#!/usr/bin/python
# -*- coding: utf-8 -*-

"""
Libervia: a Salut à Toi frontend
Copyright (C) 2013 Adrien Cossa <souliane@mailoo.org>

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""

from pyjamas.ui.Grid import Grid
from pyjamas.ui.Button import Button
from pyjamas.ui.ListBox import ListBox
from pyjamas.ui.FlowPanel import FlowPanel
from pyjamas.ui.AutoComplete import AutoCompleteTextBox
from pyjamas.ui.Label import Label
from pyjamas.ui.HorizontalPanel import HorizontalPanel
from pyjamas.ui.VerticalPanel import VerticalPanel
from pyjamas.ui.DialogBox import DialogBox
from pyjamas.ui.KeyboardListener import KEY_ENTER, KeyboardHandler
from pyjamas.ui.MouseListener import MouseHandler
from pyjamas.ui.FocusListener import FocusHandler
from pyjamas.ui.DropWidget import DropWidget
from pyjamas.ui.DragWidget import DragWidget

from pyjamas.Timer import Timer
from pyjamas import DOM

import panels
from pyjamas.ui import FocusListener, KeyboardListener, MouseListener, Event

# HTML content for the removal button (image or text)
REMOVE_BUTTON = '<span class="richTextRemoveIcon">x</span>'

# Item to be considered for an empty list box selection.
# Could be whatever which doesn't look like a JID or a group name.
EMPTY_SELECTION_ITEM = ""


class ListManager():
    """A manager for sub-panels to assign elements to lists."""

    def __init__(self, parent, keys_dict={}, contact_list=[], offsets={}, style={}):
        """
        @param parent: FlexTable parent widget for the manager
        @param keys_dict: dict with the contact keys mapped to data
        @param contact_list: list of string (the contact JID userhosts)
        @param offsets: dict to set widget positions offset within parent
        - "x_first": the x offset for the first widget's row on the grid
        - "x": the x offset for all widgets rows, except the first one if "x_first" is defined
        - "y": the y offset for all widgets columns on the grid
        """
        self.host = parent.host
        self._parent = parent
        if isinstance(keys_dict, set) or isinstance(keys_dict, list):
            tmp = {}
            for key in keys_dict:
                tmp[key] = {}
            keys_dict = tmp
        self.__keys_dict = keys_dict
        if isinstance(contact_list, set):
            contact_list = list(contact_list)
        self.__list = contact_list
        self.__list.sort()
        # store the list of contacts that are not assigned yet
        self.__remaining_list = []
        self.__remaining_list.extend(self.__list)
        # mark a change to sort the list before it's used
        self.__remaining_list_sorted = True

        self.offsets = {"x_first": 0, "x": 0, "y": 0}
        if "x" in offsets and not "x_first" in offsets:
            offsets["x_first"] = offsets["x"]
        self.offsets.update(offsets)

        self.style = {
           "keyItem": "recipientTypeItem",
           "popupMenuItem": "recipientTypeItem",
           "buttonCell": "recipientButtonCell",
           "dragoverPanel": "dragover-recipientPanel",
           "keyPanel": "recipientPanel",
           "textBox": "recipientTextBox",
           "removeButton": "recipientRemoveButton",
        }
        self.style.update(style)

    def createWidgets(self, title_format="%s"):
        """Fill the parent grid with all the widgets (some may be hidden during the initialization)."""
        self.__children = {}
        for key in self.__keys_dict:
            self.addContactKey(key, title_format)

    def addContactKey(self, key, dict_={}, title_format="%s"):
        if key not in self.__keys_dict:
            self.__keys_dict[key] = dict_
        # copy the key to its associated sub-map
        self.__keys_dict[key]["title"] = key
        self._addChild(self.__keys_dict[key], title_format)

    def _addChild(self, entry, title_format):
        """Add a button and FlowPanel for the corresponding map entry."""
        button = Button(title_format % entry["title"])
        button.setStyleName(self.style["keyItem"])
        if hasattr(entry, "desc"):
            button.setTitle(entry["desc"])
        if not "optional" in entry:
            entry["optional"] = False
        button.setVisible(not entry["optional"])
        y = len(self.__children) + self.offsets["y"]
        x = self.offsets["x_first"] if y == self.offsets["y"] else self.offsets["x"]

        self._parent.setWidget(y, x, button)
        self._parent.getCellFormatter().setStyleName(y, x, self.style["buttonCell"])

        _child = ListPanel(self, entry, self.style)
        self._parent.setWidget(y, x + 1, _child)

        self.__children[entry["title"]] = {}
        self.__children[entry["title"]]["button"] = button
        self.__children[entry["title"]]["panel"] = _child

        if hasattr(self, "popup_menu"):
            # this is done if self.registerPopupMenuPanel has been called yet
            self.popup_menu.registerClickSender(button)

    def _refresh(self):
        """Set visible the sub-panels that are non optional or non empty, hide the rest."""
        for key in self.__children:
            self.setContactPanelVisible(key, False)
        _map = self.getContacts()
        for key in _map:
            if len(_map[key]) > 0 or not self.__keys_dict[key]["optional"]:
                self.setContactPanelVisible(key, True)

    def setContactPanelVisible(self, key, visible=True, sender=None):
        """Do not remove the "sender" param as it is needed for the context menu."""
        self.__children[key]["button"].setVisible(visible)
        self.__children[key]["panel"].setVisible(visible)

    @property
    def list(self):
        """Return the full list of potential contacts."""
        return self.__list

    @property
    def keys(self):
        return self.__keys_dict.keys()

    @property
    def keys_dict(self):
        return self.__keys_dict

    @property
    def remaining_list(self):
        """Return the contacts that have not been selected yet."""
        if not self.__remaining_list_sorted:
            self.__remaining_list_sorted = True
            self.__remaining_list.sort()
        return self.__remaining_list

    def setRemainingListUnsorted(self):
        """Mark a change (deletion) so the list will be sorted before it's used."""
        self.__remaining_list_sorted = False

    def removeFromRemainingList(self, contact_):
        """Remove an available contact after it has been added to a sub-panel."""
        if contact_ in self.__remaining_list:
            self.__remaining_list.remove(contact_)

    def addToRemainingList(self, contact_):
        """Add a contact after it has been removed from a sub-panel."""
        if contact_ not in self.__list or contact_ in self.__remaining_list:
            return
        self.__remaining_list.append(contact_)
        self.__sort_remaining_list = True

    def setContacts(self, _map={}):
        """Set the contacts for each contact key."""
        for key in self.__keys_dict:
            if key in _map:
                self.__children[key]["panel"].setContacts(_map[key])
            else:
                self.__children[key]["panel"].setContacts([])
        self._refresh()

    def getContacts(self):
        """Get the contacts for all the lists.
        @return: a mapping between keys and contact lists."""
        _map = {}
        for key in self.__children:
            _map[key] = self.__children[key]["panel"].getContacts()
        return _map

    def setTargetDropCell(self, panel):
        """Used to drag and drop the contacts from one panel to another."""
        self._target_drop_cell = panel

    def getTargetDropCell(self):
        """Used to drag and drop the contacts from one panel to another."""
        return self._target_drop_cell

    def registerPopupMenuPanel(self, entries, hide, callback):
        "Register a popup menu panel that will be bound to all contact keys elements."
        self.popup_menu = panels.PopupMenuPanel(entries=entries, hide=hide, callback=callback, item_style=self.style["popupMenuItem"])


class DragAutoCompleteTextBox(AutoCompleteTextBox, DragWidget, MouseHandler):
    """A draggable AutoCompleteTextBox which is used for representing a contact.
    This class is NOT generic because of the onDragEnd method which call methods
    from ListPanel. It's probably not reusable for another scenario.
    """

    def __init__(self):
        AutoCompleteTextBox.__init__(self)
        DragWidget.__init__(self)
        self.addMouseListener(self)

    def onDragStart(self, event):
        dt = event.dataTransfer
        # The group prefix "@" is already in text so we use only the "CONTACT" type
        dt.setData('text/plain', "%s\n%s" % (self.getText(), "CONTACT_TEXTBOX"))

    def onDragEnd(self, event):
        if self.getText() == "":
            return
        # get the ListPanel containing self
        parent = self.getParent()
        while parent is not None and not isinstance(parent, ListPanel):
            parent = parent.getParent()
        if parent is None:
            return
        # it will return parent again or another ListPanel
        target = parent.getTargetDropCell()
        if target == parent:
            return
        target.addContact(self.getText())
        if hasattr(self, "remove_btn"):
            # self is not the last textbox, just remove it
            self.remove_btn.click()
        else:
            # reset the value of the last textbox
            self.setText("")

    def onMouseMove(self, sender):
        """Mouse enters the area of a DragAutoCompleteTextBox."""
        if hasattr(sender, "remove_btn"):
            sender.remove_btn.setVisible(True)

    def onMouseLeave(self, sender):
        """Mouse leaves the area of a DragAutoCompleteTextBox."""
        if hasattr(sender, "remove_btn"):
            Timer(1500, lambda: sender.remove_btn.setVisible(False))


class DropCell(DropWidget):
    """A cell where you can drop widgets. This class is NOT generic because of
    onDrop which uses methods from ListPanel. It has been created to
    separate the drag and drop methods from the others and add a bit of
    lisibility, but it's probably not reusable for another scenario.
    """

    def __init__(self, host):
        DropWidget.__init__(self)

    def onDragEnter(self, event):
        self.addStyleName(self.style["dragoverPanel"])
        DOM.eventPreventDefault(event)

    def onDragLeave(self, event):
        if event.clientX <= self.getAbsoluteLeft() or event.clientY <= self.getAbsoluteTop()\
            or event.clientX >= self.getAbsoluteLeft() + self.getOffsetWidth() - 1\
            or event.clientY >= self.getAbsoluteTop() + self.getOffsetHeight() - 1:
            # We check that we are inside widget's box, and we don't remove the style in this case because
            # if the mouse is over a widget inside the DropWidget, we don't want the style to be removed
            self.removeStyleName(self.style["dragoverPanel"])

    def onDragOver(self, event):
        DOM.eventPreventDefault(event)

    def onDrop(self, event):
        DOM.eventPreventDefault(event)
        dt = event.dataTransfer
        # 'text', 'text/plain', and 'Text' are equivalent.
        item, item_type = dt.getData("text/plain").split('\n')  # Workaround for webkit, only text/plain seems to be managed
        if item_type and item_type[-1] == '\0':  # Workaround for what looks like a pyjamas bug: the \0 should not be there, and
            item_type = item_type[:-1]           # .strip('\0') and .replace('\0','') don't work. TODO: check this and fill a bug report
        if item_type == "GROUP":
            item = "@%s" % item
            self.addContact(item)
        elif item_type == "CONTACT":
            self.addContact(item)
        elif item_type == "CONTACT_TEXTBOX":
            self._parent.setTargetDropCell(self)
            pass
        else:
            return
        self.removeStyleName(self.style["dragoverPanel"])


class ListPanel(FlowPanel, DropCell, FocusHandler, KeyboardHandler):
    """Sub-panel used for each contact key. Beware that pyjamas.ui.FlowPanel
    is not fully implemented yet and can not be used with pyjamas.ui.Label."""

    def __init__(self, parent, entry, style={}):
        """Initialization with a button and a DragAutoCompleteTextBox."""
        FlowPanel.__init__(self, Visible=(False if entry["optional"] else True))
        DropCell.__init__(self)
        self.style = style
        self.addStyleName(self.style["keyPanel"])
        self._parent = parent
        self.host = parent.host

        self._last_textbox = None
        self.__remove_cbs = []

        self.__resetLastTextBox()

    def __resetLastTextBox(self, setFocus=True):
        """Reset the last input text box with KeyboardListener."""
        if self._last_textbox is None:
            self._last_textbox = DragAutoCompleteTextBox()
            self._last_textbox.addStyleName(self.style["textBox"])
            self._last_textbox.addKeyboardListener(self)
            self._last_textbox.addFocusListener(self)
        else:
            # ensure we move it to the last position
            self.remove(self._last_textbox)
        self._last_textbox.setText("")
        self.add(self._last_textbox)
        self._last_textbox.setFocus(setFocus)

    def onKeyUp(self, sender, keycode, modifiers):
        """This is called after DragAutoCompleteTextBox.onKeyDown,
        so the completion is done before we reset the text box."""
        if not isinstance(sender, DragAutoCompleteTextBox):
            return
        if keycode == KEY_ENTER:
            self.onLostFocus(sender)
            self._last_textbox.setFocus(True)

    def onFocus(self, sender):
        """A DragAutoCompleteTextBox has the focus."""
        if not isinstance(sender, DragAutoCompleteTextBox):
            return
        if sender != self._last_textbox:
            # save the current value before it's being modified
            text = sender.getText()
            self._focused_textbox_previous_value = text
            self._parent.addToRemainingList(text)
        sender.setCompletionItems(self._parent.remaining_list)

    def onLostFocus(self, sender):
        """A DragAutoCompleteTextBox has lost the focus."""
        if not isinstance(sender, DragAutoCompleteTextBox):
            return
        self.changeContact(sender)

    def changeContact(self, sender):
        """Modify the value of a DragAutoCompleteTextBox."""
        text = sender.getText()
        if sender == self._last_textbox:
            if text != "":
                # a new box is added and the last textbox is reinitialized
                self.addContact(text, setFocusToLastTextBox=False)
            return
        if text == "":
            sender.remove_btn.click()
            return
        # text = new value needs to be removed 1. if the value is unchanged, because we
        # added it when we took the focus, or 2. if the value is changed (obvious!)
        self._parent.removeFromRemainingList(text)
        if text == self._focused_textbox_previous_value:
            return
        sender.setVisibleLength(len(text))
        self._parent.addToRemainingList(self._focused_textbox_previous_value)

    def addContact(self, contact, resetLastTextBox=True, setFocusToLastTextBox=True):
        """Add a contact and signal it to self._parent panel."""
        if contact is None or contact == "":
            return
        textbox = DragAutoCompleteTextBox()
        textbox.addStyleName(self.style["textBox"])
        textbox.setText(contact)
        self.add(textbox)
        try:
            textbox.setVisibleLength(len(str(contact)))
        except:
            #FIXME: . how come could this happen?! len(contact) is sometimes 0 but contact is not empty
            print "len(contact) returns %d where contact == %s..." % (len(str(contact)), str(contact))
        self._parent.removeFromRemainingList(contact)

        remove_btn = Button(REMOVE_BUTTON, Visible=False)
        remove_btn.setStyleName(self.style["removeButton"])

        def remove_cb(sender):
            """Callback for the button to remove this contact."""
            self.remove(textbox)
            self.remove(remove_btn)
            self._parent.addToRemainingList(contact)
            self._parent.setRemainingListUnsorted()

        remove_btn.addClickListener(remove_cb)
        self.__remove_cbs.append(remove_cb)
        self.add(remove_btn)
        self.__resetLastTextBox(setFocus=setFocusToLastTextBox)

        textbox.remove_btn = remove_btn
        textbox.addFocusListener(self)
        textbox.addKeyboardListener(self)

    def emptyContacts(self):
        """Empty the list of contacts."""
        for remove_cb in self.__remove_cbs:
            remove_cb()
        self.__remove_cbs = []

    def setContacts(self, tab):
        """Set the contacts."""
        self.emptyContacts()
        if isinstance(tab, set):
            tab = list(tab)
        tab.sort()
        for contact in tab:
            self.addContact(contact, resetLastTextBox=False)
        self.__resetLastTextBox()

    def getContacts(self):
        """Get the contacts
        @return: an array of string"""
        tab = []
        for widget in self.getChildren():
            if isinstance(widget, DragAutoCompleteTextBox):
                # not to be mixed with EMPTY_SELECTION_ITEM
                if widget.getText() != "":
                    tab.append(widget.getText())
        return tab

    def getTargetDropCell(self):
        """Returns self or another panel where something has been dropped."""
        return self._parent.getTargetDropCell()


class ContactChooserPanel(DialogBox):
    """Display the contacts chooser dialog. This has been implemented while
    prototyping and is currently not used. Left for an eventual later use.
    Replaced by the popup menu which allows to add a panel for Cc or Bcc.
    """

    def __init__(self, manager, **kwargs):
        """Display a listbox for each contact key"""
        DialogBox.__init__(self, autoHide=False, centered=True, **kwargs)
        self.setHTML("Select contacts")
        self.manager = manager
        self.listboxes = {}
        self.contacts = manager.getContacts()

        container = VerticalPanel(Visible=True)
        container.addStyleName("marginAuto")

        grid = Grid(2, len(self.manager.keys_dict))
        index = -1
        for key in self.manager.keys_dict:
            index += 1
            grid.add(Label("%s:" % self.manager.keys_dict[key]["desc"]), 0, index)
            listbox = ListBox()
            listbox.setMultipleSelect(True)
            listbox.setVisibleItemCount(15)
            listbox.addItem(EMPTY_SELECTION_ITEM)
            for element in manager.list:
                listbox.addItem(element)
            self.listboxes[key] = listbox
            grid.add(listbox, 1, index)
        self._reset()

        buttons = HorizontalPanel()
        buttons.addStyleName("marginAuto")
        btn_close = Button("Cancel", self.hide)
        buttons.add(btn_close)
        btn_reset = Button("Reset", self._reset)
        buttons.add(btn_reset)
        btn_ok = Button("OK", self._validate)
        buttons.add(btn_ok)

        container.add(grid)
        container.add(buttons)

        self.add(container)
        self.center()

    def _reset(self):
        """Reset the selections."""
        for key in self.manager.keys_dict:
            listbox = self.listboxes[key]
            for i in xrange(0, listbox.getItemCount()):
                if listbox.getItemText(i) in self.contacts[key]:
                    listbox.setItemSelected(i, "selected")
                else:
                    listbox.setItemSelected(i, "")

    def _validate(self):
        """Sets back the selected contacts to the good sub-panels."""
        _map = {}
        for key in self.manager.keys_dict:
            selections = self.listboxes[key].getSelectedItemText()
            if EMPTY_SELECTION_ITEM in selections:
                selections.remove(EMPTY_SELECTION_ITEM)
            _map[key] = selections
        self.manager.setContacts(_map)
        self.hide()