from __future__ import division

import os, codecs, base64, tempfile, urllib, gzip, cStringIO, re, sys

import numpy as np

try:
    from hashlib import md5
except ImportError:
    from md5 import md5 #Deprecated in 2.5

from matplotlib import verbose, __version__, rcParams
from matplotlib.backend_bases import RendererBase, GraphicsContextBase,\
     FigureManagerBase, FigureCanvasBase
from matplotlib.backends.backend_mixed import MixedModeRenderer
from matplotlib.cbook import is_string_like, is_writable_file_like, maxdict
from matplotlib.colors import rgb2hex
from matplotlib.figure import Figure
from matplotlib.font_manager import findfont, FontProperties
from matplotlib.ft2font import FT2Font, KERNING_DEFAULT, LOAD_NO_HINTING
from matplotlib.mathtext import MathTextParser
from matplotlib.path import Path
from matplotlib import _path
from matplotlib.transforms import Affine2D, Affine2DBase
from matplotlib import _png

from xml.sax.saxutils import escape as escape_xml_text

backend_version = __version__

# ----------------------------------------------------------------------
# SimpleXMLWriter class
#
# Based on an original by Fredrik Lundh, but modified here to:
#   1. Support modern Python idioms
#   2. Remove encoding support (it's handled by the file writer instead)
#   3. Support proper indentation
#   4. Minify things a little bit

# --------------------------------------------------------------------
# The SimpleXMLWriter module is
#
# Copyright (c) 2001-2004 by Fredrik Lundh
#
# By obtaining, using, and/or copying this software and/or its
# associated documentation, you agree that you have read, understood,
# and will comply with the following terms and conditions:
#
# Permission to use, copy, modify, and distribute this software and
# its associated documentation for any purpose and without fee is
# hereby granted, provided that the above copyright notice appears in
# all copies, and that both that copyright notice and this permission
# notice appear in supporting documentation, and that the name of
# Secret Labs AB or the author not be used in advertising or publicity
# pertaining to distribution of the software without specific, written
# prior permission.
#
# SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
# TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANT-
# ABILITY AND FITNESS.  IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR
# BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
# OF THIS SOFTWARE.
# --------------------------------------------------------------------

def escape_cdata(s):
    s = s.replace(u"&", u"&amp;")
    s = s.replace(u"<", u"&lt;")
    s = s.replace(u">", u"&gt;")
    return s

def escape_attrib(s):
    s = s.replace(u"&", u"&amp;")
    s = s.replace(u"'", u"&apos;")
    s = s.replace(u"\"", u"&quot;")
    s = s.replace(u"<", u"&lt;")
    s = s.replace(u">", u"&gt;")
    return s

##
# XML writer class.
#
# @param file A file or file-like object.  This object must implement
#    a <b>write</b> method that takes an 8-bit string.

class XMLWriter:
    def __init__(self, file):
        self.__write = file.write
        if hasattr(file, "flush"):
            self.flush = file.flush
        self.__open = 0 # true if start tag is open
        self.__tags = []
        self.__data = []
        self.__indentation = u" " * 64

    def __flush(self, indent=True):
        # flush internal buffers
        if self.__open:
            if indent:
                self.__write(u">\n")
            else:
                self.__write(u">")
            self.__open = 0
        if self.__data:
            data = u''.join(self.__data)
            self.__write(escape_cdata(data))
            self.__data = []

    ## Opens a new element.  Attributes can be given as keyword
    # arguments, or as a string/string dictionary. The method returns
    # an opaque identifier that can be passed to the <b>close</b>
    # method, to close all open elements up to and including this one.
    #
    # @param tag Element tag.
    # @param attrib Attribute dictionary.  Alternatively, attributes
    #    can be given as keyword arguments.
    # @return An element identifier.

    def start(self, tag, attrib={}, **extra):
        self.__flush()
        tag = escape_cdata(tag)
        self.__data = []
        self.__tags.append(tag)
        self.__write(self.__indentation[:len(self.__tags) - 1])
        self.__write(u"<%s" % tag)
        if attrib or extra:
            attrib = attrib.copy()
            attrib.update(extra)
            attrib = attrib.items()
            attrib.sort()
            for k, v in attrib:
                if not v == '':
                    k = escape_cdata(k)
                    v = escape_attrib(v)
                    self.__write(u" %s=\"%s\"" % (k, v))
        self.__open = 1
        return len(self.__tags)-1

    ##
    # Adds a comment to the output stream.
    #
    # @param comment Comment text, as a Unicode string.

    def comment(self, comment):
        self.__flush()
        self.__write(self.__indentation[:len(self.__tags)])
        self.__write(u"<!-- %s -->\n" % escape_cdata(comment))

    ##
    # Adds character data to the output stream.
    #
    # @param text Character data, as a Unicode string.

    def data(self, text):
        self.__data.append(text)

    ##
    # Closes the current element (opened by the most recent call to
    # <b>start</b>).
    #
    # @param tag Element tag.  If given, the tag must match the start
    #    tag.  If omitted, the current element is closed.

    def end(self, tag=None, indent=True):
        if tag:
            assert self.__tags, "unbalanced end(%s)" % tag
            assert escape_cdata(tag) == self.__tags[-1],\
                   "expected end(%s), got %s" % (self.__tags[-1], tag)
        else:
            assert self.__tags, "unbalanced end()"
        tag = self.__tags.pop()
        if self.__data:
            self.__flush(indent)
        elif self.__open:
            self.__open = 0
            self.__write(u"/>\n")
            return
        if indent:
            self.__write(self.__indentation[:len(self.__tags)])
        self.__write(u"</%s>\n" % tag)

    ##
    # Closes open elements, up to (and including) the element identified
    # by the given identifier.
    #
    # @param id Element identifier, as returned by the <b>start</b> method.

    def close(self, id):
        while len(self.__tags) > id:
            self.end()

    ##
    # Adds an entire element.  This is the same as calling <b>start</b>,
    # <b>data</b>, and <b>end</b> in sequence. The <b>text</b> argument
    # can be omitted.

    def element(self, tag, text=None, attrib={}, **extra):
        apply(self.start, (tag, attrib), extra)
        if text:
            self.data(text)
        self.end(indent=False)

    ##
    # Flushes the output stream.

    def flush(self):
        pass # replaced by the constructor

# ----------------------------------------------------------------------

def generate_transform(transform_list=[]):
    if len(transform_list):
        output = cStringIO.StringIO()
        for type, value in transform_list:
            if type == 'scale' and (value == (1.0,) or value == (1.0, 1.0)):
                continue
            if type == 'translate' and value == (0.0, 0.0):
                continue
            if type == 'rotate' and value == (0.0,):
                continue
            if type == 'matrix' and isinstance(value, Affine2DBase):
                value = value.to_values()

            output.write('%s(%s)' % (type, ' '.join(str(x) for x in value)))
        return output.getvalue()
    return ''

def generate_css(attrib={}):
    if attrib:
        output = cStringIO.StringIO()
        attrib = attrib.items()
        attrib.sort()
        for k, v in attrib:
            k = escape_attrib(k)
            v = escape_attrib(v)
            output.write("%s:%s;" % (k, v))
        return output.getvalue()
    return ''

_capstyle_d = {'projecting' : 'square', 'butt' : 'butt', 'round': 'round',}
class RendererSVG(RendererBase):
    FONT_SCALE = 100.0
    fontd = maxdict(50)

    def __init__(self, width, height, svgwriter, basename=None):
        self.width = width
        self.height = height
        self.writer = XMLWriter(svgwriter)

        self._groupd = {}
        if not rcParams['svg.image_inline']:
            assert basename is not None
            self.basename = basename
            self._imaged = {}
        self._clipd = {}
        self._char_defs = {}
        self._markers = {}
        self._path_collection_id = 0
        self._imaged = {}
        self._hatchd = {}
        self._has_gouraud = False
        self._n_gradients = 0
        self._fonts = {}
        self.mathtext_parser = MathTextParser('SVG')

        RendererBase.__init__(self)
        self._glyph_map = dict()

        svgwriter.write(svgProlog)
        self._start_id = self.writer.start(
            'svg',
            width='%ipt' % width, height='%ipt' % height,
            viewBox='0 0 %i %i' % (width, height),
            xmlns="http://www.w3.org/2000/svg",
            version="1.1",
            attrib={'xmlns:xlink': "http://www.w3.org/1999/xlink"})
        self._write_default_style()

    def finalize(self):
        self._write_clips()
        self._write_hatches()
        self._write_svgfonts()
        self.writer.close(self._start_id)

    def _write_default_style(self):
        writer = self.writer
        default_style = generate_css({
            'stroke-linejoin': 'round',
            'stroke-linecap': 'square'})
        writer.start('defs')
        writer.start('style', type='text/css')
        writer.data('*{%s}\n' % default_style)
        writer.end('style')
        writer.end('defs')

    def _make_id(self, type, content):
        return '%s%s' % (type, md5(str(content)).hexdigest()[:10])

    def _make_flip_transform(self, transform):
        return (transform +
                Affine2D()
                .scale(1.0, -1.0)
                .translate(0.0, self.height))

    def _get_font(self, prop):
        key = hash(prop)
        font = self.fontd.get(key)
        if font is None:
            fname = findfont(prop)
            font = self.fontd.get(fname)
            if font is None:
                font = FT2Font(str(fname))
                self.fontd[fname] = font
            self.fontd[key] = font
        font.clear()
        size = prop.get_size_in_points()
        font.set_size(size, 72.0)
        return font

    def _get_hatch(self, gc, rgbFace):
        """
        Create a new hatch pattern
        """
        dictkey = (gc.get_hatch(), rgbFace, gc.get_rgb())
        oid = self._hatchd.get(dictkey)
        if oid is None:
            oid = self._make_id('h', dictkey)
            self._hatchd[dictkey] = ((gc.get_hatch_path(), rgbFace, gc.get_rgb()), oid)
        else:
            _, oid = oid
        return oid
        
    def _write_hatches(self):
        if not len(self._hatchd):
            return
        HATCH_SIZE = 72
        writer = self.writer
        writer.start('defs')
        for ((path, face, stroke), oid) in self._hatchd.values():
            writer.start(
                'pattern',
                id=oid,
                patternUnits="userSpaceOnUse",
                x="0", y="0", width=str(HATCH_SIZE), height=str(HATCH_SIZE))
            path_data = self._convert_path(
                path,
                Affine2D().scale(HATCH_SIZE).scale(1.0, -1.0).translate(0, HATCH_SIZE),
                simplify=False)
            if face is None:
                fill = 'none'
            else:
                fill = rgb2hex(face)
            writer.element(
                'rect',
                x="0", y="0", width=str(HATCH_SIZE+1), height=str(HATCH_SIZE+1),
                fill=fill)
            writer.element(
                'path',
                d=path_data,
                style=generate_css({
                    'fill': rgb2hex(stroke),
                    'stroke': rgb2hex(stroke),
                    'stroke-width': str(1.0),
                    'stroke-linecap': 'butt',
                    'stroke-linejoin': 'miter'
                    })
                )
            writer.end('pattern')
        writer.end('defs')

    def _get_style(self, gc, rgbFace):
        """
        return the style string.  style is generated from the
        GraphicsContext and rgbFace
        """
        attrib = {}

        if gc.get_hatch() is not None:
            attrib['fill'] = "url(#%s)" % self._get_hatch(gc, rgbFace)
        else:
            if rgbFace is None:
                attrib['fill'] = 'none'
            elif tuple(rgbFace[:3]) != (0, 0, 0):
                attrib['fill'] = rgb2hex(rgbFace)

        if gc.get_alpha() != 1.0:
            attrib['opacity'] = str(gc.get_alpha())

        offset, seq = gc.get_dashes()
        if seq is not None:
            attrib['stroke-dasharray'] = ','.join(['%f' % val for val in seq])
            attrib['stroke-dashoffset'] = str(float(offset))

        linewidth = gc.get_linewidth()
        if linewidth:
            attrib['stroke'] = rgb2hex(gc.get_rgb())
            if linewidth != 1.0:
                attrib['stroke-width'] = str(linewidth)
            if gc.get_joinstyle() != 'round':
                attrib['stroke-linejoin'] = gc.get_joinstyle()
            if gc.get_capstyle() != 'projecting':
                attrib['stroke-linecap'] = _capstyle_d[gc.get_capstyle()]

        return generate_css(attrib)

    def _get_clip(self, gc):
        cliprect = gc.get_clip_rectangle()
        clippath, clippath_trans = gc.get_clip_path()
        if clippath is not None:
            clippath_trans = self._make_flip_transform(clippath_trans)
            dictkey = (id(clippath), str(clippath_trans))
        elif cliprect is not None:
            x, y, w, h = cliprect.bounds
            y = self.height-(y+h)
            dictkey = (x, y, w, h)
        else:
            return None

        clip = self._clipd.get(dictkey)
        if clip is None:
            oid = self._make_id('p', dictkey)
            if clippath is not None:
                self._clipd[dictkey] = ((clippath, clippath_trans), oid)
            else:
                self._clipd[dictkey] = (dictkey, oid)
        else:
            clip, oid = clip
        return oid

    def _write_clips(self):
        if not len(self._clipd):
            return
        writer = self.writer
        writer.start('defs')
        for clip, oid in self._clipd.values():
            writer.start('clipPath', id=oid)
            if len(clip) == 2:
                clippath, clippath_trans = clip
                path_data = self._convert_path(clippath, clippath_trans, simplify=False)
                writer.element('path', d=path_data)
            else:
                x, y, w, h = clip
                writer.element('rect', x=str(x), y=str(y), width=str(w), height=str(h))
            writer.end('clipPath')
        writer.end('defs')
    
    def _write_svgfonts(self):
        if not rcParams['svg.fonttype'] == 'svgfont':
            return

        writer = self.writer
        writer.start('defs')
        for font_fname, chars in self._fonts.items():
            font = FT2Font(font_fname)
            font.set_size(72, 72)
            sfnt = font.get_sfnt()
            writer.start('font', id=sfnt[(1, 0, 0, 4)])
            writer.element(
                'font-face',
                attrib={
                    'font-family': font.family_name,
                    'font-style': font.style_name.lower(),
                    'units-per-em': '72',
                    'bbox': ' '.join(str(x / 64.0) for x in font.bbox)})
            for char in chars:
                glyph = font.load_char(char, flags=LOAD_NO_HINTING)
                verts, codes = font.get_path()
                path = Path(verts, codes)
                path_data = self._convert_path(path)
                # name = font.get_glyph_name(char)
                writer.element(
                    'glyph',
                    d=path_data,
                    attrib={
                        # 'glyph-name': name,
                        'unicode': unichr(char),
                        'horiz-adv-x': str(glyph.linearHoriAdvance / 65536.0)})
            writer.end('font')
        writer.end('defs')

    def open_group(self, s, gid=None):
        """
        Open a grouping element with label *s*. If *gid* is given, use
        *gid* as the id of the group.
        """
        if gid:
            self.writer.start('g', id=gid)
        else:
            self._groupd[s] = self._groupd.get(s, 0) + 1
            self.writer.start('g', id="%s_%d" % (s, self._groupd[s]))

    def close_group(self, s):
        self.writer.end('g')

    def option_image_nocomposite(self):
        """
        if svg.image_noscale is True, compositing multiple images into one is prohibited
        """
        return rcParams['svg.image_noscale']

    def _convert_path(self, path, transform=None, clip=None, simplify=None):
        if clip:
            clip = (0.0, 0.0, self.width, self.height)
        else:
            clip = None
        return _path.convert_to_svg(path, transform, clip, simplify, 6)

    def draw_path(self, gc, path, transform, rgbFace=None):
        trans_and_flip = self._make_flip_transform(transform)
        clip = (rgbFace is None and gc.get_hatch_path() is None)
        simplify = path.should_simplify and clip
        path_data = self._convert_path(
            path, trans_and_flip, clip=clip, simplify=simplify)

        attrib = {}
        attrib['style'] = self._get_style(gc, rgbFace)

        clipid = self._get_clip(gc)
        if clipid is not None:
            attrib['clip-path'] = 'url(#%s)' % clipid

        if gc.get_url() is not None:
            self.writer.start('a', {'xlink:href': gc.get_url()})
        self.writer.element('path', d=path_data, attrib=attrib)
        if gc.get_url() is not None:
            self.writer.end('</a>')

    def draw_markers(self, gc, marker_path, marker_trans, path, trans, rgbFace=None):
        if not len(path.vertices):
            return

        writer = self.writer
        dictkey = (id(marker_path), marker_trans)
        oid = self._markers.get(dictkey)
        if oid is None:
            oid = self._make_id('m', dictkey)
            path_data = self._convert_path(
                marker_path,
                marker_trans + Affine2D().scale(1.0, -1.0),
                simplify=False)
            writer.start('defs')
            writer.element('path', id=oid, d=path_data)
            writer.end('defs')
            self._markers[dictkey] = oid

        attrib = {}
        clipid = self._get_clip(gc)
        if clipid is not None:
            attrib['clip-path'] = 'url(#%s)' % clipid
        writer.start('g', attrib=attrib)

        trans_and_flip = self._make_flip_transform(trans)
        attrib = {'xlink:href': '#%s' % oid}
        for vertices, code in path.iter_segments(trans_and_flip, simplify=False):
            if len(vertices):
                x, y = vertices[-2:]
                attrib['x'] = str(x)
                attrib['y'] = str(y)
                attrib['style'] = self._get_style(gc, rgbFace)
                writer.element('use', attrib=attrib)
        writer.end('g')

    def draw_path_collection(self, gc, master_transform, paths, all_transforms,
                             offsets, offsetTrans, facecolors, edgecolors,
                             linewidths, linestyles, antialiaseds, urls):
        writer = self.writer
        path_codes = []
        writer.start('defs')
        for i, (path, transform) in enumerate(self._iter_collection_raw_paths(
            master_transform, paths, all_transforms)):
            transform = Affine2D(transform.get_matrix()).scale(1.0, -1.0)
            d = self._convert_path(path, transform, simplify=False)
            oid = 'C%x_%x_%s' % (self._path_collection_id, i,
                                    self._make_id('', d))
            writer.element('path', id=oid, d=d)
            path_codes.append(oid)
        writer.end('defs')

        for xo, yo, path_id, gc0, rgbFace in self._iter_collection(
            gc, path_codes, offsets, offsetTrans, facecolors, edgecolors,
            linewidths, linestyles, antialiaseds, urls):
            clipid = self._get_clip(gc0)
            url = gc0.get_url()
            if url is not None:
                writer.start('a', attrib={'xlink:href': url})
            if clipid is not None:
                writer.start('g', attrib={'clip-path': 'url(#%s)' % clipid})
            attrib = {
                'xlink:href': '#%s' % path_id,
                'x': str(xo),
                'y': str(self.height - yo),
                'style': self._get_style(gc0, rgbFace)
                }
            writer.element('use', attrib=attrib)
            if clipid is not None:
                writer.end('g')
            if url is not None:
                writer.end('a')

        self._path_collection_id += 1

    def draw_gouraud_triangle(self, gc, points, colors, trans):
        # This uses a method described here:
        #
        #   http://www.svgopen.org/2005/papers/Converting3DFaceToSVG/index.html
        #
        # that uses three overlapping linear gradients to simulate a
        # Gouraud triangle.  Each gradient goes from fully opaque in
        # one corner to fully transparent along the opposite edge.
        # The line between the stop points is perpendicular to the
        # opposite edge.  Underlying these three gradients is a solid
        # triangle whose color is the average of all three points.

        writer = self.writer
        if not self._has_gouraud:
            self._has_gouraud = True
            writer.start(
                'filter',
                id='colorAdd')
            writer.element(
                'feComposite',
                attrib={'in': 'SourceGraphic'},
                in2='BackgroundImage',
                operator='arithmetic',
                k2="1", k3="1")
            writer.end('filter')

        avg_color = np.sum(colors[:, :], axis=0) / 3.0
        # Just skip fully-transparent triangles
        if avg_color[-1] == 0.0:
            return

        trans_and_flip = self._make_flip_transform(trans)
        tpoints = trans_and_flip.transform(points)

        writer.start('defs')
        for i in range(3):
            x1, y1 = points[i]
            x2, y2 = points[(i + 1) % 3]
            x3, y3 = points[(i + 2) % 3]
            c = colors[i][:]

            if x2 == x3:
                xb = x2
                yb = y1
            elif y2 == y3:
                xb = x1
                yb = y2
            else:
                m1 = (y2 - y3) / (x2 - x3)
                b1 = y2 - (m1 * x2)
                m2 = -(1.0 / m1)
                b2 = y1 - (m2 * x1)
                xb = (-b1 + b2) / (m1 - m2)
                yb = m2 * xb + b2

            writer.start(
                'linearGradient',
                id="GR%x_%d" % (self._n_gradients, i),
                x1=str(x1), y1=str(y1), x2=str(xb), y2=str(yb))
            writer.element(
                'stop',
                offset='0',
                style=generate_css({'stop-color': rgb2hex(c),
                                    'stop-opacity': str(c[-1])}))
            writer.element(
                'stop',
                offset='1',
                style=generate_css({'stop-color': rgb2hex(c),
                                    'stop-opacity': "0"}))
            writer.end('linearGradient')

        writer.element(
            'polygon',
            id='GT%x' % self._n_gradients,
            points=" ".join([str(x) for x in x1,y1,x2,y2,x3,y3]))
        writer.end('defs')

        avg_color = np.sum(colors[:, :], axis=0) / 3.0
        href = '#GT%x' % self._n_gradients
        writer.element(
            'use',
            attrib={'xlink:href': '#%s' % href,
                    'fill': rgb2hex(avg_color),
                    'fill-opacity': str(avg_color[-1])})
        for i in range(3):
            writer.element(
                'use',
                attrib={'xlink:href': '#%s' % href,
                        'fill': 'url(#GR%x_%d)' % (self._n_gradients, i),
                        'fill-opacity': '1',
                        'filter': 'url(#colorAdd)'})

        self._n_gradients += 1

    def draw_gouraud_triangles(self, gc, triangles_array, colors_array,
                               transform):
        attrib = {}
        clipid = self._get_clip(gc)
        if clipid is not None:
            attrib['clip-path'] = 'url(#%s)' % clipid

        self.writer.start('g', attrib=attrib)

        transform = transform.frozen()
        for tri, col in zip(triangles_array, colors_array):
            self.draw_gouraud_triangle(gc, tri, col, transform)

        self.writer.end('g')

    def option_scale_image(self):
        return True

    def draw_image(self, gc, x, y, im, dx=None, dy=None, transform=None):
        attrib = {}
        clipid = self._get_clip(gc)
        if clipid is not None:
            # Can't apply clip-path directly to the image because the
            # image as a transformation, which would also be applied
            # to the clip-path
            self.writer.start('g', attrib={'clip-path': 'url(#%s)' % clipid})

        trans = [1,0,0,1,0,0]
        if rcParams['svg.image_noscale']:
            trans = list(im.get_matrix())
            trans[5] = -trans[5]
            attrib['transform'] = generate_transform([('matrix', tuple(trans))])
            assert trans[1] == 0
            assert trans[2] == 0
            numrows, numcols = im.get_size()
            im.reset_matrix()
            im.set_interpolation(0)
            im.resize(numcols, numrows)

        h,w = im.get_size_out()

        url = getattr(im, '_url', None)
        if url is not None:
            self.writer.start('a', attrib={'xlink:href': url})
        if rcParams['svg.image_inline']:
            stringio = cStringIO.StringIO()
            im.flipud_out()
            rows, cols, buffer = im.as_rgba_str()
            _png.write_png(buffer, cols, rows, stringio)
            im.flipud_out()
            attrib['xlink:href'] = ("data:image/png;base64,\n" +
                                    base64.encodestring(stringio.getvalue()))
        else:
            self._imaged[self.basename] = self._imaged.get(self.basename,0) + 1
            filename = '%s.image%d.png'%(self.basename, self._imaged[self.basename])
            verbose.report( 'Writing image file for inclusion: %s' % filename)
            im.flipud_out()
            rows, cols, buffer = im.as_rgba_str()
            _png.write_png(buffer, cols, rows, filename)
            im.flipud_out()
            attrib['xlink:href'] = filename

        if transform is None:
            self.writer.element(
                'image',
                x=str(x/trans[0]), y=str((self.height-y)/trans[3]-h),
                width=str(w), height=str(h),
                attrib=attrib)
        else:
            flipped = self._make_flip_transform(transform)
            attrib['transform'] = generate_transform(
                [('matrix', flipped.to_values())])
            self.writer.element(
                'image',
                x=str(x), y=str(y+dy), width=str(dx), height=str(-dy),
                attrib=attrib)

        if url is not None:
            self.writer.end('a')
        if clipid is not None:
            self.writer.end('g')

    def _adjust_char_id(self, char_id):
        return char_id.replace("%20", "_")

    def _draw_text_as_path(self, gc, x, y, s, prop, angle, ismath):
        """
        draw the text by converting them to paths using textpath module.

        *prop*
          font property

        *s*
          text to be converted

        *usetex*
          If True, use matplotlib usetex mode.

        *ismath*
          If True, use mathtext parser. If "TeX", use *usetex* mode.
        """
        writer = self.writer

        writer.comment(s)

        glyph_map=self._glyph_map

        text2path = self._text2path
        color = rgb2hex(gc.get_rgb())
        fontsize = prop.get_size_in_points()

        style = {}
        if color != '#000000':
            style['fill'] = color
        if gc.get_alpha() != 1.0:
            style['opacity'] = str(gc.get_alpha())

        if not ismath:
            font = text2path._get_font(prop)
            _glyphs = text2path.get_glyphs_with_font(
                font, s, glyph_map=glyph_map, return_new_glyphs_only=True)
            glyph_info, glyph_map_new, rects = _glyphs
            y -= ((font.get_descent() / 64.0) *
                  (prop.get_size_in_points() / text2path.FONT_SCALE))

            if glyph_map_new:
                writer.start('defs')
                for char_id, glyph_path in glyph_map_new.iteritems():
                    path = Path(*glyph_path)
                    path_data = self._convert_path(path, simplify=False)
                    writer.element('path', id=char_id, d=path_data)
                writer.end('defs')

                glyph_map.update(glyph_map_new)

            attrib = {}
            attrib['style'] = generate_css(style)
            font_scale = fontsize / text2path.FONT_SCALE
            attrib['transform'] = generate_transform([
                ('translate', (x, y)),
                ('rotate', (-angle,)),
                ('scale', (font_scale, -font_scale))])

            writer.start('g', attrib=attrib)
            for glyph_id, xposition, yposition, scale in glyph_info:
                attrib={'xlink:href': '#%s' % glyph_id}
                if xposition != 0.0:
                    attrib['x'] = str(xposition)
                if yposition != 0.0:
                    attrib['y'] = str(yposition)
                writer.element(
                    'use',
                    attrib=attrib)

            writer.end('g')
        else:
            if ismath == "TeX":
                _glyphs = text2path.get_glyphs_tex(prop, s, glyph_map=glyph_map,
                                                   return_new_glyphs_only=True)
            else:
                _glyphs = text2path.get_glyphs_mathtext(prop, s, glyph_map=glyph_map,
                                                        return_new_glyphs_only=True)

            glyph_info, glyph_map_new, rects = _glyphs

            # we store the character glyphs w/o flipping. Instead, the
            # coordinate will be flipped when this characters are
            # used.
            if glyph_map_new:
                writer.start('defs')
                for char_id, glyph_path in glyph_map_new.iteritems():
                    char_id = self._adjust_char_id(char_id)
                    # Some characters are blank
                    if not len(glyph_path[0]):
                        path_data = ""
                    else:
                        path = Path(*glyph_path)
                        path_data = self._convert_path(path, simplify=False)
                    writer.element('path', id=char_id, d=path_data)
                writer.end('defs')

                glyph_map.update(glyph_map_new)

            attrib = {}
            font_scale = fontsize / text2path.FONT_SCALE
            attrib['style'] = generate_css(style)
            attrib['transform'] = generate_transform([
                ('translate', (x, y)),
                ('rotate', (-angle,)),
                ('scale', (font_scale, - font_scale))])

            writer.start('g', attrib=attrib)
            for char_id, xposition, yposition, scale in glyph_info:
                char_id = self._adjust_char_id(char_id)

                writer.element(
                    'use',
                    transform=generate_transform([
                        ('translate', (xposition, yposition)),
                        ('scale', (scale,)),
                        ]),
                    attrib={'xlink:href': '#%s' % char_id})

            for verts, codes in rects:
                path = Path(verts, codes)
                path_data = self._convert_path(path, simplify=False)
                writer.element('path', d=path_data)

            writer.end('g')

    def _draw_text_as_text(self, gc, x, y, s, prop, angle, ismath):
        writer = self.writer

        color = rgb2hex(gc.get_rgb())
        style = {}
        if color != '#000000':
            style['fill'] = color
        if gc.get_alpha() != 1.0:
            style['opacity'] = str(gc.get_alpha())

        if not ismath:
            font = self._get_font(prop)
            font.set_text(s, 0.0, flags=LOAD_NO_HINTING)
            y -= font.get_descent() / 64.0

            fontsize = prop.get_size_in_points()

            fontfamily = font.family_name
            fontstyle = prop.get_style()

            attrib = {}
            style['font-size'] = str(fontsize)
            style['font-family'] = str(fontfamily)
            style['font-style'] = prop.get_style().lower()
            attrib['style'] = generate_css(style)

            attrib['transform'] = generate_transform([
                ('translate', (x, y)),
                ('rotate', (-angle,))])

            writer.element('text', s, attrib=attrib)

            if rcParams['svg.fonttype'] == 'svgfont':
                fontset = self._fonts.setdefault(font.fname, set())
                for c in s:
                    fontset.add(ord(c))
        else:
            writer.comment(s)

            width, height, descent, svg_elements, used_characters = \
                   self.mathtext_parser.parse(s, 72, prop)
            svg_glyphs = svg_elements.svg_glyphs
            svg_rects = svg_elements.svg_rects

            attrib = {}
            attrib['style'] = generate_css(style)
            attrib['transform'] = generate_transform([
                ('translate', (x, y)),
                ('rotate', (-angle,))])

            # Apply attributes to 'g', not 'text', because we likely
            # have some rectangles as well with the same style and
            # transformation
            writer.start('g', attrib=attrib)

            writer.start('text')

            # Sort the characters by font, and output one tspan for
            # each
            spans = {}
            for font, fontsize, thetext, new_x, new_y, metrics in svg_glyphs:
                style = generate_css({
                    'font-size': str(fontsize),
                    'font-family': font.family_name,
                    'font-style': font.style_name.lower()})
                if thetext == 32:
                    thetext = 0xa0 # non-breaking space
                spans.setdefault(style, []).append((new_x, -new_y, thetext))

            if rcParams['svg.fonttype'] == 'svgfont':
                for font, fontsize, thetext, new_x, new_y, metrics in svg_glyphs:
                    fontset = self._fonts.setdefault(font.fname, set())
                    fontset.add(thetext)

            for style, chars in spans.items():
                chars.sort()

                same_y = True
                if len(chars) > 1:
                    last_y = chars[0][1]
                    for i in xrange(1, len(chars)):
                        if chars[i][1] != last_y:
                            same_y = False
                            break
                if same_y:
                    ys = str(chars[0][1])
                else:
                    ys = ' '.join(str(c[1]) for c in chars)

                attrib = {
                    'style': style,
                    'x': ' '.join(str(c[0]) for c in chars),
                    'y': ys
                    }

                writer.element(
                    'tspan',
                    ''.join(unichr(c[2]) for c in chars),
                    attrib=attrib)

            writer.end('text')

            if len(svg_rects):
                for x, y, width, height in svg_rects:
                    writer.element(
                        'rect',
                        x=str(x), y=str(-y + height),
                        width=str(width), height=str(height)
                        )

            writer.end('g')

    def draw_tex(self, gc, x, y, s, prop, angle):
        self._draw_text_as_path(gc, x, y, s, prop, angle, ismath="TeX")

    def draw_text(self, gc, x, y, s, prop, angle, ismath):
        clipid = self._get_clip(gc)
        if clipid is not None:
            # Cannot apply clip-path directly to the text, because
            # is has a transformation
            self.writer.start(
                'g', attrib={'clip-path': 'url(#%s)' % clipid})

        if rcParams['svg.fonttype'] == 'path':
            self._draw_text_as_path(gc, x, y, s, prop, angle, ismath)
        else:
            self._draw_text_as_text(gc, x, y, s, prop, angle, ismath)

        if clipid is not None:
            self.writer.end('g')

    def flipy(self):
        return True

    def get_canvas_width_height(self):
        return self.width, self.height

    def get_text_width_height_descent(self, s, prop, ismath):
        return self._text2path.get_text_width_height_descent(s, prop, ismath)


class FigureCanvasSVG(FigureCanvasBase):
    filetypes = {'svg': 'Scalable Vector Graphics',
                 'svgz': 'Scalable Vector Graphics'}

    def print_svg(self, filename, *args, **kwargs):
        if is_string_like(filename):
            fh_to_close = svgwriter = codecs.open(filename, 'w', 'utf-8')
        elif is_writable_file_like(filename):
            svgwriter = codecs.getwriter('utf-8')(filename)
            fh_to_close = None
        else:
            raise ValueError("filename must be a path or a file-like object")
        return self._print_svg(filename, svgwriter, fh_to_close, **kwargs)

    def print_svgz(self, filename, *args, **kwargs):
        if is_string_like(filename):
            gzipwriter = gzip.GzipFile(filename, 'w')
            fh_to_close = svgwriter = codecs.getwriter('utf-8')(gzipwriter)
        elif is_writable_file_like(filename):
            fh_to_close = gzipwriter = gzip.GzipFile(fileobj=filename, mode='w')
            svgwriter = codecs.getwriter('utf-8')(gzipwriter)
        else:
            raise ValueError("filename must be a path or a file-like object")
        return self._print_svg(filename, svgwriter, fh_to_close)

    def _print_svg(self, filename, svgwriter, fh_to_close=None, **kwargs):
        self.figure.set_dpi(72.0)
        width, height = self.figure.get_size_inches()
        w, h = width*72, height*72

        if rcParams['svg.image_noscale']:
            renderer = RendererSVG(w, h, svgwriter, filename)
        else:
            # setting mixed renderer dpi other than 72 results in
            # incorrect size of the rasterized image. It seems that the
            # svg internally uses fixed dpi of 72 and seems to cause
            # the problem. I hope someone who knows the svg backends
            # take a look at this problem. Meanwhile, the dpi
            # parameter is ignored and image_dpi is fixed at 72. - JJL

            #image_dpi = kwargs.pop("dpi", 72)
            image_dpi = 72
            _bbox_inches_restore = kwargs.pop("bbox_inches_restore", None)
            renderer = MixedModeRenderer(self.figure,
                width, height, image_dpi, RendererSVG(w, h, svgwriter, filename),
                bbox_inches_restore=_bbox_inches_restore)

        self.figure.draw(renderer)
        renderer.finalize()
        if fh_to_close is not None:
            svgwriter.close()

    def get_default_filetype(self):
        return 'svg'

class FigureManagerSVG(FigureManagerBase):
    pass

FigureManager = FigureManagerSVG

def new_figure_manager(num, *args, **kwargs):
    FigureClass = kwargs.pop('FigureClass', Figure)
    thisFig = FigureClass(*args, **kwargs)
    canvas  = FigureCanvasSVG(thisFig)
    manager = FigureManagerSVG(canvas, num)
    return manager

svgProlog = u"""\
<?xml version="1.0" encoding="utf-8" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
  "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<!-- Created with matplotlib (http://matplotlib.sourceforge.net/) -->
"""
