laravel schema builder, find columnType autoincrement

I'm working to update an existing database to use autoincremented primary keys. This DB currently has crazy named PK fields with custom values. I need to check each table first to see if it HAS an autoinc field first, then I want to drop it and replace with 'id' field.

I want to do this as a migration, here's what I have so far but I can't seem to identify if the first col is autoincrementing already so I can drop the existing PK and replace. I need to replace the hasColumn with something like a firstColumn then getColumnType...

    foreach ($tableNames as $name)
                if (!Schema::hasColumn($name, 'id')) {
                Schema::table($name, function ($table) {
                    $table->dropPrimary();
                    $table->increments('id')->first();
                });
            }
        }

via Chebli Mohamed