# (C) Copyright 2004-2021 Enthought, Inc., Austin, TX
# All rights reserved.
#
# This software is provided without warranty under the terms of the BSD
# license included in LICENSE.txt and may be redistributed only under
# the conditions described in the aforementioned license. The license
# is also available online at http://www.enthought.com/licenses/BSD.txt
#
# Thanks for using Enthought open source!

""" Defines the range editor factory for all traits user interface toolkits.
"""

from types import CodeType

from traits.api import (
    Any,
    Bool,
    CTrait,
    Enum,
    Int,
    Property,
    Range,
    Str,
    Undefined,
)


from traitsui.editor_factory import EditorFactory
from traitsui.toolkit import toolkit_object
from traitsui.view import View


class RangeEditor(EditorFactory):
    """ Editor factory for range editors.
    """

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

    #: Number of columns when displayed as an enumeration
    cols = Range(1, 20)

    #: Is user input set on every keystroke?
    auto_set = Bool(True)

    #: Is user input set when the Enter key is pressed?
    enter_set = Bool(False)

    #: Label for the low end of the range
    low_label = Str()

    #: Label for the high end of the range
    high_label = Str()

    #: FIXME: This is supported only in the wx backend so far.
    #: The width of the low and high labels
    label_width = Int()

    #: The name of an [object.]trait that defines the low value for the range
    low_name = Str()

    #: The name of an [object.]trait that defines the high value for the range
    high_name = Str()

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

    #: Is the range for floating pointer numbers (vs. integers)?
    is_float = Bool(Undefined)

    #: Function to evaluate floats/ints when they are assigned to an object
    #: trait
    evaluate = Any()

    #: The object trait containing the function used to evaluate floats/ints
    evaluate_name = Str()

    #: Low end of range
    low = Property()

    #: High end of range
    high = Property()

    #: Display mode to use
    mode = Enum(
        "auto", "slider", "xslider", "spinner", "enum", "text", "logslider"
    )

    # -------------------------------------------------------------------------
    #  Traits view definition:
    # -------------------------------------------------------------------------

    traits_view = View(
        [
            ["low", "high", "|[Range]"],
            ["low_label{Low}", "high_label{High}", "|[Range Labels]"],
            [
                "auto_set{Set automatically}",
                "enter_set{Set on enter key pressed}",
                "is_float{Is floating point range}",
                "-[Options]>",
            ],
            ["cols", "|[Number of columns for integer custom style]<>"],
        ]
    )

    def init(self, handler=None):
        """ Performs any initialization needed after all constructor traits
            have been set.
        """
        if handler is not None:
            if isinstance(handler, CTrait):
                handler = handler.handler

            if self.low_name == "":
                if isinstance(handler._low, CodeType):
                    self.low = eval(handler._low)
                else:
                    self.low = handler._low

            if self.high_name == "":
                if isinstance(handler._low, CodeType):
                    self.high = eval(handler._high)
                else:
                    self.high = handler._high
        else:
            if (self.low is None) and (self.low_name == ""):
                self.low = 0.0

            if (self.high is None) and (self.high_name == ""):
                self.high = 1.0

    def _get_low(self):
        return self._low

    def _set_low(self, low):
        old_low = self._low
        self._low = low = self._cast(low)
        if self.is_float is Undefined:
            self.is_float = isinstance(low, float)

        if (self.low_label == "") or (
            self.low_label == str(old_low)
        ):
            self.low_label = str(low)

    def _get_high(self):
        return self._high

    def _set_high(self, high):
        old_high = self._high
        self._high = high = self._cast(high)
        if self.is_float is Undefined:
            self.is_float = isinstance(high, float)

        if (self.high_label == "") or (
            self.high_label == str(old_high)
        ):
            self.high_label = str(high)

    def _cast(self, value):
        if not isinstance(value, str):
            return value

        try:
            return int(value)
        except ValueError:
            return float(value)

    # -- Private Methods ------------------------------------------------------

    def _get_low_high(self, ui):
        """ Returns the low and high values used to determine the initial range.
        """
        low, high = self.low, self.high

        if (low is None) and (self.low_name != ""):
            low = self.named_value(self.low_name, ui)
            if self.is_float is Undefined:
                self.is_float = isinstance(low, float)

        if (high is None) and (self.high_name != ""):
            high = self.named_value(self.high_name, ui)
            if self.is_float is Undefined:
                self.is_float = isinstance(high, float)

        if self.is_float is Undefined:
            self.is_float = True

        return (low, high, self.is_float)

    # -------------------------------------------------------------------------
    #  Property getters.
    # -------------------------------------------------------------------------
    def _get_simple_editor_class(self):
        """ Returns the editor class to use for a simple style.

        The type of editor depends on the type and extent of the range being
        edited:

        * One end of range is unspecified: RangeTextEditor
        * **mode** is specified and not 'auto': editor corresponding to
          **mode**
        * Floating point range with extent > 100: LargeRangeSliderEditor
        * Integer range or floating point range with extent <= 100:
          SimpleSliderEditor
        * All other cases: SimpleSpinEditor
        """
        low, high, is_float = self._low_value, self._high_value, self.is_float

        if (low is None) or (high is None):
            return toolkit_object("range_editor:RangeTextEditor")

        if (not is_float) and (abs(high - low) > 1000000000):
            return toolkit_object("range_editor:RangeTextEditor")

        if self.mode != "auto":
            return toolkit_object("range_editor:SimpleEditorMap")[self.mode]

        if is_float and (abs(high - low) > 100):
            return toolkit_object("range_editor:LargeRangeSliderEditor")

        if is_float or (abs(high - low) <= 100):
            return toolkit_object("range_editor:SimpleSliderEditor")

        return toolkit_object("range_editor:SimpleSpinEditor")

    def _get_custom_editor_class(self):
        """ Creates a custom style of range editor

        The type of editor depends on the type and extent of the range being
        edited:

        * One end of range is unspecified: RangeTextEditor
        * **mode** is specified and not 'auto': editor corresponding to
          **mode**
        * Floating point range: Same as "simple" style
        * Integer range with extent > 15: Same as "simple" style
        * Integer range with extent <= 15: CustomEnumEditor

        """
        low, high, is_float = self._low_value, self._high_value, self.is_float
        if (low is None) or (high is None):
            return toolkit_object("range_editor:RangeTextEditor")

        if self.mode != "auto":
            return toolkit_object("range_editor:CustomEditorMap")[self.mode]

        if is_float or (abs(high - low) > 15):
            return self.simple_editor_class

        return toolkit_object("range_editor:CustomEnumEditor")

    def _get_text_editor_class(self):
        """Returns the editor class to use for a text style.
        """
        return toolkit_object("range_editor:RangeTextEditor")

    # -------------------------------------------------------------------------
    #  'Editor' factory methods:
    # -------------------------------------------------------------------------

    def simple_editor(self, ui, object, name, description, parent):
        """ Generates an editor using the "simple" style.
        Overridden to set the values of the _low_value, _high_value and
        is_float traits.

        """
        self._low_value, self._high_value, self.is_float = self._get_low_high(
            ui
        )
        return super().simple_editor(ui, object, name, description, parent)

    def custom_editor(self, ui, object, name, description, parent):
        """ Generates an editor using the "custom" style.
        Overridden to set the values of the _low_value, _high_value and
        is_float traits.

        """
        self._low_value, self._high_value, self.is_float = self._get_low_high(
            ui
        )
        return super().custom_editor(ui, object, name, description, parent)


# This alias is deprecated and will be removed in TraitsUI 8.
ToolkitEditorFactory = RangeEditor
