feature: infinite scroll (#119)

Add infinite scroll support to app list and dataset list.

web/app/(commonLayout)/datasets/Datasets.tsx

@@ -1,24 +1,49 @@
 'use client'
 
-import { useEffect } from 'react'
-import useSWR from 'swr'
-import { DataSet } from '@/models/datasets';
+import { useEffect, useRef } from 'react'
+import useSWRInfinite from 'swr/infinite'
+import { debounce } from 'lodash-es';
+import { DataSetListResponse } from '@/models/datasets';
 import NewDatasetCard from './NewDatasetCard'
 import DatasetCard from './DatasetCard';
 import { fetchDatasets } from '@/service/datasets';
+import { useSelector } from '@/context/app-context';
+
+const getKey = (pageIndex: number, previousPageData: DataSetListResponse) => {
+  if (!pageIndex || previousPageData.has_more)
+    return { url: 'datasets', params: { page: pageIndex + 1, limit: 30 } }
+  return null
+}
 
 const Datasets = () => {
-  // const { datasets, mutateDatasets } = useAppContext()
-  const { data: datasetList, mutate: mutateDatasets } = useSWR({ url: '/datasets', params: { page: 1 } }, fetchDatasets)
+  const { data, isLoading, setSize, mutate } = useSWRInfinite(getKey, fetchDatasets, { revalidateFirstPage: false })
+  const loadingStateRef = useRef(false)
+  const pageContainerRef = useSelector(state => state.pageContainerRef)
+  const anchorRef = useRef<HTMLAnchorElement>(null)
 
   useEffect(() => {
-    mutateDatasets()
+    loadingStateRef.current = isLoading
+  }, [isLoading])
+
+  useEffect(() => {
+    const onScroll = debounce(() => {
+      if (!loadingStateRef.current) {
+        const { scrollTop, clientHeight } = pageContainerRef.current!
+        const anchorOffset = anchorRef.current!.offsetTop
+        if (anchorOffset - scrollTop - clientHeight < 100) {
+          setSize(size => size + 1)
+        }
+      }
+    }, 50)
+
+    pageContainerRef.current?.addEventListener('scroll', onScroll)
+    return () => pageContainerRef.current?.removeEventListener('scroll', onScroll)
   }, [])
 
   return (
     <nav className='grid content-start grid-cols-1 gap-4 px-12 pt-8 sm:grid-cols-2 lg:grid-cols-4 grow shrink-0'>
-      {datasetList?.data.map(dataset => (<DatasetCard key={dataset.id} dataset={dataset} />))}
-      <NewDatasetCard />
+      {data?.map(({ data: datasets }) => datasets.map(dataset => (<DatasetCard key={dataset.id} dataset={dataset} />)))}
+      <NewDatasetCard ref={anchorRef} />
     </nav>
   )
 }