"""Generic FAQ Wizard.

This is a CGI program that maintains a user-editable FAQ.  It uses RCS
to keep track of changes to individual FAQ entries.  It is fully
configurable; everything you might want to change when using this
program to maintain some other FAQ than the Python FAQ is contained in
the configuration module, faqconf.py.

Note that this is not an executable script; it's an importable module.
The actual script in cgi-bin minimal; it's appended at the end of this
file as a string literal.

"""

import sys, string, time, os, stat, regex, cgi, faqconf
from faqconf import *			# This imports all uppercase names

class FileError:
    def __init__(self, file):
	self.file = file

class InvalidFile(FileError):
    pass

class NoSuchSection(FileError):
    def __init__(self, section):
	FileError.__init__(self, NEWFILENAME %(section, 1))
	self.section = section

class NoSuchFile(FileError):
    def __init__(self, file, why=None):
	FileError.__init__(self, file)
	self.why = why

def replace(s, old, new):
    try:
	return string.replace(s, old, new)
    except AttributeError:
	return string.join(string.split(s, old), new)

def escape(s):
    s = replace(s, '&', '&')
    s = replace(s, '<', '&lt;')
    s = replace(s, '>', '&gt')
    return s

def escapeq(s):
    s = escape(s)
    s = replace(s, '"', '&quot;')
    return s

def _interpolate(format, args, kw):
    try:
	quote = kw['_quote']
    except KeyError:
	quote = 1
    d = (kw,) + args + (faqconf.__dict__,)
    m = MagicDict(d, quote)
    return format % m

def interpolate(format, *args, **kw):
    return _interpolate(format, args, kw)

def emit(format, *args, **kw):
    try:
	f = kw['_file']
    except KeyError:
	f = sys.stdout
    f.write(_interpolate(format, args, kw))

translate_prog = None

def translate(text):
    global translate_prog
    if not translate_prog:
	url = '\(http\|ftp\)://[^ \t\r\n]*'
	email = '\<[-a-zA-Z0-9._]+@[-a-zA-Z0-9._]+'
	translate_prog = prog = regex.compile(url + '\|' + email)
    else:
	prog = translate_prog
    i = 0
    list = []
    while 1:
	j = prog.search(text, i)
	if j < 0:
	    break
	list.append(escape(text[i:j]))
	i = j
	url = prog.group(0)
	while url[-1] in ');:,.?\'"':
	    url = url[:-1]
	url = escape(url)
	if ':' in url:
	    repl = '<A HREF="%s">%s</A>' % (url, url)
	else:
	    repl = '<A HREF="mailto:%s">&lt;%s&gt;</A>' % (url, url)
	list.append(repl)
	i = i + len(url)
    j = len(text)
    list.append(escape(text[i:j]))
    return string.join(list, '')

emphasize_prog = None

def emphasize(line):
    global emphasize_prog
    import regsub
    if not emphasize_prog:
	pat = '\*\([a-zA-Z]+\)\*'
	emphasize_prog = regex.compile(pat)
    return regsub.gsub(emphasize_prog, '<I>\\1</I>', line)

def load_cookies():
    if not os.environ.has_key('HTTP_COOKIE'):
	return {}
    raw = os.environ['HTTP_COOKIE']
    words = map(string.strip, string.split(raw, ';'))
    cookies = {}
    for word in words:
	i = string.find(word, '=')
	if i >= 0:
	    key, value = word[:i], word[i+1:]
	    cookies[key] = value
    return cookies

def load_my_cookie():
    cookies = load_cookies()
    try:
	value = cookies[COOKIE_NAME]
    except KeyError:
	return {}
    import urllib
    value = urllib.unquote(value)
    words = string.split(value, '/')
    while len(words) < 3:
	words.append('')
    author = string.join(words[:-2], '/')
    email = words[-2]
    password = words[-1]
    return {'author': author,
	    'email': email,
	    'password': password}

def send_my_cookie(ui):
    name = COOKIE_NAME
    value = "%s/%s/%s" % (ui.author, ui.email, ui.password)
    import urllib
    value = urllib.quote(value)
    now = time.time()
    then = now + COOKIE_LIFETIME
    gmt = time.gmtime(then)
    print "Set-Cookie: %s=%s; path=/cgi-bin/;" % (name, value),
    print time.strftime("expires=%a, %d-%b-%x %X GMT", gmt)

class MagicDict:

    def __init__(self, d, quote):
	self.__d = d
	self.__quote = quote

    def __getitem__(self, key):
	for d in self.__d:
	    try:
		value = d[key]
		if value:
		    value = str(value)
		    if self.__quote:
			value = escapeq(value)
		    return value
	    except KeyError:
		pass
	return ''

class UserInput:

    def __init__(self):
	self.__form = cgi.FieldStorage()

    def __getattr__(self, name):
	if name[0] == '_':
	    raise AttributeError
	try:
	    value = self.__form[name].value
	except (TypeError, KeyError):
	    value = ''
	else:
	    value = string.strip(value)
	setattr(self, name, value)
	return value

    def __getitem__(self, key):
	return getattr(self, key)

class FaqEntry:

    def __init__(self, fp, file, sec_num):
	self.file = file
	self.sec, self.num = sec_num
	if fp:
	    import rfc822
	    self.__headers = rfc822.Message(fp)
	    self.body = string.strip(fp.read())
	else:
	    self.__headers = {'title': "%d.%d. " % sec_num}
	    self.body = ''

    def __getattr__(self, name):
	if name[0] == '_':
	    raise AttributeError
	key = string.join(string.split(name, '_'), '-')
	try:
	    value = self.__headers[key]
	except KeyError:
	    value = ''
	setattr(self, name, value)
	return value

    def __getitem__(self, key):
	return getattr(self, key)

    def load_version(self):
	command = interpolate(SH_RLOG_H, self)
	p = os.popen(command)
	version = ''
	while 1:
	    line = p.readline()
	    if not line:
		break
	    if line[:5] == 'head:':
		version = string.strip(line[5:])
	p.close()
	self.version = version

    def show(self, edit=1):
	emit(ENTRY_HEADER, self)
	pre = 0
	for line in string.split(self.body, '\n'):
	    if not string.strip(line):
		if pre:
		    print '</PRE>'
		    pre = 0
		else:
		    print '<P>'
	    else:
		if line[0] not in string.whitespace:
		    if pre:
			print '</PRE>'
			pre = 0
		else:
		    if not pre:
			print '<PRE>'
			pre = 1
		if '/' in line or '@' in line:
		    line = translate(line)
		elif '<' in line or '&' in line:
		    line = escape(line)
 		if not pre and '*' in line:
 		    line = emphasize(line)
		print line
	if pre:
	    print '</PRE>'
	    pre = 0
	if edit:
	    print '<P>'
	    emit(ENTRY_FOOTER, self)
	    if self.last_changed_date:
		emit(ENTRY_LOGINFO, self)
	print '<P>'

class FaqDir:

    entryclass = FaqEntry

    __okprog = regex.compile(OKFILENAME)

    def __init__(self, dir=os.curdir):
	self.__dir = dir
	self.__files = None

    def __fill(self):
	if self.__files is not None:
	    return
	self.__files = files = []
	okprog = self.__okprog
	for file in os.listdir(self.__dir):
	    if okprog.match(file) >= 0:
		files.append(file)
	files.sort()

    def good(self, file):
	return self.__okprog.match(file) >= 0

    def parse(self, file):
	if not self.good(file):
	    return None
	sec, num = self.__okprog.group(1, 2)
	return string.atoi(sec), string.atoi(num)

    def roulette(self):
	self.__fill()
	import whrandom
	return whrandom.choice(self.__files)

    def list(self):
	# XXX Caller shouldn't modify result
	self.__fill()
	return self.__files

    def open(self, file):
	sec_num = self.parse(file)
	if not sec_num:
	    raise InvalidFile(file)
	try:
	    fp = open(file)
	except IOError, msg:
	    raise NoSuchFile(file, msg)
	try:
	    return self.entryclass(fp, file, sec_num)
	finally:
	    fp.close()

    def show(self, file, edit=1):
	self.open(file).show(edit=edit)

    def new(self, section):
	if not SECTION_TITLES.has_key(section):
	    raise NoSuchSection(section)
	maxnum = 0
	for file in self.list():
	    sec, num = self.parse(file)
	    if sec == section:
		maxnum = max(maxnum, num)
	sec_num = (section, maxnum+1)
	file = NEWFILENAME % sec_num
	return self.entryclass(None, file, sec_num)

class FaqWizard:

    def __init__(self):
	self.ui = UserInput()
	self.dir = FaqDir()

    def go(self):
	print 'Content-type: text/html'
	req = self.ui.req or 'home'
	mname = 'do_%s' % req
	try:
	    meth = getattr(self, mname)
	except AttributeError:
	    self.error("Bad request type %s." % `req`)
	else:
	    try:
		meth()
	    except InvalidFile, exc:
		self.error("Invalid entry file name %s" % exc.file)
	    except NoSuchFile, exc:
		self.error("No entry with file name %s" % exc.file)
	    except NoSuchSection, exc:
		self.error("No section number %s" % exc.section)
	self.epilogue()

    def error(self, message, **kw):
	self.prologue(T_ERROR)
	emit(message, kw)

    def prologue(self, title, entry=None, **kw):
	emit(PROLOGUE, entry, kwdict=kw, title=escape(title))

    def epilogue(self):
	emit(EPILOGUE)

    def do_home(self):
	self.prologue(T_HOME)
	emit(HOME)

    def do_debug(self):
	self.prologue("FAQ Wizard Debugging")
	form = cgi.FieldStorage()
	cgi.print_form(form)
        cgi.print_environ(os.environ)
	cgi.print_directory()
	cgi.print_arguments()

    def do_search(self):
	query = self.ui.query
	if not query:
	    self.error("Empty query string!")
	    return
	self.prologue(T_SEARCH)
	if self.ui.querytype != 'regex':
	    for c in '\\.[]?+^$*':
		if c in query:
		    query = replace(query, c, '\\'+c)
	if self.ui.casefold == 'no':
	    p = regex.compile(query)
	else:
	    p = regex.compile(query, regex.casefold)
	hits = []
	for file in self.dir.list():
	    try:
		entry = self.dir.open(file)
	    except FileError:
		constants
	    if p.search(entry.title) >= 0 or p.search(entry.body) >= 0:
		hits.append(file)
	if not hits:
	    emit(NO_HITS, self.ui, count=0)
	elif len(hits) <= MAXHITS:
	    if len(hits) == 1:
		emit(ONE_HIT, count=1)
	    else:
		emit(FEW_HITS, count=len(hits))
	    self.format_all(hits)
	else:
	    emit(MANY_HITS, count=len(hits))
	    self.format_index(hits)

    def do_all(self):
	self.prologue(T_ALL)
	files = self.dir.list()
	self.last_changed(files)
	self.format_all(files)

    def do_compat(self):
	files = self.dir.list()
	emit(COMPAT)
	self.last_changed(files)
	self.format_all(files, edit=0)
	sys.exit(0)

    def last_changed(self, files):
	latest = 0
	for file in files:
	    try:
		st = os.stat(file)
	    except os.error:
		continue
	    mtime = st[stat.ST_MTIME]
	    if mtime > latest:
		latest = mtime
	print time.strftime(LAST_CHANGED,
			    time.localtime(time.time()))

    def format_all(self, files, edit=1):
	for file in files:
	    self.dir.show(file, edit=edit)

    def do_index(self):
	self.prologue(T_INDEX)
	self.format_index(self.dir.list(), add=1)

    def format_index(self, files, add=0):
	sec = 0
	for file in files:
	    try:
		entry = self.dir.open(file)
	    except NoSuchFile:
		continue
	    if entry.sec != sec:
		if sec:
		    if add:
			emit(INDEX_ADDSECTION, sec=sec)
		    emit(INDEX_ENDSECTION, sec=sec)
		sec = entry.sec
		emit(INDEX_SECTION, sec=sec, title=SECTION_TITLES[sec])
	    emit(INDEX_ENTRY, entry)
	if sec:
	    if add:
		emit(INDEX_ADDSECTION, sec=sec)
	    emit(INDEX_ENDSECTION, sec=sec)

    def do_recent(self):
	if not self.ui.days:
	    days = 1
	else:
	    days = string.atof(self.ui.days)
	now = time.time()
	try:
	    cutoff = now - days * 24 * 3600
	except OverflowError:
	    cutoff = 0
	list = []
	for file in self.dir.list():
	    try:
		st = os.stat(file)
	    except os.error:
		continue
	    mtime = st[stat.ST_MTIME]
	    if mtime >= cutoff:
		list.append((mtime, file))
	list.sort()
	list.reverse()
	self.prologue(T_RECENT)
	if days <= 1:
	    period = "%.2g hours" % (days*24)
	else:
	    period = "%.6g days" % days
	if not list:
	    emit(NO_RECENT, period=period)
	elif len(list) == 1:
	    emit(ONE_RECENT, period=period)
	else:
	    emit(SOME_RECENT, period=period, count=len(list))
	self.format_all(map(lambda (mtime, file): file, list))
	emit(TAIL_RECENT)

    def do_roulette(self):
	self.prologue(T_ROULETTE)
	file = self.dir.roulette()
	self.dir.show(file)

    def do_help(self):
	self.prologue(T_HELP)
	emit(HELP)

    def do_show(self):
	entry = self.dir.open(self.ui.file)
	self.prologue(T_SHOW)
	entry.show()

    def do_add(self):
	self.prologue(T_ADD)
	emit(ADD_HEAD)
	sections = SECTION_TITLES.items()
	sections.sort()
	for section, title in sections:
	    emit(ADD_SECTION, section=section, title=title)
	emit(ADD_TAIL)

    def do_delete(self):
	self.prologue(T_DELETE)
	emit(DELETE)

    def do_log(self):
	entry = self.dir.open(self.ui.file)
	self.prologue(T_LOG, entry)
	emit(LOG, entry)
	self.rlog(interpolate(SH_RLOG, entry), entry)

    def rlog(self, command, entry=None):
	output = os.popen(command).read()
	sys.stdout.write('<PRE>')
	athead = 0
	lines = string.split(output, '\n')
	while lines and not lines[-1]:
	    del lines[-1]
	if lines:
	    line = lines[-1]
	    if line[:1] == '=' and len(line) >= 40 and \
	       line == line[0]*len(line):
		del lines[-1]
	for line in lines:
	    if entry and athead and line[:9] == 'revision ':
		rev = string.strip(line[9:])
		if rev != '1.1':
		    emit(DIFFLINK, entry, rev=rev, line=line)
		else:
		    print line
		athead = 0
	    else:
		athead = 0
		if line[:1] == '-' and len(line) >= 20 and \
		   line == len(line) * line[0]:
		    athead = 1
		    sys.stdout.write('<HR>')
		else:
		    print line
	print '</PRE>'

    def do_diff(self):
	entry = self.dir.open(self.ui.file)
	rev = self.ui.rev
	r = regex.compile(
	    '^\([1-9][0-9]?[0-9]?\)\.\([1-9][0-9]?[0-9]?[0-9]?\)$')
	if r.match(rev) < 0:
	    self.error("Invalid revision number: %s." % `rev`)
	[major, minor] = map(string.atoi, r.group(1, 2))
	if minor == 1:
	    self.error("No previous revision.")
	    return
	prev = '%d.%d' % (major, minor-1)
	self.prologue(T_DIFF, entry)
	self.shell(interpolate(SH_RDIFF, entry, rev=rev, prev=prev))

    def shell(self, command):
	output = os.popen(command).read()
	sys.stdout.write('<PRE>')
	print escape(output)
	print '</PRE>'

    def do_new(self):
	entry = self.dir.new(section=string.atoi(self.ui.section))
	entry.version = '*new*'
	self.prologue(T_EDIT)
	emit(EDITHEAD)
	emit(EDITFORM1, entry, editversion=entry.version)
	emit(EDITFORM2, entry, load_my_cookie())
	emit(EDITFORM3)
	entry.show(edit=0)

    def do_edit(self):
	entry = self.dir.open(self.ui.file)
	entry.load_version()
	self.prologue(T_EDIT)
	emit(EDITHEAD)
	emit(EDITFORM1, entry, editversion=entry.version)
	emit(EDITFORM2, entry, load_my_cookie())
	emit(EDITFORM3)
	entry.show(edit=0)

    def do_review(self):
	send_my_cookie(self.ui)
	if self.ui.editversion == '*new*':
	    sec, num = self.dir.parse(self.ui.file)
	    entry = self.dir.new(section=sec)
	    entry.version = "*new*"
	    if entry.file != self.ui.file:
		self.error("Commit version conflict!")
		emit(NEWCONFLICT, self.ui, sec=sec, num=num)
		return
	else:
	    entry = self.dir.open(self.ui.file)
	    entry.load_version()
	# Check that the FAQ entry number didn't change
	if string.split(self.ui.title)[:1] != string.split(entry.title)[:1]:
	    self.error("Don't change the entry number please!")
	    return
	# Check that the edited version is the current version
	if entry.version != self.ui.editversion:
	    self.error("Commit version conflict!")
	    emit(VERSIONCONFLICT, entry, self.ui)
	    return
	commit_ok = ((not PASSWORD
		      or self.ui.password == PASSWORD) 
		     and self.ui.author
		     and '@' in self.ui.email
		     and self.ui.log)
	if self.ui.commit:
	    if not commit_ok:
		self.cantcommit()
	    else:
		self.commit(entry)
	    return
	self.prologue(T_REVIEW)
	emit(REVIEWHEAD)
	entry.body = self.ui.body
	entry.title = self.ui.title
	entry.show(edit=0)
	emit(EDITFORM1, self.ui, entry)
	if commit_ok:
	    emit(COMMIT)
	else:
	    emit(NOCOMMIT)
	emit(EDITFORM2, self.ui, entry, load_my_cookie())
	emit(EDITFORM3)

    def cantcommit(self):
	self.prologue(T_CANTCOMMIT)
	print CANTCOMMIT_HEAD
	if not self.ui.passwd:
	    emit(NEED_PASSWD)
	if not self.ui.log:
	    emit(NEED_LOG)
	if not self.ui.author:
	    emit(NEED_AUTHOR)
	if not self.ui.email:
	    emit(NEED_EMAIL)
	print CANTCOMMIT_TAIL

    def commit(self, entry):
	file = entry.file
	# Normalize line endings in body
	if '\r' in self.ui.body:
	    import regsub
	    self.ui.body = regsub.gsub('\r\n?', '\n', self.ui.body)
	# Normalize whitespace in title
	self.ui.title = string.join(string.split(self.ui.title))
	# Check that there were any changes
	if self.ui.body == entry.body and self.ui.title == entry.title:
	    self.error("You didn't make any changes!")
	    return
	# XXX Should lock here
	try:
	    os.unlink(file)
	except os.error:
	    pass
	try:
	    f = open(file, 'w')
	except IOError, why:
	    self.error(CANTWRITE, file=file, why=why)
	    return
	date = time.ctime(time.time())
	emit(FILEHEADER, self.ui, os.environ, date=date, _file=f, _quote=0)
	f.write('\n')
	f.write(self.ui.body)
	f.write('\n')
	f.close()

	import tempfile
	tfn = tempfile.mktemp()
	f = open(tfn, 'w')
	emit(LOGHEADER, self.ui, os.environ, date=date, _file=f)
	f.close()

	command = interpolate(
	    SH_LOCK + '\n' + SH_CHECKIN,
	    file=file, tfn=tfn)

	p = os.popen(command)
	output = p.read()
	sts = p.close()
	# XXX Should unlock here
	if not sts:
	    self.prologue(T_COMMITTED)
	    emit(COMMITTED)
	else:
	    self.error(T_COMMITFAILED)
	    emit(COMMITFAILED, sts=sts)
	print '<PRE>%s</PRE>' % escape(output)

	try:
	    os.unlink(tfn)
	except os.error:
	    pass

	entry = self.dir.open(file)
	entry.show()

wiz = FaqWizard()
wiz.go()

# This bootstrap script should be placed in your cgi-bin directory.
# You only need to edit the first two lines: change
# /usr/local/bin/python to where your Python interpreter lives change
# the value for FAQDIR to where your FAQ lives.  The faqwiz.py and
# faqconf.py files should live there, too.

BOOTSTRAP = """\
#! /usr/local/bin/python
FAQDIR = "/usr/people/guido/python/FAQ"
import sys, os
os.chdir(FAQDIR)
sys.path.insert(0, FAQDIR)
import faqwiz
"""