using System;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Threading.Tasks;
using WingInterfaceLibrary.DTO.Report;
using WingServerCommon.Log;

namespace WingAIDiagnosisService.Manage
{
    public class UploadContent : HttpContent
    {
        private const int ChunkSize = 2097152;//2M;

        private readonly Stream _uploadStream;

        private readonly long _fileSize;

        public event EventHandler<double> ProgressChanged;



        public UploadContent(string filePath)
        {
            if (string.IsNullOrWhiteSpace(filePath) || !File.Exists(filePath))
            {
                throw new Exception("UploadFile not find");
            }
            var fileName = Path.GetFileName(filePath);
            _uploadStream = File.Open(filePath, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite);
            var mimeType = FileHelper.GetMimeType(fileName.Substring(fileName.LastIndexOf(".")));
            Headers.ContentType = MediaTypeHeaderValue.Parse(mimeType);
            Headers.ContentLength = _uploadStream.Length;
            _fileSize = _uploadStream.Length;
        }

        public UploadContent(byte[] fileData, MediaTypeHeaderValue mediaTypeHeaderValue)
        {
            if (fileData == null || fileData.Length == 0)
            {
                throw new Exception("FileData is empty");
            }
            _uploadStream = new MemoryStream(fileData);
            Headers.ContentType = mediaTypeHeaderValue;
            Headers.ContentLength = _uploadStream.Length;
            _fileSize = _uploadStream.Length;
        }

        /// <summary>
        /// 将内容写入流
        /// </summary>
        /// <param name="stream"></param>
        /// <param name="context"></param>
        /// <returns></returns>
        protected override async Task SerializeToStreamAsync(Stream stream, TransportContext context)
        {
            for (long i = 0; i < _uploadStream.Length; i += ChunkSize)
            {
                var dataToWrite = new byte[Math.Min(ChunkSize, _uploadStream.Length - i)];
                await _uploadStream.ReadAsync(dataToWrite, 0, dataToWrite.Length);
                await stream.WriteAsync(dataToWrite, 0, dataToWrite.Length);
                OnProgressChanged((double)(i * 100 / _uploadStream.Length));
            }
            OnProgressChanged(100);
        }

        /// <summary>
        /// 比较文件大小
        /// </summary>
        /// <returns></returns>
        public bool CompareFileSizes(long webFileSize)
        {
            return _fileSize == webFileSize;
        }

        protected override bool TryComputeLength(out long length)
        {
            length = _uploadStream.Length;
            return true;
        }

        private void OnProgressChanged(double e)
        {
            ProgressChanged?.Invoke(this, e);
        }

        public new void Dispose()
        {
            base.Dispose();
            _uploadStream.Close();
            ProgressChanged = null;
        }
    }
}