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diff --git a/LICENSE b/LICENSE
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+The wfs software is released under the GNU Affero General Public License,
+version 3. The AGPL requires that the modified source code of wfs is made
+available to users whenever it is modified and then either redistributed or
+made available over a network. However, since no wfs code remains in
+wfs-generated files, including subsetted fonts, the AGPL does not apply to
+those. Depending on your jurisdiction, subsetted fonts may be considered
+derivative works of the pages used to generate them.
+
+Example: If you provide wfs as a service over the Internet, you must provide
+the source code of wfs to any users. When using the service, your users must
+comply with the copyright license of the fonts they are using. They may also
+need to comply with the copyright license of the pages they are using to subset
+the fonts.
+
+A copy of the GNU Affero General Public License is provided below:
+
+
+                    GNU AFFERO GENERAL PUBLIC LICENSE
+                       Version 3, 19 November 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+                            Preamble
+
+  The GNU Affero General Public License is a free, copyleft license for
+software and other kinds of works, specifically designed to ensure
+cooperation with the community in the case of network server software.
+
+  The licenses for most software and other practical works are designed
+to take away your freedom to share and change the works.  By contrast,
+our General Public Licenses are intended to guarantee your freedom to
+share and change all versions of a program--to make sure it remains free
+software for all its users.
+
+  When we speak of free software, we are referring to freedom, not
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+
+  Developers that use our General Public Licenses protect your rights
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+  Later license versions may give you additional or different
+permissions.  However, no additional obligations are imposed on any
+author or copyright holder as a result of your choosing to follow a
+later version.
+
+  15. Disclaimer of Warranty.
+
+  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
+HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
+OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
+THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
+IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+  16. Limitation of Liability.
+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 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 Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If your software can interact with users remotely through a computer
+network, you should also make sure that it provides a way for users to
+get its source.  For example, if your program is a web application, its
+interface could display a "Source" link that leads users to an archive
+of the code.  There are many ways you could offer source, and different
+solutions will be better for different programs; see section 13 for the
+specific requirements.
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU AGPL, see
+<https://www.gnu.org/licenses/>.
diff --git a/README b/README
new file mode 100644
index 0000000..c3523ff
--- /dev/null
+++ b/README
@@ -0,0 +1,17 @@
+wfs subsets web fonts. It is similar to glyphhanger, except:
+
+Features:
+
+- written in Python, not Node
+- automatically compares before and after screenshots
+- supports automatic parallelism
+
+Anti-features:
+
+- uses Selenium instead of Puppeteer
+- no JSDOM support, mainly because getComputedStyle is very buggy
+
+Non-features:
+
+- no spidering support: there are many excellent spiders, use those and then
+  pass the URLs
diff --git a/config.py b/config.py
new file mode 100644
index 0000000..5a5e549
--- /dev/null
+++ b/config.py
@@ -0,0 +1,46 @@
+from fontTools.subset import Options
+
+config = {
+    # chrome or firefox
+    'selenium_driver_name': 'chrome',
+
+    # take screenshots before and after and check that they are identical
+    'screenshots': True,
+
+    # pyftsubset options, see pyftsubset --help
+    'ftsubset_options': [
+        '--desubroutinize',
+        '--layout-scripts=latn',
+        '--layout-features-=curs,dnom,frac,locl,mark,mkmk',
+        '--name-IDs=',
+        '--with-zopfli',
+    ],
+
+    # font configuration table.
+    # family: no default, mandatory
+    # weight: must be string, mandatory
+    # fontfile: must be string, mandatory
+    # extratext: non-DOM text to add to subset (e.g. CSS content). default: none
+    # outfile: dict of {woff, woff2} output filenames. default: s/.[ot]tf$/.subset.woff(2)/
+    'fonts': [
+        {
+            'family': 'EB Garamond',
+            'weight': '400',
+            'style': 'italic',
+            'fontfile': '../resume/EBGaramond-Italic.otf',
+            'extratext': '@'
+        },
+        {
+            'family': 'EB Garamond',
+            'weight': '400',
+            'style': 'normal',
+            'fontfile': '../resume/EBGaramond-Regular.otf'
+        },
+        {
+            'family': 'EB Garamond',
+            'weight': '500',
+            'style': 'normal',
+            'fontfile': '../resume/EBGaramond-Medium.otf'
+        }
+    ],
+}
diff --git a/wfs.py b/wfs.py
new file mode 100755
index 0000000..7df6e90
--- /dev/null
+++ b/wfs.py
@@ -0,0 +1,232 @@
+#!/usr/bin/env python3
+
+import logging
+import re
+import os
+import signal
+import sys
+
+from itertools import chain
+import multiprocessing
+from multiprocessing import Pool
+from multiprocessing.util import Finalize
+from pathlib import Path
+from urllib.parse import urlparse
+
+from fontTools.subset import Options, Subsetter, load_font
+from selenium import webdriver
+
+from config import config
+
+logging.basicConfig(format='[%(relativeCreated)d] %(message)s')
+logger = logging.getLogger('websubset')
+logger.setLevel(logging.INFO)
+
+options = Options()
+options.parse_opts(config['ftsubset_options'])
+if options.with_zopfli:
+    from fontTools.ttLib import sfnt
+    sfnt.USE_ZOPFLI = True
+
+if config['screenshots']:
+    from io import BytesIO
+    from PIL import Image, ImageChops
+    def gen_font_face(font):
+        if 'fontfile' not in font:
+            return ''
+        return ''.join([
+            '@font-face{',
+            'font-family:"', font['family'], '";',
+            'font-weight:', font['weight'], ';',
+            'font-style:', font['style'], ';',
+            'src: url("', font["fontfile"], '") format("opentype");',
+            '}'])
+
+    REPLACE_FONTS_SCRIPT = ''.join([
+        "let style = document.createElement('style'); style.innerHTML = '",
+        ''.join(gen_font_face(font) for font in config['fonts']),
+        "'; document.body.appendChild(style);"])
+
+EXTRACT_SCRIPT = r'''
+    let whitelist = new Set(arguments[0]);
+    let walker = document.createTreeWalker(document.body, NodeFilter.SHOW_TEXT);
+    let node, dict = new Map();
+    while (node = walker.nextNode()) {
+        let cs = getComputedStyle(node.parentNode);
+        let css = k => cs.getPropertyValue(k);
+        if (css('display') == 'none')
+            continue;
+        let k = css('font-family').replace(/"/g, '').replace(/,.*/, '') + ';' +
+                css('font-weight') + ';' +
+                css('font-style');
+        if (!whitelist.has(k))
+            continue;
+        const t = node.nodeValue;
+        if (dict.has(k))
+            for (let c of t)
+                dict.get(k).add(c);
+        else
+            dict.set(k, new Set(t));
+    }
+    let dict2 = {};
+    dict.forEach((v, k) => dict2[k] = [...v.keys()].join(''));
+    return dict2;
+'''
+
+DRIVER = None
+def stop_driver():
+    global DRIVER
+    if DRIVER:
+        DRIVER.quit()
+        DRIVER = None
+def hook_sys(name):
+    orig_hook = getattr(sys, name)
+    def my_hook(*args, **kwargs):
+        stop_driver()
+        orig_hook(*args, **kwargs)
+    setattr(sys, name, my_hook)
+def hook_sig(signum):
+    orig_handler = signal.getsignal(signum)
+    if orig_handler is None:
+        raise Exception('{signum} handler is None')
+    def term_handler(*_):
+        stop_driver()
+        signal.signal(signum, orig_handler)
+        os.kill(os.getpid(), signum)
+    signal.signal(signum, term_handler)
+def start_wworker(driver_name):
+    hook_sig(signal.SIGTERM)
+    global DRIVER
+    if driver_name == 'chrome':
+        chrome_options = webdriver.chrome.options.Options()
+        chrome_options.headless = True
+        DRIVER = webdriver.Chrome(options=chrome_options, desired_capabilities={'detach': True})
+    elif driver_name == 'firefox':
+        firefox_options = webdriver.firefox.options.Options()
+        firefox_options.headless = True
+        DRIVER = webdriver.Firefox(options=firefox_options)
+    else:
+        raise Exception('unknown driver name')
+    Finalize(DRIVER, stop_driver, exitpriority=16)
+
+def is_uri(path):
+    parsed = urlparse(path)
+    return parsed.scheme and parsed.netloc
+def make_uri(path):
+    if is_uri(path):
+        return path
+    else:
+        return Path(path).resolve().as_uri()
+
+def extract(path, whitelist, screenshots):
+    logger.info('fetching %s', path)
+    DRIVER.get(make_uri(path))
+    if screenshots:
+        logger.info('replacing fonts for %s', path)
+        DRIVER.execute_script(REPLACE_FONTS_SCRIPT)
+        logger.info('taking pre-screenshot for %s', path)
+        height = DRIVER.execute_script('return document.body.parentNode.scrollHeight')
+        DRIVER.set_window_size(2000, height)
+        screenshot = DRIVER.find_element_by_tag_name('body').screenshot_as_png
+    else:
+        screenshot = None
+    logger.info('extracting text from %s', path)
+    return (path, DRIVER.execute_script(EXTRACT_SCRIPT, whitelist), screenshot)
+
+def get_fontdesc(fonts, fontspec):
+    font_match = dict(zip(('family', 'weight', 'style'), fontspec.split(';')))
+    for font in fonts:
+        if font_match.items() <= font.items():
+            return font
+    return None
+
+def subset(fontdesc, text, fts_opts):
+    fontfile = fontdesc['fontfile']
+    logger.info('subsetting %s', fontfile)
+    font = load_font(fontfile, fts_opts, dontLoadGlyphNames=True)
+    subsetter = Subsetter(options=fts_opts)
+    if 'extratext' in fontdesc:
+        text += fontdesc['extratext']
+    subsetter.populate(text=text)
+    subsetter.subset(font)
+    ret = []
+    for flavor in ['woff', 'woff2']:
+        if 'outfile' in fontdesc and flavor in fontdesc['outfile']:
+            outfile = fontdesc['outfile'][flavor]
+        else:
+            outfile = re.sub(r'\.otf$', f'.subset.{flavor}', fontfile)
+        if outfile == fontfile:
+            raise Exception('cannot overwrite font file')
+        ret.append((font, flavor, outfile))
+    return ret
+
+def write_subset(font, flavor, outfile):
+    logger.info('writing %s', outfile)
+    font.flavor = flavor
+    font.save(outfile)
+
+def verify(path, screenshot_begin_png):
+    logger.info('refetching %s', path)
+    DRIVER.get(make_uri(path))
+    logger.info('taking post-screenshot for %s', path)
+    height = DRIVER.execute_script('return document.body.parentNode.scrollHeight')
+    DRIVER.set_window_size(2000, height)
+    screenshot_end_png = DRIVER.find_element_by_tag_name('body').screenshot_as_png
+
+    logger.info('checking screenshot for %s', path)
+    screenshot_begin = Image.open(BytesIO(screenshot_begin_png))
+    screenshot_end = Image.open(BytesIO(screenshot_end_png))
+    if ImageChops.difference(screenshot_begin, screenshot_end).getbbox():
+        raise Exception(f'screenshots do not match for {path}')
+
+class LocalPool:
+    def __init__(self, driver_name):
+        start_wworker(driver_name)
+
+    def starmap(self, func, args, *_):
+        return [func(*arg) for arg in args]
+
+    def close(self):
+        stop_driver()
+
+def main(argv):
+    ncpus = len(os.sched_getaffinity(0))
+    nfontfiles = sum('fontfile' in font for font in config['fonts'])
+    nwworkers = min(len(argv) - 1, ncpus)
+    nfworkers = min(nfontfiles * 2, ncpus)
+    logger.info('starting %d web workers, %d font workers', nwworkers, nfworkers)
+    with Pool(nfworkers) as fpool, \
+         Pool(nwworkers, start_wworker, (config['selenium_driver_name'],)) as wpool:
+        all_font_texts = {}
+        screenshots = []
+        whitelist = [
+                ';'.join((f['family'], f['weight'], f['style']))
+                for f in config['fonts']]
+        extract_args = ((arg, whitelist, config['screenshots']) for arg in sys.argv[1:])
+        extracted = wpool.starmap(extract, extract_args)
+        for path, font_texts, screenshot in extracted:
+            if config['screenshots']:
+                screenshots.append((path, screenshot))
+            for fontspec, text in font_texts.items():
+                if fontspec in all_font_texts:
+                    all_font_texts[fontspec] |= set(text)
+                else:
+                    all_font_texts[fontspec] = set(text)
+        if not config['screenshots']:
+            logger.info('shutting down web workers early')
+            wpool.close()
+        subset_args = (
+                (get_fontdesc(config['fonts'], fontspec), ''.join(text), options)
+                for fontspec, text in all_font_texts.items())
+        subsetted = fpool.starmap(subset, subset_args)
+        fpool.starmap(write_subset, chain(*subsetted))
+        if config['screenshots']:
+            wpool.starmap(verify, screenshots, 1)
+    if multiprocessing.active_children():
+        logger.info('waiting for workers')
+        for proc in multiprocessing.active_children():
+            proc.join()
+    logger.info('exiting successfully')
+
+if __name__ == '__main__':
+    main(sys.argv)