#!/usr/bin/env python
"""Convert PEPs to (X)HTML - courtesy of /F

Usage: %(PROGRAM)s [options] [<peps> ...]

Options:

-u, --user
    python.org username

-b, --browse
    After generating the HTML, direct your web browser to view it
    (using the Python webbrowser module).  If both -i and -b are
    given, this will browse the on-line HTML; otherwise it will
    browse the local HTML.  If no pep arguments are given, this
    will browse PEP 0.

-i, --install
    After generating the HTML, install it and the plaintext source file
    (.txt) on python.org.  In that case the user's name is used in the scp
    and ssh commands, unless "-u username" is given (in which case, it is
    used instead).  Without -i, -u is ignored.

-l, --local
    Same as -i/--install, except install on the local machine.  Use this
    when logged in to the python.org machine (dinsdale).

-q, --quiet
    Turn off verbose messages.

-h, --help
    Print this help message and exit.

The optional arguments ``peps`` are either pep numbers, .rst or .txt files.
"""

from __future__ import print_function, unicode_literals

import sys
import os
import re
import glob
import getopt
import errno
import random
import time
from io import open
try:
    from html import escape
except ImportError:
    from cgi import escape

from docutils import core, nodes, utils
from docutils.readers import standalone
from docutils.transforms import peps, references, misc, frontmatter, Transform
from docutils.parsers import rst

class DataError(Exception):
    pass

REQUIRES = {'python': '2.6',
            'docutils': '0.2.7'}
PROGRAM = sys.argv[0]
RFCURL = 'http://www.faqs.org/rfcs/rfc%d.html'
PEPURL = 'pep-%04d.html'
PEPCVSURL = ('https://hg.python.org/peps/file/tip/pep-%04d.txt')
PEPDIRRUL = 'http://www.python.org/peps/'


HOST = "dinsdale.python.org"                    # host for update
HDIR = "/data/ftp.python.org/pub/www.python.org/peps" # target host directory
LOCALVARS = "Local Variables:"

COMMENT = """<!--
This HTML is auto-generated.  DO NOT EDIT THIS FILE!  If you are writing a new
PEP, see http://www.python.org/peps/pep-0001.html for instructions and links
to templates.  DO NOT USE THIS HTML FILE AS YOUR TEMPLATE!
-->"""

# The generated HTML doesn't validate -- you cannot use <hr> and <h3> inside
# <pre> tags.  But if I change that, the result doesn't look very nice...
DTD = ('<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"\n'
       '                      "http://www.w3.org/TR/REC-html40/loose.dtd">')

fixpat = re.compile(r"((https?|ftp):[-_a-zA-Z0-9/.+~:?#$=&,]+)|(pep-\d+(.txt|.rst)?)|"
                    r"(RFC[- ]?(?P<rfcnum>\d+))|"
                    r"(PEP\s+(?P<pepnum>\d+))|"
                    r".")

EMPTYSTRING = ''
SPACE = ' '
COMMASPACE = ', '



def usage(code, msg=''):
    """Print usage message and exit.  Uses stderr if code != 0."""
    if code == 0:
        out = sys.stdout
    else:
        out = sys.stderr
    print(__doc__ % globals(), file=out)
    if msg:
        print(msg, file=out)
    sys.exit(code)



def fixanchor(current, match):
    text = match.group(0)
    link = None
    if (text.startswith('http:') or text.startswith('https:')
        or text.startswith('ftp:')):
        # Strip off trailing punctuation.  Pattern taken from faqwiz.
        ltext = list(text)
        while ltext:
            c = ltext.pop()
            if c not in '''();:,.?'"<>''':
                ltext.append(c)
                break
        link = EMPTYSTRING.join(ltext)
    elif text.startswith('pep-') and text != current:
        link = os.path.splitext(text)[0] + ".html"
    elif text.startswith('PEP'):
        pepnum = int(match.group('pepnum'))
        link = PEPURL % pepnum
    elif text.startswith('RFC'):
        rfcnum = int(match.group('rfcnum'))
        link = RFCURL % rfcnum
    if link:
        return '<a href="%s">%s</a>' % (escape(link), escape(text))
    return escape(match.group(0)) # really slow, but it works...



NON_MASKED_EMAILS = [
    'peps@python.org',
    'python-list@python.org',
    'python-dev@python.org',
    ]

def fixemail(address, pepno):
    if address.lower() in NON_MASKED_EMAILS:
        # return hyperlinked version of email address
        return linkemail(address, pepno)
    else:
        # return masked version of email address
        parts = address.split('@', 1)
        return '%s&#32;&#97;t&#32;%s' % (parts[0], parts[1])


def linkemail(address, pepno):
    parts = address.split('@', 1)
    return ('<a href="mailto:%s&#64;%s?subject=PEP%%20%s">'
            '%s&#32;&#97;t&#32;%s</a>'
            % (parts[0], parts[1], pepno, parts[0], parts[1]))


def fixfile(inpath, input_lines, outfile):
    try:
        from email.Utils import parseaddr
    except ImportError:
        from email.utils import parseaddr
    basename = os.path.basename(inpath)
    infile = iter(input_lines)
    # convert plaintext pep to minimal XHTML markup
    print(DTD, file=outfile)
    print('<html>', file=outfile)
    print(COMMENT, file=outfile)
    print('<head>', file=outfile)
    # head
    header = []
    pep = ""
    title = ""
    for line in infile:
        if not line.strip():
            break
        if line[0].strip():
            if ":" not in line:
                break
            key, value = line.split(":", 1)
            value = value.strip()
            header.append((key, value))
        else:
            # continuation line
            key, value = header[-1]
            value = value + line
            header[-1] = key, value
        if key.lower() == "title":
            title = value
        elif key.lower() == "pep":
            pep = value
    if pep:
        title = "PEP " + pep + " -- " + title
    if title:
        print('  <title>%s</title>' % escape(title), file=outfile)
    r = random.choice(list(range(64)))
    print((
        '  <link rel="STYLESHEET" href="style.css" type="text/css" />\n'
        '</head>\n'
        '<body bgcolor="white">\n'
        '<table class="navigation" cellpadding="0" cellspacing="0"\n'
        '       width="100%%" border="0">\n'
        '<tr><td class="navicon" width="150" height="35">\n'
        '<a href="../" title="Python Home Page">\n'
        '<img src="../pics/PyBanner%03d.gif" alt="[Python]"\n'
        ' border="0" width="150" height="35" /></a></td>\n'
        '<td class="textlinks" align="left">\n'
        '[<b><a href="../">Python Home</a></b>]' % r), file=outfile)
    if basename != 'pep-0000.txt':
        print('[<b><a href=".">PEP Index</a></b>]', file=outfile)
    if pep:
        try:
            print(('[<b><a href="pep-%04d.txt">PEP Source</a>'
                               '</b>]' % int(pep)), file=outfile)
        except ValueError as error:
            print(('ValueError (invalid PEP number): %s'
                                  % error), file=sys.stderr)
    print('</td></tr></table>', file=outfile)
    print('<div class="header">\n<table border="0">', file=outfile)
    for k, v in header:
        if k.lower() in ('author', 'pep-delegate', 'bdfl-delegate', 'discussions-to',
                         'sponsor'):
            mailtos = []
            for part in re.split(r',\s*', v):
                if '@' in part:
                    realname, addr = parseaddr(part)
                    if k.lower() == 'discussions-to':
                        m = linkemail(addr, pep)
                    else:
                        m = fixemail(addr, pep)
                    mailtos.append('%s &lt;%s&gt;' % (realname, m))
                elif part.startswith('http:'):
                    mailtos.append(
                        '<a href="%s">%s</a>' % (part, part))
                else:
                    mailtos.append(part)
            v = COMMASPACE.join(mailtos)
        elif k.lower() in ('replaces', 'superseded-by', 'requires'):
            otherpeps = ''
            for otherpep in re.split(r',?\s+', v):
                otherpep = int(otherpep)
                otherpeps += '<a href="pep-%04d.html">%i</a> ' % (otherpep,
                                                                  otherpep)
            v = otherpeps
        elif k.lower() in ('last-modified',):
            date = v or time.strftime('%d-%b-%Y',
                                      time.localtime(os.stat(inpath)[8]))
            if date.startswith('$' 'Date: ') and date.endswith(' $'):
                date = date[6:-2]
            if basename == 'pep-0000.txt':
                v = date
            else:
                try:
                    url = PEPCVSURL % int(pep)
                    v = '<a href="%s">%s</a> ' % (url, escape(date))
                except ValueError as error:
                    v = date
        elif k.lower() in ('content-type',):
            url = PEPURL % 9
            pep_type = v or 'text/plain'
            v = '<a href="%s">%s</a> ' % (url, escape(pep_type))
        elif k.lower() == 'version':
            if v.startswith('$' 'Revision: ') and v.endswith(' $'):
                v = escape(v[11:-2])
        else:
            v = escape(v)
        print('  <tr><th>%s:&nbsp;</th><td>%s</td></tr>' \
              % (escape(k), v), file=outfile)
    print('</table>', file=outfile)
    print('</div>', file=outfile)
    print('<hr />', file=outfile)
    print('<div class="content">', file=outfile)
    need_pre = 1
    for line in infile:
        if line[0] == '\f':
            continue
        if line.strip() == LOCALVARS:
            break
        if line[0].strip():
            if not need_pre:
                print('</pre>', file=outfile)
            print('<h3>%s</h3>' % line.strip(), file=outfile)
            need_pre = 1
        elif not line.strip() and need_pre:
            continue
        else:
            # PEP 0 has some special treatment
            if basename == 'pep-0000.txt':
                parts = line.split()
                if len(parts) > 1 and re.match(r'\s*\d{1,4}', parts[1]):
                    # This is a PEP summary line, which we need to hyperlink
                    url = PEPURL % int(parts[1])
                    if need_pre:
                        print('<pre>', file=outfile)
                        need_pre = 0
                    print(re.sub(
                        parts[1],
                        '<a href="%s">%s</a>' % (url, parts[1]),
                        line, 1), end='', file=outfile)
                    continue
                elif parts and '@' in parts[-1]:
                    # This is a pep email address line, so filter it.
                    url = fixemail(parts[-1], pep)
                    if need_pre:
                        print('<pre>', file=outfile)
                        need_pre = 0
                    print(re.sub(
                        parts[-1], url, line, 1), end='', file=outfile)
                    continue
            line = fixpat.sub(lambda x, c=inpath: fixanchor(c, x), line)
            if need_pre:
                print('<pre>', file=outfile)
                need_pre = 0
            outfile.write(line)
    if not need_pre:
        print('</pre>', file=outfile)
    print('</div>', file=outfile)
    print('</body>', file=outfile)
    print('</html>', file=outfile)


docutils_settings = None
"""Runtime settings object used by Docutils.  Can be set by the client
application when this module is imported."""

class PEPHeaders(Transform):

    """
    Process fields in a PEP's initial RFC-2822 header.
    """

    default_priority = 360

    pep_url = 'pep-%04d'
    pep_cvs_url = PEPCVSURL
    rcs_keyword_substitutions = (
          (re.compile(r'\$' r'RCSfile: (.+),v \$$', re.IGNORECASE), r'\1'),
          (re.compile(r'\$[a-zA-Z]+: (.+) \$$'), r'\1'),)

    def apply(self):
        if not len(self.document):
            # @@@ replace these DataErrors with proper system messages
            raise DataError('Document tree is empty.')
        header = self.document[0]
        if not isinstance(header, nodes.field_list) or \
              'rfc2822' not in header['classes']:
            raise DataError('Document does not begin with an RFC-2822 '
                            'header; it is not a PEP.')
        pep = None
        for field in header:
            if field[0].astext().lower() == 'pep': # should be the first field
                value = field[1].astext()
                try:
                    pep = int(value)
                    cvs_url = self.pep_cvs_url % pep
                except ValueError:
                    pep = value
                    cvs_url = None
                    msg = self.document.reporter.warning(
                        '"PEP" header must contain an integer; "%s" is an '
                        'invalid value.' % pep, base_node=field)
                    msgid = self.document.set_id(msg)
                    prb = nodes.problematic(value, value or '(none)',
                                            refid=msgid)
                    prbid = self.document.set_id(prb)
                    msg.add_backref(prbid)
                    if len(field[1]):
                        field[1][0][:] = [prb]
                    else:
                        field[1] += nodes.paragraph('', '', prb)
                break
        if pep is None:
            raise DataError('Document does not contain an RFC-2822 "PEP" '
                            'header.')
        if pep == 0:
            # Special processing for PEP 0.
            pending = nodes.pending(peps.PEPZero)
            self.document.insert(1, pending)
            self.document.note_pending(pending)
        if len(header) < 2 or header[1][0].astext().lower() != 'title':
            raise DataError('No title!')
        for field in header:
            name = field[0].astext().lower()
            body = field[1]
            if len(body) > 1:
                raise DataError('PEP header field body contains multiple '
                                'elements:\n%s' % field.pformat(level=1))
            elif len(body) == 1:
                if not isinstance(body[0], nodes.paragraph):
                    raise DataError('PEP header field body may only contain '
                                    'a single paragraph:\n%s'
                                    % field.pformat(level=1))
            elif name == 'last-modified':
                date = time.strftime(
                      '%d-%b-%Y',
                      time.localtime(os.stat(self.document['source'])[8]))
                if cvs_url:
                    body += nodes.paragraph(
                        '', '', nodes.reference('', date, refuri=cvs_url))
            else:
                # empty
                continue
            para = body[0]
            if name in ('author', 'bdfl-delegate', 'pep-delegate', 'sponsor'):
                for node in para:
                    if isinstance(node, nodes.reference):
                        node.replace_self(peps.mask_email(node))
            elif name == 'discussions-to':
                for node in para:
                    if isinstance(node, nodes.reference):
                        node.replace_self(peps.mask_email(node, pep))
            elif name in ('replaces', 'superseded-by', 'requires'):
                newbody = []
                space = nodes.Text(' ')
                for refpep in re.split(r',?\s+', body.astext()):
                    pepno = int(refpep)
                    newbody.append(nodes.reference(
                        refpep, refpep,
                        refuri=(self.document.settings.pep_base_url
                                + self.pep_url % pepno)))
                    newbody.append(space)
                para[:] = newbody[:-1] # drop trailing space
            elif name == 'last-modified':
                utils.clean_rcs_keywords(para, self.rcs_keyword_substitutions)
                if cvs_url:
                    date = para.astext()
                    para[:] = [nodes.reference('', date, refuri=cvs_url)]
            elif name == 'content-type':
                pep_type = para.astext()
                uri = self.document.settings.pep_base_url + self.pep_url % 12
                para[:] = [nodes.reference('', pep_type, refuri=uri)]
            elif name == 'version' and len(body):
                utils.clean_rcs_keywords(para, self.rcs_keyword_substitutions)

class PEPReader(standalone.Reader):

    supported = ('pep',)
    """Contexts this reader supports."""

    settings_spec = (
        'PEP Reader Option Defaults',
        'The --pep-references and --rfc-references options (for the '
        'reStructuredText parser) are on by default.',
        ())

    config_section = 'pep reader'
    config_section_dependencies = ('readers', 'standalone reader')

    def get_transforms(self):
        transforms = standalone.Reader.get_transforms(self)
        # We have PEP-specific frontmatter handling.
        transforms.remove(frontmatter.DocTitle)
        transforms.remove(frontmatter.SectionSubTitle)
        transforms.remove(frontmatter.DocInfo)
        transforms.extend([PEPHeaders, peps.Contents, peps.TargetNotes])
        return transforms

    settings_default_overrides = {'pep_references': 1, 'rfc_references': 1}

    inliner_class = rst.states.Inliner

    def __init__(self, parser=None, parser_name=None):
        """`parser` should be ``None``."""
        if parser is None:
            parser = rst.Parser(rfc2822=True, inliner=self.inliner_class())
        standalone.Reader.__init__(self, parser, '')


def fix_rst_pep(inpath, input_lines, outfile):
    output = core.publish_string(
        source=''.join(input_lines),
        source_path=inpath,
        destination_path=outfile.name,
        reader=PEPReader(),
        parser_name='restructuredtext',
        writer_name='pep_html',
        settings=docutils_settings,
        # Allow Docutils traceback if there's an exception:
        settings_overrides={'traceback': 1, 'halt_level': 2})
    outfile.write(output.decode('utf-8'))


def get_pep_type(input_lines):
    """
    Return the Content-Type of the input.  "text/plain" is the default.
    Return ``None`` if the input is not a PEP.
    """
    pep_type = None
    for line in input_lines:
        line = line.rstrip().lower()
        if not line:
            # End of the RFC 2822 header (first blank line).
            break
        elif line.startswith('content-type: '):
            pep_type = line.split()[1] or 'text/plain'
            break
        elif line.startswith('pep: '):
            # Default PEP type, used if no explicit content-type specified:
            pep_type = 'text/plain'
    return pep_type


def get_input_lines(inpath):
    try:
        infile = open(inpath, encoding='utf-8')
    except IOError as e:
        if e.errno != errno.ENOENT: raise
        print('Error: Skipping missing PEP file:', e.filename, file=sys.stderr)
        sys.stderr.flush()
        return None
    lines = infile.read().splitlines(1) # handles x-platform line endings
    infile.close()
    return lines


def find_pep(pep_str):
    """Find the .rst or .txt file indicated by a cmd line argument"""
    if os.path.exists(pep_str):
        return pep_str
    num = int(pep_str)
    rstpath = "pep-%04d.rst" % num
    if os.path.exists(rstpath):
        return rstpath
    return "pep-%04d.txt" % num

def make_html(inpath, verbose=0):
    input_lines = get_input_lines(inpath)
    if input_lines is None:
        return None
    pep_type = get_pep_type(input_lines)
    if pep_type is None:
        print('Error: Input file %s is not a PEP.' % inpath, file=sys.stderr)
        sys.stdout.flush()
        return None
    elif pep_type not in PEP_TYPE_DISPATCH:
        print(('Error: Unknown PEP type for input file %s: %s'
                              % (inpath, pep_type)), file=sys.stderr)
        sys.stdout.flush()
        return None
    elif PEP_TYPE_DISPATCH[pep_type] == None:
        pep_type_error(inpath, pep_type)
        return None
    outpath = os.path.splitext(inpath)[0] + ".html"
    if verbose:
        print(inpath, "(%s)" % pep_type, "->", outpath)
        sys.stdout.flush()
    outfile = open(outpath, "w", encoding='utf-8')
    PEP_TYPE_DISPATCH[pep_type](inpath, input_lines, outfile)
    outfile.close()
    os.chmod(outfile.name, 0o664)
    return outpath

def push_pep(htmlfiles, txtfiles, username, verbose, local=0):
    quiet = ""
    if local:
        if verbose:
            quiet = "-v"
        target = HDIR
        copy_cmd = "cp"
        chmod_cmd = "chmod"
    else:
        if not verbose:
            quiet = "-q"
        if username:
            username = username + "@"
        target = username + HOST + ":" + HDIR
        copy_cmd = "scp"
        chmod_cmd = "ssh %s%s chmod" % (username, HOST)
    files = htmlfiles[:]
    files.extend(txtfiles)
    files.append("style.css")
    files.append("pep.css")
    filelist = SPACE.join(files)
    rc = os.system("%s %s %s %s" % (copy_cmd, quiet, filelist, target))
    if rc:
        sys.exit(rc)
##    rc = os.system("%s 664 %s/*" % (chmod_cmd, HDIR))
##    if rc:
##        sys.exit(rc)


PEP_TYPE_DISPATCH = {'text/plain': fixfile,
                     'text/x-rst': fix_rst_pep}
PEP_TYPE_MESSAGES = {}

def check_requirements():
    # Check Python:
    # This is pretty much covered by the __future__ imports...
    if sys.version_info < (2, 6, 0):
        PEP_TYPE_DISPATCH['text/plain'] = None
        PEP_TYPE_MESSAGES['text/plain'] = (
            'Python %s or better required for "%%(pep_type)s" PEP '
            'processing; %s present (%%(inpath)s).'
            % (REQUIRES['python'], sys.version.split()[0]))
    # Check Docutils:
    try:
        import docutils
    except ImportError:
        PEP_TYPE_DISPATCH['text/x-rst'] = None
        PEP_TYPE_MESSAGES['text/x-rst'] = (
            'Docutils not present for "%(pep_type)s" PEP file %(inpath)s.  '
            'See README.rst for installation.')
    else:
        installed = [int(part) for part in docutils.__version__.split('.')]
        required = [int(part) for part in REQUIRES['docutils'].split('.')]
        if installed < required:
            PEP_TYPE_DISPATCH['text/x-rst'] = None
            PEP_TYPE_MESSAGES['text/x-rst'] = (
                'Docutils must be reinstalled for "%%(pep_type)s" PEP '
                'processing (%%(inpath)s).  Version %s or better required; '
                '%s present.  See README.rst for installation.'
                % (REQUIRES['docutils'], docutils.__version__))

def pep_type_error(inpath, pep_type):
    print('Error: ' + PEP_TYPE_MESSAGES[pep_type] % locals(), file=sys.stderr)
    sys.stdout.flush()


def browse_file(pep):
    import webbrowser
    file = find_pep(pep)
    if file.startswith('pep-') and file.endswith((".txt", '.rst')):
        file = file[:-3] + "html"
    file = os.path.abspath(file)
    url = "file:" + file
    webbrowser.open(url)

def browse_remote(pep):
    import webbrowser
    file = find_pep(pep)
    if file.startswith('pep-') and file.endswith((".txt", '.rst')):
        file = file[:-3] + "html"
    url = PEPDIRRUL + file
    webbrowser.open(url)


def main(argv=None):
    # defaults
    update = 0
    local = 0
    username = ''
    verbose = 1
    browse = 0

    check_requirements()

    if argv is None:
        argv = sys.argv[1:]

    try:
        opts, args = getopt.getopt(
            argv, 'bilhqu:',
            ['browse', 'install', 'local', 'help', 'quiet', 'user='])
    except getopt.error as msg:
        usage(1, msg)

    for opt, arg in opts:
        if opt in ('-h', '--help'):
            usage(0)
        elif opt in ('-i', '--install'):
            update = 1
        elif opt in ('-l', '--local'):
            update = 1
            local = 1
        elif opt in ('-u', '--user'):
            username = arg
        elif opt in ('-q', '--quiet'):
            verbose = 0
        elif opt in ('-b', '--browse'):
            browse = 1

    if args:
        pep_list = []
        html = []
        for pep in args:
            file = find_pep(pep)
            pep_list.append(file)
            newfile = make_html(file, verbose=verbose)
            if newfile:
                html.append(newfile)
                if browse and not update:
                    browse_file(pep)
    else:
        # do them all
        pep_list = []
        html = []
        files = glob.glob("pep-*.txt") + glob.glob("pep-*.rst")
        files.sort()
        for file in files:
            pep_list.append(file)
            newfile = make_html(file, verbose=verbose)
            if newfile:
                html.append(newfile)
        if browse and not update:
            browse_file("0")

    if update:
        push_pep(html, pep_list, username, verbose, local=local)
        if browse:
            if args:
                for pep in args:
                    browse_remote(pep)
            else:
                browse_remote("0")



if __name__ == "__main__":
    main()
