#!/usr/bin/env python3
"""
Pandoc filter to convert svg files to pdf as suggested at:
https://github.com/jgm/pandoc/issues/265#issuecomment-27317316
"""

__author__ = "Jerome Robert"

import mimetypes
import subprocess
import os
import sys
from pandocfilters import toJSONFilter, Str, Para, Image

fmt_to_option = {
    "latex": ("--export-filename","pdf"),
    "beamer": ("--export-filename","pdf"),
    #use PNG because EMF and WMF break transparency
    "docx": ("--export-png", "png"),
    #because of IE
    "html": ("--export-png", "png")
}

def svg_to_any(key, value, fmt, meta):
    if key == 'Image':
       if len(value) == 2:
           # before pandoc 1.16
           alt, [src, title] = value
           attrs = None
       else:
           attrs, alt, [src, title] = value
       mimet,_ = mimetypes.guess_type(src)
       option = fmt_to_option.get(fmt)
       if mimet == 'image/svg+xml' and option:
           base_name,_ = os.path.splitext(src)
           eps_name = base_name + "." + option[1]
           try:
               mtime = os.path.getmtime(eps_name)
           except OSError:
               mtime = -1
           if mtime < os.path.getmtime(src):
               cmd_line = ['inkscape', option[0], eps_name, src]
               sys.stderr.write("Running %s\n" % " ".join(cmd_line))
               subprocess.call(cmd_line, stdout=sys.stderr.fileno())
           if attrs:
               return Image(attrs, alt, [eps_name, title])
           else:
               return Image(alt, [eps_name, title])

if __name__ == "__main__":
  toJSONFilter(svg_to_any)
