From 15740651dfa33f6a6b078ede5696e04ef3d36d35 Mon Sep 17 00:00:00 2001
From: Kentai Radiquum <kentai.waah@gmail.com>
Date: Sat, 13 Jul 2024 06:26:37 +0500
Subject: [PATCH] feat: add infinite scrolling

---
 app/home/[slug]/page.js        | 43 +++++++++++++++++++++++++++-------
 app/hooks/useScrollPosition.js | 26 ++++++++++++++++++++
 2 files changed, 61 insertions(+), 8 deletions(-)
 create mode 100644 app/hooks/useScrollPosition.js

diff --git a/app/home/[slug]/page.js b/app/home/[slug]/page.js
index 61766d2..50c51af 100644
--- a/app/home/[slug]/page.js
+++ b/app/home/[slug]/page.js
@@ -1,10 +1,12 @@
 "use client";
-import useSWR from "swr";
+import useSWRInfinite from "swr/infinite";
 import { ReleaseSection } from "../../components/ReleaseSection/ReleaseSection";
 import { Spinner } from "../../components/Spinner/Spinner";
+import { useState, useEffect } from "react";
+import { useScrollPosition } from "@/app/hooks/useScrollPosition";
 
-const fetcher = async (...args) => {
-  const res = await fetch(...args);
+const fetcher = async url => {
+  const res = await fetch(url);
 
   if (!res.ok) {
     const error = new Error("An error occurred while fetching the data.");
@@ -24,11 +26,35 @@ const SectionTitleMapping = {
 };
 
 export default function HomeStatus({ params }) {
-  const { data, error, isLoading } = useSWR(
-    `/api/home?status=${params.slug}`,
-    fetcher
+  const getKey = (pageIndex, previousPageData) => {
+    if (previousPageData && !previousPageData.content.length) return null;
+    return `/api/home?status=${params.slug}&page=${pageIndex}`;
+  };
+
+  const { data, error, isLoading, size, setSize } = useSWRInfinite(
+    getKey,
+    fetcher,
+    {"initialSize": 2, "revalidateFirstPage": false}
   );
 
+  const [content, setContent] = useState(null);
+  useEffect(() => {
+    if (data) {
+      let allReleases = [];
+      for (let i = 0; i < data.length; i++) {
+        allReleases.push(...data[i].content);
+      }
+      setContent(allReleases);
+    }
+  }, [data]);
+
+  const scrollPosition = useScrollPosition();
+  useEffect(() => {
+    if (scrollPosition >= 98 && scrollPosition <= 99) {
+        setSize(size + 1)
+    }
+    }, [scrollPosition]);
+
   if (error) return <div>failed to load</div>;
   if (isLoading)
     return (
@@ -39,12 +65,13 @@ export default function HomeStatus({ params }) {
 
   return (
     <main className="flex flex-col pt-2 pb-16 sm:pt-4 sm:pb-0">
-      {data && (
+      {content && (
         <ReleaseSection
           sectionTitle={SectionTitleMapping[params.slug]}
-          content={data.content}
+          content={content}
         />
       )}
+      <button className="mx-auto w-[calc(100%-10rem)] border border-black rounded-lg p-4 mb-6 flex items-center justify-center gap-2 hover:bg-black hover:text-white transition" onClick={() => setSize(size + 1)}> <span className="w-10 h-10 iconify mdi--plus"> </span> <span className="text-lg">Load More</span></button>
     </main>
   );
 }
diff --git a/app/hooks/useScrollPosition.js b/app/hooks/useScrollPosition.js
new file mode 100644
index 0000000..7fa1dd5
--- /dev/null
+++ b/app/hooks/useScrollPosition.js
@@ -0,0 +1,26 @@
+import { useEffect, useState } from "react";
+
+export function useScrollPosition() {
+  const [scrollPosition, setScrollPosition] = useState(0);
+
+  function handleScroll() {
+    const height =
+      document.documentElement.scrollHeight -
+      document.documentElement.clientHeight;
+
+    const windowScroll = document.documentElement.scrollTop;
+
+    const scrolled = (windowScroll / height) * 100;
+
+    setScrollPosition(scrolled);
+  }
+
+  useEffect(() => {
+    window.addEventListener("scroll", handleScroll, { passive: true });
+    return () => {
+      window.removeEventListener("scroll", handleScroll);
+    };
+  });
+
+  return Math.floor(scrollPosition);
+}
\ No newline at end of file