from __pyjamas__ import JS, wnd
from pyjamas import Window
from pyjamas.Timer import Timer
from browser_side import dialog
from sat.core.i18n import _

TIMER_DELAY = 5000


class Notification(object):
    """
    If the browser supports it, the user allowed it to and the tab is in the
    background, send desktop notifications on messages.

    Requires both Web Notifications and Page Visibility API.
    """

    def __init__(self):
        self.enabled = False
        user_agent = None
        notif_permission = None
        JS("""
        if (!('hidden' in document))
            document.hidden = false;

        user_agent = navigator.userAgent

        if (!('Notification' in window))
            return;

        notif_permission = Notification.permission

        if (Notification.permission === 'granted')
            this.enabled = true;

        else if (Notification.permission === 'default') {
            Notification.requestPermission(function(permission){
                if (permission !== 'granted')
                    return;

                self.enabled = true; //need to use self instead of this
            });
        }
        """)

        if "Chrome" in user_agent and notif_permission not in ['granted', 'denied']:
            self.user_agent = user_agent
            self._installChromiumWorkaround()

        wnd().onfocus = self.onFocus
        # wnd().onblur = self.onBlur
        self._notif_count = 0
        self._orig_title = Window.getTitle()

    def _installChromiumWorkaround(self):
        # XXX: Workaround for Chromium behaviour, it's doens't manage requestPermission on onLoad event
        # see https://code.google.com/p/chromium/issues/detail?id=274284
        # FIXME: need to be removed if Chromium behaviour changes
        try:
            version_full = [s for s in self.user_agent.split() if "Chrome" in s][0].split('/')[1]
            version = int(version_full.split('.')[0])
        except (IndexError, ValueError):
            print "Can't find Chromium version"
            version = 0
        print "Chromium version: %d" % (version,)
        if version < 22:
            print "Notification use the old prefixed version or are unmanaged"
            return
        if version < 32:
            dialog.InfoDialog(_("Notifications activation for Chromium"), _('You need to activate notifications manually for your Chromium version.<br/>To activate notifications, click on the favicon on the left of the address bar')).show()
            return

        print "==> Installing Chromium notifications request workaround <=="
        self._old_click = wnd().onclick
        wnd().onclick = self._chromiumWorkaround

    def _chromiumWorkaround(self):
        print "Activating workaround"
        JS("""
            Notification.requestPermission(function(permission){
                if (permission !== 'granted')
                    return;
                self.enabled = true; //need to use self instead of this
            });
        """)
        wnd().onclick = self._old_click

    def onFocus(self):
        Window.setTitle(self._orig_title)
        self._notif_count = 0

    # def onBlur(self):
    #     pass

    def isHidden(self):
        JS("""return document.hidden;""")

    def _notify(self, title, body, icon):
        if not self.enabled:
            return
        notification = None
        JS("""
           notification = new Notification(title, {body: body, icon: icon});
           // Probably won’t work, but it doesn’t hurt to try.
           notification.addEventListener('click', function() {
               window.focus();
           });
           """)
        notification.onshow = lambda: Timer(TIMER_DELAY, lambda timer: notification.close())

    def highlightTab(self):
        self._notif_count += 1
        Window.setTitle("%s (%d)" % (self._orig_title, self._notif_count))

    def notify(self, title, body, icon='/media/icons/apps/48/sat.png'):
        if self.isHidden():
            self._notify(title, body, icon)
            self.highlightTab()