using System;
using System.Collections.Generic;

namespace HanvonF710XAttendanceService
{
    internal sealed class MachineUserDeleteItem
    {
        public MachineUserDeleteItem(string serialNumber, string deviceEnrollId)
        {
            SerialNumber = serialNumber ?? "";
            DeviceEnrollId = deviceEnrollId ?? "";
        }

        public string SerialNumber { get; }
        public string DeviceEnrollId { get; }
    }

    internal static class MachineUserDeleteBatcher
    {
        public static int CountBatches(int itemCount, int batchSize)
        {
            if (itemCount <= 0)
            {
                return 0;
            }

            int size = batchSize > 0 ? batchSize : MachineUserDeleteSettings.DefaultBatchSize;
            return (itemCount + size - 1) / size;
        }

        public static List<List<T>> SplitIntoBatches<T>(IReadOnlyList<T> items, int batchSize)
        {
            var batches = new List<List<T>>();
            if (items == null || items.Count == 0)
            {
                return batches;
            }

            int size = batchSize > 0 ? batchSize : MachineUserDeleteSettings.DefaultBatchSize;
            for (int i = 0; i < items.Count; i += size)
            {
                int take = Math.Min(size, items.Count - i);
                var batch = new List<T>(take);
                for (int j = 0; j < take; j++)
                {
                    batch.Add(items[i + j]);
                }

                batches.Add(batch);
            }

            return batches;
        }
    }
}