#!/usr/bin/env python
# Copyright 2016  QvarnLabs Ab
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# =*= License: GPL-3+ =*=


import os
import shutil
import subprocess
import sys
import tempfile
import fnmatch
import re


def process_uml_blocks(mdwnpath, mdwndir, filename):
    blocks = []
    tmproot = os.path.join(T, os.path.splitext(filename)[0] + '_uml')

    with open(mdwnpath) as f:
        content = f.read()

        # Find UML code blocks to be replaced.
        blocks = re.findall(
            r"(?:\t| {4})@startuml[\s\S]*?(?:\t| {4})@enduml",
            content
        )

    for i, block in enumerate(blocks, start=1):
        umlpath = '%s%d.puml' % (tmproot, i)
        imgpath = '%s%d.png' % (tmproot, i)

        # Remove whitespace and save UML file.
        with open(umlpath, 'w') as f:
            f.write(re.sub(r"(?m)^(\t| {4})", "", block) + '\n')

        # Create a diagram image at imgpath and copy it.
        subprocess.check_call(['plantuml', umlpath])
        shutil.copy2(imgpath, mdwndir)

        # Replace diagram code with a link to the image.
        content = ''
        with open(mdwnpath) as f:
            content = f.read()
        with open(mdwnpath, 'w') as f:
            link = '[[!img  %s]]' % os.path.basename(imgpath)
            f.write(re.sub(re.escape(block), link, content))


def process_uml_includes(mdwnpath, mdwndir):
    includes = []

    with open(mdwnpath) as f:
        content = f.read()

        # Find include statements,
        # put file name in a separate group.
        includes = re.findall(
            r"(?m)^(<!-{2,3} INCLUDE_UML: (.+\.puml) -->)",
            content
        )

    for inc in includes:
        # Don't need to copy an image this time
        subprocess.check_call(['plantuml', os.path.join(mdwndir, inc[1])])

        # Replace include statement with a link to the image.
        content = ''
        with open(mdwnpath) as f:
            content = f.read()
        with open(mdwnpath, 'w') as f:
            link = '[[!img  %s.png]]' % os.path.splitext(inc[1])[0]
            f.write(re.sub('(?m)^' + inc[0], link, content))


def process_uml(T, dirname='.', ignore=['.git', '.ikiwiki']):
    for topdir, dirs, files in os.walk(os.path.abspath(dirname), topdown=True):
        # Filter dirs by modifying the list in-place,
        # as described in os.walk documentation.
        dirs[:] = [d for d in dirs if d not in ignore]

        for filename in fnmatch.filter(files, '*.mdwn'):
            mdwnpath = os.path.join(topdir, filename)

            process_uml_blocks(mdwnpath, topdir, filename)
            process_uml_includes(mdwnpath, topdir)


def mangle_setup(src, dest, html):
    with open(src) as f:
        text = f.read()

    lines = [
        line
        for line in text.splitlines()
        if not line.startswith('destdir:')
    ]

    lines.append('destdir: {}'.format(html))

    mangled = ''.join(line + '\n' for line in lines)

    with open(dest, 'w') as f:
        f.write(mangled)


def run_ikiwiki(T):
    setup = os.path.join(T, 'ikiwiki.setup')
    html = os.path.join(T, 'html')
    mangle_setup('ikiwiki.setup', setup, html)
    subprocess.check_call(['ikiwiki', '--setup', setup, '--gettime'])
    subprocess.check_call(
        ['rsync', '-ahHSvs', '--delete', html + '/.', rsync_target])


static_http = sys.argv[1]
dirname = sys.argv[2]
rsync_target = 'static@{}:/srv/http/{}/.'.format(static_http, dirname)

T = tempfile.mkdtemp()
try:
    process_uml(T)
    run_ikiwiki(T)
except BaseException as e:
    shutil.rmtree(T)
    raise
else:
    shutil.rmtree(T)