Attempt to provide sensible errors on network issues

Currently the add-on works fine if all is well, however various things
can go wrong which makes the add-on bail out with no proper error.

And since the cause of network errors could be anywhere, we do not want
the end-user to have to dig deep into Kodi logs to find probable
suspects.

So we do want to return the exact error message (i.e. Connection
refused, No route to host, etc.) so the user can relate it to other
possible problems. (WIFI issues, Internet down or unreliable, etc.)

Author: dagwieers

resources/language/resource.language.en_gb/strings.po

@@ -918,6 +918,30 @@ msgctxt "#30967"
 msgid "Could not retrieve this program list. VRT Search API url is too long. Unfollowing some favorite programs will reduce url length and may fix this problem."
 msgstr ""
 
+msgctxt "#30968"
+msgid "There is a problem connecting to the Internet. This could be related to Kodi, your network, your ISP or VRT NU.\n\nError: {error}\nURL: {url}"
+msgstr ""
+
+msgctxt "#30969"
+msgid "Unable to open URL"
+msgstr ""
+
+msgctxt "#30971"
+msgid "Install Widevine using 'InputStream Helper' add-on"
+msgstr ""
+
+msgctxt "#30972"
+msgid "Installing Widevine libraries using the 'InputStream Helper' add-on is done at your own risk and the VRT NU add-on is not responsible for any results. Nor is it guaranteed that Widevine will be (re)installed correctly."
+msgstr ""
+
+msgctxt "#30973"
+msgid "Installation of Widevine failed!"
+msgstr ""
+
+msgctxt "#30974"
+msgid "Installation of Widevine completed!"
+msgstr ""
+
 msgctxt "#30975"
 msgid "Failed to get user token from VRT NU"
 msgstr ""

resources/language/resource.language.nl_nl/strings.po

@@ -918,6 +918,30 @@ msgctxt "#30967"
 msgid "Could not retrieve this program list. VRT Search API url is too long. Unfollowing some favorite programs will reduce url length and may fix this problem."
 msgstr "Deze programmalijst kan niet opgehaald worden. VRT Search API url is te lang. Enkele favoriete programma's vergeten zal de lengte van de URL verminderen en dit probleem mogelijk oplossen."
 
+msgctxt "#30968"
+msgid "There is a problem connecting to the Internet. This could be related to Kodi, your network, your ISP or VRT NU.\n\nError: {error}\nURL: {url}"
+msgstr "Er is een fout opgetreden met het Internet gebruik. Dit kan liggen aan Kodi, aan jouw netwerk, aan jouw ISP of aan VRT NU.\n\nFout: {error}\nURL: {url}"
+
+msgctxt "#30969"
+msgid "Unable to open URL"
+msgstr "Probleem bij het openen van een URL"
+
+msgctxt "#30971"
+msgid "Install Widevine using 'InputStream Helper' add-on"
+msgstr "Installeer Widevine met de 'InputStream Helper' add-on"
+
+msgctxt "#30972"
+msgid "Installing Widevine libraries using the 'InputStream Helper' add-on is done at your own risk and the VRT NU add-on is not responsible for any results. Nor is it guaranteed that Widevine will be (re)installed correctly."
+msgstr "Het installeren van de Widevine bestanden met de 'InputStream Helper' add-on is op eigen risico en de VRT NU add-on is niet verantwoordelijk voor enig resultaat. Ook wordt het niet gegarandeerd dat Widevine succesvol kan worden geinstalleerd."
+
+msgctxt "#30973"
+msgid "Installation of Widevine failed!"
+msgstr "Widevine installatie mislukt!"
+
+msgctxt "#30974"
+msgid "Installation of Widevine completed!"
+msgstr "Widevine installatie gelukt"
+
 msgctxt "#30975"
 msgid "Failed to get user token from VRT NU"
 msgstr "Ophalen van het gebruikerstoken van VRT NU is mislukt"

resources/lib/tokenresolver.py

@@ -11,11 +11,12 @@
 
 try:  # Python 3
     import http.cookiejar as cookielib
-    from urllib.parse import urlencode, unquote
-    from urllib.request import build_opener, install_opener, ProxyHandler, HTTPCookieProcessor, HTTPErrorProcessor, urlopen, Request
+    from urllib.error import URLError
+    from urllib.parse import unquote, urlencode
+    from urllib.request import HTTPCookieProcessor, HTTPErrorProcessor, ProxyHandler, Request, build_opener, install_opener, urlopen
 except ImportError:  # Python 2
     from urllib import urlencode
-    from urllib2 import build_opener, install_opener, ProxyHandler, HTTPCookieProcessor, HTTPErrorProcessor, unquote, urlopen, Request
+    from urllib2 import HTTPCookieProcessor, HTTPErrorProcessor, ProxyHandler, Request, URLError, build_opener, install_opener, unquote, urlopen
     import cookielib
 
 
@@ -234,9 +235,17 @@ def _get_new_user_xvrttoken(self):
         cookiejar = cookielib.CookieJar()
         opener = build_opener(HTTPCookieProcessor(cookiejar), ProxyHandler(self._proxies))
         log(2, 'URL get: {url}', url=unquote(self._USER_TOKEN_GATEWAY_URL))
-        opener.open(self._USER_TOKEN_GATEWAY_URL)
+        try:
+            opener.open(self._USER_TOKEN_GATEWAY_URL)
+        except URLError as exc:
+            ok_dialog(heading=localize(30963), message=localize(30964, error=exc, url=unquote(self._USER_TOKEN_GATEWAY_URL)))
+            raise
         log(2, 'URL post: {url}', url=unquote(self._VRT_LOGIN_URL))
-        opener.open(self._VRT_LOGIN_URL, data=data)
+        try:
+            opener.open(self._VRT_LOGIN_URL, data=data)
+        except URLError as exc:
+            ok_dialog(heading=localize(30963), message=localize(30964, error=exc, url=unquote(self._VRT_LOGIN_URL)))
+            raise
         xvrttoken = TokenResolver._create_token_dictionary(cookiejar)
         refreshtoken = TokenResolver._create_token_dictionary(cookiejar, cookie_name='vrtlogin-rt')
         if xvrttoken is None:
@@ -256,7 +265,11 @@ def _get_fresh_token(self, refresh_token, token_name, token_variant=None):
         opener = build_opener(HTTPCookieProcessor(cookiejar), ProxyHandler(self._proxies))
         log(2, 'URL get: {url}', url=refresh_url)
         req = Request(refresh_url, headers=headers)
-        opener.open(req)
+        try:
+            opener.open(req)
+        except URLError as exc:
+            ok_dialog(heading=localize(30963), message=localize(30964, error=exc, url=req.full_url))
+            raise
         token = TokenResolver._create_token_dictionary(cookiejar, token_name)
         if token is None:
             return None
@@ -270,7 +283,11 @@ def _get_roaming_xvrttoken(self, xvrttoken):
         opener = build_opener(NoRedirection, ProxyHandler(self._proxies))
         log(2, 'URL get: {url}', url=unquote(self._ROAMING_TOKEN_GATEWAY_URL))
         req = Request(self._ROAMING_TOKEN_GATEWAY_URL, headers=headers)
-        req_info = opener.open(req).info()
+        try:
+            req_info = opener.open(req).info()
+        except URLError as exc:
+            ok_dialog(heading=localize(30963), message=localize(30964, error=exc, url=req.full_url))
+            raise
         try:  # Python 3
             cookie_value += '; state=' + req_info.get('Set-Cookie').split('state=')[1].split('; ')[0]
         except AttributeError:  # Python 2
@@ -279,20 +296,29 @@ def _get_roaming_xvrttoken(self, xvrttoken):
         else:
             url = req_info.get('Location')
         log(2, 'URL get: {url}', url=unquote(url))
-        try:  # Python 3
-            url = opener.open(url).info().get('Location')
-        except AttributeError:  # Python 2
-            url = opener.open(url).info().getheader('Location')
-        headers = {'Cookie': cookie_value}
+        try:
+            try:  # Python 3
+                url = opener.open(url).info().get('Location')
+            except AttributeError:  # Python 2
+                url = opener.open(url).info().getheader('Location')
+        except URLError as exc:
+            ok_dialog(heading=localize(30963), message=localize(30964, error=exc, url=url))
+            raise
+
         if url is None:
             return None
 
+        headers = {'Cookie': cookie_value}
         log(2, 'URL get: {url}', url=unquote(url))
         req = Request(url, headers=headers)
-        try:  # Python 3
-            setcookie_header = opener.open(req).info().get('Set-Cookie')
-        except AttributeError:  # Python 2
-            setcookie_header = opener.open(req).info().getheader('Set-Cookie')
+        try:
+            try:  # Python 3
+                setcookie_header = opener.open(req).info().get('Set-Cookie')
+            except AttributeError:  # Python 2
+                setcookie_header = opener.open(req).info().getheader('Set-Cookie')
+        except URLError as exc:
+            ok_dialog(heading=localize(30963), message=localize(30964, error=exc, url=req.full_url))
+            raise
         return TokenResolver._create_token_dictionary(setcookie_header)
 
     @staticmethod