From 2debcc60ea829bfb6fe9d832ab1f918c451bd1ff Mon Sep 17 00:00:00 2001
From: stefanaz2 <sfrunza@seneca.ca>
Date: Sat, 29 Oct 2022 21:22:16 -0400
Subject: [PATCH] issue410 on first click searchbar shows top 5 subreddits by
 popularity

---
 components/Search.tsx  |   3 +-
 pages/api/preSearch.ts | 138 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 140 insertions(+), 1 deletion(-)
 create mode 100644 pages/api/preSearch.ts

diff --git a/components/Search.tsx b/components/Search.tsx
index 849f6bd2..e6da8a2a 100644
--- a/components/Search.tsx
+++ b/components/Search.tsx
@@ -46,6 +46,7 @@ export default function Search() {
   const {setSubreddit, searchInput, setSearchInput} = useRedditContext()
   const {classes} = useStyles()
   const [debounced] = useDebouncedValue(searchInput, 300)
+  const {data: beforeSearch} = useSWR(`/api/preSearch?limit=5`, fetcher)
   const {data: results} = useSWR(`/api/search?term=${debounced}`, fetcher, {
     revalidateIfStale: true,
     revalidateOnFocus: false,
@@ -63,7 +64,7 @@ export default function Search() {
     <Autocomplete
       aria-label="Search sub-reddits"
       className={classes.searchBar}
-      data={results ? results : []}
+      data={results ? results : beforeSearch ? beforeSearch : []}
       icon={<IconSearch />}
       itemComponent={AutoCompleteItem}
       nothingFound="No subs found. Start typing to search."
diff --git a/pages/api/preSearch.ts b/pages/api/preSearch.ts
new file mode 100644
index 00000000..826c6fa8
--- /dev/null
+++ b/pages/api/preSearch.ts
@@ -0,0 +1,138 @@
+import type {NextRequest} from 'next/server'
+
+export const config = {
+  runtime: 'experimental-edge'
+}
+
+/**
+ * Popular Subreddit Reddit API.
+ *
+ * @example
+ * /api/preSearch?limit=5
+ *
+ * @see https://www.reddit.com/dev/api#GET_subreddits_{where}
+ * @see https://nextjs.org/docs/api-routes/edge-api-routes
+ * @see https://nextjs.org/docs/api-reference/edge-runtime
+ */
+export default async function search(req: NextRequest) {
+  // Parse and sanitize query params from request.
+  const limit = req.nextUrl.searchParams.get('limit') || '5'
+
+  try {
+    // Generate random device ID.
+    // @see https://developer.mozilla.org/en-US/docs/Web/API/Crypto/getRandomValues
+    const array = new Uint32Array(24)
+    const deviceId = self.crypto.getRandomValues(array)
+
+    // Try and fetch a new access token.
+    const tokenResponse = await fetch(
+      `https://www.reddit.com/api/v1/access_token?grant_type=client_credentials&device_id=${deviceId}`,
+      {
+        method: 'POST',
+        headers: {
+          'Content-Type': 'application/json charset=UTF-8',
+          'User-Agent': 'reddit-image-viewer/* by Greg Rickaby',
+          Authorization: `Basic ${btoa(
+            `${process.env.REDDIT_CLIENT_ID}:${process.env.REDDIT_CLIENT_SECRET}`
+          )}`
+        }
+      }
+    )
+
+    // Bad response? Bail...
+    if (tokenResponse.status != 200) {
+      return new Response(
+        JSON.stringify({
+          error: `${tokenResponse.statusText}`
+        }),
+        {
+          status: tokenResponse.status,
+          statusText: tokenResponse.statusText
+        }
+      )
+    }
+
+    // Get the access token.
+    const token = await tokenResponse.json()
+
+    // Issue with token? Bail...
+    if (token.error) {
+      return new Response(
+        JSON.stringify({
+          error: token.error
+        }),
+        {
+          status: token.status,
+          statusText: token.statusText
+        }
+      )
+    }
+
+    // Attempt to fetch subreddits.
+    const response = await fetch(
+      `https://oauth.reddit.com/subreddits/popular?limit=${limit}`,
+      {
+        headers: {
+          authorization: `Bearer ${token.access_token}`
+        }
+      }
+    )
+
+    // No response? Bail...
+    if (response.status != 200) {
+      return new Response(
+        JSON.stringify({
+          error: `${response.statusText}`
+        }),
+        {
+          status: response.status,
+          statusText: response.statusText
+        }
+      )
+    }
+
+    // Parse the response.
+    const subs = await response.json()
+
+    // No data in the response? Bail...
+    if (!subs.data && !subs.data.children.length) {
+      return new Response(
+        JSON.stringify({
+          error: `No data returned from Reddit.`
+        }),
+        {
+          status: 400,
+          statusText: 'Bad Request'
+        }
+      )
+    }
+
+    // Filter uneeded data to keep the payload small.
+    const filtered = subs.data.children.map(
+      (sub: {data: {over18?: string; url?: string; display_name?: string}}) => {
+        return {
+          over_18: sub.data.over18 ? true : false,
+          url: sub.data.url ? sub.data.url : '',
+          value: sub.data.display_name ? sub.data.display_name : ''
+        }
+      }
+    )
+
+    // Send the response.
+    return new Response(JSON.stringify(filtered), {
+      headers: {
+        'Content-Type': 'application/json',
+        'Cache-Control': 'public, s-maxage=1, stale-while-revalidate=59'
+      },
+      status: 200,
+      statusText: 'OK'
+    })
+  } catch (error) {
+    // Issue? Leave a message and bail.
+    console.error(error)
+    return new Response(JSON.stringify({error: `${error}`}), {
+      status: 500,
+      statusText: 'Internal Server Error'
+    })
+  }
+}