﻿// Licensed to the Apache Software Foundation (ASF) under one or more
// contributor license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// The ASF licenses this file to You under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with
// the License.  You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

using System.Collections.Generic;
using Apache.Arrow.Memory;

namespace Apache.Arrow
{
    public static class ArrowArrayConcatenator
    {
        public static IArrowArray Concatenate(IReadOnlyList<IArrowArray> arrowArrayList, MemoryAllocator allocator = default)
        {
            if (arrowArrayList == null || arrowArrayList.Count == 0)
            {
                return null;
            }

            if (arrowArrayList.Count == 1)
            {
                return arrowArrayList[0];
            }

            var arrayDataList = new List<ArrayData>(arrowArrayList.Count);

            foreach (IArrowArray array in arrowArrayList)
            {
                arrayDataList.Add(array.Data);
            }

            return ArrowArrayFactory.BuildArray(ArrayDataConcatenator.Concatenate(arrayDataList, allocator));
        }
    }
}