"""
@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
import six

from core import globalvar
import wx

from grass.pydispatch.signal import Signal

from core.gcmd import RunCommand, GError, GMessage
from dbmgr.vinfo import CreateDbInfoDesc, VectorDBInfo, GetUnicodeValue
from gui_core.wrap import Button, TextCtrl, StaticText, StaticBox

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 = 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 = StaticBox(parent=self.panel, id=wx.ID_ANY,
                           label=" %s " % _("Query"))
        sqlboxsizer = wx.StaticBoxSizer(sqlbox, wx.VERTICAL)

        self.text_sql = 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 = Button(parent=self.panel, id=wx.ID_CLEAR)
        self.btn_clear.SetToolTip(_("Set SQL statement to default"))
        self.btn_apply = Button(parent=self.panel, id=wx.ID_APPLY)
        self.btn_apply.SetToolTip(_("Apply SQL statement"))
        self.btn_close = Button(parent=self.panel, id=wx.ID_CLOSE)
        self.btn_close.SetToolTip(_("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 six.iteritems(self.btn_logic):
            btn = 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 = 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)

        if modeChoices:
            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 = 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 = Button(parent=self.valuespanel, id=wx.ID_ANY,
                                    label=_("Get all values"))
        self.btn_unique.Enable(False)
        self.btn_uniquesample = Button(
            parent=self.valuespanel,
            id=wx.ID_ANY,
            label=_("Get sample"))
        self.btn_uniquesample.SetToolTip(
            _("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 = TextCtrl(
            parent=self.valuespanel,
            id=wx.ID_ANY,
            style=wx.TE_PROCESS_ENTER)
        gotosizer.Add(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)
        if modeChoices:
            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
        #
        if modeChoices:
            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 six.iteritems(self.btn_logic):
            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']

        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
        string = False
        for item in self.list_values.GetItems():
            if idx == 0 and item.startswith("'"):
                string = True
            if string:
                item = item[1:-1] # strip "'"
            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 six.iteritems(btns):
            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.SetToolTip(
            _("Example: %s") %
            "SELECT * FROM roadsmajor WHERE MULTILANE = 'no' OR OBJECTID < 10")

        self.btn_verify = Button(parent=self.panel, id=wx.ID_ANY,
                                    label=_("Verify"))
        self.btn_verify.SetToolTip(_("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 six.iteritems(self.btn_arithmetic):
            btn = 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 = 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 six.iteritems(self.btn_arithmetic):
            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 (,)']
        }

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

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

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

        super(SQLBuilderWhere, self).__init__(
            parent, title, vectmap, id=wx.ID_ANY, 
            layer=layer)
        
    def OnClear(self, event):
        self.text_sql.SetValue('')
        
    def OnApply(self, event):
        self.parent.SetValue(self.text_sql.GetValue())

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

        event.Skip()

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

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

        newsqlstr = ''
        if inspoint > 0 and sqlstr[inspoint-1] != ' ':
            newsqlstr += ' '
        newsqlstr += value
        if inspoint < len(sqlstr):
            newsqlstr += ' ' if sqlstr[inspoint] != ' ' else ''
        
        if newsqlstr:
            self.text_sql.SetValue(sqlstr[:inspoint] + newsqlstr + sqlstr[inspoint:])
            self.text_sql.SetInsertionPoint(inspoint + len(newsqlstr))
                    
        wx.CallAfter(self.text_sql.SetFocus)

        
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()
