import { useCallback, useEffect, useState } from 'react';
import * as api from '../api/client';
import { BotIcon, CheckIcon, ArchiveIcon } from './icons';

/**
 * Agent 管理面板（管理员）：默认预算 + 停用/恢复。
 *
 * 预算决定「派给某个 Agent 的新任务默认多少个来回」。
 * 停用/恢复控制 Agent 的准入：停用后密钥撤销、注册被拒，邮件与会话保留。
 */
export default function QuotaPanel() {
  const [stats, setStats] = useState<api.AgentStats[]>([]);
  const [error, setError] = useState<string | null>(null);
  const [busy, setBusy] = useState<string | null>(null);
  const [drafts, setDrafts] = useState<Record<string, string>>({});
  const [confirming, setConfirming] = useState<string | null>(null);
  const [confirmAction, setConfirmAction] = useState<'toggle' | 'delete' | null>(null);
  const [notice, setNotice] = useState<string | null>(null);

  const load = useCallback(async () => {
    try {
      const r = await api.adminListAgentStats();
      setStats(r.quotas);
      setError(null);
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err));
    }
  }, []);

  useEffect(() => {
    load();
  }, [load]);

  const apply = async (name: string, defaultRounds: number) => {
    setBusy(name);
    setError(null);
    try {
      await api.adminSetDefaultRounds(name, defaultRounds);
      await load();
      setDrafts(d => {
        const next = { ...d };
        delete next[name];
        return next;
      });
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err));
    } finally {
      setBusy(null);
    }
  };

  const deleteAgent = async (name: string) => {
    setBusy(name);
    setError(null);
    setNotice(null);
    try {
      const result = await api.adminDeleteAgent(name);
      await load();
      setConfirming(null);
      setConfirmAction(null);
      const revoked = typeof result.keys_revoked === 'number' && result.keys_revoked > 0
        ? `（已撤销 ${result.keys_revoked} 把密钥）`
        : '';
      setNotice(`${name} 已删除${revoked}`);
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err));
    } finally {
      setBusy(null);
    }
  };

  const toggleStatus = async (name: string, currentDisabled: boolean) => {
    setBusy(name);
    setError(null);
    setNotice(null);
    try {
      const result = await api.adminSetAgentStatus(name, !currentDisabled);
      await load();
      setConfirming(null);
      // 撤销了几把密钥是停用操作里最有信息量的部分 —— 恢复后要重新签发几把，
      // 只说「已停用」的话用户不知道还有这一步。
      const revoked = typeof result.keys_revoked === 'number' && result.keys_revoked > 0
        ? `（已撤销 ${result.keys_revoked} 把密钥）`
        : '';
      // 恢复路径必须把「密钥不会自动回来」说出口。否则用户点完恢复就算完事，
      // 而插件拿着已撤销的密钥无限重试并被 401 —— 本会话就踩过：
      // opencode 被停用后拿旧密钥重试了 18 小时，gateway 日志里 2690 次 401。
      setNotice(result.disabled
        ? `${name} 已停用${revoked}`
        : `${name} 已恢复为离线。密钥不会自动回来 —— 请到「密钥」面板重新签发一把并写进插件配置，否则它会一直被拒（401）。`);
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err));
    } finally {
      setBusy(null);
    }
  };

  const statusBadge = (s: api.AgentStats) => {
    const st = s.status ?? 'offline';
    const cls = st === 'online'
      ? 'bg-green-50 text-green-700'
      : st === 'disabled'
        ? 'bg-red-50 text-red-600'
        : 'bg-gray-50 text-gray-500';
    const label = st === 'online' ? '在线' : st === 'disabled' ? '已停用' : '离线';
    return <span className={`text-3xs px-1.5 py-0.5 rounded ${cls}`}>{label}</span>;
  };

  return (
    <div className="space-y-3">
      <div className="flex items-center gap-2">
        <BotIcon className="w-4 h-4 text-gray-500" />
        <h3 className="text-sm font-semibold text-gray-900">Agent 管理</h3>
        <span className="text-xs text-gray-400">{stats.length}</span>
      </div>

      <p className="text-2xs text-gray-500">
        <strong className="font-medium text-gray-600">默认预算</strong>：派给某个 Agent 的新任务默认多少个来回（填 0 = 不限）。
        这只是默认值 —— 写信时可以单独指定，之后在对话页里还能随时调整。
        插件自动转发的最终总结与权限询问不占用预算。
        <br />
        <strong className="font-medium text-gray-600">停用</strong>：撤销该 Agent 的全部密钥、
        从地址补全与联系人里隐藏，拒绝它重新注册，并让别人发信给它时收到 409。
        <span className="text-gray-400">邮件、会话、模型范围全部保留，随时可恢复 —— 但密钥不会自动回来，恢复后需重新签发。</span>
        <br />
        <strong className="font-medium text-gray-600">删除</strong>：在停用的基础上清掉运行态（日历事件置 cancelled）。
        <span className="text-gray-400">邮件与会话保留（历史是审计凭据），此名字今后不可再注册。</span>
      </p>

      {error && <div className="text-2xs text-red-600 bg-red-50 rounded px-2 py-1.5">{error}</div>}
      {notice && <div className="text-2xs text-green-700 bg-green-50 rounded px-2 py-1.5">{notice}</div>}

      {stats.length === 0 ? (
        <div className="text-xs text-gray-400 py-3">暂无已注册的 Agent</div>
      ) : (
        <div className="border border-gray-200 rounded-md divide-y divide-gray-100">
          {stats.map(s => {
            const draft = drafts[s.agent_name] ?? String(s.default_rounds);
            const dirty = draft !== String(s.default_rounds);
            const invalid = draft.trim() !== '' && !/^\d+$/.test(draft.trim());
            const isDisabled = s.status === 'disabled';
            const isConfirming = confirming === s.agent_name;

            return (
              <div key={s.agent_name} className="px-3 py-2.5 flex items-center gap-x-3 gap-y-1 flex-wrap">
                <span className="text-xs font-mono text-gray-900 w-32 shrink-0 truncate">
                  {s.agent_name}
                </span>

                {statusBadge(s)}

                <div className="min-w-0 flex-1 text-2xs text-gray-500">
                  {s.default_rounds === 0 ? '默认不限来回' : `默认 ${s.default_rounds} 个来回`}
                  <span className="text-gray-400">
                    {' · '}进行中 {s.active_sessions} 个任务 · 累计发信 {s.sent_total}
                  </span>
                </div>

                <input
                  value={draft}
                  onChange={e => setDrafts(d => ({ ...d, [s.agent_name]: e.target.value }))}
                  inputMode="numeric"
                  title="新任务默认往返数；0 = 不限"
                  className={`w-16 text-xs border rounded px-1.5 py-1 shrink-0 focus:outline-none focus:ring-2 focus:ring-blue-100 ${
                    invalid ? 'border-red-300' : 'border-gray-300'
                  }`}
                />
                <button
                  onClick={() => apply(s.agent_name, Number(draft.trim() || '0'))}
                  disabled={!dirty || invalid || busy === s.agent_name}
                  title="保存默认预算"
                  className="tap shrink-0 text-gray-400 hover:text-blue-600 disabled:opacity-30"
                >
                  <CheckIcon className="w-4 h-4" />
                </button>

                {/* 停用/恢复/删除 按钮 */}
                {isConfirming ? (
                  <div className="flex items-center gap-1">
                    <span className="text-3xs text-gray-500">确认{confirmAction === 'delete' ? '删除' : ''}？</span>
                    <button
                      onClick={() => confirmAction === 'delete'
                        ? deleteAgent(s.agent_name)
                        : toggleStatus(s.agent_name, isDisabled)}
                      disabled={busy === s.agent_name}
                      className="tap text-3xs px-1.5 py-0.5 rounded bg-red-50 text-red-600 hover:bg-red-100"
                    >
                      {confirmAction === 'delete' ? '删除' : (isDisabled ? '恢复' : '停用')}
                    </button>
                    <button
                      onClick={() => { setConfirming(null); setConfirmAction(null); }}
                      className="tap text-3xs text-gray-400 hover:text-gray-600"
                    >
                      取消
                    </button>
                  </div>
                ) : (
                  <div className="flex items-center gap-1">
                    <button
                      onClick={() => { setConfirming(s.agent_name); setConfirmAction('toggle'); }}
                      disabled={busy === s.agent_name}
                      title={isDisabled
                        ? '恢复此 Agent（恢复为离线；停用时撤销的密钥不会自动回来，必须重新签发）'
                        : '停用此 Agent（撤销全部密钥并从补全里隐藏；邮件与会话保留，可恢复）'}
                      className={`tap shrink-0 inline-flex items-center gap-1 text-2xs px-1.5 py-0.5 rounded border ${
                        isDisabled
                          ? 'border-green-200 text-green-700 hover:bg-green-50'
                          : 'border-gray-200 text-gray-500 hover:text-red-600 hover:border-red-200'
                      } disabled:opacity-30`}
                    >
                      <ArchiveIcon className="w-3 h-3" />
                      {isDisabled ? '恢复' : '停用'}
                    </button>
                    <button
                      onClick={() => { setConfirming(s.agent_name); setConfirmAction('delete'); }}
                      disabled={busy === s.agent_name}
                      title="彻底删除此 Agent（清除密钥与运行态；邮件保留但此名今后不可再用）"
                      className="tap shrink-0 text-3xs px-1.5 py-0.5 rounded border border-red-200 text-red-400 hover:text-red-600 hover:border-red-300 disabled:opacity-30"
                    >
                      删除
                    </button>
                  </div>
                )}
              </div>
            );
          })}
        </div>
      )}
    </div>
  );
}