feat: Users API, ownership transfer and removal of the legacy role string

internal/infrastructure/persistence/database/legacyUserRoleBackfill.go

@@ -0,0 +1,94 @@
+package database
+
+import (
+	"RenewCMS/internal/domain/role"
+	entity "RenewCMS/internal/infrastructure/persistence/models"
+
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+)
+
+const (
+	usersTable         = "users"
+	legacyRoleColumn   = "role"
+	legacyOwnerValue   = "owner"
+	legacyAdminValue   = "admin"
+	legacyUnsetValue   = ""
+	unassignedRoleCond = "(role_id IS NULL OR role_id = 0)"
+)
+
+func legacyRoleColumnExists(db *gorm.DB) bool {
+	return db.Migrator().HasColumn(usersTable, legacyRoleColumn)
+}
+
+func requireBuiltInRoleID(tx *gorm.DB, name string) (uint32, error) {
+	id, found, err := builtInRoleID(tx, name)
+	if err != nil {
+		return 0, err
+	}
+	if !found {
+		return 0, role.ErrRoleNotFound
+	}
+	return id, nil
+}
+
+func BackfillLegacyUserRoles(db *gorm.DB) error {
+	if !legacyRoleColumnExists(db) {
+		return nil
+	}
+	return db.Transaction(func(tx *gorm.DB) error {
+		done, err := markerApplied(tx, legacyUserRolesMarker)
+		if err != nil || done {
+			return err
+		}
+		ownerID, err := requireBuiltInRoleID(tx, role.OwnerName)
+		if err != nil {
+			return err
+		}
+		adminID, err := requireBuiltInRoleID(tx, role.AdminName)
+		if err != nil {
+			return err
+		}
+		writerID, err := requireBuiltInRoleID(tx, role.WriterName)
+		if err != nil {
+			return err
+		}
+		legacy := clause.Column{Name: legacyRoleColumn}
+		assign := func(roleID uint32, condition string, args ...any) error {
+			return tx.Table(usersTable).Where(unassignedRoleCond).Where(condition, args...).UpdateColumn("role_id", roleID).Error
+		}
+		var owners []uint32
+		if err := tx.Table(usersTable).Where(unassignedRoleCond).Where("? = ?", legacy, legacyOwnerValue).Order("id asc").Pluck("id", &owners).Error; err != nil {
+			return err
+		}
+		if len(owners) > 0 {
+			if err := assign(ownerID, "id = ?", owners[0]); err != nil {
+				return err
+			}
+		}
+		if err := assign(adminID, "? = ?", legacy, legacyOwnerValue); err != nil {
+			return err
+		}
+		if err := assign(adminID, "? = ?", legacy, legacyAdminValue); err != nil {
+			return err
+		}
+		if len(owners) == 0 {
+			var lowest []uint32
+			if err := tx.Model(&entity.User{}).Order("id asc").Limit(1).Pluck("id", &lowest).Error; err != nil {
+				return err
+			}
+			if len(lowest) > 0 {
+				if err := assign(ownerID, "? = ? AND id = ?", legacy, legacyUnsetValue, lowest[0]); err != nil {
+					return err
+				}
+			}
+		}
+		if err := assign(adminID, "? = ?", legacy, legacyUnsetValue); err != nil {
+			return err
+		}
+		if err := assign(writerID, "1 = 1"); err != nil {
+			return err
+		}
+		return applyMarker(tx, legacyUserRolesMarker)
+	})
+}