feat(authentication): implement Spotify API token retrieval function

src/api/spotifyAuth.js

@@ -0,0 +1,31 @@
+import axios from 'axios';
+import qs from 'qs';
+
+const client_id = process.env.SPOTIFY_CLIENT_ID;
+const client_secret = process.env.SPOTIFY_CLIENT_SECRET;
+
+export default function getSpotifyAccessToken() {
+  const authOptions = {
+    method: 'POST',
+    url: 'https://accounts.spotify.com/api/token',
+    headers: {
+      Authorization: `Basic ${Buffer.from(`${client_id}:${client_secret}`).toString('base64')}`,
+      'Content-Type': 'application/x-www-form-urlencoded',
+    },
+    data: qs.stringify({
+      grant_type: 'client_credentials',
+    }),
+  };
+
+  return axios(authOptions)
+    .then((response) => {
+      if (response.status === 200) {
+        return response.data.access_token;
+      }
+      return Promise.reject(new Error(`Could not get access token for ${response.status}`));
+    })
+    .catch((error) => {
+      console.error('Auth Error:', error);
+      throw error;
+    });
+}