Add script to fetch osu! API token

scripts/get_osu_api_token.fish

@@ -0,0 +1,39 @@
+if test -z $OSU_API_CLIENT_ID || test -z $OSU_API_CLIENT_SECRET
+  echo "You need to set OSU_API_CLIENT_ID and OSU_API_CLIENT_SECRET"
+  exit 1
+end
+
+if set -q OSU_API_TOKEN
+  echo "OSU_API_TOKEN already set. Unset it to re-request the token"
+  echo "set --erase OSU_API_TOKEN"
+  exit 1
+end
+
+echo "Requesting token from osu! API..."
+
+set TOKEN_JSON (curl --request POST \
+    "https://osu.ppy.sh/oauth/token" \
+    --header "Accept: application/json" \
+    --header "Content-Type: application/x-www-form-urlencoded" \
+    --fail-with-body \
+    --silent \
+    --data "client_id=$OSU_API_CLIENT_ID&client_secret=$OSU_API_CLIENT_SECRET&grant_type=client_credentials&scope=public")
+
+if test $status -ne 0
+  echo "Error while trying to request osu! API token:"
+  echo $TOKEN_JSON
+  exit 1
+end
+
+set OSU_API_TOKEN (echo $TOKEN_JSON | jq -r ".access_token")
+if test $status -ne 0
+  echo "Error while trying to request osu! API token:"
+  echo $TOKEN_JSON
+  exit 1
+end
+
+alias curl-osu='curl --header "Authorization: Bearer $OSU_API_TOKEN" \
+         --header "Content-Type: application/json" \
+         --header "Accept: application/json"'
+
+echo "OSU_API_TOKEN set. Use `curl-osu` for a `curl` wrapper with the token already loaded."