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

from matplotlib.externals import six

import math
import os
import sys
import errno
import re
import shutil
import tempfile
import codecs
import atexit
import weakref
import warnings

import numpy as np

import matplotlib as mpl
from matplotlib.backend_bases import RendererBase, GraphicsContextBase,\
    FigureManagerBase, FigureCanvasBase
from matplotlib.backends.backend_mixed import MixedModeRenderer
from matplotlib.figure import Figure
from matplotlib.text import Text
from matplotlib.path import Path
from matplotlib import _png, rcParams
from matplotlib.cbook import is_string_like, is_writable_file_like
from matplotlib.compat import subprocess
from matplotlib.compat.subprocess import check_output


###############################################################################

# create a list of system fonts, all of these should work with xe/lua-latex
system_fonts = []
if sys.platform.startswith('win'):
    from matplotlib import font_manager
    from matplotlib.ft2font import FT2Font
    for f in font_manager.win32InstalledFonts():
        try:
            system_fonts.append(FT2Font(str(f)).family_name)
        except:
            pass # unknown error, skip this font
else:
    # assuming fontconfig is installed and the command 'fc-list' exists
    try:
        # list scalable (non-bitmap) fonts
        fc_list = check_output(['fc-list', ':outline,scalable', 'family'])
        fc_list = fc_list.decode('utf8')
        system_fonts = [f.split(',')[0] for f in fc_list.splitlines()]
        system_fonts = list(set(system_fonts))
    except:
        warnings.warn('error getting fonts from fc-list', UserWarning)

def get_texcommand():
    """Get chosen TeX system from rc."""
    texsystem_options = ["xelatex", "lualatex", "pdflatex"]
    texsystem = rcParams.get("pgf.texsystem", "xelatex")
    return texsystem if texsystem in texsystem_options else "xelatex"


def get_fontspec():
    """Build fontspec preamble from rc."""
    latex_fontspec = []
    texcommand = get_texcommand()

    if texcommand != "pdflatex":
        latex_fontspec.append("\\usepackage{fontspec}")

    if texcommand != "pdflatex" and rcParams.get("pgf.rcfonts", True):
        # try to find fonts from rc parameters
        families = ["serif", "sans-serif", "monospace"]
        fontspecs = [r"\setmainfont{%s}", r"\setsansfont{%s}",
                     r"\setmonofont{%s}"]
        for family, fontspec in zip(families, fontspecs):
            matches = [f for f in rcParams["font." + family]
                       if f in system_fonts]
            if matches:
                latex_fontspec.append(fontspec % matches[0])
            else:
                pass  # no fonts found, fallback to LaTeX defaule

    return "\n".join(latex_fontspec)


def get_preamble():
    """Get LaTeX preamble from rc."""
    latex_preamble = rcParams.get("pgf.preamble", "")
    if type(latex_preamble) == list:
        latex_preamble = "\n".join(latex_preamble)
    return latex_preamble

###############################################################################

# This almost made me cry!!!
# In the end, it's better to use only one unit for all coordinates, since the
# arithmetic in latex seems to produce inaccurate conversions.
latex_pt_to_in = 1. / 72.27
latex_in_to_pt = 1. / latex_pt_to_in
mpl_pt_to_in = 1. / 72.
mpl_in_to_pt = 1. / mpl_pt_to_in

###############################################################################
# helper functions

NO_ESCAPE = r"(?<!\\)(?:\\\\)*"
re_mathsep = re.compile(NO_ESCAPE + r"\$")
re_escapetext = re.compile(NO_ESCAPE + "([_^$%])")
repl_escapetext = lambda m: "\\" + m.group(1)
re_mathdefault = re.compile(NO_ESCAPE + r"(\\mathdefault)")
repl_mathdefault = lambda m: m.group(0)[:-len(m.group(1))]


def common_texification(text):
    """
    Do some necessary and/or useful substitutions for texts to be included in
    LaTeX documents.
    """

    # Sometimes, matplotlib adds the unknown command \mathdefault.
    # Not using \mathnormal instead since this looks odd for the latex cm font.
    text = re_mathdefault.sub(repl_mathdefault, text)

    # split text into normaltext and inline math parts
    parts = re_mathsep.split(text)
    for i, s in enumerate(parts):
        if not i % 2:
            # textmode replacements
            s = re_escapetext.sub(repl_escapetext, s)
        else:
            # mathmode replacements
            s = r"\(\displaystyle %s\)" % s
        parts[i] = s

    return "".join(parts)


def writeln(fh, line):
    # every line of a file included with \input must be terminated with %
    # if not, latex will create additional vertical spaces for some reason
    fh.write(line)
    fh.write("%\n")


def _font_properties_str(prop):
    # translate font properties to latex commands, return as string
    commands = []

    families = {"serif": r"\rmfamily", "sans": r"\sffamily",
                "sans-serif": r"\sffamily", "monospace": r"\ttfamily"}
    family = prop.get_family()[0]
    if family in families:
        commands.append(families[family])
    elif family in system_fonts and get_texcommand() != "pdflatex":
        commands.append(r"\setmainfont{%s}\rmfamily" % family)
    else:
        pass  # print warning?

    size = prop.get_size_in_points()
    commands.append(r"\fontsize{%f}{%f}" % (size, size * 1.2))

    styles = {"normal": r"", "italic": r"\itshape", "oblique": r"\slshape"}
    commands.append(styles[prop.get_style()])

    boldstyles = ["semibold", "demibold", "demi", "bold", "heavy",
                  "extra bold", "black"]
    if prop.get_weight() in boldstyles:
        commands.append(r"\bfseries")

    commands.append(r"\selectfont")
    return "".join(commands)


def make_pdf_to_png_converter():
    """
    Returns a function that converts a pdf file to a png file.
    """

    tools_available = []
    # check for pdftocairo
    try:
        check_output(["pdftocairo", "-v"], stderr=subprocess.STDOUT)
        tools_available.append("pdftocairo")
    except:
        pass
    # check for ghostscript
    gs, ver = mpl.checkdep_ghostscript()
    if gs:
        tools_available.append("gs")

    # pick converter
    if "pdftocairo" in tools_available:
        def cairo_convert(pdffile, pngfile, dpi):
            cmd = ["pdftocairo", "-singlefile", "-png",
                   "-r %d" % dpi, pdffile, os.path.splitext(pngfile)[0]]
            # for some reason this doesn't work without shell
            check_output(" ".join(cmd), shell=True, stderr=subprocess.STDOUT)
        return cairo_convert
    elif "gs" in tools_available:
        def gs_convert(pdffile, pngfile, dpi):
            cmd = [gs, '-dQUIET', '-dSAFER', '-dBATCH', '-dNOPAUSE', '-dNOPROMPT',
                   '-sDEVICE=png16m', '-dUseCIEColor', '-dTextAlphaBits=4',
                   '-dGraphicsAlphaBits=4', '-dDOINTERPOLATE', '-sOutputFile=%s' % pngfile,
                   '-r%d' % dpi, pdffile]
            check_output(cmd, stderr=subprocess.STDOUT)
        return gs_convert
    else:
        raise RuntimeError("No suitable pdf to png renderer found.")


class LatexError(Exception):
    def __init__(self, message, latex_output=""):
        Exception.__init__(self, message)
        self.latex_output = latex_output


class LatexManagerFactory(object):
    previous_instance = None

    @staticmethod
    def get_latex_manager():
        texcommand = get_texcommand()
        latex_header = LatexManager._build_latex_header()
        prev = LatexManagerFactory.previous_instance

        # check if the previous instance of LatexManager can be reused
        if prev and prev.latex_header == latex_header and prev.texcommand == texcommand:
            if rcParams.get("pgf.debug", False):
                print("reusing LatexManager")
            return prev
        else:
            if rcParams.get("pgf.debug", False):
                print("creating LatexManager")
            new_inst = LatexManager()
            LatexManagerFactory.previous_instance = new_inst
            return new_inst

class WeakSet(object):
    # TODO: Poor man's weakref.WeakSet.
    #       Remove this once python 2.6 support is dropped from matplotlib.

    def __init__(self):
        self.weak_key_dict = weakref.WeakKeyDictionary()

    def add(self, item):
        self.weak_key_dict[item] = None

    def discard(self, item):
        if item in self.weak_key_dict:
            del self.weak_key_dict[item]

    def __iter__(self):
        return six.iterkeys(self.weak_key_dict)


class LatexManager(object):
    """
    The LatexManager opens an instance of the LaTeX application for
    determining the metrics of text elements. The LaTeX environment can be
    modified by setting fonts and/or a custem preamble in the rc parameters.
    """
    _unclean_instances = WeakSet()

    @staticmethod
    def _build_latex_header():
        latex_preamble = get_preamble()
        latex_fontspec = get_fontspec()
        # Create LaTeX header with some content, else LaTeX will load some
        # math fonts later when we don't expect the additional output on stdout.
        # TODO: is this sufficient?
        latex_header = [r"\documentclass{minimal}",
                        latex_preamble,
                        latex_fontspec,
                        r"\begin{document}",
                        r"text $math \mu$",  # force latex to load fonts now
                        r"\typeout{pgf_backend_query_start}"]
        return "\n".join(latex_header)

    @staticmethod
    def _cleanup_remaining_instances():
        unclean_instances = list(LatexManager._unclean_instances)
        for latex_manager in unclean_instances:
            latex_manager._cleanup()

    def _stdin_writeln(self, s):
        self.latex_stdin_utf8.write(s)
        self.latex_stdin_utf8.write("\n")
        self.latex_stdin_utf8.flush()

    def _expect(self, s):
        exp = s.encode("utf8")
        buf = bytearray()
        while True:
            b = self.latex.stdout.read(1)
            buf += b
            if buf[-len(exp):] == exp:
                break
            if not len(b):
                raise LatexError("LaTeX process halted", buf.decode("utf8"))
        return buf.decode("utf8")

    def _expect_prompt(self):
        return self._expect("\n*")

    def __init__(self):
        # store references for __del__
        self._os_path = os.path
        self._shutil = shutil
        self._debug = rcParams.get("pgf.debug", False)

        # create a tmp directory for running latex, remember to cleanup
        self.tmpdir = tempfile.mkdtemp(prefix="mpl_pgf_lm_")
        LatexManager._unclean_instances.add(self)

        # test the LaTeX setup to ensure a clean startup of the subprocess
        self.texcommand = get_texcommand()
        self.latex_header = LatexManager._build_latex_header()
        latex_end = "\n\\makeatletter\n\\@@end\n"
        try:
            latex = subprocess.Popen([self.texcommand, "-halt-on-error"],
                                     stdin=subprocess.PIPE,
                                     stdout=subprocess.PIPE,
                                     cwd=self.tmpdir)
        except OSError as e:
            if e.errno == errno.ENOENT:
                raise RuntimeError("Latex command not found. "
                    "Install '%s' or change pgf.texsystem to the desired command."
                    % self.texcommand
                )
            else:
                raise RuntimeError("Error starting process '%s'" % self.texcommand)
        test_input = self.latex_header + latex_end
        stdout, stderr = latex.communicate(test_input.encode("utf-8"))
        if latex.returncode != 0:
            raise LatexError("LaTeX returned an error, probably missing font or error in preamble:\n%s" % stdout)

        # open LaTeX process for real work
        latex = subprocess.Popen([self.texcommand, "-halt-on-error"],
                                 stdin=subprocess.PIPE, stdout=subprocess.PIPE,
                                 cwd=self.tmpdir)
        self.latex = latex
        self.latex_stdin_utf8 = codecs.getwriter("utf8")(self.latex.stdin)
        # write header with 'pgf_backend_query_start' token
        self._stdin_writeln(self._build_latex_header())
        # read all lines until our 'pgf_backend_query_start' token appears
        self._expect("*pgf_backend_query_start")
        self._expect_prompt()

        # cache for strings already processed
        self.str_cache = {}

    def _cleanup(self):
        if not self._os_path.isdir(self.tmpdir):
            return
        try:
            self.latex.communicate()
            self.latex_stdin_utf8.close()
            self.latex.stdout.close()
        except:
            pass
        try:
            self._shutil.rmtree(self.tmpdir)
            LatexManager._unclean_instances.discard(self)
        except:
            sys.stderr.write("error deleting tmp directory %s\n" % self.tmpdir)

    def __del__(self):
        if self._debug:
            print("deleting LatexManager")
        self._cleanup()

    def get_width_height_descent(self, text, prop):
        """
        Get the width, total height and descent for a text typesetted by the
        current LaTeX environment.
        """

        # apply font properties and define textbox
        prop_cmds = _font_properties_str(prop)
        textbox = "\\sbox0{%s %s}" % (prop_cmds, text)

        # check cache
        if textbox in self.str_cache:
            return self.str_cache[textbox]

        # send textbox to LaTeX and wait for prompt
        self._stdin_writeln(textbox)
        try:
            self._expect_prompt()
        except LatexError as e:
            msg = "Error processing '%s'\nLaTeX Output:\n%s"
            raise ValueError(msg % (text, e.latex_output))

        # typeout width, height and text offset of the last textbox
        self._stdin_writeln(r"\typeout{\the\wd0,\the\ht0,\the\dp0}")
        # read answer from latex and advance to the next prompt
        try:
            answer = self._expect_prompt()
        except LatexError as e:
            msg = "Error processing '%s'\nLaTeX Output:\n%s"
            raise ValueError(msg % (text, e.latex_output))

        # parse metrics from the answer string
        try:
            width, height, offset = answer.splitlines()[0].split(",")
        except:
            msg = "Error processing '%s'\nLaTeX Output:\n%s" % (text, answer)
            raise ValueError(msg)
        w, h, o = float(width[:-2]), float(height[:-2]), float(offset[:-2])

        # the height returned from LaTeX goes from base to top.
        # the height matplotlib expects goes from bottom to top.
        self.str_cache[textbox] = (w, h + o, o)
        return w, h + o, o


class RendererPgf(RendererBase):

    def __init__(self, figure, fh, dummy=False):
        """
        Creates a new PGF renderer that translates any drawing instruction
        into text commands to be interpreted in a latex pgfpicture environment.

        Attributes:
        * figure: Matplotlib figure to initialize height, width and dpi from.
        * fh: File handle for the output of the drawing commands.
        """
        RendererBase.__init__(self)
        self.dpi = figure.dpi
        self.fh = fh
        self.figure = figure
        self.image_counter = 0

        # get LatexManager instance
        self.latexManager = LatexManagerFactory.get_latex_manager()

        if dummy:
            # dummy==True deactivate all methods
            nop = lambda *args, **kwargs: None
            for m in RendererPgf.__dict__.keys():
                if m.startswith("draw_"):
                    self.__dict__[m] = nop
        else:
            # if fh does not belong to a filename, deactivate draw_image
            if not hasattr(fh, 'name') or not os.path.exists(fh.name):
                warnings.warn("streamed pgf-code does not support raster "
                              "graphics, consider using the pgf-to-pdf option",
                              UserWarning)
                self.__dict__["draw_image"] = lambda *args, **kwargs: None

    def draw_markers(self, gc, marker_path, marker_trans, path, trans, rgbFace=None):
        writeln(self.fh, r"\begin{pgfscope}")

        # convert from display units to in
        f = 1. / self.dpi

        # set style and clip
        self._print_pgf_clip(gc)
        self._print_pgf_path_styles(gc, rgbFace)

        # build marker definition
        bl, tr = marker_path.get_extents(marker_trans).get_points()
        coords = bl[0] * f, bl[1] * f, tr[0] * f, tr[1] * f
        writeln(self.fh, r"\pgfsys@defobject{currentmarker}{\pgfqpoint{%fin}{%fin}}{\pgfqpoint{%fin}{%fin}}{" % coords)
        self._print_pgf_path(None, marker_path, marker_trans)
        self._pgf_path_draw(stroke=gc.get_linewidth() != 0.0,
                            fill=rgbFace is not None)
        writeln(self.fh, r"}")

        # draw marker for each vertex
        for point, code in path.iter_segments(trans, simplify=False):
            x, y = point[0] * f, point[1] * f
            writeln(self.fh, r"\begin{pgfscope}")
            writeln(self.fh, r"\pgfsys@transformshift{%fin}{%fin}" % (x, y))
            writeln(self.fh, r"\pgfsys@useobject{currentmarker}{}")
            writeln(self.fh, r"\end{pgfscope}")

        writeln(self.fh, r"\end{pgfscope}")

    def draw_path(self, gc, path, transform, rgbFace=None):
        writeln(self.fh, r"\begin{pgfscope}")
        # draw the path
        self._print_pgf_clip(gc)
        self._print_pgf_path_styles(gc, rgbFace)
        self._print_pgf_path(gc, path, transform, rgbFace)
        self._pgf_path_draw(stroke=gc.get_linewidth() != 0.0,
                            fill=rgbFace is not None)
        writeln(self.fh, r"\end{pgfscope}")

        # if present, draw pattern on top
        if gc.get_hatch():
            writeln(self.fh, r"\begin{pgfscope}")
            self._print_pgf_path_styles(gc, rgbFace)

            # combine clip and path for clipping
            self._print_pgf_clip(gc)
            self._print_pgf_path(gc, path, transform, rgbFace)
            writeln(self.fh, r"\pgfusepath{clip}")

            # build pattern definition
            writeln(self.fh, r"\pgfsys@defobject{currentpattern}{\pgfqpoint{0in}{0in}}{\pgfqpoint{1in}{1in}}{")
            writeln(self.fh, r"\begin{pgfscope}")
            writeln(self.fh, r"\pgfpathrectangle{\pgfqpoint{0in}{0in}}{\pgfqpoint{1in}{1in}}")
            writeln(self.fh, r"\pgfusepath{clip}")
            scale = mpl.transforms.Affine2D().scale(self.dpi)
            self._print_pgf_path(None, gc.get_hatch_path(), scale)
            self._pgf_path_draw(stroke=True)
            writeln(self.fh, r"\end{pgfscope}")
            writeln(self.fh, r"}")
            # repeat pattern, filling the bounding rect of the path
            f = 1. / self.dpi
            (xmin, ymin), (xmax, ymax) = path.get_extents(transform).get_points()
            xmin, xmax = f * xmin, f * xmax
            ymin, ymax = f * ymin, f * ymax
            repx, repy = int(math.ceil(xmax-xmin)), int(math.ceil(ymax-ymin))
            writeln(self.fh, r"\pgfsys@transformshift{%fin}{%fin}" % (xmin, ymin))
            for iy in range(repy):
                for ix in range(repx):
                    writeln(self.fh, r"\pgfsys@useobject{currentpattern}{}")
                    writeln(self.fh, r"\pgfsys@transformshift{1in}{0in}")
                writeln(self.fh, r"\pgfsys@transformshift{-%din}{0in}" % repx)
                writeln(self.fh, r"\pgfsys@transformshift{0in}{1in}")

            writeln(self.fh, r"\end{pgfscope}")

    def _print_pgf_clip(self, gc):
        f = 1. / self.dpi
        # check for clip box
        bbox = gc.get_clip_rectangle()
        if bbox:
            p1, p2 = bbox.get_points()
            w, h = p2 - p1
            coords = p1[0] * f, p1[1] * f, w * f, h * f
            writeln(self.fh, r"\pgfpathrectangle{\pgfqpoint{%fin}{%fin}}{\pgfqpoint{%fin}{%fin}} " % coords)
            writeln(self.fh, r"\pgfusepath{clip}")

        # check for clip path
        clippath, clippath_trans = gc.get_clip_path()
        if clippath is not None:
            self._print_pgf_path(gc, clippath, clippath_trans)
            writeln(self.fh, r"\pgfusepath{clip}")

    def _print_pgf_path_styles(self, gc, rgbFace):
        # cap style
        capstyles = {"butt": r"\pgfsetbuttcap",
                     "round": r"\pgfsetroundcap",
                     "projecting": r"\pgfsetrectcap"}
        writeln(self.fh, capstyles[gc.get_capstyle()])

        # join style
        joinstyles = {"miter": r"\pgfsetmiterjoin",
                      "round": r"\pgfsetroundjoin",
                      "bevel": r"\pgfsetbeveljoin"}
        writeln(self.fh, joinstyles[gc.get_joinstyle()])

        # filling
        has_fill = rgbFace is not None

        if gc.get_forced_alpha():
            fillopacity = strokeopacity = gc.get_alpha()
        else:
            strokeopacity = gc.get_rgb()[3]
            fillopacity = rgbFace[3] if has_fill and len(rgbFace) > 3 else 1.0

        if has_fill:
            writeln(self.fh, r"\definecolor{currentfill}{rgb}{%f,%f,%f}" % tuple(rgbFace[:3]))
            writeln(self.fh, r"\pgfsetfillcolor{currentfill}")
        if has_fill and fillopacity != 1.0:
            writeln(self.fh, r"\pgfsetfillopacity{%f}" % fillopacity)

        # linewidth and color
        lw = gc.get_linewidth() * mpl_pt_to_in * latex_in_to_pt
        stroke_rgba = gc.get_rgb()
        writeln(self.fh, r"\pgfsetlinewidth{%fpt}" % lw)
        writeln(self.fh, r"\definecolor{currentstroke}{rgb}{%f,%f,%f}" % stroke_rgba[:3])
        writeln(self.fh, r"\pgfsetstrokecolor{currentstroke}")
        if strokeopacity != 1.0:
            writeln(self.fh, r"\pgfsetstrokeopacity{%f}" % strokeopacity)

        # line style
        dash_offset, dash_list = gc.get_dashes()
        if dash_list is None:
            writeln(self.fh, r"\pgfsetdash{}{0pt}")
        else:
            dash_str = r"\pgfsetdash{"
            for dash in dash_list:
                dash_str += r"{%fpt}" % dash
            dash_str += r"}{%fpt}" % dash_offset
            writeln(self.fh, dash_str)

    def _print_pgf_path(self, gc, path, transform, rgbFace=None):
        f = 1. / self.dpi
        # check for clip box / ignore clip for filled paths
        bbox = gc.get_clip_rectangle() if gc else None
        if bbox and (rgbFace is None):
            p1, p2 = bbox.get_points()
            clip = (p1[0], p1[1], p2[0], p2[1])
        else:
            clip = None
        # build path
        for points, code in path.iter_segments(transform, clip=clip):
            if code == Path.MOVETO:
                x, y = tuple(points)
                writeln(self.fh, r"\pgfpathmoveto{\pgfqpoint{%fin}{%fin}}" %
                        (f * x, f * y))
            elif code == Path.CLOSEPOLY:
                writeln(self.fh, r"\pgfpathclose")
            elif code == Path.LINETO:
                x, y = tuple(points)
                writeln(self.fh, r"\pgfpathlineto{\pgfqpoint{%fin}{%fin}}" %
                        (f * x, f * y))
            elif code == Path.CURVE3:
                cx, cy, px, py = tuple(points)
                coords = cx * f, cy * f, px * f, py * f
                writeln(self.fh, r"\pgfpathquadraticcurveto{\pgfqpoint{%fin}{%fin}}{\pgfqpoint{%fin}{%fin}}" % coords)
            elif code == Path.CURVE4:
                c1x, c1y, c2x, c2y, px, py = tuple(points)
                coords = c1x * f, c1y * f, c2x * f, c2y * f, px * f, py * f
                writeln(self.fh, r"\pgfpathcurveto{\pgfqpoint{%fin}{%fin}}{\pgfqpoint{%fin}{%fin}}{\pgfqpoint{%fin}{%fin}}" % coords)

    def _pgf_path_draw(self, stroke=True, fill=False):
        actions = []
        if stroke:
            actions.append("stroke")
        if fill:
            actions.append("fill")
        writeln(self.fh, r"\pgfusepath{%s}" % ",".join(actions))

    def draw_image(self, gc, x, y, im):
        # TODO: Almost no documentation for the behavior of this function.
        #       Something missing?

        # save the images to png files
        path = os.path.dirname(self.fh.name)
        fname = os.path.splitext(os.path.basename(self.fh.name))[0]
        fname_img = "%s-img%d.png" % (fname, self.image_counter)
        self.image_counter += 1
        _png.write_png(np.array(im)[::-1], os.path.join(path, fname_img))

        # reference the image in the pgf picture
        writeln(self.fh, r"\begin{pgfscope}")
        self._print_pgf_clip(gc)
        h, w = im.get_size_out()
        f = 1. / self.dpi  # from display coords to inch
        writeln(self.fh, r"\pgftext[at=\pgfqpoint{%fin}{%fin},left,bottom]{\pgfimage[interpolate=true,width=%fin,height=%fin]{%s}}" % (x * f, y * f, w * f, h * f, fname_img))
        writeln(self.fh, r"\end{pgfscope}")

    def draw_tex(self, gc, x, y, s, prop, angle, ismath="TeX!", mtext=None):
        self.draw_text(gc, x, y, s, prop, angle, ismath, mtext)

    def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
        # prepare string for tex
        s = common_texification(s)
        prop_cmds = _font_properties_str(prop)
        s = r"%s %s" % (prop_cmds, s)


        writeln(self.fh, r"\begin{pgfscope}")

        alpha = gc.get_alpha()
        if alpha != 1.0:
            writeln(self.fh, r"\pgfsetfillopacity{%f}" % alpha)
            writeln(self.fh, r"\pgfsetstrokeopacity{%f}" % alpha)
        rgb = tuple(gc.get_rgb())[:3]
        if rgb != (0, 0, 0):
            writeln(self.fh, r"\definecolor{textcolor}{rgb}{%f,%f,%f}" % rgb)
            writeln(self.fh, r"\pgfsetstrokecolor{textcolor}")
            writeln(self.fh, r"\pgfsetfillcolor{textcolor}")
            s = r"\color{textcolor}" + s

        f = 1.0 / self.figure.dpi
        text_args = []
        if mtext and (angle == 0 or mtext.get_rotation_mode() == "anchor"):
            # if text anchoring can be supported, get the original coordinates
            # and add alignment information
            x, y = mtext.get_transform().transform_point(mtext.get_position())
            text_args.append("x=%fin" % (x * f))
            text_args.append("y=%fin" % (y * f))

            halign = {"left": "left", "right": "right", "center": ""}
            valign = {"top": "top", "bottom": "bottom",
                      "baseline": "base", "center": ""}
            text_args.append(halign[mtext.get_ha()])
            text_args.append(valign[mtext.get_va()])
        else:
            # if not, use the text layout provided by matplotlib
            text_args.append("x=%fin" % (x * f))
            text_args.append("y=%fin" % (y * f))
            text_args.append("left")
            text_args.append("base")

        if angle != 0:
            text_args.append("rotate=%f" % angle)

        writeln(self.fh, r"\pgftext[%s]{%s}" % (",".join(text_args), s))
        writeln(self.fh, r"\end{pgfscope}")

    def get_text_width_height_descent(self, s, prop, ismath):
        # check if the math is supposed to be displaystyled
        s = common_texification(s)

        # get text metrics in units of latex pt, convert to display units
        w, h, d = self.latexManager.get_width_height_descent(s, prop)
        # TODO: this should be latex_pt_to_in instead of mpl_pt_to_in
        # but having a little bit more space around the text looks better,
        # plus the bounding box reported by LaTeX is VERY narrow
        f = mpl_pt_to_in * self.dpi
        return w * f, h * f, d * f

    def flipy(self):
        return False

    def get_canvas_width_height(self):
        return self.figure.get_figwidth(), self.figure.get_figheight()

    def points_to_pixels(self, points):
        return points * mpl_pt_to_in * self.dpi

    def new_gc(self):
        return GraphicsContextPgf()


class GraphicsContextPgf(GraphicsContextBase):
    pass

########################################################################


def draw_if_interactive():
    pass


def new_figure_manager(num, *args, **kwargs):
    """
    Create a new figure manager instance
    """
    # if a main-level app must be created, this is the usual place to
    # do it -- see backend_wx, backend_wxagg and backend_tkagg for
    # examples.  Not all GUIs require explicit instantiation of a
    # main-level app (egg backend_gtk, backend_gtkagg) for pylab
    FigureClass = kwargs.pop('FigureClass', Figure)
    thisFig = FigureClass(*args, **kwargs)
    return new_figure_manager_given_figure(num, thisFig)


def new_figure_manager_given_figure(num, figure):
    """
    Create a new figure manager instance for the given figure.
    """
    canvas = FigureCanvasPgf(figure)
    manager = FigureManagerPgf(canvas, num)
    return manager


class TmpDirCleaner(object):
    remaining_tmpdirs = set()

    @staticmethod
    def add(tmpdir):
        TmpDirCleaner.remaining_tmpdirs.add(tmpdir)

    @staticmethod
    def cleanup_remaining_tmpdirs():
        for tmpdir in TmpDirCleaner.remaining_tmpdirs:
            try:
                shutil.rmtree(tmpdir)
            except:
                sys.stderr.write("error deleting tmp directory %s\n" % tmpdir)


class FigureCanvasPgf(FigureCanvasBase):
    filetypes = {"pgf": "LaTeX PGF picture",
                 "pdf": "LaTeX compiled PGF picture",
                 "png": "Portable Network Graphics", }

    def get_default_filetype(self):
        return 'pdf'

    def _print_pgf_to_fh(self, fh, *args, **kwargs):
        if kwargs.get("dryrun", False):
            renderer = RendererPgf(self.figure, None, dummy=True)
            self.figure.draw(renderer)
            return

        header_text = """%% Creator: Matplotlib, PGF backend
%%
%% To include the figure in your LaTeX document, write
%%   \\input{<filename>.pgf}
%%
%% Make sure the required packages are loaded in your preamble
%%   \\usepackage{pgf}
%%
%% Figures using additional raster images can only be included by \input if
%% they are in the same directory as the main LaTeX file. For loading figures
%% from other directories you can use the `import` package
%%   \\usepackage{import}
%% and then include the figures with
%%   \\import{<path to file>}{<filename>.pgf}
%%
"""

        # append the preamble used by the backend as a comment for debugging
        header_info_preamble = ["%% Matplotlib used the following preamble"]
        for line in get_preamble().splitlines():
            header_info_preamble.append("%%   " + line)
        for line in get_fontspec().splitlines():
            header_info_preamble.append("%%   " + line)
        header_info_preamble.append("%%")
        header_info_preamble = "\n".join(header_info_preamble)

        # get figure size in inch
        w, h = self.figure.get_figwidth(), self.figure.get_figheight()
        dpi = self.figure.get_dpi()

        # create pgfpicture environment and write the pgf code
        fh.write(header_text)
        fh.write(header_info_preamble)
        fh.write("\n")
        writeln(fh, r"\begingroup")
        writeln(fh, r"\makeatletter")
        writeln(fh, r"\begin{pgfpicture}")
        writeln(fh, r"\pgfpathrectangle{\pgfpointorigin}{\pgfqpoint{%fin}{%fin}}" % (w, h))
        writeln(fh, r"\pgfusepath{use as bounding box, clip}")
        _bbox_inches_restore = kwargs.pop("bbox_inches_restore", None)
        renderer = MixedModeRenderer(self.figure, w, h, dpi,
                                     RendererPgf(self.figure, fh),
                                     bbox_inches_restore=_bbox_inches_restore)
        self.figure.draw(renderer)

        # end the pgfpicture environment
        writeln(fh, r"\end{pgfpicture}")
        writeln(fh, r"\makeatother")
        writeln(fh, r"\endgroup")

    def print_pgf(self, fname_or_fh, *args, **kwargs):
        """
        Output pgf commands for drawing the figure so it can be included and
        rendered in latex documents.
        """
        if kwargs.get("dryrun", False):
            self._print_pgf_to_fh(None, *args, **kwargs)
            return

        # figure out where the pgf is to be written to
        if is_string_like(fname_or_fh):
            with codecs.open(fname_or_fh, "w", encoding="utf-8") as fh:
                self._print_pgf_to_fh(fh, *args, **kwargs)
        elif is_writable_file_like(fname_or_fh):
            fh = codecs.getwriter("utf-8")(fname_or_fh)
            self._print_pgf_to_fh(fh, *args, **kwargs)
        else:
            raise ValueError("filename must be a path")

    def _print_pdf_to_fh(self, fh, *args, **kwargs):
        w, h = self.figure.get_figwidth(), self.figure.get_figheight()

        try:
            # create temporary directory for compiling the figure
            tmpdir = tempfile.mkdtemp(prefix="mpl_pgf_")
            fname_pgf = os.path.join(tmpdir, "figure.pgf")
            fname_tex = os.path.join(tmpdir, "figure.tex")
            fname_pdf = os.path.join(tmpdir, "figure.pdf")

            # print figure to pgf and compile it with latex
            self.print_pgf(fname_pgf, *args, **kwargs)

            latex_preamble = get_preamble()
            latex_fontspec = get_fontspec()
            latexcode = """
\\documentclass[12pt]{minimal}
\\usepackage[paperwidth=%fin, paperheight=%fin, margin=0in]{geometry}
%s
%s
\\usepackage{pgf}

\\begin{document}
\\centering
\\input{figure.pgf}
\\end{document}""" % (w, h, latex_preamble, latex_fontspec)
            with codecs.open(fname_tex, "w", "utf-8") as fh_tex:
                fh_tex.write(latexcode)

            texcommand = get_texcommand()
            cmdargs = [texcommand, "-interaction=nonstopmode",
                       "-halt-on-error", "figure.tex"]
            try:
                check_output(cmdargs, stderr=subprocess.STDOUT, cwd=tmpdir)
            except subprocess.CalledProcessError as e:
                raise RuntimeError("%s was not able to process your file.\n\nFull log:\n%s" % (texcommand, e.output))

            # copy file contents to target
            with open(fname_pdf, "rb") as fh_src:
                shutil.copyfileobj(fh_src, fh)
        finally:
            try:
                shutil.rmtree(tmpdir)
            except:
                TmpDirCleaner.add(tmpdir)

    def print_pdf(self, fname_or_fh, *args, **kwargs):
        """
        Use LaTeX to compile a Pgf generated figure to PDF.
        """
        if kwargs.get("dryrun", False):
            self._print_pgf_to_fh(None, *args, **kwargs)
            return

        # figure out where the pdf is to be written to
        if is_string_like(fname_or_fh):
            with open(fname_or_fh, "wb") as fh:
                self._print_pdf_to_fh(fh, *args, **kwargs)
        elif is_writable_file_like(fname_or_fh):
            self._print_pdf_to_fh(fname_or_fh, *args, **kwargs)
        else:
            raise ValueError("filename must be a path or a file-like object")

    def _print_png_to_fh(self, fh, *args, **kwargs):
        converter = make_pdf_to_png_converter()

        try:
            # create temporary directory for pdf creation and png conversion
            tmpdir = tempfile.mkdtemp(prefix="mpl_pgf_")
            fname_pdf = os.path.join(tmpdir, "figure.pdf")
            fname_png = os.path.join(tmpdir, "figure.png")
            # create pdf and try to convert it to png
            self.print_pdf(fname_pdf, *args, **kwargs)
            converter(fname_pdf, fname_png, dpi=self.figure.dpi)
            # copy file contents to target
            with open(fname_png, "rb") as fh_src:
                shutil.copyfileobj(fh_src, fh)
        finally:
            try:
                shutil.rmtree(tmpdir)
            except:
                TmpDirCleaner.add(tmpdir)

    def print_png(self, fname_or_fh, *args, **kwargs):
        """
        Use LaTeX to compile a pgf figure to pdf and convert it to png.
        """
        if kwargs.get("dryrun", False):
            self._print_pgf_to_fh(None, *args, **kwargs)
            return

        if is_string_like(fname_or_fh):
            with open(fname_or_fh, "wb") as fh:
                self._print_png_to_fh(fh, *args, **kwargs)
        elif is_writable_file_like(fname_or_fh):
            self._print_png_to_fh(fname_or_fh, *args, **kwargs)
        else:
            raise ValueError("filename must be a path or a file-like object")

    def get_renderer(self):
        return RendererPgf(self.figure, None, dummy=True)


class FigureManagerPgf(FigureManagerBase):
    def __init__(self, *args):
        FigureManagerBase.__init__(self, *args)


FigureCanvas = FigureCanvasPgf
FigureManager = FigureManagerPgf


def _cleanup_all():
    LatexManager._cleanup_remaining_instances()
    TmpDirCleaner.cleanup_remaining_tmpdirs()

atexit.register(_cleanup_all)
