wesmere-build

#!/usr/bin/env python3
'''
Builds the web page containing the Wesnoth Constitution

Copyright (C) 2020 - 2021 by Iris Morelle <shadowm@wesnoth.org>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
'''

from argparse import ArgumentParser
from datetime import datetime
from pathlib import Path
import io
import markdown
import subprocess
import sys
import tempfile

#
# We piggyback on the xsltproc -> htmlpost pipeline used by Wesmere, so we
# need to know exactly where Wesmere is installed. This can be overridden in
# the command line.
#
WESMERE_ROOT = "/home/wesnoth/git/wesmere"

#
# Markdown source, relative to the process working directory. This can be
# overridden in the command line.
#
LISAR_SRC = "Project-Constitution.md"

#
# Javascript supplement embedded into the generated web page, relative to the
# process working directory.
#
LISAR_JS = "util.js"

#
# CSS supplement embedded into the generated web page, relative to the process
# working directory.
#
LISAR_CSS = "util.css"

#
# XSLT path relative to WESMERE_ROOT.
#
WESMERE_XSLT = "static/template_inside.xsl"

#
# Path to the htmlpost program, relative to the Wesmere source.
#
WESMERE_HTMLPOST = "wesmere/bin/htmlpost"

#
# Name of the xsltproc program (in PATH or with a full or relative path).
#
XSLTPROC = "xsltproc"

#
# Authoritative URL for the Constitution's Markdown source repository.
#
LISAR_URL = "https://github.com/wesnoth/constitution"

#
# Format (as used by strftime) used to generate the footer timestamp.
#
LISAR_TS_FORMAT = "%d %B %Y %H:%M"

#
# The actual XSL passed to xsltproc. This is formatted in with the correct data
# after parsing the Markdown source. The positional parameters are as follows:
#
#   0. The path to the XSLT file.
#   1. The main contents of the page, already converted to HTML.
#   2. The timestamp to be displayed to users.
#   3. The authoritative URL for the generated document's sources.
#
LISAR_XSL = '''\
<?xml version="1.0"?>
<!DOCTYPE xml:stylesheet[
    <!ENTITY ndash "&#8211;">
    <!ENTITY mdash "&#8212;">
    <!ENTITY hbar  "&#8213;">
]>
<?xml-stylesheet type="text/xsl" href="{0}"?>
<document>
    <title>Project Constitution</title>
    <style>@ HTMLPOST:INCLUDE {4} @</style>
    <content>
        <a id="constitution"></a>

        {1}

        <div id="lastmod">Generated on {2} from &#8249;<a href="{3}">{3}</a>&#8250;.</div>

        <script>@ HTMLPOST:INCLUDE {5} @</script>
        <script src="/wesmere/js/wiki.js"></script>
    </content>
</document>
'''


def wesmere_xslt(input_xsl, xsltproc_bin, htmlpost_bin):
    "Takes a string and runs it through the Wesmere XSLT pipeline."
    try:
        # First write the unmodified XSLT output.
        with tempfile.NamedTemporaryFile(mode='w', encoding='utf-8') as tmp_xsl:
            tmp_xsl.write(input_xsl)
            tmp_xsl.flush()
            result = subprocess.run([xsltproc_bin, tmp_xsl.name],
                                    stdout=subprocess.PIPE,
                                    stderr=sys.stderr)
            if result.returncode:
                sys.exit("XSLT step failed (exit status {0}): {1}".
                         format(result.returncode, " ".join(result.args)))
            if result.stdout is None:
                sys.exit("XSLT step did not produce any output: {1}".
                         format(" ".join(result.args)))
            # Now HTMLPOST the output to wrap things up.
            with tempfile.NamedTemporaryFile(mode='w+b') as tmp_html:
                tmp_html.write(result.stdout)
                tmp_html.flush()
                result = subprocess.run([htmlpost_bin, '-M', tmp_html.name])
                if result.returncode:
                    sys.exit("HTMLPOST step failed (exit status {0}): {1}".format(result.returncode, " ".join(result.args)))
                # Copy the result to stdout
                tmp_html.seek(io.SEEK_SET)
                sys.stdout.buffer.write(tmp_html.read())
    except FileNotFoundError:
        sys.exit("Could not open a temporary file, aborting.")


def build_xsl(xslt_path, body):
    ts = datetime.now().strftime(LISAR_TS_FORMAT)
    return LISAR_XSL.format(xslt_path, body, ts, LISAR_URL, LISAR_CSS, LISAR_JS)


if __name__ == "__main__":
    aparser = ArgumentParser()
    aparser.add_argument('wesmere_root',
                         metavar='WESMERE_ROOT',
                         default=WESMERE_ROOT,
                         nargs='?')
    aparser.add_argument('input_file',
                         metavar='INPUT_FILE',
                         default=LISAR_SRC,
                         nargs='?')
    args = aparser.parse_args()
    wesmere_path = Path(args.wesmere_root)
    input_path = Path(args.input_file)
    xslt_path = wesmere_path / WESMERE_XSLT
    htmlpost_bin = wesmere_path / WESMERE_HTMLPOST
    xsltproc_bin = XSLTPROC

    try:
        body_html = None
        with open(str(input_path), 'r', encoding='utf-8') as input_file:
            text = input_file.read()
            body_html = markdown.markdown(text)
        if not xslt_path.exists():
            sys.exit("Could not open XSL stylesheet {0}, aborting.".format(xslt_path))
        xsl = build_xsl(str(xslt_path), body_html)
        wesmere_xslt(xsl, xsltproc_bin, str(htmlpost_bin))
    except FileNotFoundError as err:
        sys.exit("Could not open input file {0}, aborting.".format(err.filename))