# -*- coding: utf-8 -*-

import os
from collections import namedtuple

import wx

from outwiker.core.commands import MessageBox
from outwiker.utilites.textfile import readTextFile

from .actions.editsnippets import EditSnippetsAction
from .actions.runrecentsnippet import RunRecentSnippet
from .actions.openhelp import OpenHelpAction
from .events import RunSnippetParams
from .i18n import get_
from .snippetsloader import SnippetsLoader
from .gui.variablesdialog import VariablesDialogController
from .utils import getSnippetsDir
from . import defines
from .snippetparser import SnippetException

SnippetInfo = namedtuple('SnippetInfo', ['filename', 'menuitem', 'parentmenu'])


class GuiController(object):
    def __init__(self, application):
        self._application = application

        self._menu = None
        self._mainMenu = None

        self.MENU_POS = 6
        self._menuName = None

        self._snippets_id = {}
        self._varDialogController = VariablesDialogController(
            self._application
        )

        self._actions = [
            EditSnippetsAction,
            RunRecentSnippet,
            OpenHelpAction,
        ]

    def initialize(self):
        global _
        _ = get_()

        if self._application.mainWindow is not None:
            self._mainMenu = self._application.mainWindow.menuController.getRootMenu()
            self._menuName = _(u'Snippets')
            self._createMenu()
            self._varDialogController.onFinishDialogEvent += self._onFinishDialog
            self._application.customEvents.bind(defines.EVENT_UPDATE_MENU,
                                                self._onMenuUpdate)
            self._application.customEvents.bind(defines.EVENT_RUN_SNIPPET,
                                                self._onRunSnippet)

    def _createMenu(self):
        self._menu = wx.Menu(u'')

        # Snippet's control menu items (actions)
        controller = self._application.actionController
        [*map(lambda action: controller.appendMenuItem(action.stringId, self._menu),
              self._actions)]

        # Snippets list
        self._menu.AppendSeparator()
        self._updateMenu()

        # Added Snippet's menu to main menu
        self._mainMenu.Insert(self.MENU_POS, self._menu, self._menuName)

    def _onMenuUpdate(self, params):
        self._updateMenu()

    def _removeSnippetsFromMenu(self):
        # Remove all snippets
        for snippet_id, snippet_info in reversed(list(self._snippets_id.items())):
            menu_item = snippet_info.menuitem
            menu = snippet_info.parentmenu
            self._application.mainWindow.Unbind(wx.EVT_MENU,
                                                handler=self._onClick,
                                                id=snippet_id
                                                )
            menu.Remove(menu_item)
            menu_item.Destroy()

        # Count menu items for snippets. (+-1 because of separator exists)
        menu_snippets_count = (self._menu.GetMenuItemCount() -
                               len(self._actions)) - 1

        for _ in range(menu_snippets_count):
            menu_item = self._menu.FindItemByPosition(len(self._actions) + 1)
            self._menu.Remove(menu_item)
            menu_item.Destroy()

        self._snippets_id = {}

    def _updateMenu(self):
        self._removeSnippetsFromMenu()
        sl = SnippetsLoader(getSnippetsDir())
        snippets_tree = sl.getSnippets()
        self._buildTree(snippets_tree, self._menu)

    def _buildTree(self, snippets_tree, menu):
        # Create submenus
        for subdir in sorted(snippets_tree.dirs, key=lambda x: x.name):
            submenu = wx.Menu(u'')
            self._buildTree(subdir, submenu)
            menu.AppendSubMenu(submenu, subdir.name)

        # Create menu items
        if len(snippets_tree.dirs) != 0 and len(snippets_tree.snippets) != 0:
            menu.AppendSeparator()

        # Append snippets
        for snippet in sorted(snippets_tree.snippets):
            name = os.path.basename(snippet)
            menu_item_id = wx.Window.NewControlId()
            menu_item = menu.Append(menu_item_id, name)

            self._snippets_id[menu_item_id] = SnippetInfo(snippet,
                                                          menu_item,
                                                          menu)

            self._application.mainWindow.Bind(
                wx.EVT_MENU,
                handler=self._onClick,
                id=menu_item_id
            )

    def _destroyMenu(self):
        index = self._mainMenu.FindMenu(self._menuName)
        assert index != wx.NOT_FOUND

        actionController = self._application.actionController

        [*map(lambda action: actionController.removeMenuItem(action.stringId),
              self._actions)]
        self._mainMenu.Remove(index)
        self._menu = None

    def destroy(self):
        if self._application.mainWindow is not None:
            self._destroyMenu()
            self._varDialogController.onFinishDialogEvent -= self._onFinishDialog

        self._varDialogController.destroy()

    def _onRunSnippet(self, params):
        # type: (RunSnippetParams) -> None
        editor = self._getEditor()
        selectedText = editor.GetSelectedText() if editor is not None else u''

        snippet_fname = params.snippet_fname
        try:
            template = self._loadTemplate(snippet_fname)
        except EnvironmentError:
            MessageBox(
                _(u"Can't read the snippet\n{}").format(snippet_fname),
                _(u"Error"),
                wx.ICON_ERROR | wx.OK)
            return

        try:
            self._varDialogController.ShowDialog(
                selectedText,
                template,
                snippet_fname
            )
        except SnippetException as e:
            MessageBox(e.message, _(u"Snippet error"), wx.ICON_ERROR | wx.OK)

    def _onClick(self, event):
        assert event.GetId() in self._snippets_id
        snippet_fname = self._snippets_id[event.GetId()].filename

        eventParams = RunSnippetParams(snippet_fname)
        self._application.customEvents(defines.EVENT_RUN_SNIPPET, eventParams)

    def _loadTemplate(self, fname):
        template = readTextFile(fname)
        if template.endswith(u'\n'):
            template = template[:-1]
        return template

    def _getEditor(self):
        if self._application.selectedPage is None:
            return None
        pageView = self._application.mainWindow.pagePanel.pageView
        if 'GetEditor' in dir(pageView):
            return pageView.GetEditor()

    def _onFinishDialog(self, params):
        editor = self._getEditor()
        if editor is not None:
            editor.replaceText(params.text)
