using System;
using System.Reflection;
using HarmonyLib;
using Minio.DataModel;
using Minio.Exceptions;

namespace Hopetry.Provider
{
    public class PartSizeOverride
    {
        private static Harmony _harmony;

        /// <summary>
        /// 使用Harmony动态替换MinIO的分片计算逻辑
        /// </summary>
        public static void OverrideMinioCalculator()
        {
            try
            {
                // 初始化Harmony实例
                _harmony = new Harmony("com.hopetry.minio.patch");

                // 获取原始方法和自定义方法
                var originalMethod = typeof(Minio.Helper.Utils).GetMethod(
                    "CalculateMultiPartSize",
                    BindingFlags.Static | BindingFlags.Public,
                    null,
                    new[] { typeof(long), typeof(bool) },
                    null);

                var customMethod = typeof(PartSizeOverride).GetMethod(
                    "CustomCalculateMultiPartSize",
                    BindingFlags.Static | BindingFlags.NonPublic);

                if (originalMethod == null || customMethod == null)
                    throw new InvalidOperationException("Method not found");

                // 应用Harmony补丁（替换原始方法）
                _harmony.Patch(originalMethod,
                    new HarmonyMethod(customMethod));

                Console.WriteLine("Method override successful");
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Override failed: {ex.Message}");
                throw;
            }
        }

        /// <summary>
        /// 自定义分片计算逻辑（需严格匹配原始方法签名）
        /// </summary>
        private static bool CustomCalculateMultiPartSize(ref MultiPartInfo __result, long size, bool copy)
        {
            // 原计算逻辑保持不变
            long MaxParts = 10000;
            long MinimumPartSize = 5 * 1024L * 1024L;
            long MinimumPUTPartSize = 16 * 1024L * 1024L;
            long MaximumStreamObjectSize = MaxParts * MinimumPartSize;
            long MaxMultipartPutObjectSize = 1024L * 1024L * 1024L * 1024L * 5;
            if (size == -1) size = MaximumStreamObjectSize;
            long MinimumCOPYPartSize = 512 * 1024L * 1024L;

            if (size > MaxMultipartPutObjectSize)
                throw new EntityTooLargeException(
                    $"Your proposed upload size {size} exceeds the maximum allowed object size {MaxMultipartPutObjectSize}");

            var partSize = (double)Math.Ceiling((decimal)size / MaxParts);
            var minPartSize = copy ? MinimumCOPYPartSize : MinimumPartSize;
            partSize = (double)Math.Ceiling((decimal)partSize / minPartSize) * minPartSize;
            var partCount = Math.Ceiling(size / partSize);
            var lastPartSize = size - ((partCount - 1) * partSize);

            __result = new MultiPartInfo
            {
                PartSize = partSize,
                PartCount = partCount,
                LastPartSize = lastPartSize
            };

            // 跳过原始方法执行
            return false;
        }
    }
}