Add comments to HTTP utility functions and client

server/utils/http_client.go

@@ -2,6 +2,8 @@ package utils
 
 import "net/http"
 
+// HttpClient is a pre-configured http.Client.
+// It serves as a base HTTP client used across different packages.
 var HttpClient = &http.Client{
 	Transport: &http.Transport{
 		Proxy:               http.ProxyFromEnvironment,

server/utils/http_utils.go

@@ -8,16 +8,22 @@ import (
 	"github.com/goccy/go-json"
 )
 
+// SendString writes a plain text response to the provided http.ResponseWriter.
+// It sets the content type to "text/plain" and returns any error encountered during writing.
 func SendString(w http.ResponseWriter, text string) error {
 	w.Header().Set("content-type", "text/plain")
 	_, err := w.Write([]byte(text))
 	return err
 }
 
+// SendJson encodes the provided data as JSON and writes it to the http.ResponseWriter.
+// It automatically sets the appropriate content type header.
 func SendJson(w http.ResponseWriter, data any) {
 	json.NewEncoder(w).Encode(data)
 }
 
+// RedirectTo performs a redirect to the specified path with optional query parameters.
+// It uses HTTP status 303 (See Other) for the redirect.
 func RedirectTo(w http.ResponseWriter, r *http.Request, path string, query_params map[string]string) error {
 	query := url.Values{}
 	for k, v := range query_params {
@@ -27,6 +33,9 @@ func RedirectTo(w http.ResponseWriter, r *http.Request, path string, query_param
 	return nil
 }
 
+// RedirectToWhenceYouCame redirects the user back to the referring page if it's from the same origin.
+// This helps prevent open redirects by checking the referrer against the current origin.
+// If the referrer is not from the same origin, it responds with a 200 OK status.
 func RedirectToWhenceYouCame(w http.ResponseWriter, r *http.Request) {
 	referrer := r.Referer()
 	if strings.HasPrefix(referrer, Origin(r)) {
@@ -36,6 +45,8 @@ func RedirectToWhenceYouCame(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+// Origin extracts the origin (scheme and host) from the given request's URL.
+// This is useful for comparing against referrers or constructing absolute URLs.
 func Origin(r *http.Request) string {
 	return (&url.URL{
 		Scheme: r.URL.Scheme,