# -*- coding: utf-8 -*-
#
# Copyright (c) 2020 Martin Owens <doctormo@gmail.com>
#                    Thomas Holder <thomas.holder@schrodinger.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#
# pylint: disable=arguments-differ
"""
Provide text based element classes interface.

Because text is not rendered at all, no information about a text's path
size or actual location can be generated yet.
"""

from ..paths import Path
from ..transforms import Transform, BoundingBox
from ..units import convert_unit

from ._base import BaseElement, ShapeElement
from ._polygons import PathElementBase

class FlowRegion(ShapeElement):
    """SVG Flow Region (SVG 2.0)"""
    tag_name = 'flowRegion'

    def get_path(self):
        # This ignores flowRegionExcludes
        return sum([child.path for child in self], Path())

class FlowRoot(ShapeElement):
    """SVG Flow Root (SVG 2.0)"""
    tag_name = 'flowRoot'

    @property
    def region(self):
        """Return the first flowRegion in this flowRoot"""
        return self.findone('svg:flowRegion')

    def get_path(self):
        region = self.region
        return region.get_path() if region is not None else Path()

class FlowPara(ShapeElement):
    """SVG Flow Paragraph (SVG 2.0)"""
    tag_name = 'flowPara'

    def get_path(self):
        # XXX: These empty paths mean the bbox for text elements will be nothing.
        return Path()

class FlowDiv(ShapeElement):
    """SVG Flow Div (SVG 2.0)"""
    tag_name = 'flowDiv'

    def get_path(self):
        # XXX: These empty paths mean the bbox for text elements will be nothing.
        return Path()

class FlowSpan(ShapeElement):
    """SVG Flow Span (SVG 2.0)"""
    tag_name = 'flowSpan'

    def get_path(self):
        # XXX: These empty paths mean the bbox for text elements will be nothing.
        return Path()

class TextElement(ShapeElement):
    """A Text element"""
    tag_name = 'text'
    x = property(lambda self: convert_unit(self.get('x', 0), 'px'))
    y = property(lambda self: convert_unit(self.get('y', 0), 'px'))

    def get_path(self):
        return Path()

    def tspans(self):
        """Returns all children that are tspan elements"""
        return self.findall('svg:tspan')

    def get_text(self, sep="\n"):
        """Return the text content including tspans"""
        nodes = [self] + list(self.tspans())
        return sep.join([elem.text for elem in nodes if elem.text is not None])

    def shape_box(self, transform=None):
        """
        Returns a horrible bounding box that just contains the coord points
        of the text without width or height (which is impossible to calculate)
        """
        effective_transform = Transform(transform) * self.transform
        x, y = effective_transform.apply_to_point((self.x, self.y))
        bbox = BoundingBox(x, y)
        for tspan in self.tspans():
            bbox += tspan.bounding_box(effective_transform)
        return bbox

class TextPath(ShapeElement):
    """A textPath element"""
    tag_name = 'textPath'

    def get_path(self):
        return Path()

class Tspan(ShapeElement):
    """A tspan text element"""
    tag_name = 'tspan'
    x = property(lambda self: convert_unit(self.get('x', 0), 'px'))
    y = property(lambda self: convert_unit(self.get('y', 0), 'px'))

    @classmethod
    def superscript(cls, text):
        """Adds a superscript tspan element"""
        return cls(text, style="font-size:65%;baseline-shift:super")

    def get_path(self):
        return Path()

    def shape_box(self, transform=None):
        """
        Returns a horrible bounding box that just contains the coord points
        of the text without width or height (which is impossible to calculate)
        """
        effective_transform = Transform(transform) * self.transform
        x1, y1 = effective_transform.apply_to_point((self.x, self.y))
        fontsize = convert_unit(self.style.get('font-size', '1em'), 'px')
        x2 = self.x + 0 # XXX This is impossible to calculate!
        y2 = self.y + float(fontsize)
        x2, y2 = effective_transform.apply_to_point((x2, y2))
        return BoundingBox((x1, x2), (y1, y2))


class SVGfont(BaseElement):
    """An svg font element"""
    tag_name = 'font'

class FontFace(BaseElement):
    """An svg font font-face element"""
    tag_name = 'font-face'

class Glyph(PathElementBase):
    """An svg font glyph element"""
    tag_name = 'glyph'

class MissingGlyph(BaseElement):
    """An svg font missing-glyph element"""
    tag_name = 'missing-glyph'