#!/usr/bin/env python3

# License: CC0 https://creativecommons.org/share-your-work/public-domain/cc0/

# A messy script that figures out ZFS features. It's very messy, sorry. I am
# not responsible if this script eats your laundry.
#
# This uses manpages, because I'm lazy. If your manpages are wrong, you have a
# bug.
#
# If the script is wrong, or could be improved, feel free to contact me on
# freenode, and tell me why it's wrong. My nick is zgrep.
#
# 2018-07-05: Created.
# ????-??-??: Many things happened.
# 2020-02-23: Applied patch by rlaager.
# 2020-02-30: Show domain prefixes (via Vlad Bokov), partially apply patch by rlaager.
# 2020-03-05: Patch by rlaager (allocation_classes, ZoL -> openzfs).

from sys import argv

if len(argv) == 1:
    path = '.'
elif len(argv) != 2:
    print('Usage:', argv[0], 'path')
    exit(1)
else:
    path = argv[1]

from collections import defaultdict
from urllib.request import urlopen
from datetime import datetime
from re import sub as regex, findall
from json import loads as dejson

def zfsonlinux():
    sources = {'master':'https://raw.githubusercontent.com/openzfs/zfs/master/man/man5/zpool-features.5'}
    with urlopen('https://zfsonlinux.org') as web:
        versions = findall(r'download/zfs-([0-9.]+)', web.read().decode('utf-8', 'ignore'))
    for ver in set(versions):
        sources[ver] = 'https://raw.githubusercontent.com/openzfs/zfs/zfs-{}/man/man5/zpool-features.5'.format(ver)
    return sources

def openzfsonosx():
    sources = {'master': 'https://raw.githubusercontent.com/openzfsonosx/zfs/master/man/man5/zpool-features.5'}
    with urlopen('https://api.github.com/repos/openzfsonosx/zfs/tags') as web:
        try:
            tags = dejson(web.read().decode('utf-8', 'ignore'))
            tags = [ x['name'].lstrip('zfs-') for x in tags ]
            tags.sort()
            latest = tags[-1]
            tags = [ tag for tag in tags if 'rc' not in tag ]
            if 'rc' not in latest:
                tags = tags[-3:]
            else:
                tags = tags[-2:] + [latest]
        except:
            tags = []
    for ver in tags:
        sources[ver] = 'https://raw.githubusercontent.com/openzfsonosx/zfs/zfs-{}/man/man5/zpool-features.5'.format(ver)
    return sources

def freebsd():
    sources = {'head': 'https://svnweb.freebsd.org/base/head/cddl/contrib/opensolaris/cmd/zpool/zpool-features.7?view=co'}
    with urlopen('https://www.freebsd.org/releases/') as web:
        versions = findall(r'/releases/([0-9.]+?)R', web.read().decode('utf-8', 'ignore'))
    with urlopen('https://svnweb.freebsd.org/base/release/') as web:
        data = web.read().decode('utf-8', 'ignore')
    actualversions = []
    for ver in set(versions):
        found = list(sorted(findall( 
            r'/base/release/(' + ver.replace('.', '\\.') + r'[0-9.]*)',
            data
            )))
        if found:
            actualversions.append(found[-1])
    for ver in actualversions:
        sources[ver] = 'https://svnweb.freebsd.org/base/release/{}/cddl/contrib/opensolaris/cmd/zpool/zpool-features.7?view=co'.format(ver)
    return sources

def omniosce():
    sources = {'master': 'https://raw.githubusercontent.com/omniosorg/illumos-omnios/master/usr/src/man/man5/zpool-features.5'}
    with urlopen('https://omniosce.org/releasenotes.html') as web:
        versions = findall(r'omnios-build/blob/(r[0-9]+)', web.read().decode('utf-8', 'ignore'))
    versions.sort()
    versions = versions[-2:]
    for ver in versions:
        sources[ver] = 'https://raw.githubusercontent.com/omniosorg/illumos-omnios/{}/usr/src/man/man5/zpool-features.5'.format(ver)
    return sources

def joyent():
    sources = {'master': 'https://raw.githubusercontent.com/joyent/illumos-joyent/master/usr/src/man/man5/zpool-features.5'}
    with urlopen('https://github.com/joyent/illumos-joyent') as web:
        versions = findall(r'data-name="release-([0-9]+)"', web.read().decode('utf-8', 'ignore'))
    versions.sort()
    versions = versions[-2:]
    for ver in versions:
        sources[ver] = 'https://raw.githubusercontent.com/joyent/illumos-joyent/release-{}/usr/src/man/man5/zpool-features.5'.format(ver)
    return sources

def netbsd():
    url = 'http://cvsweb.netbsd.org/bsdweb.cgi/~checkout~/src/external/cddl/osnet/dist/cmd/zpool/zpool-features.7?content-type=text/plain&only_with_tag={}'
    sources = { 'main': url.format('MAIN') }
    with urlopen('https://netbsd.org/releases/') as web:
        tags = findall(r'href="formal-.+?/NetBSD-(.+?)\.html', web.read().decode('utf-8', 'ignore'))
    tags = [ (v, 'netbsd-' + v.replace('.', '-') + '-RELEASE') for v in tags ]
    for ver, tag in tags:
        if int(ver.split('.')[0]) >= 9:
            sources[ver] = url.format(tag)
    return sources

sources = {
        'OpenZFS on Linux': zfsonlinux(),
        'FreeBSD': freebsd(),
        'OpenZFS on OS X': openzfsonosx(),
        'OmniOS CE': omniosce(),
        'Joyent': joyent(),
        'NetBSD': netbsd(),
        'Illumos': {
            'master': 'https://raw.githubusercontent.com/illumos/illumos-gate/master/usr/src/man/man5/zpool-features.5',
            },
#        'OpenZFS on Windows': {
#            'master': 'https://raw.githubusercontent.com/openzfsonwindows/ZFSin/master/ZFSin/zfs/man/man5/zpool-features.5',
#            },
        }

features = defaultdict(list)
readonly = dict()

for name, sub in sources.items():
    for ver, url in sub.items():
        with urlopen(url) as c:
            if c.getcode() != 200:
                continue
            man = c.read().decode('utf-8')
        for line in man.split('\n'):
            if line.startswith('.It '):
                line = line[4:]
            if line.startswith('GUID'):
                guid = line.split()[-1]
                if guid == 'com.intel:allocation_classes':
                    # This is wrong in the documentation for Illumos and
                    # FreeBSD.  The actual code in zfeature_common.c uses
                    # org.zfsonlinux:allocation_classes.
                    guid = 'org.zfsonlinux:allocation_classes'
                elif guid == 'org.open-zfs:large_block':
                    guid += 's'
                domain, feature = guid.split(':', 1)
                features[(feature, domain)].append((name, ver))
            elif line.startswith('READ\\-ONLY COMPATIBLE'):
                readonly[guid] = (line.split()[-1] == 'yes')

header = list(sorted(sources.keys()))
header = list(zip(header, (sorted(sources[name],
    key=lambda x: regex(r'[^0-9]', '', x) or x) for name in header)))
header.append(('Sortix', ('current',)))

html = open(path + '/zfs.html', 'w')

f_len, d_len = zip(*features.keys())
f_len, d_len = max(map(len, f_len)), max(map(len, d_len)) + 1

html.write('''<!DOCTYPE html>
<title>ZFS Feature Matrix</title>
<meta charset="utf-8" /><meta name="referrer" content="never" />
<link rel='shortcut icon' href='/favicon.ico' type='image/x-icon'>
<style>body{font-family: "Helvetica", "Arial", sans-serif}
.yes{background-color:lightgreen}
.warn{background-color:yellow}
.no{background-color:lightsalmon}
abbr{text-decoration: none}
table{border-collapse: collapse}
th,td{padding:0.2em 0.4em;border:1px solid #aaa;background-color:#f9f9f9}
th{background-color:#eaecf0}
.l{display:inline-block;text-align:right;min-width:''' + str(d_len) + '''ex;color:#777}
.r{display:inline-block;text-align:left;min-width:''' + str(f_len) + '''ex}</style>
''')

html.write('<table>\n')
html.write('<tr><th scope="col" rowspan="2">Feature Flag</th>')
html.write('<th scole="col" rowspan="2">Read-Only<br />Compatible</th>')

for name, vers in header:
    html.write('<th scope="col" colspan="' + str(len(vers)) + '">' + name + '</th>')
html.write('</tr>\n<tr>')
for _, vers in header:
    for ver in vers:
        html.write('<td>' + ver + '</td>')
html.write('</tr>\n')

for (feature, domain), names in sorted(features.items()):
    guid = domain + ':' + feature
    html.write(f'<tr><th scope="row"><span class="l">{domain}:</span><span class="r">{feature}</span></th>')
    if readonly[guid]:
        html.write('<td class="yes">yes</td>')
    else:
        html.write('<td class="warn">no</td>')
    for name, vers in header:
        for ver in vers:
            if (name, ver) in names:
                html.write('<td class="yes">yes</td>')
            else:
                html.write('<td class="no">no</td>')
    html.write('</tr>\n')
html.write('</table>\n')

now = datetime.now().isoformat() + 'Z'
html.write('<p>This works by parsing manpages for feature flags, and is entirely dependent on good, accurate documentation.<br />Last updated on ' + now + ' using <a href="zfs.py">zfs.py</a>.</p>\n')

html.close()