使用 Redis 进行实时本地库存搜索

/**
 * Search Product in stores within search radius, Also sort results by distance from current user location to store.
 *
 * :param _inventoryFilter: Product Id (sku), searchRadiusInKm and current userLocation
 * :return: Inventory product list
 */
static async inventorySearchWithDistance(_inventoryFilter: IInventoryBodyFilter): Promise<IStoresInventory[]> {
    const nodeRedisClient = getNodeRedisClient();

    const repository = StoresInventoryRepo.getRepository();
    let retItems: IStoresInventory[] = [];

    if (nodeRedisClient && repository && _inventoryFilter?.sku
        && _inventoryFilter?.userLocation?.latitude
        && _inventoryFilter?.userLocation?.longitude) {

        const lat = _inventoryFilter.userLocation.latitude;
        const long = _inventoryFilter.userLocation.longitude;
        const radiusInKm = _inventoryFilter.searchRadiusInKm || 1000;

        const queryBuilder = repository.search()
            .where('sku')
            .eq(_inventoryFilter.sku)
            .and('quantity')
            .gt(0)
            .and('storeLocation')
            .inRadius((circle) => {
                return circle
                    .latitude(lat)
                    .longitude(long)
                    .radius(radiusInKm)
                    .kilometers
            });

        console.log(queryBuilder.query);
        /* Sample queryBuilder query
            ( ( (@sku:[1019688 1019688]) (@quantity:[(0 +inf]) ) (@storeLocation:[-78.878738 42.88023 500 km]) )
        */

        const indexName = `${StoresInventoryRepo.STORES_INVENTORY_KEY_PREFIX}:index`;
        const aggregator = await nodeRedisClient.ft.aggregate(
            indexName,
            queryBuilder.query,
            {
                LOAD: ["@storeId", "@storeLocation", "@sku", "@quantity"],
                STEPS: [{
                    type: AggregateSteps.APPLY,
                    expression: `geodistance(@storeLocation, ${long}, ${lat})/1000`,
                    AS: 'distInKm'
                }, {
                    type: AggregateSteps.SORTBY,
                    BY: "@distInKm"
                }]
            });

        /* Sample command to run query directly on CLI
            FT.AGGREGATE StoresInventory:index '( ( (@sku:[1019688 1019688]) (@quantity:[(0 +inf]) ) (@storeLocation:[-78.878738 42.88023 500 km]) )' LOAD 4 @storeId @storeLocation @sku @quantity  APPLY "geodistance(@storeLocation,-78.878738,42.88043)/1000" AS distInKm SORTBY 1 @distInKm
        */

        retItems = <IStoresInventory[]>aggregator.results;

        if (!retItems.length) {
            throw `Product not found with in ${radiusInKm}km range!`;
        }
        else {
            retItems = retItems.map((item) => {
                if (typeof item.storeLocation == "string") {
                    const location = item.storeLocation.split(",");
                    item.storeLocation = {
                        longitude: Number(location[0]),
                        latitude: Number(location[1]),
                    }
                }
                return item;
            })
        }
    }
    else {
        throw `Input params failed !`;
    }
    return retItems;
}