"""
This module contains an extension to Blosxom file entries to support
comments.

Contributors:
Ted Leung
Will Guaraldi
Wari Wahab
Robert Wall
Bill Mill
Roberto De Almeida

If you make any changes to this plugin, please a send a patch with your
changes to twl+pyblosxom@sauria.com so that we can incorporate your changes.
Thanks!

This plugin requires the pyXML module.

This module supports the following config parameters (they are not
required):

    comment_dir - the directory we're going to store all our comments in.
                  this defaults to datadir + "comments".
    comment_ext - the file extension used to denote a comment file.
                  this defaults to "cmt".
    comment_draft_ext - the file extension used for new comments that have
                        not been manually approved by you.  this defaults
                        to comment_ext (i.e. there is no draft stage)

    comment_smtp_server - the smtp server to send comments notifications
                          through.
    comment_smtp_from - the person comment notifications will be from.
                        If you omit this, the from address will be the
                        e-mail address as input in the comment form
    comment_smtp_to - the person to send comment notifications to.
    comment_rejected_words - the list of words that will cause automatic
                             rejection of the comment--this is a very
                             poor man's spam reducer.
    comment_nofollow - set this to 1 to add rel="nofollow" attributes to
                  links in the description -- these attributes are embedded
                  in the stored representation.

Comments are stored 1 per file in a parallel hierarchy to the datadir
hierarchy.  The filename of the comment is the filename of the blog
entry, plus the creation time of the comment as a float, plus the 
comment extension.  The contents of the comment file is an RSS 2.0
formatted item.

Comments now follow the blog_encoding variable specified in config.py

Each entry has to have the following properties in order to work with
comments:

 1. absolute_path - the category of the entry.  ex. "dev/pyblosxom"
 2. fn - the filename of the entry without the file extension and without
    the directory.  ex. "staticrendering"
 3. file_path - the absolute_path plus the fn.  ex. "dev/pyblosxom/staticrendering"

Also, for any entry that you don't want to have comments, just add
"nocomments" to the properties of the entry.

If you would like comment previews, you need to do 2 things.

 1) Add a preview button to comment-form.html like this:
    <input name="preview" type="submit" value="Preview" />

    You may change the contents of the value attribute, but the name of
    the input must be "preview".

 2) Still in your comment-form.html template, you need to use the comment
    values to fill in the values of your input fields like so:
    <input name="author" type="text" value="$cmt_author">
    <input name="email" type="text" value="$cmt_email">
    <input name="url" type="text" value="$cmt_link">
    <textarea name="body">$cmt_description</textarea>

    If there is no preview available, these variables will be stripped
    from the text and cause no problem.

 3) Copy comment.html to a template called comment-preview.html. All of
    the available variables from the comment template are available for
    this template.

This plugin implements Google's nofollow support for links in the body of the 
comment. If you display the link of the comment poster in your HTML template 
then you must add the rel="nofollow" attribute to your template as well
"""
import cgi, glob, os.path, re, time, cPickle, os, codecs
from xml.sax.saxutils import escape
from Pyblosxom import tools
from Pyblosxom.entries.base import EntryBase

def cb_start(args):
    request = args["request"]
    config = request.getConfiguration()
    logdir = config.get("logdir", "/tmp/")

    logfile = os.path.normpath(logdir + os.sep + "comments.log")
    tools.make_logger(logfile)

    if not config.has_key('comment_dir'):
        config['comment_dir'] = os.path.join(config['datadir'],'comments')
    if not config.has_key('comment_ext'):
        config['comment_ext'] = 'cmt'
    if not config.has_key('comment_draft_ext'):
        config['comment_draft_ext'] = config['comment_ext']
    if not config.has_key('comment_nofollow'):
        config['comment_nofollow'] = 0
    
def verify_installation(request):
    config = request.getConfiguration()

    retval = 1

    if config.has_key('comment_dir') and not os.path.isdir(config['comment_dir']):
        print 'The "comment_dir" property in the config file must refer to a directory'
        retval = 0

    smtp_keys_defined = []
    smtp_keys=['comment_smtp_server', 'comment_smtp_from', 'comment_smtp_to']
    for k in smtp_keys:
        if config.has_key(k):
            smtp_keys_defined.append(k)

    if smtp_keys_defined:
        for i in smtp_keys:
            if i not in smtp_keys_defined:
                print("Missing comment SMTP property: '%s'" % i)
                retval = 0
    
    optional_keys = ['comment_dir', 'comment_ext', 'comment_draft_ext']
    for i in optional_keys:
        if not config.has_key(i):
            print("missing optional property: '%s'" % i)

    return retval

def createhtmlmail (html, headers):
    """Create a mime-message that will render HTML in popular
    MUAs, text in better ones

    Based on: http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/67083"""
    import MimeWriter
    import mimetools
    import cStringIO
    
    out = cStringIO.StringIO() # output buffer for our message 
    htmlin = cStringIO.StringIO(html)

    text = re.sub('<.*?>', '', html)
    txtin = cStringIO.StringIO(text)
    
    writer = MimeWriter.MimeWriter(out)
    for header,value in headers:
        writer.addheader(header, value)
    writer.addheader("MIME-Version", "1.0")
    writer.startmultipartbody("alternative")
    writer.flushheaders()

    subpart = writer.nextpart()
    subpart.addheader("Content-Transfer-Encoding", "quoted-printable")
    pout = subpart.startbody("text/plain", [("charset", 'us-ascii')])
    mimetools.encode(txtin, pout, 'quoted-printable')
    txtin.close()

    subpart = writer.nextpart()
    subpart.addheader("Content-Transfer-Encoding", "quoted-printable")
    pout = subpart.startbody("text/html", [("charset", 'us-ascii')])
    mimetools.encode(htmlin, pout, 'quoted-printable')
    htmlin.close()

    writer.lastpart()
    msg = out.getvalue()
    out.close()

    return msg

def readComments(entry, config):
    """
    @param: a file entry
    @type: dict
    
    @returns: a list of comment dicts
    """
    encoding = config['blog_encoding']
    filelist = glob.glob(cmtExpr(entry, config))
    if not entry.has_key('num_comments'):
        entry['num_comments'] = len(filelist)
    comments = [readComment(f, encoding) for f in filelist]
    comments = [(cmt['cmt_time'], cmt) for cmt in comments]
    comments.sort()
    return [c[1] for c in comments]
    
def getCommentCount(entry, config):
    """
    @param: a file entry
    @type: dict
    
    @returns: the number of comments for the entry
    """
    if entry['absolute_path'] == None: return 0
    filelist = glob.glob(cmtExpr(entry,config))
    if filelist is not None:
        return len(filelist)
    return 0

def cmtExpr(entry, config):
    """
    Return a string containing the regular expression for comment entries
    
    @param: a file entry
    @type: dict
    @returns: a string with the directory path for the comment
    
    @param: configuratioin dictionary
    @type: dict
    
    @returns: a string containing the regular expression for comment entries
    """
    cmtDir = os.path.join(config['comment_dir'], entry['absolute_path'])
    cmtExpr = os.path.join(cmtDir,entry['fn']+'-*.'+config['comment_ext'])
    return cmtExpr

def readComment(filename, encoding):
    """
    Read a comment from filename
    
    @param filename: filename containing a comment
    @type filename: string

    @param encoding: encoding of comment files
    @type encoding: string
    
    @returns: a comment dict
    """
    from xml.sax import make_parser, SAXException
    from xml.sax.handler import feature_namespaces, ContentHandler
    class cmtHandler(ContentHandler):
        def __init__(self, cmt):
            self._data = ""
            self.cmt = cmt
        def startElement(self, name, atts):
            self._data = ""
        def endElement(self, name):
            self.cmt['cmt_'+name] = self._data
        def characters(self, content):
            self._data += content

    cmt = {}
    
    try:
        parser = make_parser()
        parser.setFeature(feature_namespaces, 0)
        handler = cmtHandler(cmt)
        parser.setContentHandler(handler)
        parser.parse(filename)
        cmt['cmt_time'] = float(cmt['cmt_pubDate'])                #time.time()
        cmt['cmt_pubDate'] = time.ctime(float(cmt['cmt_pubDate'])) #pretty time
        return cmt
    except: #don't error out on a bad comment
        tools.log('bad comment file: %s' % filename)

def writeComment(request, config, data, comment, encoding):
    """
    Write a comment
    
    @param config: dict containing pyblosxom config info
    @type  config: dict
    
    @param data: dict containing entry info
    @type  data: dict
    
    @param comment: dict containing comment info
    @type  comment: dict

    @return: The success or failure of creating the comment.
    @rtype: string
    """
    entry = data['entry_list'][0]
    cdir = os.path.join(config['comment_dir'],entry['absolute_path'])
    cdir = os.path.normpath(cdir)
    if not os.path.isdir(cdir):
        os.makedirs(cdir)
    cfn = os.path.join(cdir,entry['fn']+"-"+comment['pubDate']+"."+config['comment_ext'])
     
    argdict = { "request": request, "comment": comment }
    reject = tools.run_callback("comment_reject",
                                argdict,
                                donefunc=lambda x:x)
    if reject == 1:
        return "Comment rejected."

    try :
        cfile = codecs.open(cfn, "w", encoding)
    except IOError:
        tools.log("Couldn't open comment file %s for writing" % cfn)
        return
    
    def makeXMLField(name, field):
        return "<"+name+">"+cgi.escape(field[name])+"</"+name+">\n";
    
    cfile.write('<?xml version="1.0" encoding="%s"?>\n' % encoding)
    cfile.write("<item>\n")
    cfile.write(makeXMLField('title',comment))
    cfile.write(makeXMLField('author',comment))
    cfile.write(makeXMLField('link',comment))
    cfile.write(makeXMLField('source',comment))
    cfile.write(makeXMLField('pubDate',comment))
    cfile.write(makeXMLField('description',comment))
    cfile.write("</item>\n")
    cfile.close()
 
    #write latest pickle
    latest = None
    latestFilename = os.path.join(config['comment_dir'],'LATEST.cmt')
    try:
        latest = open(latestFilename,"w")
    except IOError:
        tools.log("Couldn't open latest comment pickle for writing")
        return
    else:
        modTime = float(comment['pubDate'])

    try:
        cPickle.dump(modTime,latest)
        latest.close()
    except IOError:
        # should log or e-mail
        if latest:
            latest.close()
        return
    
    if config.has_key('comment_smtp_server') and \
       config.has_key('comment_smtp_to'):
        send_email(config, entry, comment, cdir, cfn)

def send_email(config, entry, comment, comment_dir, comment_filename):
    """Send an email to the blog owner on a new comment

    @param config: configuration as parsed by Pyblosxom
    @type config: dictionary

    @param entry: a file entry
    @type config: dictionary

    @param comment: comment as generated by readComment
    @type comment: dictionary

    @param comment_dir: the comment directory
    @type comment_dir: string

    @param comment_filename: file name of current comment
    @type comment_filename: string
    """
    import smtplib
    # import the formatdate function which is in a different
    # place in Python 2.3 and up.
    try:
        from email.Utils import formatdate
    except ImportError:
        from rfc822 import formatdate

    author = escape_SMTP_commands(clean_author(comment['author']))
    description = escape_SMTP_commands(comment['description'])
    if comment.has_key('email'):
        email = comment['email']
    else:
        email = config['comment_smtp_from']
    try:
        server = smtplib.SMTP(config['comment_smtp_server'])
        curl = config['base_url']+'/'+entry['file_path']
        comment_dir = os.path.join(config['comment_dir'], entry['absolute_path'])
        comment_filename = os.path.join(comment_dir,entry['fn']+"-"+comment['pubDate']+"."+config['comment_draft_ext'])

        message = []
        message.append("From: %s" % email)
        message.append("To: %s" % config["comment_smtp_to"])
        message.append("Date: %s" % formatdate(float(comment['pubDate'])))
        message.append("Subject: write back by %s" % author)
        message.append("")
        message.append("%s\n%s\n%s\n" % (description, comment_filename, curl))
        server.sendmail(from_addr=email,
                        to_addrs=config['comment_smtp_to'], 
                        msg="\n".join(message))
        server.quit()
    except Exception, e:
        tools.log("Error sending mail: %s" % e)

def clean_author(s):
    """
    Guard against blasterattacko style attacks that embedd SMTP commands in
    author field.

    If author field is more than one line, reduce to one line

    @param the string to be checked
    @type string

    @returns the sanitized string
    """
    return s.splitlines()[0]

def escape_SMTP_commands(s):
    """
    Guard against blasterattacko style attacks that embed SMTP commands by
    using an HTML span to make the command syntactically invalid to SMTP but
    renderable by HTML

    @param the string to be checked
    @type string

    @returns the sanitized string
    """
    def repl_fn(mo):
        return '<span>'+mo.group(0)+'</span>'
    s = re.sub('([Tt]o:.*)',repl_fn,s)
    s = re.sub('([Ff]rom:.*)',repl_fn,s)
    s = re.sub('([Ss]ubject:.*)',repl_fn,s)
    return s

def sanitize(body):
    """
    This code shamelessly lifted from Sam Ruby's mombo/post.py
    """
    body=re.sub(r'\s+$','',body)
    body=re.sub('\r\n?','\n', body)

    # naked urls become hypertext links
    body=re.sub('(^|[\\s.:;?\\-\\]<])' + 
                '(http://[-\\w;/?:@&=+$.!~*\'()%,#]+[\\w/])' +
                '(?=$|[\\s.:;?\\-\\[\\]>])',
                '\\1<a href="\\2">\\2</a>',body)

    # html characters used in text become escaped
    body=escape(body)

    # passthru <a href>, <em>, <i>, <b>, <blockquote>, <br/>, <p>, 
    # <abbr>, <acronym>, <big>, <cite>, <code>, <dfn>, <kbd>, <pre>, <small>
    # <strong>, <sub>, <sup>, <tt>, <var>
    body=re.sub('&lt;a href="([^"]*)"&gt;([^&]*)&lt;/a&gt;',
                '<a href="\\1">\\2</a>', body)
    body=re.sub('&lt;a href=\'([^\']*)\'&gt;([^&]*)&lt;/a&gt;',
                '<a href="\\1">\\2</a>', body)
    body=re.sub('&lt;em&gt;([^&]*)&lt;/em&gt;', '<em>\\1</em>', body)
    body=re.sub('&lt;i&gt;([^&]*)&lt;/i&gt;', '<i>\\1</i>', body)
    body=re.sub('&lt;b&gt;([^&]*)&lt;/b&gt;', '<b>\\1</b>', body)
    body=re.sub('&lt;blockquote&gt;([^&]*)&lt;/blockquote&gt;', 
                '<blockquote>\\1</blockquote>', body)
    body=re.sub('&lt;br\s*/?&gt;\n?','\n',body)

    body=re.sub('&lt;abbr&gt;([^&]*)&lt;/abbr&gt;', '<abbr>\\1</abbr>', body)
    body=re.sub('&lt;acronym&gt;([^&]*)&lt;/acronym&gt;', '<acronym>\\1</acronym>', body)
    body=re.sub('&lt;big&gt;([^&]*)&lt;/big&gt;', '<big>\\1</big>', body)
    body=re.sub('&lt;cite&gt;([^&]*)&lt;/cite&gt;', '<cite>\\1</cite>', body)
    body=re.sub('&lt;code&gt;([^&]*)&lt;/code&gt;', '<code>\\1</code>', body)
    body=re.sub('&lt;dfn&gt;([^&]*)&lt;/dfn&gt;', '<dfn>\\1</dfn>', body)
    body=re.sub('&lt;kbd&gt;([^&]*)&lt;/kbd&gt;', '<kbd>\\1</kbd>', body)
    body=re.sub('&lt;pre&gt;([^&]*)&lt;/pre&gt;', '<pre>\\1</pre>', body)
    body=re.sub('&lt;small&gt;([^&]*)&lt;/small&gt;', '<small>\\1</small>', body)
    body=re.sub('&lt;strong&gt;([^&]*)&lt;/strong&gt;', '<strong>\\1</strong>', body)
    body=re.sub('&lt;sub&gt;([^&]*)&lt;/sub&gt;', '<sub>\\1</sub>', body)
    body=re.sub('&lt;sup&gt;([^&]*)&lt;/sup&gt;', '<sup>\\1</sup>', body)
    body=re.sub('&lt;tt&gt;([^&]*)&lt;/tt&gt;', '<tt>\\1</tt>', body)
    body=re.sub('&lt;var&gt;([^&]*)&lt;/var&gt;', '<var>\\1</var>', body)

    body=re.sub('&lt;/?p&gt;','\n\n',body).strip()

    # wiki like support: _em_, *b*, [url title]
    body=re.sub(r'\b_(\w.*?)_\b', r'<em>\1</em>', body)
    body=re.sub(r'\*(\w.*?)\*', r'<b>\1</b>', body)
    body=re.sub(r'\[(\w+:\S+\.gif) (.*?)\]', r'<img src="\1" alt="\2" />', body)
    body=re.sub(r'\[(\w+:\S+\.jpg) (.*?)\]', r'<img src="\1" alt="\2" />', body)
    body=re.sub(r'\[(\w+:\S+\.png) (.*?)\]', r'<img src="\1" alt="\2" />', body)
    body=re.sub(r'\[(\w+:\S+) (.*?)\]', r'<a href="\1">\2</a>', body).strip()

    # unordered lists: consecutive lines starting with spaces and an asterisk
    chunk=re.compile(r'^( *\*.*(?:\n *\*.*)+)',re.M).split(body)
    for i in range(1, len(chunk), 2):
        (html,stack)=('', [''])
        for indent,line in re.findall(r'( +)\* +(.*)', chunk[i]) + [('','')]:
            if indent>stack[-1]: (stack,html)=(stack+[indent],html+'<ul>\r')
            while indent<stack[-1]: (stack,html)=(stack[:-1],html+'</ul>\r')
            if line: html += '<li>'+line+'</li>\r'
            chunk[i]=html

    # white space
    chunk=re.split('\n\n+', ''.join(chunk))
#    if len(chunk)>1: body='<p>' + '</p>\r<p>'.join(chunk) + '</p>\r'
    body=re.sub('\n','<br />\n', body)
    body=re.compile('<p>(<ul>.*?</ul>)\r</p>?',re.M).sub(r'\1',body)
    body=re.compile('<p>(<blockquote>.*?</blockquote>)</p>?',re.M).sub(r'\1',body)
    body=re.sub('\r', '\n', body)
    body=re.sub('  +', '&nbsp; ', body)

    return body        
        
def dont_follow(mo):
    return '<a rel="nofollow" '+mo.group(1)+'>'

def add_dont_follow(s, config):
    url_pat_str = '<a ([^>]+)>'
    url_pat = re.compile(url_pat_str)
    if config['comment_nofollow'] == 1:
        return url_pat.sub(dont_follow, s)
    else:
        return s

def cb_prepare(args):
    """
    Handle comment related HTTP POST's.
    
    @param request: pyblosxom request object
    @type request: a Pyblosxom request object
    """
    request = args["request"]
    form = request.getHttp()['form']
    config = request.getConfiguration()
    data = request.getData()
    
    if form.has_key("title") and form.has_key("author") and \
        form.has_key("body") and not form.has_key("preview"):

        encoding = config['blog_encoding']
        decode_form(form, encoding)

        body = form['body'].value
        
        body = sanitize(body)

        # Check if the form has a URL
        url = (form.has_key('url') and [form['url'].value] or [''])[0]
        
        #it doesn't make sense to add nofollow to link here, but we should
        #escape it. If you don't like the link escaping, I'm not attached to it.
        cdict = {'title': form['title'].value, \
                 'author' : form['author'].value, \
                 'pubDate' : str(time.time()), \
                 'link' : escape_link(url), \
                 'source' : '', \
                 'description' : add_dont_follow(body, config) }
        if form.has_key('email'):
            cdict['email'] = form['email'].value

        data["comment_message"] = writeComment(request, config, data, \
                                                cdict, encoding)
def escape_link(linkstring):
    """Don't allow html in the link string"""
    for c in "<>'\"":
        linkstring = linkstring.replace(c, '')
    return linkstring

def decode_form(d, encoding):
    for key in d:
        d[key].value = d[key].value.decode(encoding)


def cb_head(args):
    renderer = args['renderer']
    template = args['template']

    newtemplate = renderer.flavour.get('comment-head','')
    if not newtemplate == '' and len(renderer.getContent()) == 1:
        args['template'] = newtemplate

        # expand all of entry vars for expansion
        entry = args['entry']
        single_entry = entry['entry_list'][0]
        single_entry['title'] # force lazy evaluation
        entry.update(single_entry)
        args['entry'] = entry
    return template
        
def cb_story(args):
    renderer = args['renderer']
    entry = args['entry']
    template = args['template']
    request = args["request"]
    config = request.getConfiguration()
    if len(renderer.getContent()) == 1 \
            and renderer.flavour.has_key('comment-story') \
            and not entry.has_key("nocomments"):
        template = renderer.flavour.get('comment-story','')
        args['template'] = args['template'] + template

    entry['num_comments'] = getCommentCount(entry, config)
    return template

def build_preview_comment(form, entry):
    """Build a prevew comment by brute force

    @param form: cgi form object (or compatible)
    @type form: Dictionary of objects with a .value propery

    @param entry: pyblosxom entry object
    @type entry: pyblosxom entry object
    """
    c = {}
    #required fields
    try:
        c['cmt_time'] = str(time.time())
        c['cmt_author'] = form['author'].value
        c['cmt_title'] = form['title'].value
        c['cmt_item'] = sanitize(form['body'].value)
        c['cmt_pubDate'] = time.ctime(time.time())
        c['cmt_description'] = sanitize(form['body'].value)
    except KeyError, e:
        c['cmt_error'] = 'Missing value: %s' % e

    #optional fields
    if 'url' in form:
        c['cmt_link'] = form['url'].value
    if 'email' in form:
        c['cmt_email'] = form['email'].value
    for key in c: entry[key] = c[key]

    return c

def cb_story_end(args):
    renderer = args['renderer']
    entry = args['entry']
    template = args['template']
    request = args["request"]
    form = request.getHttp()['form']
    config = request.getConfiguration()
    if len(renderer.getContent()) == 1 \
            and renderer.flavour.has_key('comment-story') \
            and not entry.has_key("nocomments"):
        output = []
        entry['comments'] = readComments(entry, config)
        if entry.has_key('comments'):        
            for comment in entry['comments']:
                renderer.outputTemplate(output, comment, 'comment')
            if form.has_key('preview')\
                and renderer.flavour.has_key('comment-preview'):
                com = build_preview_comment(form, entry)
                renderer.outputTemplate(output, com, 'comment-preview')
            renderer.outputTemplate(output, entry, 'comment-form')
        args['template'] = template +u"".join(output)

    entry['num_comments'] = getCommentCount(entry, config)
    return template