feat: SEO change history

updates/202610270002_create_golem15_seo_revisions.go

@@ -0,0 +1,49 @@
+package updates
+
+import (
+	"github.com/go-gormigrate/gormigrate/v2"
+	"gorm.io/gorm"
+)
+
+// createRevisions creates golem15_seo_revisions: the SEO change history
+// (D-13) with author, via, subject, a readable description and the changed
+// fields before and after; undo marks a change undone.
+var createRevisions = []*gormigrate.Migration{
+	{
+		ID: "202610270002_create_golem15_seo_revisions",
+		Migrate: func(tx *gorm.DB) error {
+			for _, stmt := range []string{
+				`CREATE TABLE golem15_seo_revisions (
+	id BIGSERIAL PRIMARY KEY,
+	batch_id TEXT NULL,
+	author_id BIGINT NULL,
+	author_label TEXT NOT NULL DEFAULT '',
+	via TEXT NOT NULL,
+	subject_kind TEXT NOT NULL,
+	subject_id TEXT NOT NULL DEFAULT '',
+	what TEXT NOT NULL DEFAULT '',
+	before jsonb NULL,
+	after jsonb NULL,
+	undone_at TIMESTAMP(0) NULL,
+	undone_by_id BIGINT NULL,
+	created_at TIMESTAMP(0) NOT NULL DEFAULT NOW()
+)`,
+				`CREATE INDEX golem15_seo_revisions_subject ON golem15_seo_revisions (subject_kind, subject_id)`,
+				`CREATE INDEX golem15_seo_revisions_created ON golem15_seo_revisions (created_at DESC)`,
+				`CREATE INDEX golem15_seo_revisions_batch ON golem15_seo_revisions (batch_id) WHERE batch_id IS NOT NULL`,
+			} {
+				if err := tx.Exec(stmt).Error; err != nil {
+					return err
+				}
+			}
+			return nil
+		},
+		Rollback: func(tx *gorm.DB) error {
+			return tx.Exec(`DROP TABLE IF EXISTS golem15_seo_revisions`).Error
+		},
+	},
+}
+
+func init() {
+	Register(createRevisions...)
+}