#!/usr/bin/env python3

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# *
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import gi

gi.require_version("Gtk", "3.0")
from gi.repository import Gtk, GObject, GLib

import os
import os.path
import sys

# Prevent loading PyXML
import xml
xml.__path__ = [x for x in xml.__path__ if "_xmlplus" not in x]

import xml.sax

from zenmapGUI.higwidgets.higdialogs import HIGAlertDialog
from zenmapGUI.higwidgets.higboxes import HIGVBox, HIGHBox, \
    hig_box_space_holder
from zenmapGUI.higwidgets.higlabels import HIGSectionLabel
from zenmapGUI.higwidgets.higtables import HIGTable
from zenmapGUI.higwidgets.higbuttons import HIGButton

from zenmapCore.NmapParser import NmapParser
from zenmapCore.UmitLogging import log
import zenmapCore.I18N  # lgtm[py/unused-import]
import zenmapCore.Diff

from zenmapGUI.FileChoosers import ResultsFileSingleChooserDialog

# In milliseconds.
NDIFF_CHECK_TIMEOUT = 200


class ScanChooser(HIGVBox):
    """This class allows the selection of scan results from the list of open
    tabs or from a file. It emits the "changed" signal when the scan selection
    has changed."""

    __gsignals__ = {
        "changed": (GObject.SignalFlags.RUN_FIRST, GObject.TYPE_NONE, ())
    }

    def __init__(self, scans, title):
        HIGVBox.__init__(self)

        self.title = title
        self.scan_dict = {}

        # Setting HIGVBox
        self.set_border_width(5)
        self.set_spacing(6)

        self._create_widgets()
        self._pack_hbox()
        self._attaching_widgets()
        self._set_scrolled()
        self._set_text_view()
        self._set_open_button()

        for scan in scans:
            self.add_scan(scan.scan_name or scan.get_nmap_command(), scan)

        self.combo_scan.connect('changed', self.show_scan)
        self.combo_scan.connect('changed', lambda x: self.emit('changed'))

        self._pack_noexpand_nofill(self.lbl_scan)
        self._pack_expand_fill(self.hbox)

    def _create_widgets(self):
        self.lbl_scan = HIGSectionLabel(self.title)
        self.hbox = HIGHBox()
        self.table = HIGTable()
        self.combo_scan = Gtk.ComboBoxText.new_with_entry()
        self.btn_open_scan = Gtk.Button.new_from_stock(Gtk.STOCK_OPEN)
        self.exp_scan = Gtk.Expander.new(_("Scan Output"))
        self.scrolled = Gtk.ScrolledWindow()
        self.txt_scan_result = Gtk.TextView()
        self.txg_tag = Gtk.TextTag.new("scan_style")

    def get_buffer(self):
        return self.txt_scan_result.get_buffer()

    def show_scan(self, widget):
        nmap_output = self.get_nmap_output()
        if nmap_output:
            self.txt_scan_result.get_buffer().set_text(nmap_output)

    def normalize_output(self, output):
        return "\n".join(output.split("\\n"))

    def _pack_hbox(self):
        self.hbox._pack_noexpand_nofill(hig_box_space_holder())
        self.hbox._pack_expand_fill(self.table)

    def _attaching_widgets(self):
        self.table.attach(self.combo_scan, 0, 1, 0, 1, yoptions=0)
        self.table.attach(
            self.btn_open_scan, 1, 2, 0, 1, yoptions=0, xoptions=0)
        self.table.attach(self.exp_scan, 0, 2, 1, 2)

    def _set_scrolled(self):
        self.scrolled.set_border_width(5)
        self.scrolled.set_size_request(-1, 130)

        # Packing scrolled window into expander
        self.exp_scan.add(self.scrolled)

        # Packing text view into scrolled window
        self.scrolled.add_with_viewport(self.txt_scan_result)

        # Setting scrolled window
        self.scrolled.set_policy(Gtk.PolicyType.AUTOMATIC, Gtk.PolicyType.AUTOMATIC)

    def _set_text_view(self):
        self.txg_table = self.txt_scan_result.get_buffer().get_tag_table()
        self.txg_table.add(self.txg_tag)
        self.txg_tag.set_property("family", "Monospace")

        self.txt_scan_result.set_wrap_mode(Gtk.WrapMode.WORD)
        self.txt_scan_result.set_editable(False)
        self.txt_scan_result.get_buffer().connect(
            "changed", self._text_changed_cb)

    def _set_open_button(self):
        self.btn_open_scan.connect('clicked', self.open_file)

    def open_file(self, widget):
        file_chooser = ResultsFileSingleChooserDialog(_("Select Scan Result"))

        response = file_chooser.run()
        file_chosen = file_chooser.get_filename()
        file_chooser.destroy()
        if response == Gtk.ResponseType.OK:
            try:
                parser = NmapParser()
                parser.parse_file(file_chosen)
            except xml.sax.SAXParseException as e:
                alert = HIGAlertDialog(
                    message_format='<b>%s</b>' % _('Error parsing file'),
                    secondary_text=_(
                        "The file is not an Nmap XML output file. "
                        "The parsing error that occurred was\n%s") % str(e))
                alert.run()
                alert.destroy()
                return False
            except Exception as e:
                alert = HIGAlertDialog(
                    message_format='<b>%s</b>' % _(
                        'Cannot open selected file'),
                    secondary_text=_("""\
                        This error occurred while trying to open the file:
                        %s""") % str(e))
                alert.run()
                alert.destroy()
                return False

            scan_name = os.path.split(file_chosen)[-1]
            self.add_scan(scan_name, parser)

            self.combo_scan.set_active(len(self.combo_scan.get_model()) - 1)

    def add_scan(self, scan_name, parser):
        scan_id = 1
        new_scan_name = scan_name
        while new_scan_name in self.scan_dict.keys():
            new_scan_name = "%s (%s)" % (scan_name, scan_id)
            scan_id += 1

        self.combo_scan.append_text(new_scan_name)
        self.scan_dict[new_scan_name] = parser

    def _text_changed_cb(self, widget):
        buff = self.txt_scan_result.get_buffer()
        buff.apply_tag(
            self.txg_tag, buff.get_start_iter(), buff.get_end_iter())

    def get_parsed_scan(self):
        """Return the currently selected scan's parsed output as an NmapParser
        object, or None if no valid scan is selected."""
        selected_scan = self.combo_scan.get_active_text()
        return self.scan_dict.get(selected_scan)

    def get_nmap_output(self):
        """Return the currently selected scan's output as a string, or None if
        no valid scan is selected."""
        if self.parsed_scan is not None:
            return self.parsed_scan.get_nmap_output()
        else:
            return None

    nmap_output = property(get_nmap_output)
    parsed_scan = property(get_parsed_scan)


class DiffWindow(Gtk.Window):
    def __init__(self, scans):
        Gtk.Window.__init__(self)
        self.set_title(_("Compare Results"))
        self.ndiff_process = None
        # We allow the user to start a new diff before the old one has
        # finished.  We have to keep references to old processes until they
        # finish to avoid problems when tearing down the Python interpreter at
        # program exit.
        self.old_processes = []
        self.timer_id = None

        self.main_vbox = HIGVBox()
        self.diff_view = DiffView()
        self.diff_view.set_size_request(-1, 100)
        self.hbox_buttons = HIGHBox()
        self.progress = Gtk.ProgressBar()
        self.btn_close = HIGButton(stock=Gtk.STOCK_CLOSE)
        self.hbox_selection = HIGHBox()
        self.scan_chooser_a = ScanChooser(scans, _("A Scan"))
        self.scan_chooser_b = ScanChooser(scans, _("B Scan"))

        self._pack_widgets()
        self._connect_widgets()

        self.set_default_size(-1, 500)

        # Initial Size Request
        self.initial_size = self.get_size()

    def _pack_widgets(self):
        self.main_vbox.set_border_width(6)

        self.hbox_selection.pack_start(self.scan_chooser_a, True, True, 0)
        self.hbox_selection.pack_start(self.scan_chooser_b, True, True, 0)

        self.main_vbox.pack_start(self.hbox_selection, False, True, 0)

        scroll = Gtk.ScrolledWindow()
        scroll.set_policy(Gtk.PolicyType.AUTOMATIC, Gtk.PolicyType.AUTOMATIC)
        scroll.add(self.diff_view)
        self.main_vbox.pack_start(scroll, True, True, 0)

        self.progress.hide()
        self.progress.set_no_show_all(True)
        self.hbox_buttons.pack_start(self.progress, False, True, 0)
        self.hbox_buttons.pack_end(self.btn_close, False, True, 0)

        self.main_vbox._pack_noexpand_nofill(self.hbox_buttons)

        self.add(self.main_vbox)

    def _connect_widgets(self):
        self.connect("delete-event", self.close)
        self.btn_close.connect("clicked", self.close)
        self.scan_chooser_a.connect('changed', self.refresh_diff)
        self.scan_chooser_b.connect('changed', self.refresh_diff)

    def refresh_diff(self, widget):
        """This method is called whenever the diff output might have changed,
        such as when a different scan was selected in one of the choosers."""
        log.debug("Refresh diff.")

        if (self.ndiff_process is not None and
                self.ndiff_process.poll() is None):
            # Put this in the list of old processes we keep track of.
            self.old_processes.append(self.ndiff_process)
            self.ndiff_process = None

        scan_a = self.scan_chooser_a.parsed_scan
        scan_b = self.scan_chooser_b.parsed_scan

        if scan_a is None or scan_b is None:
            self.diff_view.clear()
        else:
            try:
                self.ndiff_process = zenmapCore.Diff.ndiff(scan_a, scan_b)
            except OSError as e:
                alert = HIGAlertDialog(
                    message_format=_("Error running ndiff"),
                    secondary_text=_(
                        "There was an error running the ndiff program.\n\n"
                        ) + str(e))
                alert.run()
                alert.destroy()
            else:
                self.progress.show()
                if self.timer_id is None:
                    self.timer_id = GLib.timeout_add(
                        NDIFF_CHECK_TIMEOUT, self.check_ndiff_process)

    def check_ndiff_process(self):
        """Check if the ndiff subprocess is done and show the diff if it is.
        Also remove any finished processes from the old process list."""
        # Check if any old background processes have finished.
        for p in self.old_processes[:]:
            if p.poll() is not None:
                p.close()
                self.old_processes.remove(p)

        if self.ndiff_process is not None:
            # We're running the most recent scan. Check if it's done.
            status = self.ndiff_process.poll()

            if status is None:
                # Keep calling this function on a timer until the process
                # finishes.
                self.progress.pulse()
                return True

            if status == 0 or status == 1:
                # Successful completion.
                try:
                    diff = self.ndiff_process.get_scan_diff()
                except zenmapCore.Diff.NdiffParseException as e:
                    alert = HIGAlertDialog(
                        message_format=_("Error parsing ndiff output"),
                        secondary_text=str(e))
                    alert.run()
                    alert.destroy()
                else:
                    self.diff_view.show_diff(diff)
            else:
                # Unsuccessful completion.
                error_text = _(
                    "The ndiff process terminated with status code %d."
                    ) % status
                if self.ndiff_process.stderr:
                    stderr = self.ndiff_process.stderr.read()
                    if len(stderr) > 0:
                        error_text += "\n\n" + stderr
                alert = HIGAlertDialog(
                    message_format=_("Error running ndiff"),
                    secondary_text=error_text)
                alert.run()
                alert.destroy()

            self.progress.hide()
            self.ndiff_process.close()
            self.ndiff_process = None

        if len(self.old_processes) > 0:
            # Keep calling this callback.
            return True
        else:
            # All done.
            self.timer_id = None
            return False

    def close(self, widget=None, extra=None):
        self.destroy()


class DiffView(Gtk.TextView):
    REMOVE_COLOR = "#ffaaaa"
    ADD_COLOR = "#ccffcc"

    """A widget displaying a zenmapCore.Diff.ScanDiff."""
    def __init__(self):
        Gtk.TextView.__init__(self)
        self.set_editable(False)

        buff = self.get_buffer()
        # Create text markup tags.
        buff.create_tag("=", font="Monospace")
        buff.create_tag(
            "-", font="Monospace", background=self.REMOVE_COLOR)
        buff.create_tag("+", font="Monospace", background=self.ADD_COLOR)

    def clear(self):
        self.get_buffer().set_text("")

    def show_diff(self, diff):
        self.clear()
        buff = self.get_buffer()
        for line in diff.splitlines(True):
            if line.startswith("-"):
                tags = ["-"]
            elif line.startswith("+"):
                tags = ["+"]
            else:
                tags = ["="]
            buff.insert_with_tags_by_name(buff.get_end_iter(), line, *tags)

if __name__ == "__main__":
    from zenmapCore.NmapParser import NmapParser

    parsed1 = NmapParser()
    parsed2 = NmapParser()
    parsed3 = NmapParser()
    parsed4 = NmapParser()

    parsed1.parse_file("test/xml_test1.xml")
    parsed2.parse_file("test/xml_test2.xml")
    parsed3.parse_file("test/xml_test3.xml")
    parsed4.parse_file("test/xml_test4.xml")

    dw = DiffWindow({"Parsed 1": parsed1,
                     "Parsed 2": parsed2,
                     "Parsed 3": parsed3,
                     "Parsed 4": parsed4})

    dw.show_all()
    dw.connect("delete-event", lambda x, y: Gtk.main_quit())

    Gtk.main()
