Refactor feed discovery and avoid an extra HTTP request if the url provided is the feed

internal/model/feed.go

@@ -5,6 +5,7 @@ package model // import "miniflux.app/v2/internal/model"
 
 import (
 	"fmt"
+	"io"
 	"math"
 	"time"
 
@@ -144,6 +145,31 @@ type FeedCreationRequest struct {
 	UrlRewriteRules             string `json:"urlrewrite_rules"`
 }
 
+type FeedCreationRequestFromSubscriptionDiscovery struct {
+	Content      io.ReadSeeker
+	ETag         string
+	LastModified string
+
+	FeedURL                     string `json:"feed_url"`
+	CategoryID                  int64  `json:"category_id"`
+	UserAgent                   string `json:"user_agent"`
+	Cookie                      string `json:"cookie"`
+	Username                    string `json:"username"`
+	Password                    string `json:"password"`
+	Crawler                     bool   `json:"crawler"`
+	Disabled                    bool   `json:"disabled"`
+	NoMediaPlayer               bool   `json:"no_media_player"`
+	IgnoreHTTPCache             bool   `json:"ignore_http_cache"`
+	AllowSelfSignedCertificates bool   `json:"allow_self_signed_certificates"`
+	FetchViaProxy               bool   `json:"fetch_via_proxy"`
+	ScraperRules                string `json:"scraper_rules"`
+	RewriteRules                string `json:"rewrite_rules"`
+	BlocklistRules              string `json:"blocklist_rules"`
+	KeeplistRules               string `json:"keeplist_rules"`
+	HideGlobally                bool   `json:"hide_globally"`
+	UrlRewriteRules             string `json:"urlrewrite_rules"`
+}
+
 // FeedModificationRequest represents the request to update a feed.
 type FeedModificationRequest struct {
 	FeedURL                     *string `json:"feed_url"`