Calibre: Log errors on wireless connection failures (#9914)

Also, get rid of the weird and clunky `failed_connect_callback` thingy, because it makes no sense?

Re: #9908

frontend/ui/message/streammessagequeue.lua

@@ -17,7 +17,7 @@ function StreamMessageQueue:start()
     self.socket = czmq.zsocket_new(self.context, C.ZMQ_STREAM)
     self.poller = czmq.zpoller_new(self.socket, nil)
     local endpoint = string.format("tcp://%s:%d", self.host, self.port)
-    logger.warn("connect to endpoint", endpoint)
+    logger.dbg("connecting to endpoint", endpoint)
     local rc = czmq.zsocket_connect(self.socket, endpoint)
     if rc ~= 0 then
         error("cannot connect to " .. endpoint)

plugins/calibre.koplugin/wireless.lua

@@ -111,7 +111,7 @@ function CalibreWireless:find_calibre_server()
             if dgram and host then
                 -- replied diagram has greet message from calibre and calibre hostname
                 -- calibre opds port and calibre socket port we will later connect to
-                local _, _, _, replied_port = dgram:match("(.-)%(on (.-)%);(.-),(.-)$")
+                local _, _, replied_port = dgram:match("calibre wireless device client %(on (.-)%);(%d+),(%d+)$")
                 return host, replied_port
             end
         end
@@ -122,13 +122,13 @@ function CalibreWireless:checkCalibreServer(host, port)
     local socket = require("socket")
     local tcp = socket.tcp()
     tcp:settimeout(5)
-    local client = tcp:connect(host, port)
     -- In case of error, the method returns nil followed by a string describing the error. In case of success, the method returns 1.
-    if client then
+    local ok, err = tcp:connect(host, port)
+    if ok then
         tcp:close()
         return true
     end
-    return false
+    return false, err
 end
 
 -- Standard JSON/control opcodes receive callback
@@ -146,12 +146,15 @@ function CalibreWireless:JSONReceiveCallback(host, port)
                     msg = _("Invalid password")
                     this.invalid_password = nil
                     this:disconnect()
+                    logger.warn("invalid password, disconnecting")
                 elseif this.disconnected_by_server then
                     msg = _("Disconnected by calibre")
                     this.disconnected_by_server = nil
+                    logger.info("disconnected by calibre")
                 else
                     msg = T(_("Connected to calibre server at %1"),
                         BD.ltr(T("%1:%2", this.calibre_socket.host, this.calibre_socket.port)))
+                    logger.info("connected successfully")
                 end
                 UIManager:show(InfoMessage:new{
                     text = msg,
@@ -160,10 +163,6 @@ function CalibreWireless:JSONReceiveCallback(host, port)
             end
             this.connect_message = true
             UIManager:scheduleIn(1, this.password_check_callback)
-            if this.failed_connect_callback then
-                -- Don't disconnect if we connect in 10 seconds
-                UIManager:unschedule(this.failed_connect_callback)
-            end
         end
     end
 end
@@ -179,7 +178,7 @@ function CalibreWireless:initCalibreMQ(host, port)
         self.calibre_socket:start()
         self.calibre_messagequeue = UIManager:insertZMQ(self.calibre_socket)
     end
-    logger.info("connected to calibre", host, port)
+    logger.info(string.format("connecting to calibre @ %s:%s", host, port))
 end
 
 -- will callback initCalibreMQ if inbox is confirmed to be set
@@ -234,26 +233,36 @@ function CalibreWireless:connect()
     end
 
     self.connect_message = false
-    local host, port
+    local address_type, host, port, ok, err
     if G_reader_settings:hasNot("calibre_wireless_url") then
         host, port = self:find_calibre_server()
+        if host and port then
+            address_type = "discovered"
+        else
+            ok = false
+            err = _("Couldn't discover a calibre instance on the local network")
+            address_type = "unavailable"
+        end
     else
         local calibre_url = G_reader_settings:readSetting("calibre_wireless_url")
         host, port = calibre_url["address"], calibre_url["port"]
-        if not self:checkCalibreServer(host, port) then
-            host = nil
-        else
-            self.failed_connect_callback = function()
-                UIManager:show(InfoMessage:new{
-                    text = _("Cannot connect to calibre server."),
-                })
-                self:disconnect()
-            end
-            -- wait 10 seconds to connect to calibre
-            UIManager:scheduleIn(10, self.failed_connect_callback)
-        end
+        address_type = "specified"
     end
+
     if host and port then
+        ok, err = self:checkCalibreServer(host, port)
+    end
+
+    if not ok then
+        host = host or "????"
+        port = port or "??"
+        err = err or _("N/A")
+        logger.warn(string.format("Cannot connect to %s calibre server at %s:%s (%s)", address_type, host, port, err))
+        UIManager:show(InfoMessage:new{
+            text = T(_("Cannot connect to calibre server at %1 (%2)"),
+                        BD.ltr(T("%1:%2", host, port)), err)
+        })
+    else
         local inbox_dir = G_reader_settings:readSetting("inbox_dir")
         if inbox_dir then
             CalibreMetadata:init(inbox_dir)
@@ -261,17 +270,11 @@ function CalibreWireless:connect()
         else
             self:setInboxDir(host, port)
         end
-    else
-        logger.info("cannot connect to calibre server")
-        UIManager:show(InfoMessage:new{
-            text = _("Cannot connect to calibre server."),
-        })
-        return
     end
 end
 
 function CalibreWireless:disconnect()
-    logger.info("disconnect from calibre")
+    logger.info("disconnecting from calibre")
     self.connect_message = false
     if self.calibre_socket then
         self.calibre_socket:stop()