import { useEffect, useMemo, useState } from 'react';
import type { ClientRuntimeConfig } from '@dukang/shared-types';
import { request } from '../lib/api';
import {
  buildTencentLocPickerUrl,
  parseTencentLocPickerMessage,
  type TencentPickedLocation,
} from '../lib/tencentLocPicker';

type Props = {
  open: boolean;
  onClose: () => void;
  onPick: (loc: TencentPickedLocation) => void;
  latitude?: number | null;
  longitude?: number | null;
  /** 保留兼容，iframe 选点不使用 */
  region?: string | null;
};

let cachedKey: string | null | undefined;

async function loadTencentLbsKey(): Promise<string> {
  if (cachedKey) return cachedKey;
  const cfg = await request<ClientRuntimeConfig>('PARTNER_H5', '/common/client-config', {
    silent: true,
  });
  const key = (cfg.tencentLbsKey || '').trim();
  if (!key) {
    throw new Error('未配置腾讯位置服务 Key，请联系管理员在系统设置中配置');
  }
  cachedKey = key;
  return key;
}

export default function TencentLocPickerOverlay({
  open,
  onClose,
  onPick,
  latitude,
  longitude,
}: Props) {
  const [key, setKey] = useState<string | null>(cachedKey ?? null);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState('');
  /** 选点结果仅存内存，界面不展示经纬度 */
  const [pending, setPending] = useState<TencentPickedLocation | null>(null);
  const [iframeReady, setIframeReady] = useState(false);

  useEffect(() => {
    if (!open) {
      setPending(null);
      setIframeReady(false);
      setError('');
      return;
    }
    let cancelled = false;
    if (key) return;
    setLoading(true);
    void loadTencentLbsKey()
      .then((k) => {
        if (!cancelled) setKey(k);
      })
      .catch((e) => {
        if (!cancelled) setError(e instanceof Error ? e.message : '加载地图配置失败');
      })
      .finally(() => {
        if (!cancelled) setLoading(false);
      });
    return () => {
      cancelled = true;
    };
  }, [open, key]);

  useEffect(() => {
    if (!open) return;
    function onMessage(event: MessageEvent) {
      const picked = parseTencentLocPickerMessage(event.data);
      if (!picked) return;
      setPending(picked);
    }
    window.addEventListener('message', onMessage);
    return () => window.removeEventListener('message', onMessage);
  }, [open]);

  const src = useMemo(() => {
    if (!key) return '';
    const lat = latitude != null ? Number(latitude) : undefined;
    const lng = longitude != null ? Number(longitude) : undefined;
    return buildTencentLocPickerUrl(key, {
      latitude: lat != null && Number.isFinite(lat) ? lat : undefined,
      longitude: lng != null && Number.isFinite(lng) ? lng : undefined,
    });
  }, [key, latitude, longitude]);

  if (!open) return null;

  function confirmPick() {
    if (!pending) return;
    onPick(pending);
    onClose();
  }

  return (
    <div
      className="partner-locpicker-overlay"
      style={{
        position: 'fixed',
        inset: 0,
        zIndex: 1000,
        background: '#fff',
        display: 'flex',
        flexDirection: 'column',
        height: '100dvh',
        maxHeight: '-webkit-fill-available',
        paddingTop: 'env(safe-area-inset-top)',
        paddingBottom: 'env(safe-area-inset-bottom)',
        boxSizing: 'border-box',
      }}
    >
      <div
        style={{
          display: 'flex',
          flexDirection: 'column',
          padding: '12px 12px 10px',
          borderBottom: '1px solid rgba(0,0,0,0.06)',
          flexShrink: 0,
          gap: 10,
          background: '#fff',
        }}
      >
        <h2
          style={{
            margin: 0,
            textAlign: 'center',
            fontWeight: 700,
            fontSize: 17,
            lineHeight: 1.3,
          }}
        >
          地图选点
        </h2>
        <div style={{ display: 'flex', alignItems: 'center', gap: 10 }}>
          <button
            type="button"
            className="partner-btn-primary"
            style={{
              flex: 1,
              padding: '12px 16px',
              fontSize: 15,
              fontWeight: 600,
              opacity: pending ? 1 : 0.45,
              width: 'auto',
            }}
            disabled={!pending}
            onClick={confirmPick}
          >
            确认
          </button>
          <button
            type="button"
            className="partner-btn-outline"
            style={{ padding: '12px 16px', minWidth: 72, flexShrink: 0 }}
            onClick={onClose}
          >
            关闭
          </button>
        </div>
      </div>

      <p
        className="label-md text-muted"
        style={{
          margin: 0,
          padding: '8px 14px',
          borderBottom: '1px solid rgba(0,0,0,0.04)',
          flexShrink: 0,
          fontSize: 12,
        }}
      >
        {pending ? '已选定位置，请点右上角「确认」' : '在地图上点选或搜索地点，选中后点右上角「确认」'}
      </p>

      <div style={{ flex: 1, minHeight: 0, position: 'relative', background: '#f5f5f5' }}>
        {loading ? (
          <p className="label-md text-muted" style={{ padding: 24, textAlign: 'center' }}>
            正在加载地图…
          </p>
        ) : error ? (
          <div style={{ padding: 24 }}>
            <p className="label-md" style={{ color: 'var(--color-heritage-red, #a61d24)' }}>
              {error}
            </p>
            <p className="label-md text-muted" style={{ marginTop: 12 }}>
              请确认系统设置中已配置腾讯位置服务 Key，并白名单 apis.map.qq.com。
            </p>
          </div>
        ) : src ? (
          <>
            {!iframeReady ? (
              <p
                className="label-md text-muted"
                style={{
                  position: 'absolute',
                  inset: 0,
                  display: 'flex',
                  alignItems: 'center',
                  justifyContent: 'center',
                  margin: 0,
                  zIndex: 1,
                  pointerEvents: 'none',
                }}
              >
                地图加载中…
              </p>
            ) : null}
            <iframe
              title="地图选点"
              src={src}
              allow="geolocation *"
              onLoad={() => setIframeReady(true)}
              style={{
                width: '100%',
                height: '100%',
                border: 0,
                display: 'block',
                background: '#fff',
              }}
            />
          </>
        ) : null}
      </div>
    </div>
  );
}