import { useCallback, useState } from 'react';
import { View, Text, Image } from '@tarojs/components';
import Taro, { useLoad, useRouter } from '@tarojs/taro';
import PageShell from '../../components/PageShell';
import PageNavBar from '../../components/PageNavBar';
import { request, toast } from '../../lib/api';

type StorePackage = {
  name: string;
  price: string | number;
  dishes: string;
  usableTime?: string | null;
  otherNotes?: string | null;
  imageUrl?: string | null;
};

type Store = {
  id: string;
  name: string;
  packages?: StorePackage[] | null;
};

function pickStoreId(raw?: string | null) {
  return String(raw || '')
    .trim()
    .replace(/[^\d]/g, '');
}

function parsePackageIndex(raw?: string | null) {
  const n = Number.parseInt(String(raw ?? ''), 10);
  return Number.isFinite(n) && n >= 0 ? n : -1;
}

function formatPriceYuan(price: string | number) {
  const n = typeof price === 'number' ? price : Number(price);
  if (!Number.isFinite(n)) return '0';
  if (Math.abs(n - Math.round(n)) < 1e-9) return String(Math.round(n));
  return n.toFixed(2).replace(/\.?0+$/, '');
}

export default function StorePackageDetailPage() {
  const router = useRouter();
  const [storeId, setStoreId] = useState(() => pickStoreId(router.params.storeId));
  const [storeName, setStoreName] = useState('');
  const [pkg, setPkg] = useState<StorePackage | null>(null);
  const [loading, setLoading] = useState(true);
  const [loadError, setLoadError] = useState('');

  const loadPackage = useCallback(async (sid: string, index: number) => {
    if (!sid) {
      setLoading(false);
      setLoadError('缺少门店参数');
      return;
    }
    if (index < 0) {
      setLoading(false);
      setLoadError('套餐不存在');
      return;
    }
    setLoadError('');
    setLoading(true);
    try {
      const data = await request<Store>(`/stores/${sid}`);
      const packages = data?.packages ?? [];
      const item = packages[index];
      if (!data?.id || !item) {
        setPkg(null);
        setLoadError('套餐不存在或已下架');
        toast('套餐不存在或已下架');
        return;
      }
      setStoreName(data.name);
      setPkg(item);
    } catch (e) {
      const msg = e instanceof Error ? e.message : '加载失败';
      setLoadError(msg);
      toast(msg);
    } finally {
      setLoading(false);
    }
  }, []);

  useLoad((options) => {
    const sid = pickStoreId(options?.storeId || router.params.storeId);
    const index = parsePackageIndex(options?.index ?? router.params.index);
    setStoreId(sid);
    void loadPackage(sid, index);
  });

  function goBack() {
    const pages = Taro.getCurrentPages();
    if (pages.length > 1) Taro.navigateBack();
    else if (storeId) {
      Taro.redirectTo({ url: `/pages/store-detail/index?id=${storeId}` });
    } else {
      Taro.switchTab({ url: '/pages/stores/index' });
    }
  }

  function previewImage(url: string) {
    Taro.previewImage({ urls: [url], current: url }).catch(() => toast('无法预览图片'));
  }

  if (loading) {
    return (
      <PageShell variant="scroll" className="store-package-detail-page">
        <PageNavBar title="套餐详情" solid onBack={goBack} />
        <View className="page-with-nav-bar u-empty">加载中…</View>
      </PageShell>
    );
  }

  if (!pkg) {
    return (
      <PageShell variant="scroll" className="store-package-detail-page">
        <PageNavBar title="套餐详情" solid onBack={goBack} />
        <View className="page-with-nav-bar u-empty">{loadError || '套餐不存在'}</View>
      </PageShell>
    );
  }

  const imageUrl = (pkg.imageUrl || '').trim();

  return (
    <PageShell variant="scroll" className="store-package-detail-page">
      <PageNavBar title={pkg.name} solid titleVisible onBack={goBack} />

      <View className="store-package-detail-body">
        <View className="store-package-detail-inner">
          <View className="store-package-detail-header">
            <View className="store-package-detail-title-row">
              <Text className="store-package-detail-title">{pkg.name}</Text>
              <Text className="store-package-detail-price">¥{formatPriceYuan(pkg.price)}</Text>
            </View>
            {storeName ? (
              <Text className="store-package-detail-store">{storeName}</Text>
            ) : null}
          </View>

          {imageUrl ? (
            <View
              className="store-package-detail-photo"
              onClick={() => previewImage(imageUrl)}
            >
              <Image
                className="store-package-detail-photo-image"
                src={imageUrl}
                mode="widthFix"
              />
            </View>
          ) : null}

          <View className="store-package-detail-content">
            <View className="store-detail-package-field">
              <Text className="store-detail-package-field-label">菜品</Text>
              <Text className="store-detail-package-field-value">{pkg.dishes || '—'}</Text>
            </View>
            {pkg.usableTime ? (
              <View className="store-detail-package-field">
                <Text className="store-detail-package-field-label">使用时间</Text>
                <Text className="store-detail-package-field-value">{pkg.usableTime}</Text>
              </View>
            ) : null}
            {pkg.otherNotes ? (
              <View className="store-detail-package-field">
                <Text className="store-detail-package-field-label">其他说明</Text>
                <Text className="store-detail-package-field-value">{pkg.otherNotes}</Text>
              </View>
            ) : null}
          </View>
        </View>
      </View>
    </PageShell>
  );
}