# Source code for svir.dialogs.transformation_dialog

    # -*- coding: utf-8 -*-
    # /***************************************************************************
    # Irmt
    #                                 A QGIS plugin
    # OpenQuake Integrated Risk Modelling Toolkit
    #                              -------------------
    #        begin                : 2013-10-24
    #        copyright            : (C) 2014 by GEM Foundation
    #        email                : devops@openquake.org
    # ***************************************************************************/
    #
    # OpenQuake is free software: you can redistribute it and/or modify it
    # under the terms of the GNU Affero General Public License as published
    # by the Free Software Foundation, either version 3 of the License, or
    # (at your option) any later version.
    #
    # OpenQuake 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 Affero General Public License
    # along with OpenQuake.  If not, see <http://www.gnu.org/licenses/>.

    from qgis.PyQt.QtCore import pyqtSlot
    from qgis.PyQt.QtWidgets import QDialog, QDialogButtonBox, QLabel, QHBoxLayout

    from svir.calculations.transformation_algs import (RANK_VARIANTS,
                                                       QUADRATIC_VARIANTS,
                                                       LOG10_VARIANTS,
                                                       TRANSFORMATION_ALGS)
    from svir.utilities.utils import get_ui_class, log_msg
    from svir.utilities.shared import NUMERIC_FIELD_TYPES
    from svir.calculations.process_layer import ProcessLayer
    from svir.ui.multi_select_combo_box import MultiSelectComboBox

    FORM_CLASS = get_ui_class('ui_transformation.ui')

    class TransformationDialog(QDialog, FORM_CLASS):
        """
        Modal dialog giving to the user the possibility to transform
        one or multiple attributes in the active layer, using one of the available
        algorithms and variants.
        """
        def __init__(self, iface):
            QDialog.__init__(self)
            self.iface = iface
            self.attr_name_user_def = False
            self.use_advanced = False
            # Set up the user interface from Designer.
            self.setupUi(self)
            self.fields_lbl = QLabel('Fields to transform')
            self.fields_multiselect = MultiSelectComboBox(self)
            hlayout = QHBoxLayout()
            hlayout.addWidget(self.fields_lbl)
            hlayout.addWidget(self.fields_multiselect)
            self.vertical_layout.insertLayout(1, hlayout)
            self.adjustSize()
            self.ok_button = self.buttonBox.button(QDialogButtonBox.Ok)
            self.fill_fields_multiselect()

            alg_list = list(TRANSFORMATION_ALGS.keys())
            self.algorithm_cbx.addItems(alg_list)
            if self.algorithm_cbx.currentText() in ['RANK', 'QUADRATIC']:
                self.reload_variant_cbx()
            self.inverse_ckb.setDisabled(
                self.algorithm_cbx.currentText() in ['LOG10'])
            self.warning_lbl.hide()
            self.warning_lbl.setText(
                "<font color='red'>"
                "WARNING: the original attribute will be overwritten by the"
                " results of the transformation (it can not be undone)"
                "</font>")
            self.fields_multiselect.selection_changed.connect(
                self.set_ok_button)
            self.fields_multiselect.selection_changed.connect(
                self.set_new_field_editable)
            self.fields_multiselect.selection_changed.connect(
                self.update_default_fieldname)
            self.set_ok_button()
            self.set_new_field_editable()

        def set_ok_button(self):
            self.ok_button.setEnabled(
                self.fields_multiselect.selected_count() > 0)

        def set_new_field_editable(self):
            n_fields_selected = self.fields_multiselect.selected_count()
            self.new_field_name_lbl.setEnabled(n_fields_selected == 1)
            self.new_field_name_txt.setEnabled(n_fields_selected == 1)

        @pyqtSlot(int)
        def on_overwrite_ckb_stateChanged(self):
            overwrite_checked = self.overwrite_ckb.isChecked()
            self.new_field_name_lbl.setDisabled(overwrite_checked)
            self.new_field_name_txt.setDisabled(overwrite_checked)
            self.track_new_field_ckb.setDisabled(overwrite_checked)
            if overwrite_checked:
                self.attr_name_user_def = False
                self.warning_lbl.show()
            else:
                self.warning_lbl.hide()
            self.update_default_fieldname()

        @pyqtSlot()
        def on_calc_btn_clicked(self):
            self.close()
            # layer is put in editing mode. If the user clicks on ok, the field
            # calculator will update the layers attributes.
            # if the user clicks cancel, the field calculator does nothing.
            # the layer stays in editing mode with the use_advanced flag set.
            # the calling code should take care of doing layer.commitChanges()
            # if the flag is set to true.
            self.use_advanced = True
            self.iface.activeLayer().startEditing()
            self.iface.actionOpenFieldCalculator().trigger()

        @pyqtSlot(str)
        def on_algorithm_cbx_currentIndexChanged(self):
            self.reload_variant_cbx()
            self.update_default_fieldname()

        @pyqtSlot(str)
        def on_variant_cbx_currentIndexChanged(self):
            self.update_default_fieldname()

        @pyqtSlot()
        def on_new_field_name_txt_editingFinished(self):
            self.attr_name_user_def = True
            new_field_name = self.new_field_name_txt.text()
            # if the name of the new field is empty, automatically assign a name
            if not new_field_name:
                self.update_default_fieldname()

        @pyqtSlot(str)
        def on_new_field_name_txt_textEdited(self):
            # we assume exactly one item is in the selected list
            input_field_name = self._extract_field_name(
                self.fields_multiselect.get_selected_items()[0])
            new_field_name = self.new_field_name_txt.text()
            # if the name of the new field is equal to the name of the input field,
            # automatically check the 'overwrite' checkbox (and consequently
            # display the warning)
            if new_field_name == input_field_name:
                self.overwrite_ckb.setChecked(True)

        def reload_variant_cbx(self):
            self.variant_cbx.clear()
            self.variant_cbx.setEnabled(True)
            if self.algorithm_cbx.currentText() == 'RANK':
                self.variant_cbx.addItems(RANK_VARIANTS)
            elif self.algorithm_cbx.currentText() == 'QUADRATIC':
                self.variant_cbx.addItems(QUADRATIC_VARIANTS)
            elif self.algorithm_cbx.currentText() == 'LOG10':
                self.variant_cbx.addItems(LOG10_VARIANTS)
            else:
                self.variant_cbx.setDisabled(True)
            self.inverse_ckb.setDisabled(
                self.algorithm_cbx.currentText() in ['LOG10'])

        def _extract_field_name(self, field_name_plus_alias):
            # attribute_name is something like 'ABCDEFGHIL (Readable name)'
            # and we want to use only the heading code
            return field_name_plus_alias.split('(')[0].strip()

        def update_default_fieldname(self):
            if self.fields_multiselect.selected_count() != 1:
                self.new_field_name_txt.setText('')
                self.attr_name_user_def = False
                return
            if (not self.attr_name_user_def
                    or not self.new_field_name_txt.text()):
                attribute_name = self._extract_field_name(
                    self.fields_multiselect.get_selected_items()[0])
                algorithm_name = self.algorithm_cbx.currentText()
                variant = self.variant_cbx.currentText()
                inverse = self.inverse_ckb.isChecked()
                if self.overwrite_ckb.isChecked():
                    new_attr_name = attribute_name
                else:
                    try:
                        new_attr_name = ProcessLayer(
                            self.iface.activeLayer()).transform_attribute(
                                attribute_name, algorithm_name, variant,
                                inverse, simulate=True)
                    except TypeError as exc:
                        log_msg(str(exc), level='C',
                                message_bar=self.iface.messageBar(),
                                exception=exc)
                        return
                self.new_field_name_txt.setText(new_attr_name)
                self.attr_name_user_def = False

        def fill_fields_multiselect(self):
            names_plus_aliases = []
            for field_idx, field in enumerate(self.iface.activeLayer().fields()):
                if field.typeName() in NUMERIC_FIELD_TYPES:
                    alias = self.iface.activeLayer().attributeAlias(field_idx)
                    if '(' in field.name():
                        msg = (
                            'Please remove parentheses from the name of field'
                            ' %s before attempting to transform it, otherwise'
                            ' the tool will not be able to distinguish between'
                            ' the alias and the part of the name included'
                            ' between parentheses. For instance, you may'
                            ' replace "(" with "[" to avoid ambiguity.'
                            % field.name())
                        log_msg(
                            msg, level='W', message_bar=self.iface.messageBar())
                    else:
                        name_plus_alias = field.name()
                        if alias:
                            name_plus_alias += ' (%s)' % alias
                        names_plus_aliases.append(name_plus_alias)
            self.fields_multiselect.add_unselected_items(names_plus_aliases)