            {f.label}
            {f.required === true && <i className="jc-req">必填</i>}
          </em>
          {f.kind === 'textarea' ? (
            <textarea
              className="jc-sup"
              rows={3}
              value={values[f.key] ?? ''}
              onChange={(e) => setValues({ ...values, [f.key]: e.target.value })}
            />
          ) : (
            <input
              className="jc-input"
              value={values[f.key] ?? ''}
              onChange={(e) => setValues({ ...values, [f.key]: e.target.value })}
            />
          )}
        </div>
      ))}
      {error !== undefined && <div className="jc-err">{error}</div>}
      <div className="jc-mod-actions">
        <button
          type="button"
          className="card-btn primary"
          disabled={busy || missing.length > 0}
          title={missing.length > 0 ? `还缺:${missing.map((f) => f.label).join('、')}` : undefined}
          onClick={() => {
            setBusy(true);
            setError(undefined);
            onAnswer(values)
              .catch((e: unknown) => setError((e as { message?: string }).message ?? '回传失败'))
              .finally(() => setBusy(false));
          }}
        >
          <Ico name="check" s={13} />
          提交回传
        </button>
      </div>
    </>
  );
}