using System;
using System.Collections.Generic;
using System.IO;
using Google.Protobuf.WellKnownTypes;
using Sog;


namespace FileTransDataObject
{
    // 待发送的文件数据
    public class FileData
    {
        public int FileSize => fileData == null ? 0 : fileData.Length;

        public string fileName;
        public string fileMd5;
        public byte[] fileData;

        public string readFilePath;    // transNode上文件的读取路径
        public string writeFilePath;   // recvNode上文件的保存路径

        public DateTime fileWriteTime;
    }

    // 文件传输节点: 负责监控recvNode的文件接收状态
    public class FileTransNode
    {
        // 接收文件的host
        public string receiverHost;

        // 节点状态, -1 fail 0 trans 1 succ
        public int state;

        public long lastRecvMsgTime;

        // file name -> file state
        public List<FileRecvState> fileState;

        public FileTransNode()
        {
            fileState = new List<FileRecvState>();
        }
    }



    public class FileUtils
    {
        public static FileData CreateFileData(string filePath, bool loadFile)
        {
            try
            {
                return CreateFileDataInner(filePath, loadFile);
            }
            catch (Exception e)
            {
                TraceLog.Exception(e);
            }

            return null;
        }

        private static FileData CreateFileDataInner(string filePath, bool loadFile)
        {
            byte[] fileData = null;
            string fileMd5;

            if (loadFile)
            {
                // 以共享模式ReadWrite打开, 避免文件被占用
                using (FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
                {
                    fileData = new byte[fs.Length];
                    fs.Read(fileData);

                    fileMd5 = HashHelper.MD5Bytes(fileData);
                }
            }
            else
            {
                fileMd5 = HashHelper.MD5File(filePath);
            }

            // 文件不存在
            if (string.IsNullOrEmpty(fileMd5))
            {
                TraceLog.Error("FileUtils.CreateFileDataInner {0} not exist", filePath);
                return null;
            }

            var file = new FileData();
            file.fileName = Path.GetFileName(filePath);
            file.fileData = fileData;
            file.fileMd5 = fileMd5;
            file.readFilePath = Path.GetDirectoryName(filePath);
            file.fileWriteTime = File.GetLastWriteTimeUtc(filePath);

            return file;
        }
    }
}