[feature] support blur filter action (#4371)

This pull request implements the `blur` value of `filter_action` for status filtering. It was introduced by Mastodon 4.4.0. [Related docs update](https://github.com/mastodon/documentation/pull/1620)

Signed-off-by: nicole mikołajczyk <git@mkljczk.pl>
Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4371
Reviewed-by: kim <gruf@noreply.codeberg.org>
Co-authored-by: nicole mikołajczyk <git@mkljczk.pl>
Co-committed-by: nicole mikołajczyk <git@mkljczk.pl>

internal/api/model/filterv2.go

@@ -69,6 +69,8 @@ const (
 	FilterActionWarn FilterAction = "warn"
 	// FilterActionHide filters will remove this status from API results.
 	FilterActionHide FilterAction = "hide"
+	// FilterActionBlur filters will include this status in API results indicating the media attachments should be hidden/blurred.
+	FilterActionBlur FilterAction = "blur"
 )
 
 // FilterKeyword represents text to filter within a v2 filter.

internal/filter/status/api.go

@@ -100,6 +100,8 @@ func toAPIFilterAction(m gtsmodel.FilterAction) apimodel.FilterAction {
 		return apimodel.FilterActionWarn
 	case gtsmodel.FilterActionHide:
 		return apimodel.FilterActionHide
+	case gtsmodel.FilterActionBlur:
+		return apimodel.FilterActionBlur
 	}
 	return apimodel.FilterActionNone
 }

internal/filter/status/status.go

@@ -208,8 +208,8 @@ func (f *Filter) getStatusFilterResults(
 		var apiResult *apimodel.FilterResult
 
 		switch filter.Action {
-		case gtsmodel.FilterActionWarn:
+		case gtsmodel.FilterActionWarn, gtsmodel.FilterActionBlur:
-			// For filter action WARN get all possible filter matches against status.
+			// For filter action WARN or BLUR get all possible filter matches against status.
 			keywordMatches, statusMatches := getFilterMatches(filter, status.ID, fields)
 			if len(keywordMatches) == 0 && len(statusMatches) == 0 {
 				continue

internal/gtsmodel/filter.go

@@ -205,6 +205,10 @@ const (
 	// FilterActionHide means that the status should
 	// be removed from timeline results entirely.
 	FilterActionHide FilterAction = 2
+
+	// FilterActionWarn means that the status should
+	// be shown with its media attachments hidden/blurred.
+	FilterActionBlur FilterAction = 3
 )
 
 // String returns human-readable form of FilterAction.
@@ -216,6 +220,8 @@ func (act FilterAction) String() string {
 		return "warn"
 	case FilterActionHide:
 		return "hide"
+	case FilterActionBlur:
+		return "blur"
 	default:
 		panic(fmt.Sprintf("invalid filter action: %d", act))
 	}

internal/typeutils/frontendtointernal.go

@@ -70,6 +70,8 @@ func APIFilterActionToFilterAction(m apimodel.FilterAction) gtsmodel.FilterActio
 		return gtsmodel.FilterActionWarn
 	case apimodel.FilterActionHide:
 		return gtsmodel.FilterActionHide
+	case apimodel.FilterActionBlur:
+		return gtsmodel.FilterActionBlur
 	}
 	return gtsmodel.FilterActionNone
 }

internal/typeutils/internaltofrontend.go

@@ -2500,6 +2500,8 @@ func filterActionToAPIFilterAction(m gtsmodel.FilterAction) apimodel.FilterActio
 		return apimodel.FilterActionWarn
 	case gtsmodel.FilterActionHide:
 		return apimodel.FilterActionHide
+	case gtsmodel.FilterActionBlur:
+		return apimodel.FilterActionBlur
 	}
 	return apimodel.FilterActionNone
 }

internal/validate/formvalidation.go

@@ -383,14 +383,16 @@ func FilterContexts(contexts []apimodel.FilterContext) error {
 func FilterAction(action apimodel.FilterAction) error {
 	switch action {
 	case apimodel.FilterActionWarn,
-		apimodel.FilterActionHide:
+		apimodel.FilterActionHide,
+		apimodel.FilterActionBlur:
 		return nil
 	}
 	return fmt.Errorf(
-		"filter action '%s' was not recognized, valid options are '%s', '%s'",
+		"filter action '%s' was not recognized, valid options are '%s', '%s', '%s'",
 		action,
 		apimodel.FilterActionWarn,
 		apimodel.FilterActionHide,
+		apimodel.FilterActionBlur,
 	)
 }