import { useCallback, useEffect, useRef, useState } from 'react';

import {
  downloadAdminErrorReport,
  formatAdminApiError,
  getAdminErrorReport,
  isAdminApiError,
  listAdminErrorReports,
  updateAdminErrorReport,
} from '../api/adminApiClient';
import type {
  AdminErrorReportDetail,
  AdminErrorReportEntry,
} from '../api/adminApiTypes';

type Props = { token: string; onUnauthorized: (message?: string) => void };

const ADMIN_ERROR_REPORT_STATUSES = ['new', 'in-progress', 'resolved'] as const;
const ERROR_REPORT_PAGE_SIZE = 50;
const ERROR_REPORT_STATUS_LABELS: Record<string, string> = {
  new: '待处理',
  'in-progress': '处理中',
  resolved: '已解决',
};

export function parseAdminTimestamp(value: string | null | undefined) {
  const normalized = value?.trim() ?? '';
  if (/^-?\d+\.\d{6}Z$/u.test(normalized)) {
    const [secondsText, microsText] = normalized.slice(0, -1).split('.');
    const seconds = Number(secondsText);
    const micros = Number(microsText);
    return Number.isFinite(seconds) && Number.isFinite(micros)
      ? seconds * 1000 + Math.floor(micros / 1000)
      : Number.NaN;
  }
  if (/^-?\d+$/u.test(normalized)) {
    const numeric = Number(normalized);
    if (!Number.isFinite(numeric)) return Number.NaN;
    if (Math.abs(numeric) >= 1e14) return Math.floor(numeric / 1000);
    if (Math.abs(numeric) >= 1e11) return numeric;
    return numeric * 1000;
  }
  return Date.parse(normalized);
}

export function formatAdminTimestamp(value: string | null | undefined) {
  const timestamp = parseAdminTimestamp(value);
  if (!Number.isFinite(timestamp)) return '-';
  const date = new Date(timestamp);
  if (!Number.isFinite(date.getTime())) return '-';
  try {
    return new Intl.DateTimeFormat('zh-CN', {
      year: 'numeric',
      month: '2-digit',
      day: '2-digit',
      hour: '2-digit',
      minute: '2-digit',
      second: '2-digit',
    }).format(date);
  } catch {
    return '-';
  }
}

function eventText(event: Record<string, unknown>, key: string) {
  const value = event[key];
  return typeof value === 'string' || typeof value === 'number'
    ? String(value)
    : '';
}

export function AdminErrorReportsPage({ token, onUnauthorized }: Props) {
  const [reports, setReports] = useState<AdminErrorReportEntry[]>([]);
  const [selected, setSelected] = useState<AdminErrorReportDetail | null>(null);
  const [status, setStatus] = useState('');
  const [downloading, setDownloading] = useState(false);
  const [busy, setBusy] = useState(false);
  const [filterStatus, setFilterStatus] = useState('');
  const [pageOffset, setPageOffset] = useState(0);
  const [pageInfo, setPageInfo] = useState({ total: 0, hasMore: false });
  const openReportRequestId = useRef(0);
  const loadRequestId = useRef(0);
  const detailCloseButtonRef = useRef<HTMLButtonElement | null>(null);

  useEffect(() => {
    if (!selected) return;
    const previousFocus = document.activeElement as HTMLElement | null;
    const focusFrame = window.requestAnimationFrame(() => {
      detailCloseButtonRef.current?.focus();
    });
    const handleEscape = (event: KeyboardEvent) => {
      if (event.key === 'Escape') setSelected(null);
    };
    window.addEventListener('keydown', handleEscape);
    return () => {
      window.cancelAnimationFrame(focusFrame);
      window.removeEventListener('keydown', handleEscape);
      previousFocus?.focus?.();
    };
  }, [selected]);

  const load = useCallback(async () => {
    const requestId = ++loadRequestId.current;
    setStatus('');
    try {
      const response = await listAdminErrorReports(token, {
        status: filterStatus || undefined,
        limit: ERROR_REPORT_PAGE_SIZE,
        offset: pageOffset,
      });
      if (requestId === loadRequestId.current) {
        const lastValidOffset = response.total
          ? Math.floor((response.total - 1) / ERROR_REPORT_PAGE_SIZE) *
            ERROR_REPORT_PAGE_SIZE
          : 0;
        if (pageOffset > lastValidOffset) {
          setPageOffset(lastValidOffset);
          return;
        }
        setReports(response.reports);
        setPageInfo({ total: response.total, hasMore: response.hasMore });
      }
    } catch (error) {
      if (requestId !== loadRequestId.current) return;
      if (isAdminApiError(error) && error.status === 401)
        return onUnauthorized();
      setStatus(formatAdminApiError(error));
    }
  }, [filterStatus, onUnauthorized, pageOffset, token]);

  const loadRef = useRef(load);
  useEffect(() => {
    loadRef.current = load;
  }, [load]);

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

  async function openReport(batchId: string) {
    const requestId = ++openReportRequestId.current;
    setStatus('');
    try {
      const detail = await getAdminErrorReport(token, batchId);
      if (requestId === openReportRequestId.current) setSelected(detail);
    } catch (error) {
      if (requestId !== openReportRequestId.current) return;
      if (isAdminApiError(error) && error.status === 401)
        return onUnauthorized();
      setStatus(formatAdminApiError(error));
    }
  }

  async function saveStatus(nextStatus: string) {
    if (!selected || busy) return;
    setBusy(true);
    setStatus('');
    try {
      const updated = await updateAdminErrorReport(token, selected.batchId, {
        status: nextStatus,
        note: selected.note,
      });
      setSelected((current) =>
        current ? { ...current, ...updated } : current,
      );
      await loadRef.current();
    } catch (error) {
      if (isAdminApiError(error) && error.status === 401) onUnauthorized();
      else setStatus(formatAdminApiError(error));
    } finally {
      setBusy(false);
    }
  }

  async function download(batchId: string) {
    if (downloading) return;
    setDownloading(true);
    setStatus('');
    try {
      const blob = await downloadAdminErrorReport(token, batchId);
      const url = URL.createObjectURL(blob);
      const anchor = document.createElement('a');
      anchor.href = url;
      anchor.download = `${batchId}.zip`;
      document.body.appendChild(anchor);
      anchor.click();
      anchor.remove();
      setTimeout(() => URL.revokeObjectURL(url), 10_000);
    } catch (error) {
      if (isAdminApiError(error) && error.status === 401) onUnauthorized();
      else setStatus(formatAdminApiError(error));
    } finally {
      setDownloading(false);
    }
  }

  return (
    <section className="admin-panel">
      <div className="admin-panel-header">
        <div>
          <h1>错误报告</h1>
          <p>查看用户提交的脱敏诊断包。</p>
        </div>
        <label>
          状态{' '}
          <select
            value={filterStatus}
            onChange={(event) => {
              setFilterStatus(event.target.value);
              setPageOffset(0);
            }}
          >
            <option value="">全部</option>
            {ADMIN_ERROR_REPORT_STATUSES.map((value) => (
              <option key={value} value={value}>
                {value}
              </option>
            ))}
          </select>
        </label>
      </div>
      {status ? (
        <p className="admin-alert" role="status">
          {status}
        </p>
      ) : null}
      <div className="admin-table-wrap">
        <table className="admin-table">
          <thead>
            <tr>
              <th>报告</th>
              <th>事件</th>
              <th>来源</th>
              <th>状态</th>
              <th>用户</th>
              <th>时间</th>
            </tr>
          </thead>
          <tbody>
            {reports.map((report) => (
              <tr
                key={report.batchId}
                onClick={() => void openReport(report.batchId)}
                role="button"
                tabIndex={0}
                onKeyDown={(event) => {
                  if (event.key === 'Enter' || event.key === ' ') {
                    event.preventDefault();
                    void openReport(report.batchId);
                  }
                }}
              >
                <td>{report.batchId}</td>
                <td>{report.eventCount}</td>
                <td>{report.source ?? '-'}</td>
                <td>
                  <span
                    className={`admin-error-report-status is-${report.status}`}
                  >
                    {ERROR_REPORT_STATUS_LABELS[report.status] ?? report.status}
                  </span>
                </td>
                <td>{report.userId}</td>
                <td>{formatAdminTimestamp(report.createdAt)}</td>
              </tr>
            ))}
          </tbody>
        </table>
      </div>
      <div className="admin-detail-modal__actions" aria-label="错误报告分页">
        <span>
          {pageInfo.total === 0
            ? '暂无报告'
            : `第 ${pageOffset + 1}-${Math.min(pageOffset + reports.length, pageInfo.total)} 条，共 ${pageInfo.total} 条`}
        </span>
        <button
          type="button"
          onClick={() =>
            setPageOffset((offset) =>
              Math.max(0, offset - ERROR_REPORT_PAGE_SIZE),
            )
          }
          disabled={pageOffset === 0}
        >
          上一页
        </button>
        <button
          type="button"
          onClick={() =>
            setPageOffset((offset) => offset + ERROR_REPORT_PAGE_SIZE)
          }
          disabled={!pageInfo.hasMore}
        >
          下一页
        </button>
      </div>
      {selected ? (
        <div
          className="admin-detail-modal"
          role="dialog"
          aria-label="错误报告详情"
          aria-modal="true"
          onMouseDown={(event) => {
            if (event.target === event.currentTarget) setSelected(null);
          }}
        >
          <div className="admin-detail-modal__panel admin-error-report-detail">
            <header className="admin-error-report-detail__header">
              <div className="admin-error-report-detail__heading">
                <span className="admin-error-report-detail__eyebrow">
                  错误报告详情
                </span>
                <h2>{selected.batchId}</h2>
                <div className="admin-error-report-detail__badges">
                  <span
                    className={`admin-error-report-status is-${selected.status}`}
                  >
                    {ERROR_REPORT_STATUS_LABELS[selected.status] ??
                      selected.status}
                  </span>
                  <span className="admin-error-report-detail__badge">
                    {selected.firstSource ?? selected.source ?? '未知来源'}
                  </span>
                </div>
              </div>
              <button
                type="button"
                className="admin-error-report-detail__close"
                ref={detailCloseButtonRef}
                onClick={() => setSelected(null)}
                aria-label="关闭错误报告详情"
              >
                ×
              </button>
            </header>
            <div className="admin-error-report-detail__summary">
              <div>
                <span>用户</span>
                <strong>{selected.userId}</strong>
              </div>
              <div>
                <span>发生时间</span>
                <strong>{formatAdminTimestamp(selected.createdAt)}</strong>
              </div>
              <div>
                <span>错误事件</span>
                <strong>{selected.eventCount}</strong>
              </div>
              <div>
                <span>应用日志</span>
                <strong>{selected.logCount}</strong>
              </div>
            </div>
            <div className="admin-error-report-detail__body">
              <section className="admin-error-report-detail__section">
                <div className="admin-error-report-detail__section-heading">
                  <div>
                    <h3>错误事件</h3>
                    <span>展示最近 20 条，完整内容请下载诊断包。</span>
                  </div>
                  <span className="admin-error-report-detail__count">
                    {selected.events.length} 条
                  </span>
                </div>
                <div className="admin-error-report-event-list">
                  {selected.events.length === 0 ? (
                    <p className="admin-error-report-detail__empty">
                      归档中没有可展示的错误事件。
                    </p>
                  ) : null}
                  {selected.events.slice(0, 20).map((event, index) => {
                    const message = eventText(event, 'message') || '未知错误';
                    const stack = eventText(event, 'stack');
                    const occurredAt = eventText(event, 'occurredAt');
                    return (
                      <article
                        className="admin-error-report-event"
                        key={`${index}-${message}`}
                      >
                        <div className="admin-error-report-event__topline">
                          <span className="admin-error-report-event__index">
                            #{index + 1}
                          </span>
                          <span>{eventText(event, 'source') || 'client'}</span>
                          <span>{eventText(event, 'count') || '1'} 次</span>
                          <time>{formatAdminTimestamp(occurredAt)}</time>
                        </div>
                        <p className="admin-error-report-event__message">
                          {message}
                        </p>
                        {eventText(event, 'fingerprint') ? (
                          <code>{eventText(event, 'fingerprint')}</code>
                        ) : null}
                        {stack ? (
                          <details>
                            <summary>查看调用栈</summary>
                            <pre>{stack}</pre>
                          </details>
                        ) : null}
                      </article>
                    );
                  })}
                </div>
              </section>
              {selected.userDescription ? (
                <section className="admin-error-report-detail__section">
                  <div className="admin-error-report-detail__section-heading">
                    <div>
                      <h3>用户描述</h3>
                    </div>
                  </div>
                  <p className="admin-error-report-detail__description">
                    {selected.userDescription}
                  </p>
                </section>
              ) : null}
              <section className="admin-error-report-detail__section admin-error-report-detail__section--note">
                <label className="admin-detail-modal__note">
                  <span>处理备注</span>
                  <textarea
                    value={selected.note ?? ''}
                    onChange={(event) =>
                      setSelected((current) =>
                        current
                          ? { ...current, note: event.target.value }
                          : current,
                      )
                    }
                    maxLength={2000}
                    rows={4}
                    placeholder="记录处理结论或后续跟进事项"
                    disabled={busy}
                  />
                </label>
              </section>
            </div>
            <footer className="admin-error-report-detail__footer">
              <label className="admin-error-report-detail__status-field">
                状态
                <select
                  value={selected.status}
                  onChange={(event) => void saveStatus(event.target.value)}
                  disabled={busy}
                >
                  {ADMIN_ERROR_REPORT_STATUSES.map((value) => (
                    <option key={value} value={value}>
                      {ERROR_REPORT_STATUS_LABELS[value]}
                    </option>
                  ))}
                </select>
              </label>
              <div className="admin-error-report-detail__footer-actions">
                <button
                  type="button"
                  onClick={() => void saveStatus(selected.status)}
                  disabled={busy}
                >
                  {busy ? '保存中…' : '保存备注'}
                </button>
                <button
                  type="button"
                  onClick={() => void download(selected.batchId)}
                  disabled={downloading}
                >
                  {downloading ? '下载中…' : '下载诊断包'}
                </button>
              </div>
            </footer>
          </div>
        </div>
      ) : null}
    </section>
  );
}