save a copy when clearing the log

data/default_config.json

@@ -92,6 +92,7 @@
       "replay_archive_tool": "7z",
       "show_ip": false,
       "show_info": true,
+      "log_save_path": "./config/",
       "password": "123456",
       "port": 7933
     },

ygopro-server.coffee

@@ -2070,6 +2070,11 @@ if settings.modules.http
         return
       else
         response.writeHead(200)
+        if settings.modules.tournament_mode.log_save_path
+          fs.writeFile(settings.modules.tournament_mode.log_save_path + 'duel_log.' + moment().format('YYYY-MM-DD HH-mm-ss') + '.json', JSON.stringify(duel_log, null, 2), (err) ->
+            if err
+              log.warn 'DUEL LOG SAVE ERROR', err
+          )
         duel_log.duel_log = []
         setting_save(duel_log)
         response.end(addCallback(u.query.callback, "[{name:'Success'}]"))

ygopro-server.js

@@ -2630,6 +2630,13 @@
           return;
         } else {
           response.writeHead(200);
+          if (settings.modules.tournament_mode.log_save_path) {
+            fs.writeFile(settings.modules.tournament_mode.log_save_path + 'duel_log.' + moment().format('YYYY-MM-DD HH-mm-ss') + '.json', JSON.stringify(duel_log, null, 2), function(err) {
+              if (err) {
+                return log.warn('DUEL LOG SAVE ERROR', err);
+              }
+            });
+          }
           duel_log.duel_log = [];
           setting_save(duel_log);
           response.end(addCallback(u.query.callback, "[{name:'Success'}]"));