# encoding: utf-8

"""
Style object hierarchy.
"""

from __future__ import (
    absolute_import, division, print_function, unicode_literals
)

from . import BabelFish
from ..enum.style import WD_STYLE_TYPE
from ..shared import ElementProxy
from ..text.font import Font
from ..text.parfmt import ParagraphFormat


def StyleFactory(style_elm):
    """
    Return a style object of the appropriate |BaseStyle| subclass, according
    to the type of *style_elm*.
    """
    style_cls = {
        WD_STYLE_TYPE.PARAGRAPH: _ParagraphStyle,
        WD_STYLE_TYPE.CHARACTER: _CharacterStyle,
        WD_STYLE_TYPE.TABLE:     _TableStyle,
        WD_STYLE_TYPE.LIST:      _NumberingStyle
    }[style_elm.type]

    return style_cls(style_elm)


class BaseStyle(ElementProxy):
    """
    Base class for the various types of style object, paragraph, character,
    table, and numbering. These properties and methods are inherited by all
    style objects.
    """

    __slots__ = ()

    @property
    def builtin(self):
        """
        Read-only. |True| if this style is a built-in style. |False|
        indicates it is a custom (user-defined) style. Note this value is
        based on the presence of a `customStyle` attribute in the XML, not on
        specific knowledge of which styles are built into Word.
        """
        return not self._element.customStyle

    def delete(self):
        """
        Remove this style definition from the document. Note that calling
        this method does not remove or change the style applied to any
        document content. Content items having the deleted style will be
        rendered using the default style, as is any content with a style not
        defined in the document.
        """
        self._element.delete()
        self._element = None

    @property
    def hidden(self):
        """
        |True| if display of this style in the style gallery and list of
        recommended styles is suppressed. |False| otherwise. In order to be
        shown in the style gallery, this value must be |False| and
        :attr:`.quick_style` must be |True|.
        """
        return self._element.semiHidden_val

    @hidden.setter
    def hidden(self, value):
        self._element.semiHidden_val = value

    @property
    def locked(self):
        """
        Read/write Boolean. |True| if this style is locked. A locked style
        does not appear in the styles panel or the style gallery and cannot
        be applied to document content. This behavior is only active when
        formatting protection is turned on for the document (via the
        Developer menu).
        """
        return self._element.locked_val

    @locked.setter
    def locked(self, value):
        self._element.locked_val = value

    @property
    def name(self):
        """
        The UI name of this style.
        """
        name = self._element.name_val
        if name is None:
            return None
        return BabelFish.internal2ui(name)

    @name.setter
    def name(self, value):
        self._element.name_val = value

    @property
    def priority(self):
        """
        The integer sort key governing display sequence of this style in the
        Word UI. |None| indicates no setting is defined, causing Word to use
        the default value of 0. Style name is used as a secondary sort key to
        resolve ordering of styles having the same priority value.
        """
        return self._element.uiPriority_val

    @priority.setter
    def priority(self, value):
        self._element.uiPriority_val = value

    @property
    def quick_style(self):
        """
        |True| if this style should be displayed in the style gallery when
        :attr:`.hidden` is |False|. Read/write Boolean.
        """
        return self._element.qFormat_val

    @quick_style.setter
    def quick_style(self, value):
        self._element.qFormat_val = value

    @property
    def style_id(self):
        """
        The unique key name (string) for this style. This value is subject to
        rewriting by Word and should generally not be changed unless you are
        familiar with the internals involved.
        """
        return self._element.styleId

    @style_id.setter
    def style_id(self, value):
        self._element.styleId = value

    @property
    def type(self):
        """
        Member of :ref:`WdStyleType` corresponding to the type of this style,
        e.g. ``WD_STYLE_TYPE.PARAGRAPH``.
        """
        type = self._element.type
        if type is None:
            return WD_STYLE_TYPE.PARAGRAPH
        return type

    @property
    def unhide_when_used(self):
        """
        |True| if an application should make this style visible the next time
        it is applied to content. False otherwise. Note that |docx| does not
        automatically unhide a style having |True| for this attribute when it
        is applied to content.
        """
        return self._element.unhideWhenUsed_val

    @unhide_when_used.setter
    def unhide_when_used(self, value):
        self._element.unhideWhenUsed_val = value


class _CharacterStyle(BaseStyle):
    """
    A character style. A character style is applied to a |Run| object and
    primarily provides character-level formatting via the |Font| object in
    its :attr:`.font` property.
    """

    __slots__ = ()

    @property
    def base_style(self):
        """
        Style object this style inherits from or |None| if this style is
        not based on another style.
        """
        base_style = self._element.base_style
        if base_style is None:
            return None
        return StyleFactory(base_style)

    @base_style.setter
    def base_style(self, style):
        style_id = style.style_id if style is not None else None
        self._element.basedOn_val = style_id

    @property
    def font(self):
        """
        The |Font| object providing access to the character formatting
        properties for this style, such as font name and size.
        """
        return Font(self._element)


class _ParagraphStyle(_CharacterStyle):
    """
    A paragraph style. A paragraph style provides both character formatting
    and paragraph formatting such as indentation and line-spacing.
    """

    __slots__ = ()

    def __repr__(self):
        return '_ParagraphStyle(\'%s\') id: %s' % (self.name, id(self))

    @property
    def next_paragraph_style(self):
        """
        |_ParagraphStyle| object representing the style to be applied
        automatically to a new paragraph inserted after a paragraph of this
        style. Returns self if no next paragraph style is defined. Assigning
        |None| or *self* removes the setting such that new paragraphs are
        created using this same style.
        """
        next_style_elm = self._element.next_style
        if next_style_elm is None:
            return self
        if next_style_elm.type != WD_STYLE_TYPE.PARAGRAPH:
            return self
        return StyleFactory(next_style_elm)

    @next_paragraph_style.setter
    def next_paragraph_style(self, style):
        if style is None or style.style_id == self.style_id:
            self._element._remove_next()
        else:
            self._element.get_or_add_next().val = style.style_id

    @property
    def paragraph_format(self):
        """
        The |ParagraphFormat| object providing access to the paragraph
        formatting properties for this style such as indentation.
        """
        return ParagraphFormat(self._element)


class _TableStyle(_ParagraphStyle):
    """
    A table style. A table style provides character and paragraph formatting
    for its contents as well as special table formatting properties.
    """

    __slots__ = ()

    def __repr__(self):
        return '_TableStyle(\'%s\') id: %s' % (self.name, id(self))


class _NumberingStyle(BaseStyle):
    """
    A numbering style. Not yet implemented.
    """

    __slots__ = ()