from PyQt5 import QtWidgets

from androguard.gui.helpers import Signature
from androguard.gui.xrefwindow import XrefDialogClass

import logging
log = logging.getLogger("androguard.gui")


class HashableQTreeWidgetItem(QtWidgets.QTreeWidgetItem):
    # TODO this is a pure workaround to have a hash method!
    # It seems that for python2 is __hash__ available
    # But not on python3
    def __hash__(self):
        return hash(self.__str__())


class TreeWindow(QtWidgets.QTreeWidget):
    def __init__(self, parent=None, win=None, session=None):
        super().__init__(parent)
        self.itemDoubleClicked.connect(self.itemDoubleClickedHandler)
        self.mainwin = win
        self.session = session
        self.createActions()
        self.header().close()
        self.root_path_node = ({}, self)

        self.setupCaches()

    def setupCaches(self):
        self._reverse_cache = {}

    def fill(self):
        """Parse all the paths (['Lcom/example/myclass/MyActivity$1;', ...])
           and build a tree using the QTreeWidgetItem insertion method."""
        log.debug("Fill classes tree")

        for idx, filename, digest, classes in self.session.get_classes():
            for c in sorted(classes, key=lambda c: c.name):
                sig = Signature(c)
                path_node = self.root_path_node

                path = None
                if not sig.class_path:
                    path = '.'
                    if path not in path_node[0]:
                        path_node[0][path] = (
                            {}, HashableQTreeWidgetItem(path_node[1]))
                        path_node[0][path][1].setText(0, path)
                    path_node = path_node[0][path]
                else:
                    # Namespaces
                    for path in sig.class_path:
                        if path not in path_node[0]:
                            path_node[0][path] = (
                                {}, HashableQTreeWidgetItem(path_node[1]))
                            path_node[0][path][1].setText(0, path)
                        path_node = path_node[0][path]

                # Class
                path_node[0][path] = ({}, HashableQTreeWidgetItem(path_node[1]))

                class_name = sig.class_name

                if idx > 0:
                    class_name += "@%d" % idx

                c.current_title = class_name
                self._reverse_cache[path_node[0][path][1]] = (c, filename,
                                                              digest)

                path_node[0][path][1].setText(0, class_name)

    def itemDoubleClickedHandler(self, item, column):
        log.debug("item %s has been double clicked at column %s" %
                        (str(item), str(column)))
        if item.childCount() != 0:
            self.mainwin.showStatus("Sources not available.")
            return

        current_class, current_filename, current_digest = self._reverse_cache[
            item
        ]
        self.mainwin.openBinWindow(current_class)

    def createActions(self):
        self.xrefAct = QtWidgets.QAction(
            "Xref from/to",
            self,
            statusTip="List the references where this element is used",
            triggered=self.actionXref)
        self.expandAct = QtWidgets.QAction("Expand",
                                           self,
                                           statusTip="Expand all the subtrees",
                                           triggered=self.actionExpand)
        self.collapseAct = QtWidgets.QAction("Collapse",
                                             self,
                                             statusTip="Collapse all the subtrees",
                                             triggered=self.actionCollapse)

    def actionXref(self):
        item = self.currentItem()
        if item.childCount() != 0:
            self.mainwin.showStatus("Xref not availables")
            return

        current_class, _, _ = self._reverse_cache[item]

        current_analysis = self.session.get_analysis(current_class)
        if not current_analysis:
            self.mainwin.showStatus("No xref returned (no analysis object).")
            return

        class_analysis = current_analysis.get_class_analysis(
            current_class.get_name())
        if not class_analysis:
            self.mainwin.showStatus(
                "No xref returned (no class_analysis object).")
            return

        xwin = XrefDialogClass(parent=self.mainwin,
                               win=self.mainwin,
                               current_class=current_class,
                               class_analysis=class_analysis)
        xwin.show()

    def expand_children(self, item):
        self.expandItem(item)
        for i in range(item.childCount()):
            self.expand_children(item.child(i))

    def actionExpand(self):
        self.expand_children(self.currentItem())

    def collapse_children(self, item):
        for i in range(item.childCount()):
            self.collapse_children(item.child(i))
        self.collapseItem(item)

    def actionCollapse(self):
        self.collapse_children(self.currentItem())

    def contextMenuEvent(self, event):
        menu = QtWidgets.QMenu(self)
        menu.addAction(self.xrefAct)
        menu.addAction(self.expandAct)
        menu.addAction(self.collapseAct)
        menu.exec_(event.globalPos())
