From 728368d712e280ce1d45204df411f42210f5d46a Mon Sep 17 00:00:00 2001
From: Delba de Oliveira <32464864+delbaoliveira@users.noreply.github.com>
Date: Mon, 9 Oct 2023 16:59:24 +0100
Subject: [PATCH] Fix pagination bugs and refactor/abstract styling logic
 (#205)

* Simplify TS

* Abstract away pagination logic

* Clean up

* Fix bugs and refactor styling logic

* Add comments

* Fix border bug for single page

* Fix search pagination
---
 .../15-final/app/dashboard/customers/page.tsx |  10 +-
 .../15-final/app/dashboard/invoices/page.tsx  |  12 +-
 dashboard/15-final/app/lib/utils.ts           |  33 ++++
 .../15-final/app/ui/invoices/pagination.tsx   | 171 ++++++++++--------
 dashboard/15-final/app/ui/search.tsx          |   2 +
 5 files changed, 140 insertions(+), 88 deletions(-)

diff --git a/dashboard/15-final/app/dashboard/customers/page.tsx b/dashboard/15-final/app/dashboard/customers/page.tsx
index c45ee90..dcd62af 100644
--- a/dashboard/15-final/app/dashboard/customers/page.tsx
+++ b/dashboard/15-final/app/dashboard/customers/page.tsx
@@ -4,12 +4,10 @@ import CustomersTable from '@/app/ui/customers/table';
 export default async function Page({
   searchParams,
 }: {
-  searchParams:
-    | {
-        query: string | undefined;
-        page: string | undefined;
-      }
-    | undefined;
+  searchParams?: {
+    query?: string;
+    page?: string;
+  };
 }) {
   const query = searchParams?.query || '';
 
diff --git a/dashboard/15-final/app/dashboard/invoices/page.tsx b/dashboard/15-final/app/dashboard/invoices/page.tsx
index 11bfce8..fcf178a 100644
--- a/dashboard/15-final/app/dashboard/invoices/page.tsx
+++ b/dashboard/15-final/app/dashboard/invoices/page.tsx
@@ -8,15 +8,13 @@ import { lusitana } from '@/app/ui/fonts';
 export default async function Page({
   searchParams,
 }: {
-  searchParams:
-    | {
-        query: string | undefined;
-        page: string | undefined;
-      }
-    | undefined;
+  searchParams?: {
+    query?: string;
+    page?: string;
+  };
 }) {
   const query = searchParams?.query || '';
-  const currentPage = query ? 1 : Number(searchParams?.page || '1');
+  const currentPage = Number(searchParams?.page || '1');
 
   const { invoices, totalPages } = await fetchFilteredInvoices(
     query,
diff --git a/dashboard/15-final/app/lib/utils.ts b/dashboard/15-final/app/lib/utils.ts
index 4dce958..b7f7cff 100644
--- a/dashboard/15-final/app/lib/utils.ts
+++ b/dashboard/15-final/app/lib/utils.ts
@@ -34,3 +34,36 @@ export const generateYAxis = (revenue: Revenue[]) => {
 
   return { yAxisLabels, topLabel };
 };
+
+export const generatePagination = (currentPage: number, totalPages: number) => {
+  // If the total number of pages is 7 or less,
+  // display all pages without any ellipsis.
+  if (totalPages <= 7) {
+    return Array.from({ length: totalPages }, (_, i) => i + 1);
+  }
+
+  // If the current page is among the first 3 pages,
+  // show the first 3, an ellipsis, and the last 2 pages.
+  if (currentPage <= 3) {
+    return [1, 2, 3, '...', totalPages - 1, totalPages];
+  }
+
+  // If the current page is among the last 3 pages,
+  // show the first 2, an ellipsis, and the last 3 pages.
+  if (currentPage >= totalPages - 2) {
+    return [1, 2, '...', totalPages - 2, totalPages - 1, totalPages];
+  }
+
+  // If the current page is somewhere in the middle,
+  // show the first page, an ellipsis, the current page and its neighbors,
+  // another ellipsis, and the last page.
+  return [
+    1,
+    '...',
+    currentPage - 1,
+    currentPage,
+    currentPage + 1,
+    '...',
+    totalPages,
+  ];
+};
diff --git a/dashboard/15-final/app/ui/invoices/pagination.tsx b/dashboard/15-final/app/ui/invoices/pagination.tsx
index 5af0925..a9c6dba 100644
--- a/dashboard/15-final/app/ui/invoices/pagination.tsx
+++ b/dashboard/15-final/app/ui/invoices/pagination.tsx
@@ -1,9 +1,10 @@
 'use client';
 
 import { ArrowLeftIcon, ArrowRightIcon } from '@heroicons/react/24/outline';
-import { usePathname, useSearchParams } from 'next/navigation';
 import clsx from 'clsx';
 import Link from 'next/link';
+import { generatePagination } from '@/app/lib/utils';
+import { usePathname, useSearchParams } from 'next/navigation';
 
 export default function Pagination({
   currentPage,
@@ -15,94 +16,114 @@ export default function Pagination({
   const pathname = usePathname();
   const searchParams = useSearchParams();
 
-  const allPages = Array.from({ length: totalPages }, (_, i) => i + 1);
-  const PreviousPageTag = Link;
-  const NextPageTag = Link;
-
-  const createPageUrl = (pageNumber: number | string) => {
+  const createPageURL = (pageNumber: number | string) => {
     const params = new URLSearchParams(searchParams);
     params.set('page', pageNumber.toString());
     return `${pathname}?${params.toString()}`;
   };
 
-  let pagesToShow = [];
-
-  if (totalPages <= 7) {
-    pagesToShow = allPages;
-  } else if (currentPage <= 3) {
-    pagesToShow = [1, 2, 3, '...', totalPages - 1, totalPages];
-  } else if (currentPage >= totalPages - 2) {
-    pagesToShow = [1, 2, '...', totalPages - 2, totalPages - 1, totalPages];
-  } else {
-    pagesToShow = [
-      1,
-      '...',
-      currentPage - 1,
-      currentPage,
-      currentPage + 1,
-      '...',
-      totalPages,
-    ];
-  }
+  const allPages = generatePagination(currentPage, totalPages);
 
   return (
     <div className="inline-flex">
-      <PreviousPageTag
-        href={createPageUrl(currentPage - 1)}
-        className={clsx(
-          'mr-2 flex h-10 w-10 items-center justify-center rounded-md ring-1 ring-inset ring-gray-300 hover:bg-gray-100 md:mr-4',
-          {
-            'pointer-events-none text-gray-300 hover:bg-transparent':
-              currentPage === 1,
-          },
-        )}
-      >
-        <ArrowLeftIcon className="w-4" />
-      </PreviousPageTag>
-      <div className="flex -space-x-px ">
-        {pagesToShow.map((page, i) => {
-          if (page === '...') {
-            return (
-              <span
-                key={`ellipsis-${i}`}
-                className="flex h-10 w-10 items-center justify-center text-sm ring-1 ring-inset ring-gray-300"
-              >
-                ...
-              </span>
-            );
-          }
+      <PaginationArrow
+        direction="left"
+        href={createPageURL(currentPage - 1)}
+        isDisabled={currentPage <= 1}
+      />
+
+      <div className="flex -space-x-px">
+        {allPages.map((page, index) => {
+          let position: 'first' | 'last' | 'single' | 'middle' | undefined;
+
+          if (index === 0) position = 'first';
+          if (index === allPages.length - 1) position = 'last';
+          if (allPages.length === 1) position = 'single';
+          if (page === '...') position = 'middle';
 
-          const PageTag = page === currentPage || page === '...' ? 'p' : Link;
           return (
-            <PageTag
+            <PaginationNumber
               key={page}
-              href={createPageUrl(page)}
-              className={clsx(
-                i === 0 && 'rounded-l-md',
-                i === pagesToShow.length - 1 && 'rounded-r-md',
-                'flex h-10 w-10 items-center justify-center text-sm ring-1 ring-inset ring-gray-300 hover:bg-gray-100',
-                {
-                  'z-10 bg-blue-600 text-white ring-blue-600 hover:bg-blue-600':
-                    currentPage === page,
-                },
-              )}
-            >
-              {page}
-            </PageTag>
+              href={createPageURL(page)}
+              page={page}
+              position={position}
+              isActive={currentPage === page}
+            />
           );
         })}
       </div>
-      <NextPageTag
-        href={createPageUrl(currentPage + 1)}
-        className={clsx(
-          'ml-2 flex h-10 w-10 items-center justify-center rounded-md ring-1 ring-inset ring-gray-300 hover:bg-gray-100 md:ml-4',
-          {
-            'text-gray-300': currentPage === totalPages,
-          },
-        )}
-      >
-        <ArrowRightIcon className="w-4" />
-      </NextPageTag>
+
+      <PaginationArrow
+        direction="right"
+        href={createPageURL(currentPage + 1)}
+        isDisabled={currentPage >= totalPages}
+      />
     </div>
   );
 }
+
+function PaginationNumber({
+  page,
+  href,
+  isActive,
+  position,
+}: {
+  page: number | string;
+  href: string;
+  position?: 'first' | 'last' | 'middle' | 'single';
+  isActive: boolean;
+}) {
+  const className = clsx(
+    'flex h-10 w-10 items-center justify-center text-sm border',
+    {
+      'rounded-l-md': position === 'first' || position === 'single',
+      'rounded-r-md': position === 'last' || position === 'single',
+      'z-10 bg-blue-600 border-blue-600 text-white': isActive,
+      'hover:bg-gray-100': !isActive && position !== 'middle',
+      'text-gray-300': position === 'middle',
+    },
+  );
+
+  return isActive || position === 'middle' ? (
+    <div className={className}>{page}</div>
+  ) : (
+    <Link href={href} className={className}>
+      {page}
+    </Link>
+  );
+}
+
+function PaginationArrow({
+  href,
+  direction,
+  isDisabled,
+}: {
+  href: string;
+  direction: 'left' | 'right';
+  isDisabled?: boolean;
+}) {
+  const className = clsx(
+    'flex h-10 w-10 items-center justify-center rounded-md border',
+    {
+      'pointer-events-none text-gray-300': isDisabled,
+      'hover:bg-gray-100': !isDisabled,
+      'mr-2 md:mr-4': direction === 'left',
+      'ml-2 md:ml-4': direction === 'right',
+    },
+  );
+
+  const icon =
+    direction === 'left' ? (
+      <ArrowLeftIcon className="w-4" />
+    ) : (
+      <ArrowRightIcon className="w-4" />
+    );
+
+  return isDisabled ? (
+    <div className={className}>{icon}</div>
+  ) : (
+    <Link className={className} href={href}>
+      {icon}
+    </Link>
+  );
+}
diff --git a/dashboard/15-final/app/ui/search.tsx b/dashboard/15-final/app/ui/search.tsx
index bb58994..7c89054 100644
--- a/dashboard/15-final/app/ui/search.tsx
+++ b/dashboard/15-final/app/ui/search.tsx
@@ -13,6 +13,8 @@ export default function Search({ placeholder }: { placeholder: string }) {
     console.log(`Searching... ${term}`);
 
     const params = new URLSearchParams(searchParams);
+
+    params.set('page', '1');
     if (term) {
       params.set('query', term);
     } else {