Geografic-Information-System/gui/wxpython/dbmgr/sqlbuilder.py

"""
@package dbmgr.sqlbuilder

@brief GRASS SQL Select/Update Builder

Classes:
 - sqlbuilder::SQLBuilder
 - sqlbuilder::SQLBuilderSelect
 - sqlbuilder::SQLBuilderUpdate

Usage:
@code
python sqlbuilder.py select|update vector_map
@endcode

(C) 2007-2014 by the GRASS Development Team

This program is free software under the GNU General Public License
(>=v2). Read the file COPYING that comes with GRASS for details.

@author Jachym Cepicky <jachym.cepicky gmail.com> (original author)
@author Martin Landa <landa.martin gmail.com>
@author Hamish Bowman <hamish_b yahoo.com>
@author Refactoring, SQLBUilderUpdate by Stepan Turek <stepan.turek seznam.cz> (GSoC 2012, mentor: Martin Landa)
"""

from __future__ import print_function

import os
import sys

from core import globalvar
from core.utils import _
import wx

from grass.pydispatch.signal import Signal

from core.gcmd import RunCommand, GError, GMessage
from dbmgr.vinfo import CreateDbInfoDesc, VectorDBInfo, GetUnicodeValue

import grass.script as grass


class SQLBuilder(wx.Frame):
    """SQLBuider class
    Base class for classes, which builds SQL statements.
    """

    def __init__(self, parent, title, vectmap, modeChoices, id=wx.ID_ANY,
                 layer=1):
        wx.Frame.__init__(self, parent, id, title)

        self.SetIcon(wx.Icon(os.path.join(globalvar.ICONDIR, 'grass_sql.ico'),
                             wx.BITMAP_TYPE_ICO))

        self.parent = parent

        # variables
        self.vectmap = vectmap  # fullname
        if not "@" in self.vectmap:
            self.vectmap = grass.find_file(
                self.vectmap, element='vector')['fullname']
            if not self.vectmap:
                grass.fatal(_("Vector map <%s> not found") % vectmap)
        self.mapname, self.mapset = self.vectmap.split("@", 1)

        # db info
        self.layer = layer
        self.dbInfo = VectorDBInfo(self.vectmap)
        self.tablename = self.dbInfo.GetTable(self.layer)
        self.driver, self.database = self.dbInfo.GetDbSettings(self.layer)

        self.colvalues = []     # array with unique values in selected column

        self.panel = wx.Panel(parent=self, id=wx.ID_ANY)

        # statusbar
        self.statusbar = self.CreateStatusBar(number=1)

        self._doLayout(modeChoices)

        self.panel.SetAutoLayout(True)
        self.panel.SetSizer(self.pagesizer)
        self.pagesizer.Fit(self.panel)

        self.SetMinSize((400, 600))
        self.SetClientSize(self.panel.GetSize())
        self.CenterOnParent()

    def _doLayout(self, modeChoices, showDbInfo=False):
        """Do dialog layout"""

        self.pagesizer = wx.BoxSizer(wx.VERTICAL)

        # dbInfo
        if showDbInfo:
            databasebox = wx.StaticBox(parent=self.panel, id=wx.ID_ANY,
                                   label=" %s " % _("Database connection"))
            databaseboxsizer = wx.StaticBoxSizer(databasebox, wx.VERTICAL)
            databaseboxsizer.Add(
                CreateDbInfoDesc(
                    self.panel,
                    self.dbInfo,
                    layer=self.layer),
                proportion=1,
                flag=wx.EXPAND | wx.ALL,
                border=3)
        
        #
        # text areas
        #
        # sql box
        sqlbox = wx.StaticBox(parent=self.panel, id=wx.ID_ANY,
                              label=" %s " % _("Query"))
        sqlboxsizer = wx.StaticBoxSizer(sqlbox, wx.VERTICAL)

        self.text_sql = wx.TextCtrl(parent=self.panel, id=wx.ID_ANY,
                                    value='', size=(-1, 50),
                                    style=wx.TE_MULTILINE)

        self.text_sql.SetInsertionPointEnd()
        wx.CallAfter(self.text_sql.SetFocus)

        sqlboxsizer.Add(self.text_sql, flag=wx.EXPAND)

        #
        # buttons
        #
        self.btn_clear = wx.Button(parent=self.panel, id=wx.ID_CLEAR)
        self.btn_clear.SetToolTipString(_("Set SQL statement to default"))
        self.btn_apply = wx.Button(parent=self.panel, id=wx.ID_APPLY)
        self.btn_apply.SetToolTipString(
            _("Apply SQL statement in Attribute Table Manager"))
        self.btn_close = wx.Button(parent=self.panel, id=wx.ID_CLOSE)
        self.btn_close.SetToolTipString(_("Close the dialog"))

        self.btn_logic = {'is': ['=', ],
                          'isnot': ['!=', ],
                          'like': ['LIKE', ],
                          'gt': ['>', ],
                          'ge': ['>=', ],
                          'lt': ['<', ],
                          'le': ['<=', ],
                          'or': ['OR', ],
                          'not': ['NOT', ],
                          'and': ['AND', ],
                          'brac': ['()', ],
                          'prc': ['%', ]}

        self.btn_logicpanel = wx.Panel(parent=self.panel, id=wx.ID_ANY)
        for key, value in self.btn_logic.iteritems():
            btn = wx.Button(parent=self.btn_logicpanel, id=wx.ID_ANY,
                            label=value[0])
            self.btn_logic[key].append(btn.GetId())

        self.buttonsizer = wx.FlexGridSizer(cols=4, hgap=5, vgap=5)
        self.buttonsizer.Add(self.btn_clear)
        self.buttonsizer.Add(self.btn_apply)
        self.buttonsizer.Add(self.btn_close)

        btn_logicsizer = wx.GridBagSizer(5, 5)
        btn_logicsizer.Add(
            self.FindWindowById(
                self.btn_logic['is'][1]), pos=(
                0, 0))
        btn_logicsizer.Add(
            self.FindWindowById(
                self.btn_logic['isnot'][1]), pos=(
                1, 0))
        btn_logicsizer.Add(
            self.FindWindowById(
                self.btn_logic['like'][1]), pos=(
                2, 0))

        btn_logicsizer.Add(
            self.FindWindowById(
                self.btn_logic['gt'][1]), pos=(
                0, 1))
        btn_logicsizer.Add(
            self.FindWindowById(
                self.btn_logic['ge'][1]), pos=(
                1, 1))
        btn_logicsizer.Add(
            self.FindWindowById(
                self.btn_logic['or'][1]), pos=(
                2, 1))

        btn_logicsizer.Add(
            self.FindWindowById(
                self.btn_logic['lt'][1]), pos=(
                0, 2))
        btn_logicsizer.Add(
            self.FindWindowById(
                self.btn_logic['le'][1]), pos=(
                1, 2))
        btn_logicsizer.Add(
            self.FindWindowById(
                self.btn_logic['not'][1]), pos=(
                2, 2))

        btn_logicsizer.Add(
            self.FindWindowById(
                self.btn_logic['brac'][1]), pos=(
                0, 3))
        btn_logicsizer.Add(
            self.FindWindowById(
                self.btn_logic['prc'][1]), pos=(
                1, 3))
        btn_logicsizer.Add(
            self.FindWindowById(
                self.btn_logic['and'][1]), pos=(
                2, 3))

        self.btn_logicpanel.SetSizer(btn_logicsizer)

        #
        # list boxes (columns, values)
        #
        self.hsizer = wx.BoxSizer(wx.HORIZONTAL)

        columnsbox = wx.StaticBox(parent=self.panel, id=wx.ID_ANY,
                                  label=" %s " % _("Columns"))
        columnsizer = wx.StaticBoxSizer(columnsbox, wx.VERTICAL)
        self.list_columns = wx.ListBox(
            parent=self.panel,
            id=wx.ID_ANY,
            choices=self.dbInfo.GetColumns(
                self.tablename),
            style=wx.LB_MULTIPLE)
        columnsizer.Add(self.list_columns, proportion=1,
                        flag=wx.EXPAND)

        modesizer = wx.BoxSizer(wx.VERTICAL)

        self.mode = wx.RadioBox(parent=self.panel, id=wx.ID_ANY,
                                label=" %s " % _("Interactive insertion"),
                                choices=modeChoices,
                                style=wx.RA_SPECIFY_COLS,
                                majorDimension=1)

        self.mode.SetSelection(1)  # default 'values'
        modesizer.Add(self.mode, proportion=1,
                      flag=wx.ALIGN_CENTER_HORIZONTAL | wx.EXPAND, border=5)

        # self.list_columns.SetMinSize((-1,130))
        # self.list_values.SetMinSize((-1,100))

        self.valuespanel = wx.Panel(parent=self.panel, id=wx.ID_ANY)
        valuesbox = wx.StaticBox(parent=self.valuespanel, id=wx.ID_ANY,
                                 label=" %s " % _("Values"))
        valuesizer = wx.StaticBoxSizer(valuesbox, wx.VERTICAL)
        self.list_values = wx.ListBox(parent=self.valuespanel, id=wx.ID_ANY,
                                      choices=self.colvalues,
                                      style=wx.LB_MULTIPLE)
        valuesizer.Add(self.list_values, proportion=1,
                       flag=wx.EXPAND)
        self.valuespanel.SetSizer(valuesizer)

        self.btn_unique = wx.Button(parent=self.valuespanel, id=wx.ID_ANY,
                                    label=_("Get all values"))
        self.btn_unique.Enable(False)
        self.btn_uniquesample = wx.Button(
            parent=self.valuespanel,
            id=wx.ID_ANY,
            label=_("Get sample"))
        self.btn_uniquesample.SetToolTipString(
            _("Get first 256 unique values as sample"))
        self.btn_uniquesample.Enable(False)

        buttonsizer3 = wx.BoxSizer(wx.HORIZONTAL)
        buttonsizer3.Add(self.btn_uniquesample, proportion=0,
                         flag=wx.ALIGN_CENTER_HORIZONTAL | wx.RIGHT, border=5)
        buttonsizer3.Add(self.btn_unique, proportion=0,
                         flag=wx.ALIGN_CENTER_HORIZONTAL)

        valuesizer.Add(buttonsizer3, proportion=0,
                       flag=wx.TOP, border=5)

        # go to
        gotosizer = wx.BoxSizer(wx.HORIZONTAL)
        self.goto = wx.TextCtrl(
            parent=self.valuespanel,
            id=wx.ID_ANY,
            style=wx.TE_PROCESS_ENTER)
        gotosizer.Add(wx.StaticText(parent=self.valuespanel, id=wx.ID_ANY,
                                    label=_("Go to:")), proportion=0,
                      flag=wx.ALIGN_CENTER_VERTICAL | wx.RIGHT, border=5)
        gotosizer.Add(self.goto, proportion=1,
                      flag=wx.EXPAND)
        valuesizer.Add(gotosizer, proportion=0,
                       flag=wx.ALL | wx.EXPAND, border=5)

        self.hsizer.Add(columnsizer, proportion=1,
                        flag=wx.EXPAND)
        self.hsizer.Add(self.valuespanel, proportion=1,
                        flag=wx.EXPAND)

        self.close_onapply = wx.CheckBox(parent=self.panel, id=wx.ID_ANY,
                                         label=_("Close dialog on apply"))
        self.close_onapply.SetValue(True)

        if showDbInfo:
            self.pagesizer.Add(databaseboxsizer,
                               flag=wx.ALL | wx.EXPAND, border=5)
        self.pagesizer.Add(
            modesizer,
            proportion=0,
            flag=wx.LEFT | wx.RIGHT | wx.BOTTOM | wx.EXPAND,
            border=5)
        self.pagesizer.Add(
            self.hsizer,
            proportion=1,
            flag=wx.LEFT | wx.RIGHT | wx.BOTTOM | wx.EXPAND,
            border=5)
        # self.pagesizer.Add(self.btn_uniqe,0,wx.ALIGN_LEFT|wx.TOP,border=5)
        # self.pagesizer.Add(self.btn_uniqesample,0,wx.ALIGN_LEFT|wx.TOP,border=5)
        self.pagesizer.Add(self.btn_logicpanel, proportion=0,
                           flag=wx.ALIGN_CENTER_HORIZONTAL)
        self.pagesizer.Add(sqlboxsizer, proportion=0,
                           flag=wx.EXPAND | wx.LEFT | wx.RIGHT, border=5)
        self.pagesizer.Add(self.buttonsizer, proportion=0,
                           flag=wx.ALIGN_RIGHT | wx.ALL, border=5)
        self.pagesizer.Add(
            self.close_onapply,
            proportion=0,
            flag=wx.LEFT | wx.RIGHT | wx.BOTTOM | wx.EXPAND,
            border=5)

        #
        # bindings
        #
        self.mode.Bind(wx.EVT_RADIOBOX, self.OnMode)
        # self.text_sql.Bind(wx.EVT_ACTIVATE, self.OnTextSqlActivate)TODO

        self.btn_unique.Bind(wx.EVT_BUTTON, self.OnUniqueValues)
        self.btn_uniquesample.Bind(wx.EVT_BUTTON, self.OnSampleValues)

        for key, value in self.btn_logic.iteritems():
            self.FindWindowById(value[1]).Bind(wx.EVT_BUTTON, self.OnAddMark)

        self.btn_close.Bind(wx.EVT_BUTTON, self.OnClose)
        self.btn_clear.Bind(wx.EVT_BUTTON, self.OnClear)
        self.btn_apply.Bind(wx.EVT_BUTTON, self.OnApply)

        self.list_columns.Bind(wx.EVT_LISTBOX, self.OnAddColumn)
        self.list_values.Bind(wx.EVT_LISTBOX, self.OnAddValue)
        self.goto.Bind(wx.EVT_TEXT, self.OnGoTo)
        self.goto.Bind(wx.EVT_TEXT_ENTER, self.OnAddValue)

    def OnUniqueValues(self, event, justsample=False):
        """Get unique values"""
        vals = []
        try:
            idx = self.list_columns.GetSelections()[0]
            column = self.list_columns.GetString(idx)
        except:
            self.list_values.Clear()
            return

        self.list_values.Clear()

        sql = "SELECT DISTINCT {column} FROM {table} ORDER BY {column}".format(
            column=column, table=self.tablename)
        if justsample:
            sql += " LIMIT {}".format(255)
        data = grass.db_select(
            sql=sql,
            database=self.database,
            driver=self.driver,
            sep='{_sep_}')
        if not data:
            return

        desc = self.dbInfo.GetTableDesc(
            self.dbInfo.GetTable(self.layer))[column]

        i = 0
        items = []
        for item in data: #sorted(set(map(lambda x: desc['ctype'](x[0]), data))):
            if desc['type'] not in ('character', 'text'):
                items.append(str(item[0]))
            else:
                items.append(u"'{}'".format(GetUnicodeValue(item[0])))
            i += 1

        self.list_values.AppendItems(items)
        
    def OnSampleValues(self, event):
        """Get sample values"""
        self.OnUniqueValues(None, True)

    def OnAddColumn(self, event):
        """Add column name to the query"""
        idx = self.list_columns.GetSelections()
        for i in idx:
            column = self.list_columns.GetString(i)
            self._add(element='column', value=column)

        if not self.btn_uniquesample.IsEnabled():
            self.btn_uniquesample.Enable(True)
            self.btn_unique.Enable(True)

    def OnAddValue(self, event):
        """Add value"""
        selection = self.list_values.GetSelections()
        if not selection:
            event.Skip()
            return

        idx = selection[0]
        value = self.list_values.GetString(idx)
        idx = self.list_columns.GetSelections()[0]
        column = self.list_columns.GetString(idx)

        ctype = self.dbInfo.GetTableDesc(
            self.dbInfo.GetTable(
                self.layer))[column]['type']

        if ctype == 'character':
            value = "'%s'" % value

        self._add(element='value', value=value)

    def OnGoTo(self, event):
        # clear all previous selections
        for item in self.list_values.GetSelections():
            self.list_values.Deselect(item)

        gotoText = event.GetString()
        lenLimit = len(gotoText)
        found = idx = 0
        for item in self.list_values.GetItems():
            if item[:lenLimit] == gotoText:
                found = idx
                break
            idx += 1

        if found > 0:
            self.list_values.SetSelection(found)

    def OnAddMark(self, event):
        """Add mark"""
        mark = None
        if self.btn_logicpanel and \
           self.btn_logicpanel.IsShown():
            btns = self.btn_logic
        elif self.btn_arithmeticpanel and \
                self.btn_arithmeticpanel.IsShown():
            btns = self.btn_arithmetic

        for key, value in btns.iteritems():
            if event.GetId() == value[1]:
                mark = value[0]
                break

        self._add(element='mark', value=mark)

    def GetSQLStatement(self):
        """Return SQL statement"""
        return self.text_sql.GetValue().strip().replace("\n", " ")

    def OnClose(self, event):
        self.Destroy()
        event.Skip()


class SQLBuilderSelect(SQLBuilder):
    """Class for building SELECT SQL statement"""

    def __init__(self, parent, vectmap, id=wx.ID_ANY,
                 layer=1, evtHandler=None):

        self.evtHandler = evtHandler

        # set dialog title
        title = _("GRASS SQL Builder (%(type)s) - <%(map)s>") % \
            {'type': "SELECT", 'map': vectmap}

        modeChoices = [_("Column to show (SELECT clause)"),
                       _("Constraint for query (WHERE clause)")]

        SQLBuilder.__init__(self, parent, title, vectmap, id=wx.ID_ANY,
                            modeChoices=modeChoices, layer=layer)

    def _doLayout(self, modeChoices):
        """Do dialog layout"""

        SQLBuilder._doLayout(self, modeChoices)

        self.text_sql.SetValue("SELECT * FROM %s" % self.tablename)
        self.text_sql.SetToolTipString(
            _("Example: %s") %
            "SELECT * FROM roadsmajor WHERE MULTILANE = 'no' OR OBJECTID < 10")

        self.btn_verify = wx.Button(parent=self.panel, id=wx.ID_ANY,
                                    label=_("Verify"))
        self.btn_verify.SetToolTipString(_("Verify SQL statement"))

        self.buttonsizer.Insert(1, self.btn_verify)

        self.text_sql.Bind(wx.EVT_TEXT, self.OnText)
        self.btn_verify.Bind(wx.EVT_BUTTON, self.OnVerify)

        self.text_sql.SetInsertionPoint(self.text_sql.GetLastPosition())
        self.statusbar.SetStatusText(_("SQL statement not verified"), 0)

    def OnApply(self, event):
        """Apply button pressed"""
        if self.evtHandler:
            self.evtHandler(event='apply')

        if self.close_onapply.IsChecked():
            self.Destroy()

        event.Skip()

    def OnClear(self, event):
        """Clear button pressed"""
        self.text_sql.SetValue("SELECT * FROM %s" % self.tablename)

    def OnMode(self, event):
        """Adjusts builder for chosen mode"""
        if self.mode.GetSelection() == 0:
            self.valuespanel.Hide()
            self.btn_logicpanel.Hide()
        elif self.mode.GetSelection() == 1:
            self.valuespanel.Show()
            self.btn_logicpanel.Show()
        self.pagesizer.Layout()

    def OnText(self, event):
        """Query string changed"""
        if len(self.text_sql.GetValue()) > 0:
            self.btn_verify.Enable(True)
        else:
            self.btn_verify.Enable(False)

    def OnVerify(self, event):
        """Verify button pressed"""
        ret, msg = RunCommand('db.select',
                              getErrorMsg=True,
                              table=self.tablename,
                              sql=self.text_sql.GetValue(),
                              flags='t',
                              driver=self.driver,
                              database=self.database)

        if ret != 0 and msg:
            self.statusbar.SetStatusText(_("SQL statement is not valid"), 0)
            GError(parent=self,
                   message=_("SQL statement is not valid.\n\n%s") % msg)
        else:
            self.statusbar.SetStatusText(_("SQL statement is valid"), 0)

    def _add(self, element, value):
        """Add element to the query

        :param element: element to add (column, value)
        """
        sqlstr = self.text_sql.GetValue()
        curspos = self.text_sql.GetInsertionPoint()
        newsqlstr = ''
        if element == 'column':
            if self.mode.GetSelection() == 0:  # -> column
                idx1 = len('select')
                idx2 = sqlstr.lower().find('from')
                colstr = sqlstr[idx1:idx2].strip()
                if colstr == '*':
                    cols = []
                else:
                    cols = colstr.split(',')
                if value in cols:
                    cols.remove(value)
                else:
                    cols.append(value)

                if len(cols) < 1:
                    cols = ['*', ]
                newsqlstr = 'SELECT ' + ','.join(cols) + ' '
                curspos = len(newsqlstr)
                newsqlstr += sqlstr[idx2:]
            else:  # -> where
                newsqlstr = ''
                if sqlstr.lower().find('where') < 0:
                    newsqlstr += ' WHERE'
                newsqlstr += ' ' + value
                curspos = self.text_sql.GetLastPosition() + len(newsqlstr)
                newsqlstr = sqlstr + newsqlstr

        elif element in ['value', 'mark']:
            addstr = ' ' + value + ' '
            newsqlstr = sqlstr[:curspos] + addstr + sqlstr[curspos:]
            curspos += len(addstr)

        if newsqlstr:
            self.text_sql.SetValue(newsqlstr)

        wx.CallAfter(self.text_sql.SetFocus)
        self.text_sql.SetInsertionPoint(curspos)

    def CloseOnApply(self):
        """Return True if the dialog will be close on apply"""
        return self.close_onapply.IsChecked()

    def OnClose(self, event):
        """Close button pressed"""
        if self.evtHandler:
            self.evtHandler(event='close')

        SQLBuilder.OnClose(self, event)


class SQLBuilderUpdate(SQLBuilder):
    """Class for building UPDATE SQL statement"""

    def __init__(self, parent, vectmap, id=wx.ID_ANY,
                 layer=1, column=None):

        self.column = column
        # set dialog title
        title = _("GRASS SQL Builder (%(type)s) - <%(map)s>") % \
            {'type': "UPDATE", 'map': vectmap}

        modeChoices = [_("Column to set (SET clause)"),
                       _("Constraint for query (WHERE clause)"),
                       _("Calculate column value to set")]

        SQLBuilder.__init__(self, parent, title, vectmap, id=wx.ID_ANY,
                            modeChoices=modeChoices, layer=layer)

        # signals
        self.sqlApplied = Signal("SQLBuilder.sqlApplied")
        if parent:  # TODO: replace by giface
            self.sqlApplied.connect(parent.Update)

    def _doLayout(self, modeChoices):
        """Do dialog layout"""

        SQLBuilder._doLayout(self, modeChoices)

        self.initText = "UPDATE %s SET" % self.tablename
        if self.column:
            self.initText += " %s = " % self.column

        self.text_sql.SetValue(self.initText)

        self.btn_arithmetic = {'eq': ['=', ],
                               'brac': ['()', ],
                               'plus': ['+', ],
                               'minus': ['-', ],
                               'divide': ['/', ],
                               'multiply': ['*', ]}

        self.btn_arithmeticpanel = wx.Panel(parent=self.panel, id=wx.ID_ANY)

        for key, value in self.btn_arithmetic.iteritems():
            btn = wx.Button(parent=self.btn_arithmeticpanel, id=wx.ID_ANY,
                            label=value[0])
            self.btn_arithmetic[key].append(btn.GetId())

        btn_arithmeticsizer = wx.GridBagSizer(hgap=5, vgap=5)

        btn_arithmeticsizer.Add(
            self.FindWindowById(
                self.btn_arithmetic['eq'][1]), pos=(
                0, 0))
        btn_arithmeticsizer.Add(
            self.FindWindowById(
                self.btn_arithmetic['brac'][1]), pos=(
                1, 0))

        btn_arithmeticsizer.Add(
            self.FindWindowById(
                self.btn_arithmetic['plus'][1]), pos=(
                0, 1))
        btn_arithmeticsizer.Add(
            self.FindWindowById(
                self.btn_arithmetic['minus'][1]), pos=(
                1, 1))

        btn_arithmeticsizer.Add(
            self.FindWindowById(
                self.btn_arithmetic['divide'][1]), pos=(
                0, 2))
        btn_arithmeticsizer.Add(
            self.FindWindowById(
                self.btn_arithmetic['multiply'][1]), pos=(
                1, 2))

        self.btn_arithmeticpanel.SetSizer(btn_arithmeticsizer)

        self.pagesizer.Insert(3, self.btn_arithmeticpanel,
                              proportion=0, flag=wx.ALIGN_CENTER_HORIZONTAL)

        self.funcpanel = wx.Panel(parent=self.panel, id=wx.ID_ANY)
        self._initSqlFunctions()
        funcsbox = wx.StaticBox(parent=self.funcpanel, id=wx.ID_ANY,
                                label=" %s " % _("Functions"))
        funcsizer = wx.StaticBoxSizer(funcsbox, wx.VERTICAL)
        self.list_func = wx.ListBox(parent=self.funcpanel, id=wx.ID_ANY,
                                    choices=self.sqlFuncs['sqlite'].keys(),
                                    style=wx.LB_SORT)

        funcsizer.Add(self.list_func, proportion=1,
                      flag=wx.EXPAND)

        self.funcpanel.SetSizer(funcsizer)

        self.hsizer.Insert(2, self.funcpanel,
                           proportion=1, flag=wx.EXPAND)

        self.list_func.Bind(wx.EVT_LISTBOX, self.OnAddFunc)
        for key, value in self.btn_arithmetic.iteritems():
            self.FindWindowById(value[1]).Bind(wx.EVT_BUTTON, self.OnAddMark)
        self.mode.SetSelection(0)
        self.OnMode(None)
        self.text_sql.SetInsertionPoint(self.text_sql.GetLastPosition())

    def OnApply(self, event):
        """Apply button pressed"""

        ret, msg = RunCommand('db.execute',
                              getErrorMsg=True,
                              parent=self,
                              stdin=self.text_sql.GetValue(),
                              input='-',
                              driver=self.driver,
                              database=self.database)

        if ret != 0 and msg:
            self.statusbar.SetStatusText(_("SQL statement was not applied"), 0)
        else:
            self.statusbar.SetStatusText(_("SQL statement applied"), 0)

        self.sqlApplied.emit()

    def OnClear(self, event):
        """Clear button pressed"""
        self.text_sql.SetValue(self.initText)

    def OnMode(self, event):
        """Adjusts builder for chosen mode"""
        if self.mode.GetSelection() == 0:
            self.valuespanel.Hide()
            self.btn_logicpanel.Hide()
            self.btn_arithmeticpanel.Hide()
            self.funcpanel.Hide()
        elif self.mode.GetSelection() == 1:
            self.valuespanel.Show()
            self.btn_logicpanel.Show()
            self.btn_arithmeticpanel.Hide()
            self.funcpanel.Hide()
        elif self.mode.GetSelection() == 2:
            self.valuespanel.Hide()
            self.btn_logicpanel.Hide()
            self.btn_arithmeticpanel.Show()
            self.funcpanel.Show()
        self.pagesizer.Layout()

    def OnAddFunc(self, event):
        """Add function to the query"""

        if self.driver == 'dbf':
            GMessage(
                parent=self,
                message=_(
                    "Dbf driver does not support usage of SQL functions."))
            return

        idx = self.list_func.GetSelections()
        for i in idx:
            func = self.sqlFuncs['sqlite'][self.list_func.GetString(i)][0]
            self._add(element='func', value=func)

    def _add(self, element, value):
        """Add element to the query

        :param element: element to add (column, value)
        """
        sqlstr = self.text_sql.GetValue()
        curspos = self.text_sql.GetInsertionPoint()
        newsqlstr = ''

        if element in  ['value', 'mark', 'func'] or \
                (element == 'column' and self.mode.GetSelection() == 2):
            addstr = ' ' + value + ' '
            newsqlstr = sqlstr[:curspos] + addstr + sqlstr[curspos:]
            curspos += len(addstr)
        elif element == 'column':
            if self.mode.GetSelection() == 0:  # -> column
                idx1 = sqlstr.lower().find('set') + len('set')
                idx2 = sqlstr.lower().find('where')

                if idx2 >= 0:
                    colstr = sqlstr[idx1:idx2].strip()
                else:
                    colstr = sqlstr[idx1:].strip()

                cols = [col.split('=')[0].strip() for col in colstr.split(',')]
                if unicode(value) in cols:
                    self.text_sql.SetInsertionPoint(curspos)
                    wx.CallAfter(self.text_sql.SetFocus)
                    return
                if colstr:
                    colstr += ','
                colstr = ' ' + colstr
                colstr += ' ' + value + '= '
                newsqlstr = sqlstr[:idx1] + colstr
                if idx2 >= 0:
                    newsqlstr += sqlstr[idx2:]
                curspos = idx1 + len(colstr)

            elif self.mode.GetSelection() == 1:  # -> where
                newsqlstr = ''
                if sqlstr.lower().find('where') < 0:
                    newsqlstr += ' WHERE'
                newsqlstr += ' ' + value
                curspos = self.text_sql.GetLastPosition() + len(newsqlstr)
                newsqlstr = sqlstr + newsqlstr

        if newsqlstr:
            self.text_sql.SetValue(newsqlstr)

        wx.CallAfter(self.text_sql.SetFocus)
        self.text_sql.SetInsertionPoint(curspos)

    def _initSqlFunctions(self):

        self.sqlFuncs = {}
        # TODO add functions for other drivers
        self.sqlFuncs['sqlite'] = {
            'ABS': ['ABS()'],
            'LENGTH': ['LENGTH()'],
            'LOWER': ['LOWER()'],
            'LTRIM': ['LTRIM(,)'],
            'MAX': ['MAX()'],
            'MIN': ['MIN()'],
            'RTRIM': ['RTRIM(,)'],
            'SUBSTR': ['SUBSTR (,[,])'],
            'TRIM': ['TRIM (,)']
        }

if __name__ == "__main__":
    if len(sys.argv) not in [3, 4]:
        print(__doc__, file=sys.stderr)
        sys.exit()

    if len(sys.argv) == 3:
        layer = 1
    else:
        layer = int(sys.argv[3])

    if sys.argv[1] == 'select':
        sqlBuilder = SQLBuilderSelect
    elif sys.argv[1] == 'update':
        sqlBuilder = SQLBuilderUpdate
    else:
        print(__doc__, file=sys.stderr)
        sys.exit()

    app = wx.App(0)
    sqlb = sqlBuilder(parent=None, vectmap=sys.argv[2], layer=layer)
    sqlb.Show()

    app.MainLoop()