# Copyright (C) 2005--2010, Sandro Dentella <sandro@e-den.it>
#
#  This program is free software: you can redistribute it and/or modify
#  it under the terms of the GNU 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 General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""

.. _filter_panel:

================
FilterPanel
================

The filter panel is the panel where all filter conditions can be written (remeber that
constraints are different in the sense that are filters applied w/o possibility to remove
them). It opens as a window separate from the main window so that it's easy to hide or keep
it at hand.

Each sqlwidget has a FilterPanel even if it doesn't show it

.. autoclass:: FilterPanel
   :members: hide, show, get_tools, reload, set_page, tree, replace_column, add_column
.. autoclass:: FilterTool
   :members: set_value, get_value, set_operator, get_operator

When the filter is used from a SqlTable, the output is displayed directly
into the SqlTable.  When the filter is used from a SqlMask the output is
shown in a special tab of the FilterPanel that is really a :ref:`View
<views>` on the output that can be customized to a good degree. Default
representation is ``str(obj)`` unless a you have defined a ``format``
in the :ref:`database attribute description <sqlkit_table>` for that table.

Customizing the output tab
==========================

The default representation of records is a :ref:`View <views>` with a single
column named ``__obj__`` that is a field that creates a str(obj) as
explained above.

If you want to change that representation you just need to substitute the
column in the treeview::

  from sqlkit.import fields
  from sqlkit.db.utils import DictLike

  class CountMovies(fields.IntegerField):
      '''
      A field that counts the movies
      '''
      def clean_value(self, value):
          ## missing a field_name attribute on obj the objct itselt is passed
          return len(value.movies)

  my_mask.filter_panel.replace_column(CountMovies)

Alternatively you can :ref:`add a column <add_view_column>` to the output view
after creating the field and the column you would add it to the view as follows::

    count = CountMovies('n_movies')
    col = columns.VarcharColumn(t, 'n_movies', 'Movie Count', field=count)
    my_mask.filter_panel.view.add_column(col)

At this point you can sort the output on each column and even get totals in it.
  
"""
import re
import gtk
import warnings
from datetime import *

import gobject
import sqlalchemy
from sqlalchemy.sql import select, Join
from babel import dates

from sqlkit import debug as dbg, _, exc, fields
from sqlkit.db import minspect
from sqlkit.db.utils import tables, get_description, DictLike
from sqlkit.db.django_syntax import django2components
from sqlkit.misc import datetools, utils
from sqlkit.layout import layout, misc
from sqlkit.widgets.table import columns, modelproxy
import completion

FILTER_MENU = '''
<menubar name="FilterMain">
   <menu action="FilterMenu">
     <menuitem action="GoFilter" />
     <menuitem action="GoOutput" />
     <separator name="sep"/>
     <menuitem action="Reload" />
     <separator name="sep2"/>
     <menuitem action="Close" />
  </menu>
</menubar>
'''
OP_MSGID = {
    'REGEXP' : _('Match as regexp'),
    'match' : _('Match as LIKE, "%" automatically added'),
    'ICONTAINS' : _('Match as LIKE case insensitive, "%" automatically added'),
    '~' : _('Match as regexp'),
    '~*' : _('Match as regexp, case insensitive'),
    '!~' : _('Negation of match as regexp'),
    '!~*' : _('Negation of match case insensitive'),
    '=' : _('Equal'),
    '!=' : _('Not equal'),
    '>' : _('Greater then (after than)'),
    '>=' : _('Greater or equal'),
    '<' : _('Less than (before then)'),
    '<=' : _('Less than or equal'),
    'LIKE' : _('LIKE: a "%" means any char - case sensitive'),
    'NOT LIKE' : _('Negation of LIKE'),
    'ILIKE' : _('As LIKE but case insensitive'),
    'NOT ILIKE' : _('Negation of ILIKE'),
    'IS TRUE' : _('The boolean is True'),
    'IS FALSE' : _('The boolean is False'),
    'IS NOT TRUE' : _('The boolean is not True'),
    'IS NOT FALSE' : _('The boolean is not False'),
    'IS NULL' : _('The value is not set'),
    'IS NOT NULL' : _('The value is set'),
#    '' : _(''),
    }


class FilterPanel(object):
    """A panel that manages filter conditions of a query: number of records,
    field names and output to point & click in case of a panel of a SqlMask

    """

    tree = None
    """The name of an attribute that will work as grouping attribute.
    The output TreeView will show records grouped by the same attribute as parent/child.
    It should be improved as the parent is a the record and not a row with the only
    grouping attribute.
    """

    def __init__(self, master, visible=True):
        
        """constructor need to know who is the 'master' ie the widget (a mask
        or a table instance) that will display the result. 

        The filter for a SqlMask has a TreeView to show the results and to easy
        browse them.

        """
        self.master = master
        self.dont_record_display = False
        self.master.connect('delete-event', self.destroy)
        self.get_layout(visible=visible)
        self.row = 0  # counter for position of fields
        self.default_reload = True
        
        self.search_filter_widgets = []         ## list of FilterTools instances
        self.search_filter_field_names = []     ## field_names used
        self.bind_name = self.master.metadata.bind.name
        self.tree = False
        self._last_focused_entry = None
        if master.is_mask():
            self._id_record_selected = master.connect('record-selected', self.record_selected_cb)
        self.prepare_actions()

    def record_selected_cb(self, mask):
        """
        callback on record selection
        """
        self.select_output_path(obj=mask.current, block=True)
        
    def get_layout(self, visible=True):
        """create the filter panel widget"""
        if self.master.is_mask():
            lay = """
            {H.a {V.menu } {O.a tb=gtk-refresh ts=limit tb=gtk-close } }
            {N.0 %filter
               {|T.fld }
               %output
               { TVS=out}
            }
            """
        else:
            lay = """
            {H.a {V.menu } {O.a tb=gtk-refresh ts=limit tb=gtk-close } }
               {|T.fld }

            """
        self.l = layout.Layout(lay, title=_('Filter Panel'), opts="s", label_map=self.master.label_map)
        self.l.prop('Window', 'visible', visible)
        self.l.prop('O.a', 'show_arrow', 'FALSE')
        self.l.prop('A=.fld', 'yscale', '0')
        self.l.elements['H.a'].pack_properties['y-options'] = ''
        self.l.prop('O.a', 'toolbar_style', 'gtk.TOOLBAR_ICONS')

        if self.master.is_mask():
            ## TIP: filter page of the filter panel
            self.l.tip('filter', _('Add filters for your query'))
            ## TIP: output page of the filter panel
            self.l.tip('output', _('Result page for your query'))

        self.w = self.l.show(x=self.hide)
#        self.w['s=limit'].set_value(self.master.limit)
        adj = self.w['s=limit'].get_adjustment()
        adj.set_all(self.master.limit, 0, 10000, 10, 100, 0)
        self.l.connect(
            ('tb=gtk-close', 'clicked', self.hide),
            ('tb=gtk-refresh', 'clicked', self.reload_cb)
                        )
        self.w['label-cursor'] = gtk.gdk.Cursor(gtk.gdk.HAND1)
        if 'TV=out' in self.w:
            self._add_treeview()
        if 'N.0' in self.w:
            self.w['N.0'].connect_after('switch-page', self.on_switch_page)

    def _add_treeview(self):

        class ObjField(fields.VarcharField):
            """
            A field that represents the obj for filter_panel
            """
            def clean_value(self, value):
                return str(value)

        field = ObjField('__obj__')
        self.master.gui_fields['__obj__'] = field
        col = columns.VarcharColumn(self.master, '__obj__', _('output'), field=field)
        self.view = self.create_view()
        self.view.add_column(col)
        self.selection = self.view.treeview.get_selection()
        self.selection.connect('changed',self.on_selection_changed)

    def prepare_actions(self):
        self.actiongroup   = gtk.ActionGroup('Filter')

        self.actiongroup.add_actions([
            ('FilterMenu', None, _('Filter actions')),
            ('Reload', gtk.STOCK_REFRESH, _('Reload from db'), '<Control>r', None, self.reload_cb),
            ('Close', gtk.STOCK_CLOSE, _('Close the panel'), '<Control>q', None, self.hide),
            ], )
        self.actiongroup.add_actions([
            ('GoFilter', None, _('Go to filter panel'), '<Control>l', None, self.set_page),], 'filter')
        self.actiongroup.add_actions([
            ('GoOutput', None, _('Go to output panel'), '<Control>o', None, self.set_page),], 'output')
        self.ui_manager = gtk.UIManager()
        self.accel_group = self.ui_manager.get_accel_group()
        self.l.widgets['Window'].add_accel_group(self.accel_group)
        self.ui_manager.insert_action_group(self.actiongroup, 10)
        self.ui_manager.add_ui_from_string(FILTER_MENU)
        
        ## pack menu and toolbar if it's a toplevel
        header = self.l.widgets['V.menu']
        menu    = self.ui_manager.get_widget('/FilterMain')
        header.add(menu)
        #header.add(toolbar)


    def go_to_filter(self, action):
        
        self.set_page('filter')
        
    def replace_column(self, field_class, field_name='__obj__'):
        """
        Replace the column of the output treeview with a customized one

        :param field_class: a subclass of ``sqlwidget.fields.Field``
               with a proper ``clean_value`` method
        :param field_name: the field_name of the column, Default: ``__obj__`` (i.e. the
               name used for the default column of the output treeview

        """
        
        field = field_class(field_name)
        col = columns.VarcharColumn(self.master, '__obj__', _('output'), field=field)
        self.view.treeview.remove_column(self.view.tvcolumns['__obj__'])
        self.view.add_column(col, 0)
        self.master.gui_fields[field_name] = field
        
    def add_column(self, field_name):
        """
        Add a column among already defined fields in gui_fields

        :param field_name: the field_name of the field

        """
        
        self.view.setup_columns([field_name])
        
    def sb(self, message, seconds=None):
        """
        Write messag on the status bar
        """
        self.l.sb(message, seconds=seconds)
        
    def add_filter(self, active=True, **kwargs):
        """
        add a filter using django-like syntax

        :param active: make the filter active (default True). This hides the possibility to
            add a filter on a field named ``active``. In this case you can use the longer version
            that is ``active__eq=True``
        :param kwargs: any paramenter allowed per syntax of the django_like syntax as explained
            in the :ref:`chapter on constraints <constraints>`
        
        """
        for key, val in kwargs.iteritems():
            path, op, op_str, value, col, join_args = django2components(self.master.mapper, {key: val})
            master = self.get_related_master(self.master, path)
            filter_tool = self.add(None, None, col.name, master, force=True)
            if not filter_tool: 
                return
            filter_tool.set_active(active)

            if filter_tool.is_filter_value(value):
                filter_tool.set_value(value)
            filter_tool.set_operator(op, value)

    def get_related_master(self, master, path=None):
        """
        Return the SqlTool that manages the data at 'path'.
        E.g.: if the mapper is the one for movie, and the 'path'  is 'genres'
        as in the doc example, ``get_master``  would return the SqlTable that
        manages the collection of records returned by the relation 'genres'
        """

        for elem in path:
            master = master.related[elem]
        return master


    def add(self, wdg, ev, field_name, master, after=None, show=True, force=False, value=None):
        """
        add a FilterTool to the filter panel + operator and string entry
        after: entry will be positioned after widget 'after'
        """
        if not self.master.ui_manager.get_action('/Main/File/Filters').is_sensitive():
            return
        ## FIXME: after and show?
        search_path = "%s__%s" % ("__".join(master.relationship_path), field_name)
        if not search_path in self.search_filter_field_names or force:
            widget = get_filter_widget(field_name, self, master, value)
            self.search_filter_widgets += [ widget]
            self.search_filter_field_names  += [search_path]

        self.set_page(name='filter')

        if show:
            self.w['Window'].show_all()
        self.w['Window'].present()
        try:
            return widget
        except:
            return None

    def set_page(self, action=None, name=None):
        """
        set the tab in the filter. Tab name can be 'filter' or 'output'.
        Sqlmasks only have 'filter'.

        :param name: name of the tab in the filter widget: *filter* or *output*
        """
        if 'N.0' in self.w:
            if name == 'filter':
                self.w['N.0'].set_current_page(0)

            if name == 'output' and self.master.is_mask():
                self.w['N.0'].set_current_page(1)
        
        
    def hide(self, widget=None, event=None):
        """
        Hide the Filterpanel

        :param widget: not neeeded: it' here to allow using it in callback
        :param event: not needed: see above
        """

        self.w['Window'].set_property('visible', False)
        return True  # stops further processing...
    
    def show(self):
        """
        Present the filter panel
        """
        self.w['Window'].present()
        
    def get_tools(self, field_name):
        """
        return a list of FilterTool for *field_name*

        :param field_name: name of the field
        
        """
        return [w for w in self.search_filter_widgets if w.field_name == field_name]

    def destroy(self, window=None):

        if window:
            self.w['Window'].destroy()
        for attr in ('easytv', 'search_filter_widgets', 'l', 'model', 'selection', 'w'):
            try:
                delattr(self, attr)
            except AttributeError, e:
                pass
            
    def entry_focus_cb(self, entry, event=None):

        self._last_focused_entry = entry
        
    def on_switch_page(self, notebook, junk, page_n):

        if page_n == 0 and self._last_focused_entry:
            gobject.idle_add(self._last_focused_entry.grab_focus)
        
##### reload & TreeView
    def reload(self):
        """issue a reload operation on master. Callback of reload button"""

        length = 0
        if 'TV=out' in self.w:
            display = False
        else:
            display = True
            
        if self.default_reload:
            try:
                length = self.master.reload(limit=self.get_limit(), display=display )
            except (exc.DialogValidationError, exc.ValidationError), e:
                return

        if 'TV=out' in self.w:
            if length:
                self.master.modelproxy.fill_model(clear=True)

                self.set_page(name='output')
                self.select_output_path(0, block=False)
                self.view.treeview.grab_focus()
                self.tv_resize()
                self.view.on_zoom_fit()
            else:
                self.model.clear()

        self.l.sb(_('Total N. of records: %s' % length))

    def select_output_path(self, path=None, obj=None, block=False):
        """
        Select path ``path``. If path is null and obj is not null try finding path at which is obj

        :param block: block record display (when selction is already an answer to record_display)
        """
        if block:
            self.dont_record_display = True
        if path is None and obj:
            path = self.get_path_for_obj(obj)

        if path is not None and len(self.model):
            self.selection.select_path(path)
            self.view.treeview.scroll_to_cell(path)
        self.dont_record_display = False
            
    def get_path_for_obj(self, obj):
        """
        return 
        """
        path_list = [0]
        def compare(model, path, iter):
            if self.model.get_value(iter, 0) == obj:
                
                path_list[0] = path
                return True
        
        self.model.foreach(compare)
        return path_list[0]

    def reload_cb(self, widget):
        """callback from reload button
        """
        self.reload()

    def set_reload(self, mapper=None, join=None, tables=None):
        """A different method to filter & select is provided
        the scenario is that you have many synced sqlwidgets, you want to provide the
        possibility to select a record in a table with different records in other
        tables and be able to select one particular pair of them from the
        filter tree.

        You need to pass a join to issue the select on and a method in
        actions called 'on_filter_reload' to wich is passed only an
        argument: a dictionary with all the attributes of the collected
        record.

        If you pass tables to set_reload, each table is autoloaded and joined
        to the preceding. The returned join is used.
        
        """
        self.default_reload = False

        if tables:
            if isinstance(tables, str):
                T = {}
                tables = re.split('[ ,]+',tables)
                for tbl in tables:
                    T[tbl] = sqlalchemy.Table(
                        tbl, self.master.metadata, autoload=True)

                for tbl in tables[1:]:
                    join = T[tables[0]].join(T[tbl])
                
        if join:
            class Join(object): pass
            mapper = sqlalchemy.mapper(Join, join)

        self.mapper = mapper
        self.map_fields = minspect.InspectMapper(mapper)

    def create_view(self, field_list=None):
        """
        create a sqlkit.widgets.table.column.View to represent the objects
        """
        if not hasattr(self.master, 'views'):
            self.master.views = utils.Container()
        treeview = self.w['TV=out']

        view = columns.View(master=self.master, name='filter_panel', treeview=treeview,
                    field_list=field_list, ro=True)
        self.master.modelproxy = modelproxy.ModelProxy(self.master, treeview=treeview)
        self.model = self.master.modelproxy.modelstore
        view.treeview.set_model(self.master.modelproxy.modelstore)
        self.master.views['filter_panel'] = view
        return view
        
    def tv_resize(self):
        tv = self.w['TV=out']
        tv.realize()
        X, Y, width, height, bit = tv.window.get_geometry()
        if height < 100:
            tv.set_property('height-request', 300)
            
    def on_selection_changed(self, *args):
        # when clicking on the teeview we get 2 args: treeView, event
        # when changing selection we only have 1 arg: gtk.treeSelection
        # when clicking 'Refresh' we get e gtk.TreeSelection but no
        #      iter get selected
        ## first guess: we selected w/ pointer
        if self.dont_record_display:
            return
        model, iter = self.selection.get_selected()

        ## we don't have a selection
        if iter is None:
            try:
                ## we moved along the treeview w/ arrows
                wdg, ev = args
                path = wdg.get_path_at_pos(int(ev.x), int(ev.y))[0]
                iter = model.get_iter(path)
            except (ValueError, TypeError), e:
                ## ValueError: deselecting when clicking 'reload'
                ## TypeError: no data in the treeview
                return
            
        if self.default_reload:
            try:
                idx = self.master.records.index(model.get_value(iter, 0))
            except ValueError:
                return
            self.master.handler_block(self._id_record_selected)
            self.master.record_display(index=idx)
            self.master.handler_unblock(self._id_record_selected)
    
##### SQL
    def get_limit(self):
        """
        Get limits of the select we are issuing
        """
        self.w['s=limit'].update()
        return  self.w['s=limit'].get_value_as_int()
    
    def add_filter_conditions(self, query):
        """Adds to the query all filter conditions
        """
        
        for tool in self.search_filter_widgets:
            query = tool.add_filter_condition(query)

        return  query


    def sql_dbg(self, bool_conds):
        for c in bool_conds:
            print "DBG: ", c.left, c.operator, c.right
        

class FilterTool(object):
    """
    A tool that handles the the filter and provides a mean to modify the query of the
    master (sqlwidget). With the FilterTool you can programmatically set the filter
    active/inactive, change the operator and the filter values.

    You will normally do all this with the ``.add_filter`` method of sqlwidget, but
    you may occasionally need to fine tune the filter in a second time
    """
    STR_STD_OPERATORS = [ 'LIKE', 'NOT LIKE', 'ILIKE', 'NOT ILIKE']
    NULL_OPERATORS = [ 'IS NULL', 'IS NOT NULL' ]
    STD_OPERATORS = [ '>=','<=', '=', '!=', '>', '<', ] + NULL_OPERATORS

    def __init__(self, field_name, panel, master):

        self.panel = panel
        self.master = master
        self.field_name = field_name
        self.master.connect('delete-event', self.destroy)
        self.db_spec = self.master.mapper_info.fields[field_name]

        ## db_spec['table'] may not be defined if the column correspond to an expression
        
        if self.db_spec['table'] is not None and self.master.relationship_path:
            ## use an alias in case we have another filter to the same table
            self.table = self.db_spec['table'].alias()
        else:
            self.table = self.db_spec['table']

        prop = self.master.mapper.get_property(self.field_name)
        cols = prop.columns
        
        if len(cols) >= 2:
            msg = """I'm not able to understand which column you want here:  field_name '%s' has
            several columns: %s""" % (self.field_name, prop.columns)
            raise NotImplementedError(msg)

        if isinstance(self.master.mapper.local_table, Join):
            ## FIXME: no aliasing in this case
            self.col = cols[0]
        else:
            ## Note: here self.table can be the alias of self.master.mapper_info.field[field_name].table
            if self.table is not None:
                self.col = self.table.c[self.field_name]
            else:
                ## no aliasing here: is any possible to alias a _Label/expression?
                self.col = self.db_spec['col']

        self.bind_name = self.master.metadata.bind.name
        self.widget = FilterWidget(self)

    def destroy(self, window=None):
        del self.widget
        
##### handling
    def is_filter_value(self, value):
        """
        return True if this value can be written
        This may be dependant on the FilterTool but for the moment is not.
        """
        ## NOTE!!! value in (False, True) is WRONG as '0 == False' is True
        # and so 0 in (False,) is True!...
        if value is False or value is True:
            return False
        return True
    
    def set_value(self, value):
        """
        set the value of the filter. It can be a string or an object (eg. a date())
        """
        self.widget.set_value(value)

    def get_value(self):
        """
        return the current value of the filter
        """
        
        value = self.widget.get_value() 
        f = self.master.gui_fields[self.field_name]
        return f.clean_value(value)

    def get_row_value(self):
        """
        return the current value of the filter
        """
        
        return self.widget.get_value() 

    def set_active(self, active):
        """make the filter active"""

        self.widget.set_active(active)

    def get_active(self):
        """set the filter inactive"""
        
        return self.widget.get_active()

    def set_operator(self, op, value):
        """
        Set the active operator entry in ComboBox/OptionMenu for operator choice
        :param op: the operator
        :param value: the value of the operator 
        """
        self.widget.set_operator(op, value)

    def get_operator(self):
        """
        return the active operator entry in ComboBox/OptionMenu 
        """
        return self.widget.get_operator()

    def get_suitable_operators(self):
        """return list of operators meaningfull for engine/data type
        """
        return self.STD_OPERATORS

    def string_representation(self, value):
        """
        return a string representation suitable for filter entry
        """
        field = self.master.gui_fields[self.field_name]
        return field.get_human_value(value)
    
    def add_filter_condition(self, query):
        if not self.get_active():
            return query
        
        op_value = self.get_operator()

        query = query.reset_joinpoint()

        if self.master.relationship_path:
            # query = query.join(*self.master.relationship_path)
            if len(self.master.relationship_path) == 1:
                query = query.join( (self.table, self.master.relationship_path[0]))
            else:
                ## NOTE: if relationship_path is longer that 1, the table is not aliased, i.e.: if you place
                ## 2 search conditions to the same table (e.g. searching on staff and manager of a project-
                ## and both manager and staff are m2m relation to User)
                ## will most surely lead to no result
                query = query.join(*self.master.relationship_path)

        if op_value in ('IS NULL', 'IS NOT NULL',
                        'IS TRUE', 'IS FALSE', 'IS NOT TRUE', 'IS NOT FALSE'):
            # NULL
            if op_value == 'IS NULL':
                return query.filter(self.col == None)
            elif op_value == 'IS NOT NULL':
                return query.filter(self.col != None)

            # True/False
            if op_value == 'IS TRUE':
                return query.filter(self.col == True)
            elif op_value == 'IS FALSE':
                return query.filter(self.col == False)

            if op_value == 'IS NOT TRUE':
                return query.filter(self.col != True)
            elif op_value == 'IS NOT FALSE':
                return query.filter(self.col != False)

        else:
            try:
                value = self.get_value()
            except exc.ValidationError, e:
                msg = _("value '%s' cannot be used for field '%s'") % (self.get_row_value(), self.field_name)
                self.master.sb(msg)
                self.panel.sb(msg)
                raise e
            
            if value not in (None, ''):
                if not re.match('postgres|mysql', self.bind_name) and \
                       op_value in ('ICONTAINS', 'MATCH'):
                    op_value = 'ILIKE'
                    value = '%' + value + '%'

                query = self._compose_field_whereclause(query, value, op_value)
            return query
        

    def _compose_field_whereclause(self, query, value, op_value):
        """
        return a sql whereclause for field

        """
        
        if op_value == "ILIKE":
            return query.filter(self.col.ilike(value))

        else:
            return query.filter(self.col.op(op_value)(value))

    def add_filter_cb(self, menuitem, event, n ):
        self.panel.add(None, None, self.field_name, self.master, force=True)
        
    def __repr__(self):
        return "<%s - %s>" % (self.__class__.__name__, self.master.get_label(self.field_name))

class FilterStringTool(FilterTool):

    def get_suitable_operators(self ):
        
        STD_OPERATORS = self.STR_STD_OPERATORS + self.STD_OPERATORS

        if self.bind_name.startswith('postgres'):
            return  ['~*', '~', '!~*', '!~' ] + STD_OPERATORS

        elif self.bind_name.startswith('mysql'):
            return [ 'REGEXP' ] + STD_OPERATORS

        else:
            return ['ICONTAINS'] + STD_OPERATORS
        
class FilterBooleanTool(FilterTool):

    def get_suitable_operators(self):
        return [ 'IS TRUE', 'IS FALSE', 'IS NOT TRUE', 'IS NOT FALSE' ] + self.NULL_OPERATORS

class FilterDateTool(FilterTool):


    def _compose_field_whereclause(self, query, value, op_value):
        """
        Implement the mini date algebra to allow for relative dates

        """

        try:
            start, stop = datetools.string2dates(value)
        except datetools.WrongRelativeDateFormat:
            msg = _("value '%s' does not seem a valid date and cannot be transformed into a date" % value)
            self.master.dialog(type='ok', icon='gtk-dialog-error', text=msg)
            raise exc.ParseFilterError

        # If 'stop' is not None it means I have a period (eg.: 'y > M')
        # and I use operators to delimit this
        # period ignoring the operator from the widget
                        
        op_value = self.get_operator()
        if not stop:
            query = query.filter(self.col.op(op_value)(start))
        else:
            ## start
            query = query.filter(self.col.op(">=")(start))
            ## stop
            query = query.filter(self.col.op("<=")(stop))

        return  query

    def get_value(self):
        # no cleaning of value until in _compose_field_whereclause
        return self.widget.get_value() 

    def string_representation(self, value):
        """
        when date algebra is used we dont need to do anything
        """
        if isinstance(value, date): 
            return FilterTool.string_representation(self, value)
        else:
            return value
        
        
class FilterFKeyTool(FilterTool):

    def __init__(self, field_name, panel, master):

        FilterTool.__init__(self, field_name, panel, master)

        foreign_keys = self.master.mapper_info.fields[self.field_name]['fkey']
        self.ftable, self.fcol = minspect.get_foreign_info(foreign_keys, names=False)

    def get_suitable_operators(self):

        if self.bind_name.startswith('postgres'):
            return  ['~*', '~', '!~*', '~*' ] + self.STD_OPERATORS

        elif self.bind_name.startswith('mysql'):
            return ['REGEXP' ] + self.STD_OPERATORS

        else:
            return ['ICONTAINS' ] + self.STD_OPERATORS

    def get_value(self):
        # no need to clean this value
        return self.widget.get_value()
    
    def string_representation(self, value):
        """
        a boolean must be always a string
        """
        return str(value)
    
    def _compose_field_whereclause(self, query, value, op_value):
        """return a sql whereclause for field

        In case field is a fkey, and the destination lookup field is not in
        the mapper, it composes a subselect
        """
        fdescr = get_description(self.ftable, attr='description')

        if op_value == "ILIKE":
            ids = select([self.fcol], self.ftable.columns[fdescr].ilike(value))
        else:
            ids = select([self.fcol], self.ftable.columns[fdescr].op(op_value)(value))

        query = query.reset_joinpoint()

        if self.master.relationship_path:
            query = query.join(*self.master.relationship_path)

        return query.filter(self.col.in_(ids))


def get_filter_widget(field_name, panel, master, value=None):
    """
    return an instance of a proper FilterTool according to type
    """

    args = field_name, panel, master
    if master.is_date(field_name) or master.is_datetime(field_name):
        return FilterDateTool(*args)

    elif master.is_fkey(field_name):
        return FilterFKeyTool(*args)

    elif master.is_boolean(field_name):
        return FilterBooleanTool(*args)
    
    elif master.is_number(field_name):
        return FilterTool(*args)
    
    else:
        return FilterStringTool(*args)
        


# _('output')  _('filter')


class FilterWidget(object):
    
    def __init__(self, tool):

        ## I'd like *not* to .present the widget for any successive field added
        ## but I have not been able to get focus on the window w/o .present()
        self.tool = tool
        self.label_text = tool.master.get_label(tool.field_name)

        ## labels
        self.field_name_event_box = gtk.EventBox()
        self.field_label           = gtk.Label(self.label_text)
        # TIP: appears in the menu in the filter panel to add a second entry of the same field
        label_str = _("Add a new filter on this field '%s'") % self.label_text.replace('_', '__')
        self.field_name_event_box.set_tooltip_text(label_str)
        self.check_button         = gtk.CheckButton()

        self.check_button.set_active(True)
        #self.tool.panel.l.tooltips.set_tip(self.check_button, _("Use this filter"))
        self.check_button.set_tooltip_text( _("Use this filter"))
        
        self.field_name_event_box.add(self.field_label)
        self.field_label.set_property('xalign', 0)
        self.field_name_event_box.connect('button-press-event', self.tool.add_filter_cb, 1)

        ## combo for operator
        self.operator = self.get_operator_chooser()

        ## get_active_text per riprenderlo...
        ## entry

        self.field_widget = gtk.Entry()
        self.field_widget.connect('focus-in-event', self.tool.panel.entry_focus_cb)
        self.field_widget.connect('activate', self.tool.panel.reload_cb)
        if isinstance(self.tool, FilterDateTool):
            self.field_widget.connect('changed', self.date_changed_cb)

        Tbl = self.tool.panel.w['T.fld']
        r = self.tool.panel.row
        c = 0
        widgets = [ self.field_name_event_box, self.operator, self.check_button ]
        ftype  = self.tool.master.get_field_type(self.tool.field_name)
        if not issubclass(ftype, bool):
            widgets += [self.field_widget]
            
        for wdg in widgets:
            Tbl.attach(wdg, c, c+1, r, r+1, xpadding=4)
            c += 1
        self.tool.panel.row += 1
        Tbl.show_all()
        self.field_widget.grab_focus()

    def get_operator_chooser(self):
        """
        Build the chooser for the operator.
        I used deprecated OptionMenu since ComboBox does not give the opportunity to
        add tooltips
        """

        operators = self.tool.get_suitable_operators()
        warnings.simplefilter('ignore', DeprecationWarning)
        operator = gtk.OptionMenu()
        operator.set_tooltip_text(_('Click here to select an operator'))
        warnings.resetwarnings()

        menu = gtk.Menu()
        operator.set_menu(menu)

        for op in operators:
            entry = gtk.MenuItem(op)
            menu.append(entry)
            entry.set_data('value', op)
            entry.set_tooltip_text(OP_MSGID[op])
        operator.set_history(0)

        return operator
        
    def set_active(self, active):
        self.check_button.set_active(active)

    def get_active(self):
        return self.check_button.get_active()

    def set_operator(self, op, value):
        """
        Set the active operator entry in ComboBox for operator choice
        """
        operator_list = self.tool.get_suitable_operators()
        if op == 'IS NULL' and value is False:
            op = 'IS NOT NULL'

        if op in '=' and isinstance(self.tool, FilterBooleanTool):
            if value == True:
                op = 'IS TRUE'
            else:
                op = 'IS FALSE'

        try:
            index = operator_list.index(op.upper())
            self.operator.set_history(index)
        except ValueError, e:
            print "operator '%s' not available in this context" % op.upper()
            print "used: %s -- list: %s" % (op, operator_list)
            raise
            pass

    def get_operator(self):
        """
        return operator set in widget
        """
        return self.operator.get_menu().get_active().get_data('value')

    def get_value(self):
        """
        return value of filter string if any
        """
        return self.field_widget.get_text() 
    
    def set_value(self, value):
        """
        set string for FilterWidget
        """
        
        self.field_widget.set_text(self.tool.string_representation(value))


    def date_changed_cb(self, entry, ):
        """
        date changed: show the new date and set a tooltip
        """
        try:
            dates_ = datetools.string2dates(entry.get_text())
        except:
            entry.set_tooltip_text('')
            self.tool.panel.l.sb(_('incomplete date format'))
            return
            
        dates_ = [dates.format_date(d, locale=dates.default_locale()) for d in dates_ if d]
        text = " - ".join(dates_)
        entry.set_tooltip_text(text)
        self.tool.panel.l.sb(text)


#     def pop_menu(self, wdg, ev, num_button):
#         print "POP_MENU", self, self.menu
#         if ev.button == num_button:
#             self.menu.popup(None, None, None, ev.button, ev.time )
        








