[feature] Implement Filter API v2 (#2936)

* Use correct entity name

* We support server-side filters now

* Document filter v1 methods that can throw a 409

* Validate v1 filter phrase as filter title

* Always check v1 filter API status codes in tests

* Document keyword minimum requirement on filter API v1

* Make it possible to specify filter keyword update columns per filter keyword

* Implement v2 filter API

* Fix lint and tests

* Update Swagger spec

* Fix filter update test

* Update Swagger spec *correctly*

* Update actual files Swagger spec was generated from

* Remove keywords_attributes and statuses_attributes

* Add test for serialization of empty filter

* More helpful messages when object is owned by wrong account

3 files changed, 19 insertions, 10 deletions

diff --git a/internal/db/bundb/filter.go b/internal/db/bundb/filter.go
index d09a5067d..30a8494a7 100644
--- a/internal/db/bundb/filter.go
+++ b/internal/db/bundb/filter.go
@@ -19,6 +19,7 @@ package bundb
 
 import (
 	"context"
+	"errors"
 	"slices"
 	"time"
 
@@ -197,10 +198,14 @@ func (f *filterDB) UpdateFilter(
 	ctx context.Context,
 	filter *gtsmodel.Filter,
 	filterColumns []string,
-	filterKeywordColumns []string,
+	filterKeywordColumns [][]string,
 	deleteFilterKeywordIDs []string,
 	deleteFilterStatusIDs []string,
 ) error {
+	if len(filter.Keywords) != len(filterKeywordColumns) {
+		return errors.New("number of filter keywords must match number of lists of filter keyword columns")
+	}
+
 	updatedAt := time.Now()
 	filter.UpdatedAt = updatedAt
 	for _, filterKeyword := range filter.Keywords {
@@ -214,8 +219,10 @@ func (f *filterDB) UpdateFilter(
 	if len(filterColumns) > 0 {
 		filterColumns = append(filterColumns, "updated_at")
 	}
-	if len(filterKeywordColumns) > 0 {
-		filterKeywordColumns = append(filterKeywordColumns, "updated_at")
+	for i := range filterKeywordColumns {
+		if len(filterKeywordColumns[i]) > 0 {
+			filterKeywordColumns[i] = append(filterKeywordColumns[i], "updated_at")
+		}
 	}
 
 	// Update database.
@@ -229,11 +236,11 @@ func (f *filterDB) UpdateFilter(
 			return err
 		}
 
-		if len(filter.Keywords) > 0 {
+		for i, filterKeyword := range filter.Keywords {
 			if _, err := NewUpsert(tx).
-				Model(&filter.Keywords).
+				Model(filterKeyword).
 				Constraint("id").
-				Column(filterKeywordColumns...).
+				Column(filterKeywordColumns[i]...).
 				Exec(ctx); err != nil {
 				return err
 			}
diff --git a/internal/db/bundb/filter_test.go b/internal/db/bundb/filter_test.go
index 7940b6651..d1249d16b 100644
--- a/internal/db/bundb/filter_test.go
+++ b/internal/db/bundb/filter_test.go
@@ -127,7 +127,7 @@ func (suite *FilterTestSuite) TestFilterCRUD() {
 	}
 	check.Statuses = append(check.Statuses, newStatus)
 
-	if err := suite.db.UpdateFilter(ctx, check, nil, nil, nil, nil); err != nil {
+	if err := suite.db.UpdateFilter(ctx, check, nil, [][]string{nil, nil}, nil, nil); err != nil {
 		t.Fatalf("error updating filter: %v", err)
 	}
 	// Now fetch newly updated filter.
@@ -175,7 +175,7 @@ func (suite *FilterTestSuite) TestFilterCRUD() {
 	check.Keywords = []*gtsmodel.FilterKeyword{filterKeyword}
 	check.Statuses = nil
 
-	if err := suite.db.UpdateFilter(ctx, check, nil, nil, []string{newKeyword.ID}, nil); err != nil {
+	if err := suite.db.UpdateFilter(ctx, check, nil, [][]string{{"whole_word"}}, []string{newKeyword.ID}, nil); err != nil {
 		t.Fatalf("error updating filter: %v", err)
 	}
 	check, err = suite.db.GetFilterByID(ctx, filter.ID)
@@ -222,7 +222,7 @@ func (suite *FilterTestSuite) TestFilterCRUD() {
 		StatusID:  newStatus.StatusID,
 	}
 	check.Statuses = []*gtsmodel.FilterStatus{redundantStatus}
-	if err := suite.db.UpdateFilter(ctx, check, nil, nil, nil, nil); err != nil {
+	if err := suite.db.UpdateFilter(ctx, check, nil, [][]string{nil}, nil, nil); err != nil {
 		t.Fatalf("error updating filter: %v", err)
 	}
 	check, err = suite.db.GetFilterByID(ctx, filter.ID)
diff --git a/internal/db/filter.go b/internal/db/filter.go
index 18943b4f9..eee61a99d 100644
--- a/internal/db/filter.go
+++ b/internal/db/filter.go
@@ -42,11 +42,13 @@ type Filter interface {
 	// and deletes indicated filter keywords and statuses by ID.
 	// It uses a transaction to ensure no partial updates.
 	// The column lists are optional; if not specified, all columns will be updated.
+	// The filter keyword columns list is *per keyword*.
+	// To update all keyword columns, provide a list where every element is an empty list.
 	UpdateFilter(
 		ctx context.Context,
 		filter *gtsmodel.Filter,
 		filterColumns []string,
-		filterKeywordColumns []string,
+		filterKeywordColumns [][]string,
 		deleteFilterKeywordIDs []string,
 		deleteFilterStatusIDs []string,
 	) error