import os, os.path
import sys
import time
import traceback

from PyQt4.QtCore import *
from PyQt4.QtGui import *

from distutils.version import LooseVersion
from sfa.util.version import version_core

import sface.screens
from sface.config import config
from sface.logwindow import LogWindow
from sface.rspecwindow import RSpecWindow, ResourcesWindow
from sface.screens.sfascreen import SfaScreen
from sface.xmlrpcwindow import get_tracker, init_tracker

MINIMUM_SFA_VERSION = "1.0-37"

# depending on the platform..
# could probably use Qt's resource system but looks overkill for just one file...
def locate_image_file (filename):
    for dir in [ '/usr/share', '/Applications/sface.app/Contents/Resources/sface' ] :
        for suffix in ['png','jpg']:
            attempt=os.path.join(dir,'images',"%s.%s"%(filename,suffix))
            if os.path.isfile(attempt) : return attempt
    return os.path.join('/could/not/locate/image/file',filename)

def load_screens(dirname):
    modnames = []
    for fn in os.listdir(dirname):
        if not fn.endswith(".py"):
            continue
        modname = fn.rsplit(".py",1)[0]
        if modname == "sfascreen":
            # ignore this, it's the base class, not a screen
            continue
        modnames.append(modname)

    # we want the stock screens to show up in a specific order. plugins can
    # show up in any order afterward.

    sort_order = ["mainscreen", "userscreen", "configscreen", "helpscreen"]
    sort_order.reverse()
    for modname in sort_order:
        if modname in modnames:
            modnames.remove(modname)
            modnames.insert(0,modname)

    # import each module and find whatever class(es) is descendant from
    # SfaScreen within the module. Might be a better idea to just define a
    # screens=[] variable in each module

    screens = []
    for modname in modnames:
        try:
            mod = __import__("sface.screens." + modname, fromlist=["modname"])
        except:
            print "Exception while importing screen", modname
            traceback.print_exc()
            continue

        for object in dir(mod):
            object = getattr(mod, object)
            if hasattr(object, "__bases__") and sface.screens.sfascreen.SfaScreen in object.__bases__:
                screens.append(object)

    return screens

def check_version():
    sfa_version = version_core()['code_tag']
    if (LooseVersion(sfa_version) < LooseVersion(MINIMUM_SFA_VERSION)):
        QMessageBox.warning(None, "Old SFA Version", "sfa version %s is required. "
                                                         "Your installed version is %s. "
                                                         "Please upgrade your sfa and sfa-client packages."
                                                         % (MINIMUM_SFA_VERSION, sfa_version) )
        sys.exit(-1)

class Nav(QWidget):
    def __init__(self, screens, parent=None):
        QWidget.__init__(self, parent)

        self.title = QLabel("", self)
        scene=QGraphicsScene()
        pixmap = QPixmap(locate_image_file('graphic-sfa64'))
        logolabel=QLabel("",self)
        logolabel.setPixmap(pixmap)

        hlayout = QHBoxLayout()
        hlayout.addWidget(logolabel)
        hlayout.addWidget(self.title)
        hlayout.addStretch()
        gotolabel=QLabel("Go to: ", self)
        gotolabel.setAlignment(Qt.AlignRight)
        hlayout.addWidget(gotolabel)

        self.screenLabels = []
        for screen in screens:
            label = QLabel(screen.getLinkText(), self)
            label.setAlignment(Qt.AlignRight)
            self.screenLabels.append(label)
            hlayout.addWidget(label)

        self.setLayout(hlayout)

    def setTitle(self, title):
        self.title.setText(title)


class Status(QLabel):
    def __init__(self, parent=None):
        QLabel.__init__(self, "", parent)
        self.setMaximumWidth(640)
        self.sliceUpdateDate()

    def set(self, msg, timeout):
        self.setText(msg)
        if timeout:
            QTimer.singleShot(timeout, self.reset)

    def sliceUpdateDate(self):
        rspec_file = config.getSliceRSpecFile()
        if not os.path.exists(rspec_file):
            return

        creation_time = os.stat(rspec_file).st_ctime
        last_update = time.ctime(creation_time)
        self.set("Slice data last refreshed on %s" % last_update, timeout=None)

    def reset(self):
        self.setText("")
        QTimer.singleShot(1500, self.sliceUpdateDate)


class MainWindow(QWidget):
    def __init__(self, parent=None):
        QWidget.__init__(self, parent)

        check_version()

        # These are top-level windows and should be initialized with parent set
        # to our parent. Otherwise, getting a segfault on exit in Ubuntu.
        self.logWindow = LogWindow(parent)
        self.rspecWindow = RSpecWindow(parent)
        self.resourcesWindow = ResourcesWindow(parent)
        self.trackerWindow = init_tracker(parent)

        self.pix = QLabel(self)

        screenClasses = load_screens(os.path.dirname(sface.screens.__file__))
        self.screenWidgets = []

        self.screens = QStackedWidget(self)
        for screen in screenClasses:
            # use a try/catch block to isolate the screen. Third-party plugins
            # could be buggy.
            try:
                screenWidget = screen(self)
                self.screenWidgets.append(screenWidget)
                self.screens.addWidget(screenWidget)
            except:
                print "Exception while creating screen", screen.__name__
                traceback.print_exc()

        self.screens.addWidget(self.pix)
        self.next_screen = None

        self.nav = Nav(self.screenWidgets, self)

        if self.screenWidgets:
            self.nav.setTitle(self.screenWidgets[0].getTitleText())

        self.status = Status(self)
        self.tracker = QLabel("<a href='showtracker'>Xmlrpc</a>", self)
        self.log = QLabel("<a href='showlog'>Log</a>", self)
        self.rspec = QLabel("<a href='showlog'>RSpec</a>", self)
        self.resources = QLabel("<a href='showlog'>Resources</a>", self)

        hlayout = QHBoxLayout()
        hlayout.addWidget(self.status)
        hlayout.addStretch()
        hlayout.addWidget(self.tracker)
        hlayout.addWidget(self.rspec)
        hlayout.addWidget(self.resources)
        hlayout.addWidget(self.log)

        layout = QVBoxLayout()
        layout.addWidget(self.nav)
        layout.addWidget(self.screens)
        layout.addLayout(hlayout)
        self.setLayout(layout)
        self.resize(800, 500)

        for link in self.nav.screenLabels:
            self.connect(link, SIGNAL('linkActivated(QString)'),
                         self.animateToScreen)

        self.connect(self.tracker, SIGNAL('linkActivated(QString)'),
                     self.showTrackerWindow)
        self.connect(self.log, SIGNAL('linkActivated(QString)'),
                     self.showLogWindow)
        self.connect(self.rspec, SIGNAL('linkActivated(QString)'),
                     self.showRSpecWindow)
        self.connect(self.resources, SIGNAL('linkActivated(QString)'),
                     self.showResourcesWindow)

    def redirectOutputToLog(self):
        self.logWindow.redirectOutput()

    def showTrackerWindow(self):
        tracker = get_tracker()
        tracker.show()
        tracker.resize(500, 640)
        tracker.raise_()
        tracker.activateWindow()

    def showLogWindow(self, link):
        self.logWindow.show()
        self.logWindow.resize(800, 200)
        self.logWindow.raise_()
        self.logWindow.activateWindow()

    def showRSpecWindow(self, link):
        self.rspecWindow.show()
        self.rspecWindow.resize(500, 640)
        self.rspecWindow.raise_()
        self.rspecWindow.activateWindow()

    def showResourcesWindow(self, link):
        self.resourcesWindow.show()
        self.resourcesWindow.resize(500, 640)
        self.resourcesWindow.raise_()
        self.resourcesWindow.activateWindow()

    def animatePixmap(self, y):
        self.pix.move(0, y)

    def animateToScreen(self, link):
        for screen in self.screenWidgets:
            if link == screen.name:
                self.next_screen = screen

        curr_screen = self.screens.currentWidget()

        if self.next_screen == curr_screen:
            self.setStatus("Already showing %s" % curr_screen.getTitleText(), timeout=1000)
            return

        # This is an optimization to have a smoother animation. We
        # render the widget into a pixmap and animate that instead of
        # moving the whole widget around.
        pixmap = QPixmap(self.screens.size())
        curr_screen.render(pixmap)
        self.screens.setCurrentWidget(self.pix)
        self.pix.setPixmap(pixmap)

        timeLine = QTimeLine(500, self)
        timeLine.setFrameRange(0, self.screens.height());
        self.connect(timeLine, SIGNAL('frameChanged(int)'), self.animatePixmap)
        self.connect(timeLine, SIGNAL('finished()'), self.toNextScreen)
        timeLine.start()

    def toNextScreen(self):
        self.screens.setCurrentWidget(self.next_screen)
        self.nav.setTitle(self.next_screen.getTitleText())

    def setStatus(self, msg, timeout):
        self.status.set(msg, timeout)

    def nodeSelectionChanged(self, hostname):
        if self.rspecWindow.isVisible():
            self.rspecWindow.showNode(hostname)

    def closeEvent(self, event):
        # give the screens an opportunity to veto the close
        for screen in self.screenWidgets:
            if not screen.canClose():
                event.ignore()
                return

        # give the screens an opportunity to close gracefully
        for screen in self.screenWidgets:
            screen.mainWindowClose()

        QWidget.closeEvent(self, event)