Refactored common rate limit code into separate module

internal/backends/funkwhale/client.go

@@ -23,15 +23,13 @@ package funkwhale
 
 import (
 	"errors"
-	"net/http"
 	"strconv"
-	"time"
 
 	"github.com/go-resty/resty/v2"
+	"go.uploadedlobster.com/scotty/internal/ratelimit"
 )
 
 const MaxItemsPerGet = 50
-const DefaultRateLimitWaitSeconds = 5
 
 type Client struct {
 	HttpClient *resty.Client
@@ -46,25 +44,7 @@ func NewClient(serverUrl string, token string) Client {
 	client.SetHeader("Accept", "application/json")
 
 	// Handle rate limiting (see https://docs.funkwhale.audio/developer/api/rate-limit.html)
-	client.SetRetryCount(5)
-	client.AddRetryCondition(
-		func(r *resty.Response, err error) bool {
-			code := r.StatusCode()
-			return code == http.StatusTooManyRequests || code >= http.StatusInternalServerError
-		},
-	)
-	client.SetRetryMaxWaitTime(time.Duration(1 * time.Minute))
-	client.SetRetryAfter(func(client *resty.Client, resp *resty.Response) (time.Duration, error) {
-		var err error
-		var retryAfter int = DefaultRateLimitWaitSeconds
-		if resp.StatusCode() == http.StatusTooManyRequests {
-			retryAfter, err = strconv.Atoi(resp.Header().Get("Retry-After"))
-			if err != nil {
-				retryAfter = DefaultRateLimitWaitSeconds
-			}
-		}
-		return time.Duration(retryAfter * int(time.Second)), err
-	})
+	ratelimit.EnableHTTPHeaderRateLimit(client, "Retry-After")
 
 	return Client{
 		HttpClient: client,