"""
Select Provider Page, used in First Run Wizard
"""
from functools import partial
import logging

import requests

from PyQt4 import QtCore
from PyQt4 import QtGui

from leap.base import exceptions as baseexceptions
#from leap.crypto import certs
from leap.eip import exceptions as eipexceptions

from leap.gui.constants import APP_LOGO
from leap.gui.progress import InlineValidationPage
from leap.gui import styles
from leap.util.web import get_https_domain_and_port

logger = logging.getLogger(__name__)

# XXX check newer version in progress...


def delay(obj, method_str):
    """
    this is a hack to get responsiveness in the ui
    """
    QtCore.QTimer().singleShot(
        10,
        lambda: QtCore.QMetaObject.invokeMethod(
            obj, method_str))


class SelectProviderPage(InlineValidationPage):

    #disableCheckButton = QtCore.pyqtSignal()
    launchChecks = QtCore.pyqtSignal()

    def __init__(self, parent=None, providers=None):
        super(SelectProviderPage, self).__init__(parent)

        self.setTitle(self.tr("Enter Provider"))
        self.setSubTitle(self.tr(
            "Please enter the domain of the provider you want "
            "to use for your connection.")
        )
        self.setPixmap(
            QtGui.QWizard.LogoPixmap,
            QtGui.QPixmap(APP_LOGO))

        self.did_cert_check = False
        self.current_page = 'providerselection'

        self.is_done = False

        self.setupSteps()
        self.setupUI()

        self.launchChecks.connect(
            self.launch_checks)

        self.providerNameEdit.editingFinished.connect(
            lambda: self.providerCheckButton.setFocus(True))

    def setupUI(self):
        """
        initializes the UI
        """
        providerNameLabel = QtGui.QLabel("h&ttps://")
        # note that we expect the bare domain name
        # we will add the scheme later
        providerNameEdit = QtGui.QLineEdit()
        providerNameEdit.cursorPositionChanged.connect(
            self.reset_validation_status)
        providerNameLabel.setBuddy(providerNameEdit)

        # add regex validator
        providerDomainRe = QtCore.QRegExp(r"^[a-z\d_-.]+$")
        providerNameEdit.setValidator(
            QtGui.QRegExpValidator(providerDomainRe, self))
        self.providerNameEdit = providerNameEdit

        # Eventually we will seed a list of
        # well known providers here.

        #providercombo = QtGui.QComboBox()
        #if providers:
            #for provider in providers:
                #providercombo.addItem(provider)
        #providerNameSelect = providercombo

        self.registerField("provider_domain*", self.providerNameEdit)
        #self.registerField('provider_name_index', providerNameSelect)

        validationMsg = QtGui.QLabel("")
        validationMsg.setStyleSheet(styles.ErrorLabelStyleSheet)
        self.validationMsg = validationMsg
        providerCheckButton = QtGui.QPushButton(self.tr("chec&k!"))
        self.providerCheckButton = providerCheckButton

        # cert info

        # this is used in the callback
        # for the checkbox changes.
        # tricky, since the first time came
        # from the exception message.
        # should get string from exception too!
        self.bad_cert_status = self.tr(
            "Server certificate could not be verified.")

        self.certInfo = QtGui.QLabel("")
        self.certInfo.setWordWrap(True)
        self.certWarning = QtGui.QLabel("")
        self.trustProviderCertCheckBox = QtGui.QCheckBox(
            "&Trust this provider certificate.")

        self.trustProviderCertCheckBox.stateChanged.connect(
            self.onTrustCheckChanged)
        self.providerNameEdit.textChanged.connect(
            self.onProviderChanged)
        self.providerCheckButton.clicked.connect(
            self.onCheckButtonClicked)

        layout = QtGui.QGridLayout()
        layout.addWidget(validationMsg, 0, 2)
        layout.addWidget(providerNameLabel, 1, 1)
        layout.addWidget(providerNameEdit, 1, 2)
        layout.addWidget(providerCheckButton, 1, 3)

        # add certinfo group
        # XXX not shown now. should move to validation box.
        #layout.addWidget(certinfoGroup, 4, 1, 4, 2)
        #self.certinfoGroup = certinfoGroup
        #self.certinfoGroup.hide()

        # add validation frame
        self.setupValidationFrame()
        layout.addWidget(self.valFrame, 4, 2, 4, 2)
        self.valFrame.hide()

        self.setLayout(layout)

    # certinfo

    def setupCertInfoGroup(self):
        # XXX not used now.
        certinfoGroup = QtGui.QGroupBox(
            self.tr("Certificate validation"))
        certinfoLayout = QtGui.QVBoxLayout()
        certinfoLayout.addWidget(self.certInfo)
        certinfoLayout.addWidget(self.certWarning)
        certinfoLayout.addWidget(self.trustProviderCertCheckBox)
        certinfoGroup.setLayout(certinfoLayout)
        self.certinfoGroup = self.certinfoGroup

    # progress frame

    def setupValidationFrame(self):
        qframe = QtGui.QFrame
        valFrame = qframe()
        valFrame.setFrameStyle(qframe.NoFrame)
        valframeLayout = QtGui.QVBoxLayout()
        zeros = (0, 0, 0, 0)
        valframeLayout.setContentsMargins(*zeros)

        valframeLayout.addWidget(self.stepsTableWidget)
        valFrame.setLayout(valframeLayout)
        self.valFrame = valFrame

    @QtCore.pyqtSlot()
    def onDisableCheckButton(self):
        print 'CHECK BUTTON DISABLED!!!'
        self.providerCheckButton.setDisabled(True)

    @QtCore.pyqtSlot()
    def launch_checks(self):
        self.do_checks()

    def onCheckButtonClicked(self):
        QtCore.QMetaObject.invokeMethod(
            self, "onDisableCheckButton")

        QtCore.QMetaObject.invokeMethod(
            self, "showStepsFrame")

        delay(self, "launch_checks")

    def _do_checks(self):
        """
        generator that yields actual checks
        that are executed in a separate thread
        """

        wizard = self.wizard()
        curpage = "providerselection"

        full_domain = self.providerNameEdit.text()

        # we check if we have a port in the domain string.
        domain, port = get_https_domain_and_port(full_domain)
        _domain = u"%s:%s" % (domain, port) if port != 443 else unicode(domain)

        netchecker = wizard.netchecker()

        providercertchecker = wizard.providercertchecker()
        eipconfigchecker = wizard.eipconfigchecker(domain=_domain)

        def fail():
            self.is_done = False
            return False

        yield(("head_sentinel", 0), lambda: None)

        ########################
        # 1) try name resolution
        ########################

        def namecheck():
            """
            in which we check if
            we are able to name resolve
            this domain
            """
            try:
                netchecker.check_name_resolution(
                    domain)

            except baseexceptions.LeapException as exc:
                logger.error(exc.message)
                wizard.set_validation_error(
                    curpage, exc.usermessage)
                return fail()

            except Exception as exc:
                wizard.set_validation_error(
                    curpage, exc.message)
                return fail()

            else:
                return True

        logger.debug('checking name resolution')
        yield(("check name", 20), namecheck)

        #########################
        # 2) try https connection
        #########################

        def httpscheck():
            """
            in which we check
            if the provider
            is offering service over
            https
            """
            try:
                providercertchecker.is_https_working(
                    "https://%s" % _domain,
                    verify=True)

            except eipexceptions.HttpsBadCertError as exc:
                logger.debug('exception')
                # XXX skipping for now...
                ##############################################
                # We had this validation logic
                # in the provider selection page before
                ##############################################
                #if self.trustProviderCertCheckBox.isChecked():
                    #pass
                #else:
                wizard.set_validation_error(
                    curpage, exc.usermessage)
                #fingerprint = certs.get_cert_fingerprint(
                    #domain=domain, sep=" ")

                # it's ok if we've trusted this fgprt before
                #trustedcrts = wizard.trusted_certs
                #if trustedcrts and \
                # fingerprint.replace(' ', '') in trustedcrts:
                    #pass
                #else:
                    # let your user face panick :P
                    #self.add_cert_info(fingerprint)
                    #self.did_cert_check = True
                    #self.completeChanged.emit()
                    #return False
                return fail()

            except baseexceptions.LeapException as exc:
                wizard.set_validation_error(
                    curpage, exc.usermessage)
                return fail()

            except Exception as exc:
                wizard.set_validation_error(
                    curpage, exc.message)
                return fail()

            else:
                return True

        logger.debug('checking https connection')
        yield(("https check", 40), httpscheck)

        ##################################
        # 3) try download provider info...
        ##################################

        def fetchinfo():
            try:
                # XXX we already set _domain in the initialization
                # so it should not be needed here.
                eipconfigchecker.fetch_definition(domain=_domain)
                wizard.set_providerconfig(
                    eipconfigchecker.defaultprovider.config)
            except requests.exceptions.SSLError:
                # XXX we should have catched this before.
                # but cert checking is broken.
                wizard.set_validation_error(
                    curpage,
                    self.tr(
                        "Could not get info from provider."))
                return fail()
            except requests.exceptions.ConnectionError:
                wizard.set_validation_error(
                    curpage,
                    self.tr(
                        "Could not download provider info "
                        "(refused conn.)."))
                return fail()

            except Exception as exc:
                wizard.set_validation_error(
                    curpage, exc.message)
                return fail()

            else:
                return True

        yield(("fetch info", 80), fetchinfo)

        # done!

        self.is_done = True
        yield(("end_sentinel", 100), lambda: None)

    def _inline_validation_ready(self):
        """
        called after _do_checks has finished.
        """
        self.domain_checked = True
        self.completeChanged.emit()
        # let's set focus...
        if self.is_done:
            self.wizard().clean_validation_error(self.current_page)
            nextbutton = self.wizard().button(QtGui.QWizard.NextButton)
            nextbutton.setFocus()
        else:
            self.providerNameEdit.setFocus()

    # cert trust verification
    # (disabled for now)

    def is_insecure_cert_trusted(self):
        return self.trustProviderCertCheckBox.isChecked()

    def onTrustCheckChanged(self, state):
        checked = False
        if state == 2:
            checked = True

        if checked:
            self.reset_validation_status()
        else:
            self.set_validation_status(self.bad_cert_status)

        # trigger signal to redraw next button
        self.completeChanged.emit()

    def add_cert_info(self, certinfo):
        self.certWarning.setText(
            "Do you want to <b>trust this provider certificate?</b>")
        self.certInfo.setText(
            'SHA-256 fingerprint: <i>%s</i><br>' % certinfo)
        self.certInfo.setWordWrap(True)
        self.certinfoGroup.show()

    def onProviderChanged(self, text):
        self.is_done = False
        provider = self.providerNameEdit.text()
        if provider:
            self.providerCheckButton.setDisabled(False)
        else:
            self.providerCheckButton.setDisabled(True)
        self.completeChanged.emit()

    def reset_validation_status(self):
        """
        empty the validation msg
        and clean the inline validation widget.
        """
        self.validationMsg.setText('')
        self.steps.removeAllSteps()
        self.clearTable()
        self.domain_checked = False

    # pagewizard methods

    def isComplete(self):
        provider = self.providerNameEdit.text()

        if not self.is_done:
            return False

        if not provider:
            return False
        else:
            if self.is_insecure_cert_trusted():
                return True
            if not self.did_cert_check:
                if self.is_done:
                    # XXX sure?
                    return True
            return False

    def populateErrors(self):
        # XXX could move this to ValidationMixin
        # with some defaults for the validating fields
        # (now it only allows one field, manually specified)

        #logger.debug('getting errors')
        errors = self.wizard().get_validation_error(
            self.current_page)
        if errors:
            bad_str = getattr(self, 'bad_string', None)
            cur_str = self.providerNameEdit.text()
            showerr = self.validationMsg.setText
            markred = lambda: self.providerNameEdit.setStyleSheet(
                styles.ErrorLineEdit)
            umarkrd = lambda: self.providerNameEdit.setStyleSheet(
                styles.RegularLineEdit)
            if bad_str is None:
                # first time we fall here.
                # save the current bad_string value
                self.bad_string = cur_str
                showerr(errors)
                markred()
            else:
                # not the first time
                # XXX hey, this is getting convoluted.
                # roll out this.
                # but be careful about all the possibilities
                # with going back and forth once you
                # enter a domain.
                if cur_str == bad_str:
                    showerr(errors)
                    markred()
                else:
                    if not getattr(self, 'domain_checked', None):
                        showerr('')
                        umarkrd()
                    else:
                        self.bad_string = cur_str
                        showerr(errors)

    def cleanup_errormsg(self):
        """
        we reset bad_string to None
        should be called before leaving the page
        """
        self.bad_string = None
        self.domain_checked = False

    def paintEvent(self, event):
        """
        we hook our populate errors
        on paintEvent because we need it to catch
        when user enters the page coming from next,
        and initializePage does not cover that case.
        Maybe there's a better event to hook upon.
        """
        super(SelectProviderPage, self).paintEvent(event)
        self.populateErrors()

    def initializePage(self):
        self.validationMsg.setText('')
        if hasattr(self, 'certinfoGroup'):
            # XXX remove ?
            self.certinfoGroup.hide()
        self.is_done = False
        self.providerCheckButton.setDisabled(True)
        self.valFrame.hide()
        self.steps.removeAllSteps()
        self.clearTable()

    def validatePage(self):
        # some cleanup before we leave the page
        self.cleanup_errormsg()

        # go
        return True

    def nextId(self):
        wizard = self.wizard()
        if not wizard:
            return
        return wizard.get_page_index('providerinfo')