import { useEffect, useState } from 'react';
import {
  getWechatAgentRouteStatus,
  getWechatBindingStatus,
  resetWechatAgentRoute,
  type WechatAgentRouteStatus,
} from '../api/client';
import { buildWechatAuthorizeUrl } from '../utils/wechat';

function formatRouteTime(timestamp: number | null) {
  if (!timestamp) return '暂无';
  const date = new Date(timestamp);
  if (Number.isNaN(date.getTime())) return '暂无';
  const pad = (value: number) => String(value).padStart(2, '0');
  return `${date.getMonth() + 1}-${date.getDate()} ${pad(date.getHours())}:${pad(date.getMinutes())}`;
}

export function WechatAccountButton({
  returnTo,
  onBeforeAction,
}: {
  returnTo?: string;
  onBeforeAction?: () => void;
}) {
  const [bound, setBound] = useState<boolean | null>(null);
  const [nickname, setNickname] = useState<string | null>(null);
  const [debugOpen, setDebugOpen] = useState(false);
  const [route, setRoute] = useState<WechatAgentRouteStatus | null>(null);
  const [routeLoading, setRouteLoading] = useState(false);
  const [routeError, setRouteError] = useState<string | null>(null);
  const [resetting, setResetting] = useState(false);

  useEffect(() => {
    void getWechatBindingStatus().then((status) => {
      if (!status.enabled) {
        setBound(null);
        return;
      }
      setBound(status.bound);
      setNickname(status.nickname ?? null);
    });
  }, []);

  useEffect(() => {
    if (!debugOpen) return;
    let cancelled = false;
    setRouteLoading(true);
    setRouteError(null);
    void getWechatAgentRouteStatus()
      .then((status) => {
        if (cancelled) return;
        setRoute(status);
      })
      .catch((err) => {
        if (cancelled) return;
        setRouteError(err instanceof Error ? err.message : '获取公众号 Agent 状态失败');
      })
      .finally(() => {
        if (!cancelled) setRouteLoading(false);
      });
    return () => {
      cancelled = true;
    };
  }, [debugOpen]);

  if (bound === null) return null;

  if (bound) {
    return (
      <>
        <button
          type="button"
          className="ghost-btn wechat-account-bound wechat-account-debug-trigger"
          title="查看微信绑定与公众号 Agent 调试信息"
          onClick={() => {
            onBeforeAction?.();
            setDebugOpen(true);
          }}
        >
          微信已绑{nickname ? ` · ${nickname}` : ''}
        </button>

        {debugOpen && (
          <div className="wechat-debug-overlay" onClick={() => setDebugOpen(false)}>
            <section
              className="wechat-debug-card"
              onClick={(event) => event.stopPropagation()}
              aria-modal="true"
              role="dialog"
              aria-label="公众号 Agent 调试"
            >
              <div className="wechat-debug-head">
                <div>
                  <p className="wechat-debug-eyebrow">Wechat Agent</p>
                  <h3>公众号调试</h3>
                </div>
                <button
                  type="button"
                  className="wechat-debug-close"
                  aria-label="关闭"
                  onClick={() => setDebugOpen(false)}
                >
                  ×
                </button>
              </div>

              <div className="wechat-debug-grid">
                <div className="wechat-debug-item">
                  <span>微信绑定</span>
                  <strong>{nickname ? `已绑定 · ${nickname}` : '已绑定'}</strong>
                </div>
                <div className="wechat-debug-item">
                  <span>公众号通道</span>
                  <strong>
                    {route?.enabled ? '已启用' : routeLoading ? '读取中…' : '未启用'}
                  </strong>
                </div>
                <div className="wechat-debug-item">
                  <span>OpenID</span>
                  <code>{route?.openid ?? '暂无'}</code>
                </div>
                <div className="wechat-debug-item">
                  <span>Agent Session</span>
                  <code>{route?.agentSessionId ?? '暂无'}</code>
                </div>
                <div className="wechat-debug-item">
                  <span>路由状态</span>
                  <strong>{route?.routeStatus ?? '暂无'}</strong>
                </div>
                <div className="wechat-debug-item">
                  <span>最近刷新</span>
                  <strong>{formatRouteTime(route?.updatedAt ?? null)}</strong>
                </div>
              </div>

              {routeLoading && <p className="wechat-debug-hint">正在读取公众号 Agent 路由状态…</p>}
              {routeError && <p className="wechat-debug-error">{routeError}</p>}
              {!routeLoading && !routeError && route && !route.enabled && (
                <p className="wechat-debug-hint">
                  当前环境未启用公众号消息转发，所以不会影响现有 H5 聊天。
                </p>
              )}

              <div className="wechat-debug-actions">
                <button
                  type="button"
                  className="ghost-btn"
                  disabled={routeLoading || resetting || !route?.enabled}
                  onClick={() => {
                    setRouteLoading(true);
                    setRouteError(null);
                    void getWechatAgentRouteStatus()
                      .then((status) => setRoute(status))
                      .catch((err) =>
                        setRouteError(err instanceof Error ? err.message : '刷新路由状态失败'),
                      )
                      .finally(() => setRouteLoading(false));
                  }}
                >
                  刷新状态
                </button>
                <button
                  type="button"
                  className="ghost-btn"
                  disabled={routeLoading || resetting || !route?.enabled}
                  onClick={() => {
                    setResetting(true);
                    setRouteError(null);
                    void resetWechatAgentRoute()
                      .then((status) => setRoute(status))
                      .catch((err) =>
                        setRouteError(err instanceof Error ? err.message : '重建公众号 Agent 路由失败'),
                      )
                      .finally(() => setResetting(false));
                  }}
                >
                  {resetting ? '重建中…' : '一键重建'}
                </button>
              </div>
            </section>
          </div>
        )}
      </>
    );
  }

  return (
    <button
      type="button"
      className="ghost-btn"
      onClick={() => {
        onBeforeAction?.();
        window.location.href = buildWechatAuthorizeUrl({
          intent: 'bind',
          returnTo: returnTo ?? window.location.pathname,
        });
      }}
    >
      绑定微信
    </button>
  );
}