[feature] Add opt-in RSS feed for account's latest Public posts (#897)

* start adding rss functionality

* add gorilla/feeds dependency

* first bash at building rss feed
still needs work, this is an interim commit

* tidy up a bit

* add publicOnly option to GetAccountLastPosted

* implement rss endpoint

* fix test

* add initial user docs for rss

* update rss logo

* docs update

* add rssFeed to frontend

* feed -> feed.rss

* enableRSS

* increase rss logo size a lil bit

* add rss toggle

* move emojify to text package

* fiddle with rss feed formatting

* add Text field to test statuses

* move status to rss item to typeconverter

* update bun schema for enablerss

* simplify 304 checking

* assume account not rss

* update tests

* update swagger docs

* allow more characters in title, trim nicer

* update last posted to be more consistent

4 files changed, 16 insertions, 5 deletions

diff --git a/internal/api/client/account/accountupdate.go b/internal/api/client/account/accountupdate.go
index e2b2a731c..f89259a96 100644
--- a/internal/api/client/account/accountupdate.go
+++ b/internal/api/client/account/accountupdate.go
@@ -110,6 +110,11 @@ import (
 //			Custom CSS to use when rendering this account's profile or statuses.
 //			String must be no more than 5,000 characters (~5kb).
 //		type: string
+//	-
+//		name: enable_rss
+//		in: formData
+//		description: Enable RSS feed for this account's Public posts at `/[username]/feed.rss`
+//		type: boolean
 //
 //	security:
 //	- OAuth2 Bearer:
@@ -202,7 +207,8 @@ func parseUpdateAccountForm(c *gin.Context) (*model.UpdateCredentialsRequest, er
 			form.Source.Language == nil &&
 			form.Source.StatusFormat == nil &&
 			form.FieldsAttributes == nil &&
-			form.CustomCSS == nil) {
+			form.CustomCSS == nil &&
+			form.EnableRSS == nil) {
 		return nil, errors.New("empty form submitted")
 	}
 
diff --git a/internal/api/client/instance/instancepatch_test.go b/internal/api/client/instance/instancepatch_test.go
index ade5cd406..50b19c079 100644
--- a/internal/api/client/instance/instancepatch_test.go
+++ b/internal/api/client/instance/instancepatch_test.go
@@ -63,7 +63,7 @@ func (suite *InstancePatchTestSuite) TestInstancePatch1() {
 	b, err := io.ReadAll(result.Body)
 	suite.NoError(err)
 
-	suite.Equal(`{"uri":"http://localhost:8080","account_domain":"localhost:8080","title":"Example Instance","description":"\u003cp\u003eThis is the GoToSocial testrig. It doesn't federate or anything.\u003c/p\u003e\u003cp\u003eWhen the testrig is shut down, all data on it will be deleted.\u003c/p\u003e\u003cp\u003eDon't use this in production!\u003c/p\u003e","short_description":"\u003cp\u003eThis is the GoToSocial testrig. It doesn't federate or anything.\u003c/p\u003e\u003cp\u003eWhen the testrig is shut down, all data on it will be deleted.\u003c/p\u003e\u003cp\u003eDon't use this in production!\u003c/p\u003e","email":"someone@example.org","version":"0.0.0-testrig","registrations":true,"approval_required":true,"invites_enabled":false,"configuration":{"statuses":{"max_characters":5000,"max_media_attachments":6,"characters_reserved_per_url":25},"media_attachments":{"supported_mime_types":["image/jpeg","image/gif","image/png"],"image_size_limit":10485760,"image_matrix_limit":16777216,"video_size_limit":41943040,"video_frame_rate_limit":60,"video_matrix_limit":16777216},"polls":{"max_options":6,"max_characters_per_option":50,"min_expiration":300,"max_expiration":2629746},"accounts":{"allow_custom_css":true},"emojis":{"emoji_size_limit":51200}},"urls":{"streaming_api":"wss://localhost:8080"},"stats":{"domain_count":2,"status_count":16,"user_count":4},"thumbnail":"http://localhost:8080/assets/logo.png","contact_account":{"id":"01F8MH17FWEB39HZJ76B6VXSKF","username":"admin","acct":"admin","display_name":"","locked":false,"bot":false,"created_at":"2022-05-17T13:10:59.000Z","note":"","url":"http://localhost:8080/@admin","avatar":"","avatar_static":"","header":"http://localhost:8080/assets/default_header.png","header_static":"http://localhost:8080/assets/default_header.png","followers_count":1,"following_count":1,"statuses_count":4,"last_status_at":"2021-10-20T10:41:37.000Z","emojis":[],"fields":[]},"max_toot_chars":5000}`, string(b))
+	suite.Equal(`{"uri":"http://localhost:8080","account_domain":"localhost:8080","title":"Example Instance","description":"\u003cp\u003eThis is the GoToSocial testrig. It doesn't federate or anything.\u003c/p\u003e\u003cp\u003eWhen the testrig is shut down, all data on it will be deleted.\u003c/p\u003e\u003cp\u003eDon't use this in production!\u003c/p\u003e","short_description":"\u003cp\u003eThis is the GoToSocial testrig. It doesn't federate or anything.\u003c/p\u003e\u003cp\u003eWhen the testrig is shut down, all data on it will be deleted.\u003c/p\u003e\u003cp\u003eDon't use this in production!\u003c/p\u003e","email":"someone@example.org","version":"0.0.0-testrig","registrations":true,"approval_required":true,"invites_enabled":false,"configuration":{"statuses":{"max_characters":5000,"max_media_attachments":6,"characters_reserved_per_url":25},"media_attachments":{"supported_mime_types":["image/jpeg","image/gif","image/png"],"image_size_limit":10485760,"image_matrix_limit":16777216,"video_size_limit":41943040,"video_frame_rate_limit":60,"video_matrix_limit":16777216},"polls":{"max_options":6,"max_characters_per_option":50,"min_expiration":300,"max_expiration":2629746},"accounts":{"allow_custom_css":true},"emojis":{"emoji_size_limit":51200}},"urls":{"streaming_api":"wss://localhost:8080"},"stats":{"domain_count":2,"status_count":16,"user_count":4},"thumbnail":"http://localhost:8080/assets/logo.png","contact_account":{"id":"01F8MH17FWEB39HZJ76B6VXSKF","username":"admin","acct":"admin","display_name":"","locked":false,"bot":false,"created_at":"2022-05-17T13:10:59.000Z","note":"","url":"http://localhost:8080/@admin","avatar":"","avatar_static":"","header":"http://localhost:8080/assets/default_header.png","header_static":"http://localhost:8080/assets/default_header.png","followers_count":1,"following_count":1,"statuses_count":4,"last_status_at":"2021-10-20T10:41:37.000Z","emojis":[],"fields":[],"enable_rss":true},"max_toot_chars":5000}`, string(b))
 }
 
 func (suite *InstancePatchTestSuite) TestInstancePatch2() {
@@ -93,7 +93,7 @@ func (suite *InstancePatchTestSuite) TestInstancePatch2() {
 	b, err := io.ReadAll(result.Body)
 	suite.NoError(err)
 
-	suite.Equal(`{"uri":"http://localhost:8080","account_domain":"localhost:8080","title":"Geoff's Instance","description":"\u003cp\u003eThis is the GoToSocial testrig. It doesn't federate or anything.\u003c/p\u003e\u003cp\u003eWhen the testrig is shut down, all data on it will be deleted.\u003c/p\u003e\u003cp\u003eDon't use this in production!\u003c/p\u003e","short_description":"\u003cp\u003eThis is the GoToSocial testrig. It doesn't federate or anything.\u003c/p\u003e\u003cp\u003eWhen the testrig is shut down, all data on it will be deleted.\u003c/p\u003e\u003cp\u003eDon't use this in production!\u003c/p\u003e","email":"admin@example.org","version":"0.0.0-testrig","registrations":true,"approval_required":true,"invites_enabled":false,"configuration":{"statuses":{"max_characters":5000,"max_media_attachments":6,"characters_reserved_per_url":25},"media_attachments":{"supported_mime_types":["image/jpeg","image/gif","image/png"],"image_size_limit":10485760,"image_matrix_limit":16777216,"video_size_limit":41943040,"video_frame_rate_limit":60,"video_matrix_limit":16777216},"polls":{"max_options":6,"max_characters_per_option":50,"min_expiration":300,"max_expiration":2629746},"accounts":{"allow_custom_css":true},"emojis":{"emoji_size_limit":51200}},"urls":{"streaming_api":"wss://localhost:8080"},"stats":{"domain_count":2,"status_count":16,"user_count":4},"thumbnail":"http://localhost:8080/assets/logo.png","contact_account":{"id":"01F8MH17FWEB39HZJ76B6VXSKF","username":"admin","acct":"admin","display_name":"","locked":false,"bot":false,"created_at":"2022-05-17T13:10:59.000Z","note":"","url":"http://localhost:8080/@admin","avatar":"","avatar_static":"","header":"http://localhost:8080/assets/default_header.png","header_static":"http://localhost:8080/assets/default_header.png","followers_count":1,"following_count":1,"statuses_count":4,"last_status_at":"2021-10-20T10:41:37.000Z","emojis":[],"fields":[]},"max_toot_chars":5000}`, string(b))
+	suite.Equal(`{"uri":"http://localhost:8080","account_domain":"localhost:8080","title":"Geoff's Instance","description":"\u003cp\u003eThis is the GoToSocial testrig. It doesn't federate or anything.\u003c/p\u003e\u003cp\u003eWhen the testrig is shut down, all data on it will be deleted.\u003c/p\u003e\u003cp\u003eDon't use this in production!\u003c/p\u003e","short_description":"\u003cp\u003eThis is the GoToSocial testrig. It doesn't federate or anything.\u003c/p\u003e\u003cp\u003eWhen the testrig is shut down, all data on it will be deleted.\u003c/p\u003e\u003cp\u003eDon't use this in production!\u003c/p\u003e","email":"admin@example.org","version":"0.0.0-testrig","registrations":true,"approval_required":true,"invites_enabled":false,"configuration":{"statuses":{"max_characters":5000,"max_media_attachments":6,"characters_reserved_per_url":25},"media_attachments":{"supported_mime_types":["image/jpeg","image/gif","image/png"],"image_size_limit":10485760,"image_matrix_limit":16777216,"video_size_limit":41943040,"video_frame_rate_limit":60,"video_matrix_limit":16777216},"polls":{"max_options":6,"max_characters_per_option":50,"min_expiration":300,"max_expiration":2629746},"accounts":{"allow_custom_css":true},"emojis":{"emoji_size_limit":51200}},"urls":{"streaming_api":"wss://localhost:8080"},"stats":{"domain_count":2,"status_count":16,"user_count":4},"thumbnail":"http://localhost:8080/assets/logo.png","contact_account":{"id":"01F8MH17FWEB39HZJ76B6VXSKF","username":"admin","acct":"admin","display_name":"","locked":false,"bot":false,"created_at":"2022-05-17T13:10:59.000Z","note":"","url":"http://localhost:8080/@admin","avatar":"","avatar_static":"","header":"http://localhost:8080/assets/default_header.png","header_static":"http://localhost:8080/assets/default_header.png","followers_count":1,"following_count":1,"statuses_count":4,"last_status_at":"2021-10-20T10:41:37.000Z","emojis":[],"fields":[],"enable_rss":true},"max_toot_chars":5000}`, string(b))
 }
 
 func (suite *InstancePatchTestSuite) TestInstancePatch3() {
@@ -123,7 +123,7 @@ func (suite *InstancePatchTestSuite) TestInstancePatch3() {
 	b, err := io.ReadAll(result.Body)
 	suite.NoError(err)
 
-	suite.Equal(`{"uri":"http://localhost:8080","account_domain":"localhost:8080","title":"GoToSocial Testrig Instance","description":"\u003cp\u003eThis is the GoToSocial testrig. It doesn't federate or anything.\u003c/p\u003e\u003cp\u003eWhen the testrig is shut down, all data on it will be deleted.\u003c/p\u003e\u003cp\u003eDon't use this in production!\u003c/p\u003e","short_description":"\u003cp\u003eThis is some html, which is \u003cem\u003eallowed\u003c/em\u003e in short descriptions.\u003c/p\u003e","email":"admin@example.org","version":"0.0.0-testrig","registrations":true,"approval_required":true,"invites_enabled":false,"configuration":{"statuses":{"max_characters":5000,"max_media_attachments":6,"characters_reserved_per_url":25},"media_attachments":{"supported_mime_types":["image/jpeg","image/gif","image/png"],"image_size_limit":10485760,"image_matrix_limit":16777216,"video_size_limit":41943040,"video_frame_rate_limit":60,"video_matrix_limit":16777216},"polls":{"max_options":6,"max_characters_per_option":50,"min_expiration":300,"max_expiration":2629746},"accounts":{"allow_custom_css":true},"emojis":{"emoji_size_limit":51200}},"urls":{"streaming_api":"wss://localhost:8080"},"stats":{"domain_count":2,"status_count":16,"user_count":4},"thumbnail":"http://localhost:8080/assets/logo.png","contact_account":{"id":"01F8MH17FWEB39HZJ76B6VXSKF","username":"admin","acct":"admin","display_name":"","locked":false,"bot":false,"created_at":"2022-05-17T13:10:59.000Z","note":"","url":"http://localhost:8080/@admin","avatar":"","avatar_static":"","header":"http://localhost:8080/assets/default_header.png","header_static":"http://localhost:8080/assets/default_header.png","followers_count":1,"following_count":1,"statuses_count":4,"last_status_at":"2021-10-20T10:41:37.000Z","emojis":[],"fields":[]},"max_toot_chars":5000}`, string(b))
+	suite.Equal(`{"uri":"http://localhost:8080","account_domain":"localhost:8080","title":"GoToSocial Testrig Instance","description":"\u003cp\u003eThis is the GoToSocial testrig. It doesn't federate or anything.\u003c/p\u003e\u003cp\u003eWhen the testrig is shut down, all data on it will be deleted.\u003c/p\u003e\u003cp\u003eDon't use this in production!\u003c/p\u003e","short_description":"\u003cp\u003eThis is some html, which is \u003cem\u003eallowed\u003c/em\u003e in short descriptions.\u003c/p\u003e","email":"admin@example.org","version":"0.0.0-testrig","registrations":true,"approval_required":true,"invites_enabled":false,"configuration":{"statuses":{"max_characters":5000,"max_media_attachments":6,"characters_reserved_per_url":25},"media_attachments":{"supported_mime_types":["image/jpeg","image/gif","image/png"],"image_size_limit":10485760,"image_matrix_limit":16777216,"video_size_limit":41943040,"video_frame_rate_limit":60,"video_matrix_limit":16777216},"polls":{"max_options":6,"max_characters_per_option":50,"min_expiration":300,"max_expiration":2629746},"accounts":{"allow_custom_css":true},"emojis":{"emoji_size_limit":51200}},"urls":{"streaming_api":"wss://localhost:8080"},"stats":{"domain_count":2,"status_count":16,"user_count":4},"thumbnail":"http://localhost:8080/assets/logo.png","contact_account":{"id":"01F8MH17FWEB39HZJ76B6VXSKF","username":"admin","acct":"admin","display_name":"","locked":false,"bot":false,"created_at":"2022-05-17T13:10:59.000Z","note":"","url":"http://localhost:8080/@admin","avatar":"","avatar_static":"","header":"http://localhost:8080/assets/default_header.png","header_static":"http://localhost:8080/assets/default_header.png","followers_count":1,"following_count":1,"statuses_count":4,"last_status_at":"2021-10-20T10:41:37.000Z","emojis":[],"fields":[],"enable_rss":true},"max_toot_chars":5000}`, string(b))
 }
 
 func (suite *InstancePatchTestSuite) TestInstancePatch4() {
@@ -214,7 +214,7 @@ func (suite *InstancePatchTestSuite) TestInstancePatch6() {
 	b, err := io.ReadAll(result.Body)
 	suite.NoError(err)
 
-	suite.Equal(`{"uri":"http://localhost:8080","account_domain":"localhost:8080","title":"GoToSocial Testrig Instance","description":"\u003cp\u003eThis is the GoToSocial testrig. It doesn't federate or anything.\u003c/p\u003e\u003cp\u003eWhen the testrig is shut down, all data on it will be deleted.\u003c/p\u003e\u003cp\u003eDon't use this in production!\u003c/p\u003e","short_description":"\u003cp\u003eThis is the GoToSocial testrig. It doesn't federate or anything.\u003c/p\u003e\u003cp\u003eWhen the testrig is shut down, all data on it will be deleted.\u003c/p\u003e\u003cp\u003eDon't use this in production!\u003c/p\u003e","email":"","version":"0.0.0-testrig","registrations":true,"approval_required":true,"invites_enabled":false,"configuration":{"statuses":{"max_characters":5000,"max_media_attachments":6,"characters_reserved_per_url":25},"media_attachments":{"supported_mime_types":["image/jpeg","image/gif","image/png"],"image_size_limit":10485760,"image_matrix_limit":16777216,"video_size_limit":41943040,"video_frame_rate_limit":60,"video_matrix_limit":16777216},"polls":{"max_options":6,"max_characters_per_option":50,"min_expiration":300,"max_expiration":2629746},"accounts":{"allow_custom_css":true},"emojis":{"emoji_size_limit":51200}},"urls":{"streaming_api":"wss://localhost:8080"},"stats":{"domain_count":2,"status_count":16,"user_count":4},"thumbnail":"http://localhost:8080/assets/logo.png","contact_account":{"id":"01F8MH17FWEB39HZJ76B6VXSKF","username":"admin","acct":"admin","display_name":"","locked":false,"bot":false,"created_at":"2022-05-17T13:10:59.000Z","note":"","url":"http://localhost:8080/@admin","avatar":"","avatar_static":"","header":"http://localhost:8080/assets/default_header.png","header_static":"http://localhost:8080/assets/default_header.png","followers_count":1,"following_count":1,"statuses_count":4,"last_status_at":"2021-10-20T10:41:37.000Z","emojis":[],"fields":[]},"max_toot_chars":5000}`, string(b))
+	suite.Equal(`{"uri":"http://localhost:8080","account_domain":"localhost:8080","title":"GoToSocial Testrig Instance","description":"\u003cp\u003eThis is the GoToSocial testrig. It doesn't federate or anything.\u003c/p\u003e\u003cp\u003eWhen the testrig is shut down, all data on it will be deleted.\u003c/p\u003e\u003cp\u003eDon't use this in production!\u003c/p\u003e","short_description":"\u003cp\u003eThis is the GoToSocial testrig. It doesn't federate or anything.\u003c/p\u003e\u003cp\u003eWhen the testrig is shut down, all data on it will be deleted.\u003c/p\u003e\u003cp\u003eDon't use this in production!\u003c/p\u003e","email":"","version":"0.0.0-testrig","registrations":true,"approval_required":true,"invites_enabled":false,"configuration":{"statuses":{"max_characters":5000,"max_media_attachments":6,"characters_reserved_per_url":25},"media_attachments":{"supported_mime_types":["image/jpeg","image/gif","image/png"],"image_size_limit":10485760,"image_matrix_limit":16777216,"video_size_limit":41943040,"video_frame_rate_limit":60,"video_matrix_limit":16777216},"polls":{"max_options":6,"max_characters_per_option":50,"min_expiration":300,"max_expiration":2629746},"accounts":{"allow_custom_css":true},"emojis":{"emoji_size_limit":51200}},"urls":{"streaming_api":"wss://localhost:8080"},"stats":{"domain_count":2,"status_count":16,"user_count":4},"thumbnail":"http://localhost:8080/assets/logo.png","contact_account":{"id":"01F8MH17FWEB39HZJ76B6VXSKF","username":"admin","acct":"admin","display_name":"","locked":false,"bot":false,"created_at":"2022-05-17T13:10:59.000Z","note":"","url":"http://localhost:8080/@admin","avatar":"","avatar_static":"","header":"http://localhost:8080/assets/default_header.png","header_static":"http://localhost:8080/assets/default_header.png","followers_count":1,"following_count":1,"statuses_count":4,"last_status_at":"2021-10-20T10:41:37.000Z","emojis":[],"fields":[],"enable_rss":true},"max_toot_chars":5000}`, string(b))
 }
 
 func (suite *InstancePatchTestSuite) TestInstancePatch7() {
diff --git a/internal/api/mime.go b/internal/api/mime.go
index b495b059b..d02b64ab0 100644
--- a/internal/api/mime.go
+++ b/internal/api/mime.go
@@ -25,6 +25,7 @@ type MIME string
 const (
 	AppJSON           MIME = `application/json`
 	AppXML            MIME = `application/xml`
+	AppRSSXML         MIME = `application/rss+xml`
 	AppActivityJSON   MIME = `application/activity+json`
 	AppActivityLDJSON MIME = `application/ld+json; profile="https://www.w3.org/ns/activitystreams"`
 	AppForm           MIME = `application/x-www-form-urlencoded`
diff --git a/internal/api/model/account.go b/internal/api/model/account.go
index b085e84e7..f8bb4f4a0 100644
--- a/internal/api/model/account.go
+++ b/internal/api/model/account.go
@@ -92,6 +92,8 @@ type Account struct {
 	Source *Source `json:"source,omitempty"`
 	// CustomCSS to include when rendering this account's profile or statuses.
 	CustomCSS string `json:"custom_css,omitempty"`
+	// Account has enabled RSS feed.
+	EnableRSS bool `json:"enable_rss,omitempty"`
 }
 
 // AccountCreateRequest models account creation parameters.
@@ -155,6 +157,8 @@ type UpdateCredentialsRequest struct {
 	FieldsAttributes *[]UpdateField `form:"fields_attributes" json:"fields_attributes" xml:"fields_attributes"`
 	// Custom CSS to be included when rendering this account's profile or statuses.
 	CustomCSS *string `form:"custom_css" json:"custom_css" xml:"custom_css"`
+	// Enable RSS feed of public toots for this account at /@[username]/feed.rss
+	EnableRSS *bool `form:"enable_rss" json:"enable_rss" xml:"enable_rss"`
 }
 
 // UpdateSource is to be used specifically in an UpdateCredentialsRequest.