diff --git a/HW3_1/server.cpp b/HW3_1/server.cpp
@@ -47,7 +47,6 @@ int main(int argc, char **argv)
     vector<connection_server> listen_file_connections;
     vector<connection_server> download_connections;
 
-    vector<user> users_filelist;
 
     while(true)
     {
@@ -63,8 +62,13 @@ int main(int argc, char **argv)
 
         for(int i = 0; i < new_connections.size(); )
         {
-            new_connections[i].read_from_socket();
-            if(new_connections[i].can_parse_packet())
+            if(new_connections[i].read_from_socket() == 0)
+            {
+                cout << "client close connection.\n";
+                new_connections[i].close_socket();
+                new_connections.erase(new_connections.begin());
+            }
+            else if(new_connections[i].can_parse_packet())
             {
                 cout << "request: " << new_connections[i].get_request_type() << "\n";
                 cout << "username: " << new_connections[i].packet.username << "\n";
@@ -73,13 +77,13 @@ int main(int argc, char **argv)
                 {
                     case CLI_RQ_UPLOAD_CONNECTION:
                         cout << "this is /put session!\n";
-                        main_connections.push_back(new_connections[i]);
+                        upload_connections.push_back(new_connections[i]);
                         //push this connection to client's main session connection
                         break;
                     case CLI_RQ_USERNAME:
-                        cout << "client passs username!\n";
-                        new_connections[i].initialize_filelist(users_filelist);
-                        upload_connections.push_back(new_connections[i]);
+                        cout << "client passs username, this is main session!\n";
+                        new_connections[i].initialize_filelist(users);
+                        main_connections.push_back(new_connections[i]);
                         //push this connection to client's upload session connection
                         break;
                     default:
@@ -100,26 +104,61 @@ int main(int argc, char **argv)
             {
                 string filename = main_connections[i].pop_filename();
                 main_connections[i].set_filename(filename);
-                download_connections.push_back(main_connections[i]);
+                listen_file_connections.push_back(main_connections[i]);
+                //這裡沒開檔，等確定 client 連上新開的 socket 再開
             }
         }
         //this loop let users download their files
 
         for(int i = 0; i < download_connections.size(); i++)
         {
-
+            download_connections[i].write_to_socket();
+            if(download_connections[i].is_write_completely_packet())
+            {
+                cout << "write payload len: " << download_connections[i].get_payload_len() << "\n";
+                download_connections[i].reset_buffer_and_fill_member_from_packet();
+                if(download_connections[i].get_request_type() != SERV_RQ_DOWNFIN)
+                {
+                    download_connections[i].read_payload_from_file();
+                    if(download_connections[i].get_payload_len() == 0)
+                    {
+                        cout << "all file content has been sent to client!\n";
+                        download_connections[i].set_request_type(SERV_RQ_DOWNFIN);
+                    }
+                    else
+                    {
+                        download_connections[i].set_request_type(SERV_RQ_DOWNLOADING);
+                    }
+                    i++;
+                }
+                else
+                {
+                    cout << "close download file!\n";
+                    download_connections[i].close_file();
+                    download_connections[i].close_socket();
+                    download_connections.erase(download_connections.begin() + i);
+                }
+            }
         }
 
-        for(int i = 0; i < upload_connections.size(); i++)
+        for(int i = 0; i < upload_connections.size();)
         {
-            upload_connections[i].read_from_socket();
-            if(upload_connections[i].can_parse_packet())
+            if(upload_connections[i].read_from_socket() == 0)
+            {
+                cout << "client has closed upload session(and main session, but I don't know how to close it using current function)\n";
+                upload_connections[i].close_socket();
+                upload_connections[i].close_file();
+                upload_connections.erase(upload_connections.begin() + i);
+                continue;
+            }
+            else if(upload_connections[i].can_parse_packet())
             {
                 upload_connections[i].reset_buffer_and_fill_member_from_packet();
                 switch(upload_connections[i].get_request_type())
                 {
                     case CLI_RQ_UPLOADFILE:
-                        upload_connections[i].openfile_to_write();
+                        upload_connections[i].openfile_to_write_server();
+                        cout << "server open file to deal with client's /put command\n";
                         break;
                     case CLI_RQ_UPLOADING:
                         if(upload_connections[i].file_is_close())
@@ -129,6 +168,7 @@ int main(int argc, char **argv)
                         else
                         {
                             upload_connections[i].wrtie_payload_to_file();
+                            cout << "write byte: " << upload_connections[i].get_payload_len() << "\n";
                         }
                         break;
                     case CLI_RQ_UPFIN:
@@ -138,13 +178,91 @@ int main(int argc, char **argv)
                         }
                         else
                         {
+                            cout << "server receive all client's file content, close file!\n";
+                            //這時候要把這個新 put 的 file 丟到其他同 username 的 clients
+                            for(int j = 0; j < main_connections.size(); j++)
+                            {
+                                if(upload_connections[i].get_username() == main_connections[j].get_username()
+                                    && upload_connections[i].get_socket_fd() != main_connections[j].get_socket_fd())
+                                {
+                                    cout << "/put socket_fd: " << upload_connections[i].get_socket_fd() << "\n";
+                                    cout << "main socket_fd: " << main_connections[j].get_socket_fd() << "\n";
+                                    main_connections[j].append_file_to_list(upload_connections[i].get_filename());
+                                }
+                            }
+
+                            //在來是更新 users
+                            int username_in_users_flag = 0;
+                            for(int j = 0; j < users.size(); j++)
+                            {
+                                if(upload_connections[i].get_username() == users[j].name);
+                                {
+                                    username_in_users_flag = 1;
+                                    users[j].filelist.push_back(upload_connections[i].get_filename());
+                                    break;
+                                }
+                            }
+                            if(username_in_users_flag == 0)
+                            {
+                                user new_user;
+                                new_user.name = upload_connections[i].get_username();
+                                new_user.filelist.push_back(upload_connections[i].get_filename());
+                            }
+
                             upload_connections[i].close_file();
+                            //關檔案
                         }
                         break;
                 }
             }
+            i++;
         }
         //this loop receive users' /put command
+
+        for (int i = 0; i < listen_file_connections.size(); i++)
+        {
+            switch(listen_file_connections[i].get_download_socket_state())
+            {
+                case FTM_OPEN_LISTEN_SOCKET:
+                    cout << "listen!\n";
+                    listen_file_connections[i].listen(LISTEN_ARBITRARY_PORT);
+                    cout << "WHAT?\n";
+                    listen_file_connections[i].set_sockaddr_by_getsockname();
+                    listen_file_connections[i].set_request_type(SERV_RQ_DOWNLOAD);
+                    listen_file_connections[i].set_download_socket_state(FTM_WRITE_SOCKADDR_TO_CLI);
+                    break;
+                case FTM_WRITE_SOCKADDR_TO_CLI:
+                    listen_file_connections[i].write_to_socket();
+                    if(listen_file_connections[i].is_write_completely_packet())
+                    {
+                        listen_file_connections[i].reset_buffer_and_fill_member_from_packet();
+                        listen_file_connections[i].set_download_socket_state(FTM_LISTEN_CLI);
+                    }
+                    break;
+                case FTM_LISTEN_CLI:
+                    if(listen_file_connections[i].nonblocking_accept() >= 0)
+                    {
+                        //close this particular listening socket
+                        listen_file_connections[i].close_listening_socket();
+                        listen_file_connections[i].openfile_to_read_server();
+
+                        listen_file_connections[i].read_payload_from_file();
+                        listen_file_connections[i].set_request_type(SERV_RQ_DOWNLOADING);
+                        // 一樣是先把 payload 讀進來，這樣 download socket 那個 loop 比較好寫
+
+                        download_connections.push_back(listen_file_connections[i]);
+                        listen_file_connections.erase(listen_file_connections.begin() + i);
+
+                        i--;
+                        // 這個 i-- 跟前面把 element 刪掉是一樣的道理，只是如果這裡不寫 i--，那 i++ 就要分開寫在很多地方ㄌ
+                    }
+            }
+        }
+        /* 1. create listening socket
+         * 2. accepting socket
+         * 3. throw new accepting socket to download connections
+         */ 
+
     }
 }
 /*