# ------------------------------------------------------------------------------
# Copyright (c) 2008, Riverbank Computing Limited
# All rights reserved.
#
# This software is provided without warranty under the terms of the BSD license.
# However, when used with the GPL version of PyQt the additional terms
# described in the PyQt GPL exception also apply

#
# Author: Riverbank Computing Limited
# ------------------------------------------------------------------------------

""" Defines the various range editors and the range editor factory, for the
PyQt user interface toolkit.
"""


from math import log10

from pyface.qt import QtCore, QtGui

from traits.api import TraitError, Str, Float, Any, Bool

# FIXME: ToolkitEditorFactory is a proxy class defined here just for backward
# compatibility. The class has been moved to the
# traitsui.editors.range_editor file.
from traitsui.editors.range_editor import ToolkitEditorFactory

from .editor_factory import TextEditor

from .editor import Editor

from .constants import OKColor, ErrorColor

from .helper import IconButton


# -------------------------------------------------------------------------
#  'BaseRangeEditor' class:
# -------------------------------------------------------------------------


class BaseRangeEditor(Editor):
    """ The base class for Range editors. Using an evaluate trait, if specified,
        when assigning numbers the object trait.
    """

    # -------------------------------------------------------------------------
    #  Trait definitions:
    # -------------------------------------------------------------------------

    #: Function to evaluate floats/ints
    evaluate = Any()

    def _set_value(self, value):
        if self.evaluate is not None:
            value = self.evaluate(value)
        Editor._set_value(self, value)


class SimpleSliderEditor(BaseRangeEditor):
    """ Simple style of range editor that displays a slider and a text field.

    The user can set a value either by moving the slider or by typing a value
    in the text field.
    """

    # -------------------------------------------------------------------------
    #  Trait definitions:
    # -------------------------------------------------------------------------

    #: Low value for the slider range
    low = Any()

    #: High value for the slider range
    high = Any()

    #: Formatting string used to format value and labels
    format = Str()

    def init(self, parent):
        """ Finishes initializing the editor by creating the underlying toolkit
            widget.
        """
        factory = self.factory
        if not factory.low_name:
            self.low = factory.low

        if not factory.high_name:
            self.high = factory.high

        self.format = factory.format

        self.evaluate = factory.evaluate
        self.sync_value(factory.evaluate_name, "evaluate", "from")

        self.sync_value(factory.low_name, "low", "from")
        self.sync_value(factory.high_name, "high", "from")

        self.control = QtGui.QWidget()
        panel = QtGui.QHBoxLayout(self.control)
        panel.setContentsMargins(0, 0, 0, 0)

        fvalue = self.value

        try:
            if not (self.low <= fvalue <= self.high):
                fvalue = self.low
            fvalue_text = self.format % fvalue
        except:
            fvalue_text = ""
            fvalue = self.low

        ivalue = self._convert_to_slider(fvalue)

        self._label_lo = QtGui.QLabel()
        self._label_lo.setAlignment(
            QtCore.Qt.AlignRight | QtCore.Qt.AlignVCenter
        )
        if factory.label_width > 0:
            self._label_lo.setMinimumWidth(factory.label_width)
        panel.addWidget(self._label_lo)

        self.control.slider = slider = QtGui.QSlider(QtCore.Qt.Horizontal)
        slider.setTracking(factory.auto_set)
        slider.setMinimum(0)
        slider.setMaximum(10000)
        slider.setPageStep(1000)
        slider.setSingleStep(100)
        slider.setValue(ivalue)
        slider.valueChanged.connect(self.update_object_on_scroll)
        panel.addWidget(slider)

        self._label_hi = QtGui.QLabel()
        panel.addWidget(self._label_hi)
        if factory.label_width > 0:
            self._label_hi.setMinimumWidth(factory.label_width)

        self.control.text = text = QtGui.QLineEdit(fvalue_text)
        text.editingFinished.connect(self.update_object_on_enter)

        # The default size is a bit too big and probably doesn't need to grow.
        sh = text.sizeHint()
        sh.setWidth(sh.width() // 2)
        text.setMaximumSize(sh)

        panel.addWidget(text)

        low_label = factory.low_label
        if factory.low_name != "":
            low_label = self.format % self.low

        high_label = factory.high_label
        if factory.high_name != "":
            high_label = self.format % self.high

        self._label_lo.setText(low_label)
        self._label_hi.setText(high_label)

        self.set_tooltip(slider)
        self.set_tooltip(self._label_lo)
        self.set_tooltip(self._label_hi)
        self.set_tooltip(text)

    def update_object_on_scroll(self, pos):
        """ Handles the user changing the current slider value.
        """
        value = self._convert_from_slider(pos)
        self.control.text.setText(self.format % value)
        try:
            self.value = value
        except Exception as exc:
            from traitsui.api import raise_to_debug

            raise_to_debug()

    def update_object_on_enter(self):
        """ Handles the user pressing the Enter key in the text field.
        """
        # it is possible we get the event after the control has gone away
        if self.control is None:
            return

        try:
            try:
                value = eval(str(self.control.text.text()).strip())
            except Exception as ex:
                # The entered something that didn't eval as a number, (e.g.,
                # 'foo') pretend it didn't happen
                value = self.value
                self.control.text.setText(str(value))
                # for compound editor, value may be non-numeric
                if not isinstance(value, (int, float)):
                    return

            if not self.factory.is_float:
                value = int(value)

            self.value = value
            blocked = self.control.slider.blockSignals(True)
            try:
                self.control.slider.setValue(
                    self._convert_to_slider(self.value)
                )
            finally:
                self.control.slider.blockSignals(blocked)
        except TraitError as excp:
            pass

    def update_editor(self):
        """ Updates the editor when the object trait changes externally to the
            editor.
        """
        value = self.value
        low = self.low
        high = self.high
        try:
            text = self.format % value
            1 / (low <= value <= high)
        except:
            text = ""
            value = low

        ivalue = self._convert_to_slider(value)

        self.control.text.setText(text)

        blocked = self.control.slider.blockSignals(True)
        try:
            self.control.slider.setValue(ivalue)
        finally:
            self.control.slider.blockSignals(blocked)

    def get_error_control(self):
        """ Returns the editor's control for indicating error status.
        """
        return self.control.text

    def _low_changed(self, low):
        if self.value < low:
            if self.factory.is_float:
                self.value = float(low)
            else:
                self.value = int(low)

        if self._label_lo is not None:
            self._label_lo.setText(self.format % low)
            self.update_editor()

    def _high_changed(self, high):
        if self.value > high:
            if self.factory.is_float:
                self.value = float(high)
            else:
                self.value = int(high)

        if self._label_hi is not None:
            self._label_hi.setText(self.format % high)
            self.update_editor()

    def _convert_to_slider(self, value):
        """ Returns the slider setting corresponding to the user-supplied value.
        """
        if self.high > self.low:
            ivalue = int(
                (float(value - self.low) / (self.high - self.low)) * 10000.0
            )
        else:
            ivalue = self.low

            if ivalue is None:
                ivalue = 0
        return ivalue

    def _convert_from_slider(self, ivalue):
        """ Returns the float or integer value corresponding to the slider
        setting.
        """
        value = self.low + ((float(ivalue) / 10000.0) * (self.high - self.low))
        if not self.factory.is_float:
            value = int(round(value))
        return value


# -------------------------------------------------------------------------
class LogRangeSliderEditor(SimpleSliderEditor):
    # -------------------------------------------------------------------------
    """ A slider editor for log-spaced values
    """

    def _convert_to_slider(self, value):
        """ Returns the slider setting corresponding to the user-supplied value.
        """
        value = max(value, self.low)
        ivalue = int(
            (log10(value) - log10(self.low))
            / (log10(self.high) - log10(self.low))
            * 10000.0
        )
        return ivalue

    def _convert_from_slider(self, ivalue):
        """ Returns the float or integer value corresponding to the slider
        setting.
        """
        value = float(ivalue) / 10000.0 * (log10(self.high) - log10(self.low))
        # Do this to handle floating point errors, where fvalue may exceed
        # self.high.
        fvalue = min(self.low * 10 ** (value), self.high)
        if not self.factory.is_float:
            fvalue = int(round(fvalue))
        return fvalue


class LargeRangeSliderEditor(BaseRangeEditor):
    """ A slider editor for large ranges.

    The editor displays a slider and a text field. A subset of the total range
    is displayed in the slider; arrow buttons at each end of the slider let
    the user move the displayed range higher or lower.
    """

    # -------------------------------------------------------------------------
    #  Trait definitions:
    # -------------------------------------------------------------------------

    #: Low value for the slider range
    low = Any(0)

    #: High value for the slider range
    high = Any(1)

    #: Low end of displayed range
    cur_low = Float()

    #: High end of displayed range
    cur_high = Float()

    #: Flag indicating that the UI is in the process of being updated
    ui_changing = Bool(False)

    def init(self, parent):
        """ Finishes initializing the editor by creating the underlying toolkit
            widget.
        """
        factory = self.factory

        # Initialize using the factory range defaults:
        self.low = factory.low
        self.high = factory.high
        self.evaluate = factory.evaluate

        # Hook up the traits to listen to the object.
        self.sync_value(factory.low_name, "low", "from")
        self.sync_value(factory.high_name, "high", "from")
        self.sync_value(factory.evaluate_name, "evaluate", "from")

        self.init_range()
        low = self.cur_low
        high = self.cur_high

        self._set_format()

        self.control = QtGui.QWidget()
        panel = QtGui.QHBoxLayout(self.control)
        panel.setContentsMargins(0, 0, 0, 0)

        fvalue = self.value

        try:
            fvalue_text = self._format % fvalue
            1 / (low <= fvalue <= high)
        except:
            fvalue_text = ""
            fvalue = low

        if high > low:
            ivalue = int((float(fvalue - low) / (high - low)) * 10000)
        else:
            ivalue = low

        # Lower limit label:
        self.control.label_lo = label_lo = QtGui.QLabel()
        label_lo.setAlignment(QtCore.Qt.AlignRight | QtCore.Qt.AlignVCenter)
        panel.addWidget(label_lo)

        # Lower limit button:
        self.control.button_lo = IconButton(
            QtGui.QStyle.SP_ArrowLeft, self.reduce_range
        )
        panel.addWidget(self.control.button_lo)

        # Slider:
        self.control.slider = slider = QtGui.QSlider(QtCore.Qt.Horizontal)
        slider.setTracking(factory.auto_set)
        slider.setMinimum(0)
        slider.setMaximum(10000)
        slider.setPageStep(1000)
        slider.setSingleStep(100)
        slider.setValue(ivalue)
        slider.valueChanged.connect(self.update_object_on_scroll)
        panel.addWidget(slider)

        # Upper limit button:
        self.control.button_hi = IconButton(
            QtGui.QStyle.SP_ArrowRight, self.increase_range
        )
        panel.addWidget(self.control.button_hi)

        # Upper limit label:
        self.control.label_hi = label_hi = QtGui.QLabel()
        panel.addWidget(label_hi)

        # Text entry:
        self.control.text = text = QtGui.QLineEdit(fvalue_text)
        text.editingFinished.connect(self.update_object_on_enter)

        # The default size is a bit too big and probably doesn't need to grow.
        sh = text.sizeHint()
        sh.setWidth(sh.width() // 2)
        text.setMaximumSize(sh)

        panel.addWidget(text)

        label_lo.setText(str(low))
        label_hi.setText(str(high))
        self.set_tooltip(slider)
        self.set_tooltip(label_lo)
        self.set_tooltip(label_hi)
        self.set_tooltip(text)

        # Update the ranges and button just in case.
        self.update_range_ui()

    def update_object_on_scroll(self, pos):
        """ Handles the user changing the current slider value.
        """
        value = self.cur_low + (
            (float(pos) / 10000.0) * (self.cur_high - self.cur_low)
        )

        self.control.text.setText(self._format % value)

        if self.factory.is_float:
            self.value = value
        else:
            self.value = int(value)

    def update_object_on_enter(self):
        """ Handles the user pressing the Enter key in the text field.
        """
        try:
            self.value = eval(str(self.control.text.text()).strip())
        except TraitError as excp:
            pass

    def update_editor(self):
        """ Updates the editor when the object trait changes externally to the
            editor.
        """
        value = self.value
        low = self.low
        high = self.high
        try:
            text = self._format % value
            1 / (low <= value <= high)
        except:
            value = low
        self.value = value

        if not self.ui_changing:
            self.init_range()
            self.update_range_ui()

    def update_range_ui(self):
        """ Updates the slider range controls.
        """
        low, high = self.cur_low, self.cur_high
        value = self.value
        self._set_format()
        self.control.label_lo.setText(self._format % low)
        self.control.label_hi.setText(self._format % high)

        if high > low:
            ivalue = int((float(value - low) / (high - low)) * 10000.0)
        else:
            ivalue = low

        blocked = self.control.slider.blockSignals(True)
        self.control.slider.setValue(ivalue)
        self.control.slider.blockSignals(blocked)

        text = self._format % self.value
        self.control.text.setText(text)
        self.control.button_lo.setEnabled(low != self.low)
        self.control.button_hi.setEnabled(high != self.high)

    def init_range(self):
        """ Initializes the slider range controls.
        """
        value = self.value
        low, high = self.low, self.high
        if (high is None) and (low is not None):
            high = -low

        mag = abs(value)
        if mag <= 10.0:
            cur_low = max(value - 10, low)
            cur_high = min(value + 10, high)
        else:
            d = 0.5 * (10 ** int(log10(mag) + 1))
            cur_low = max(low, value - d)
            cur_high = min(high, value + d)

        self.cur_low, self.cur_high = cur_low, cur_high

    def reduce_range(self):
        """ Reduces the extent of the displayed range.
        """
        low, high = self.low, self.high
        if abs(self.cur_low) < 10:
            self.cur_low = max(-10, low)
            self.cur_high = min(10, high)
        elif self.cur_low > 0:
            self.cur_high = self.cur_low
            self.cur_low = max(low, self.cur_low / 10)
        else:
            self.cur_high = self.cur_low
            self.cur_low = max(low, self.cur_low * 10)

        self.ui_changing = True
        self.value = min(max(self.value, self.cur_low), self.cur_high)
        self.ui_changing = False
        self.update_range_ui()

    def increase_range(self):
        """ Increased the extent of the displayed range.
        """
        low, high = self.low, self.high
        if abs(self.cur_high) < 10:
            self.cur_low = max(-10, low)
            self.cur_high = min(10, high)
        elif self.cur_high > 0:
            self.cur_low = self.cur_high
            self.cur_high = min(high, self.cur_high * 10)
        else:
            self.cur_low = self.cur_high
            self.cur_high = min(high, self.cur_high / 10)

        self.ui_changing = True
        self.value = min(max(self.value, self.cur_low), self.cur_high)
        self.ui_changing = False
        self.update_range_ui()

    def _set_format(self):
        self._format = "%d"
        factory = self.factory
        low, high = self.cur_low, self.cur_high
        diff = high - low
        if factory.is_float:
            if diff > 99999:
                self._format = "%.2g"
            elif diff > 1:
                self._format = "%%.%df" % max(0, 4 - int(log10(high - low)))
            else:
                self._format = "%.3f"

    def get_error_control(self):
        """ Returns the editor's control for indicating error status.
        """
        return self.control.text

    def _low_changed(self, low):
        if self.control is not None:
            if self.value < low:
                if self.factory.is_float:
                    self.value = float(low)
                else:
                    self.value = int(low)

            self.update_editor()

    def _high_changed(self, high):
        if self.control is not None:
            if self.value > high:
                if self.factory.is_float:
                    self.value = float(high)
                else:
                    self.value = int(high)

            self.update_editor()


class SimpleSpinEditor(BaseRangeEditor):
    """ A simple style of range editor that displays a spin box control.
    """

    # -------------------------------------------------------------------------
    #  Trait definitions:
    # -------------------------------------------------------------------------

    # Low value for the slider range
    low = Any()

    # High value for the slider range
    high = Any()

    def init(self, parent):
        """ Finishes initializing the editor by creating the underlying toolkit
            widget.
        """
        factory = self.factory
        if not factory.low_name:
            self.low = factory.low

        if not factory.high_name:
            self.high = factory.high

        self.sync_value(factory.low_name, "low", "from")
        self.sync_value(factory.high_name, "high", "from")
        low = self.low
        high = self.high

        self.control = QtGui.QSpinBox()
        self.control.setMinimum(low)
        self.control.setMaximum(high)
        self.control.setValue(self.value)
        self.control.valueChanged.connect(self.update_object)
        self.set_tooltip()

    def update_object(self, value):
        """ Handles the user selecting a new value in the spin box.
        """
        self._locked = True
        try:
            self.value = value
        finally:
            self._locked = False

    def update_editor(self):
        """ Updates the editor when the object trait changes externally to the
            editor.
        """
        if not self._locked:
            blocked = self.control.blockSignals(True)
            try:
                self.control.setValue(int(self.value))
            except Exception:
                from traitsui.api import raise_to_debug

                raise_to_debug()
            finally:
                self.control.blockSignals(blocked)

    def _low_changed(self, low):
        if self.value < low:
            if self.factory.is_float:
                self.value = float(low)
            else:
                self.value = int(low)

        if self.control:
            self.control.setMinimum(low)
            self.control.setValue(int(self.value))

    def _high_changed(self, high):
        if self.value > high:
            if self.factory.is_float:
                self.value = float(high)
            else:
                self.value = int(high)

        if self.control:
            self.control.setMaximum(high)
            self.control.setValue(int(self.value))


class RangeTextEditor(TextEditor):
    """ Editor for ranges that displays a text field. If the user enters a
    value that is outside the allowed range, the background of the field
    changes color to indicate an error.
    """

    # -------------------------------------------------------------------------
    #  Trait definitions:
    # -------------------------------------------------------------------------

    #: Function to evaluate floats/ints
    evaluate = Any()

    def init(self, parent):
        """ Finishes initializing the editor by creating the underlying toolkit
            widget.
        """
        TextEditor.init(self, parent)
        self.evaluate = self.factory.evaluate
        self.sync_value(self.factory.evaluate_name, "evaluate", "from")

    def update_object(self):
        """ Handles the user entering input data in the edit control.
        """
        try:
            value = eval(str(self.control.text()))
            if self.evaluate is not None:
                value = self.evaluate(value)
            self.value = value
            col = OKColor
        except Exception:
            col = ErrorColor

        if self.control is not None:
            pal = QtGui.QPalette(self.control.palette())
            pal.setColor(QtGui.QPalette.Base, col)
            self.control.setPalette(pal)


# -------------------------------------------------------------------------
#  'SimpleEnumEditor' factory adaptor:
# -------------------------------------------------------------------------


def SimpleEnumEditor(
    parent, factory, ui, object, name, description, **kwargs
):
    return CustomEnumEditor(
        parent, factory, ui, object, name, description, "simple"
    )


def CustomEnumEditor(
    parent, factory, ui, object, name, description, style="custom", **kwargs
):
    """ Factory adapter that returns a enumeration editor of the specified
    style.
    """
    if factory._enum is None:
        import traitsui.editors.enum_editor as enum_editor

        factory._enum = enum_editor.ToolkitEditorFactory(
            values=list(range(factory.low, factory.high + 1)),
            cols=factory.cols,
        )

    if style == "simple":
        return factory._enum.simple_editor(
            ui, object, name, description, parent
        )

    return factory._enum.custom_editor(ui, object, name, description, parent)


# -------------------------------------------------------------------------
#  Defines the mapping between editor factory 'mode's and Editor classes:
# -------------------------------------------------------------------------

# Mapping between editor factory modes and simple editor classes
SimpleEditorMap = {
    "slider": SimpleSliderEditor,
    "xslider": LargeRangeSliderEditor,
    "spinner": SimpleSpinEditor,
    "enum": SimpleEnumEditor,
    "text": RangeTextEditor,
    "logslider": LogRangeSliderEditor,
}
# Mapping between editor factory modes and custom editor classes
CustomEditorMap = {
    "slider": SimpleSliderEditor,
    "xslider": LargeRangeSliderEditor,
    "spinner": SimpleSpinEditor,
    "enum": CustomEnumEditor,
    "text": RangeTextEditor,
    "logslider": LogRangeSliderEditor,
}
