using Microsoft.VisualBasic.Devices;

namespace ECommon.Storage
{
    public class ChunkUtil
    {
        public struct ChunkApplyMemoryInfo
        {
            public ulong PhysicalMemoryMB;
            public ulong UsedMemoryPercent;
            public ulong UsedMemoryMB;
            public ulong MaxAllowUseMemoryMB;
            public ulong ChunkSizeMB;
            public ulong AvailableMemoryMB;
        }
        public static bool IsMemoryEnoughToCacheChunk(ulong chunkSize, uint maxUseMemoryPercent, out ChunkApplyMemoryInfo applyMemoryInfo)
        {
            applyMemoryInfo = new ChunkApplyMemoryInfo();

            uint bytesPerMB = 1024 * 1024;
            var computerInfo = new ComputerInfo();
            var usedMemory = computerInfo.TotalPhysicalMemory - computerInfo.AvailablePhysicalMemory;

            applyMemoryInfo.PhysicalMemoryMB = computerInfo.TotalPhysicalMemory / bytesPerMB;
            applyMemoryInfo.AvailableMemoryMB = computerInfo.AvailablePhysicalMemory / bytesPerMB;
            applyMemoryInfo.UsedMemoryMB = usedMemory / bytesPerMB;
            applyMemoryInfo.UsedMemoryPercent = applyMemoryInfo.UsedMemoryMB * 100 / applyMemoryInfo.PhysicalMemoryMB;
            applyMemoryInfo.ChunkSizeMB = chunkSize / bytesPerMB;
            applyMemoryInfo.MaxAllowUseMemoryMB = applyMemoryInfo.PhysicalMemoryMB * maxUseMemoryPercent / 100;
            return applyMemoryInfo.UsedMemoryMB + applyMemoryInfo.ChunkSizeMB <= applyMemoryInfo.MaxAllowUseMemoryMB;
        }
        public static bool IsMemoryEnoughToCacheChunk(ulong chunkSize, uint maxUseMemoryPercent)
        {
            var computerInfo = new ComputerInfo();
            var maxAllowUseMemory = computerInfo.TotalPhysicalMemory * maxUseMemoryPercent / 100;
            var currentUsedMemory = computerInfo.TotalPhysicalMemory - computerInfo.AvailablePhysicalMemory;

            return currentUsedMemory + chunkSize <= maxAllowUseMemory;
        }
        /// <summary>获取当前使用的物理内存百分比
        /// </summary>
        /// <returns></returns>
        public static ulong GetUsedMemoryPercent()
        {
            var computerInfo = new ComputerInfo();
            var usedPhysicalMemory = computerInfo.TotalPhysicalMemory - computerInfo.AvailablePhysicalMemory;
            var usedMemoryPercent = usedPhysicalMemory * 100 / computerInfo.TotalPhysicalMemory;
            return usedMemoryPercent;
        }
    }
}