#!/usr/bin/env python3

"""
a2x - A toolchain manager for AsciiDoc (converts Asciidoc text files to other
      file formats)

Please note, the a2x was originally licensed under the MIT license. Any changes
on or after 12/31/2021 are licensed under the GPLv2+. See below for licenses, and
due to sub-licensing, this file MUST carry both licenses unless all MIT code has
been rewritten.

-----

Copyright (C) 2021-2022 AsciiDoc Contributors.

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 2 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.

----

Free use of this software is granted under the terms of the MIT license.

Copyright (C) 2002-2013 Stuart Rackham.
Copyright (C) 2013-2022 AsciiDoc Contributors.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
"""

# Please note, the contents of this module are considered "private" and may
# change within the 10.0+ releases. If you come to depend on a specific method
# or class, please leave a GitHub issue stating as much.

import io
import os
import fnmatch
from html.parser import HTMLParser
import re
import shutil
import subprocess
import sys
import traceback
from typing import List, NoReturn, Tuple, Union
from urllib.parse import urlparse
import zipfile
import xml.dom.minidom
import mimetypes

from . import asciidoc
from .collections import DefaultAttrDict as AttrDict

CONF_DIR = os.path.join(os.path.dirname(__file__), 'resources')
METADATA = {}
with open(os.path.join(os.path.dirname(__file__), '__metadata__.py')) as f:
    exec(f.read(), METADATA)
VERSION = METADATA['__version__']

PROG = os.path.basename(os.path.splitext(__file__)[0])


######################################################################
# Default configuration file parameters.
######################################################################

# Optional environment variable dictionary passed to
# executing programs. If set to None the existing
# environment is used.
ENV = None

# External executables.
ASCIIDOC = 'asciidoc'
XSLTPROC = 'xsltproc'
DBLATEX = 'dblatex'         # pdf generation.
FOP = 'fop'                 # pdf generation (--fop option).
W3M = 'w3m'                 # primary text file generator.
LYNX = 'lynx'               # alternate text file generator.
XMLLINT = 'xmllint'         # Set to '' to disable.
EPUBCHECK = 'epubcheck'     # Set to '' to disable.
# External executable default options.
ASCIIDOC_OPTS = []
BACKEND_OPTS = ''
DBLATEX_OPTS = ''
FOP_OPTS = ''
LYNX_OPTS = '-dump'
W3M_OPTS = '-dump -cols 70 -T text/html -no-graph'
XSLTPROC_OPTS = ''

######################################################################
# End of configuration file parameters.
######################################################################


#####################################################################
# Utility functions
#####################################################################

OPTIONS = None  # These functions read verbose and dry_run command options.


def errmsg(msg: str) -> None:
    print('%s: %s\n' % (PROG, msg), file=sys.stderr)


def warning(msg: str) -> None:
    errmsg('WARNING: %s' % msg)


def infomsg(msg: str) -> None:
    print('%s: %s' % (PROG, msg))


def die(msg: str, exit_code: int = 1) -> NoReturn:
    errmsg('ERROR: %s' % msg)
    sys.exit(exit_code)


def trace() -> None:
    """Print traceback to stderr."""
    errmsg('-'*60)
    traceback.print_exc(file=sys.stderr)
    errmsg('-'*60)


def verbose(msg: str) -> None:
    if OPTIONS.verbose or OPTIONS.dry_run:
        infomsg(msg)


def flatten(array: Union[List, Tuple]) -> List:
    ret = []
    for x in array:
        if isinstance(x, (list, tuple)):
            ret += x
        else:
            ret.append(x)
    return ret


def isexecutable(file_name: str) -> bool:
    return os.path.isfile(file_name) and os.access(file_name, os.X_OK)


def find_executable(file_name):
    '''
    Search for executable file_name in the system PATH.
    Return full path name or None if not found.
    '''
    def _find_executable(file_name):
        if os.path.split(file_name)[0] != '':
            # file_name includes directory so don't search path.
            if not isexecutable(file_name):
                return None
            else:
                return file_name
        for p in os.environ.get('PATH', os.defpath).split(os.pathsep):
            f = os.path.join(p, file_name)
            if isexecutable(f):
                return os.path.realpath(f)
        return None
    if os.name == 'nt' and os.path.splitext(file_name)[1] == '':
        for ext in ('.cmd', '.bat', '.exe'):
            result = _find_executable(file_name + ext)
            if result:
                break
    else:
        result = _find_executable(file_name)
    return result


def write_file(filename, data, mode='w', encoding='utf-8'):
    with open(filename, mode=mode, encoding=encoding) as f:
        f.write(data)


def read_file(filename, mode='r', encoding='utf-8'):
    with open(filename, mode=mode, encoding=encoding) as f:
        return f.read()


def shell_cd(path):
    verbose('chdir %s' % path)
    if not OPTIONS.dry_run:
        os.chdir(path)


def shell_makedirs(path):
    if os.path.isdir(path):
        return
    verbose('creating %s' % path)
    if not OPTIONS.dry_run:
        os.makedirs(path)


def shell_copy(src, dst):
    verbose('copying "%s" to "%s"' % (src, dst))
    if not OPTIONS.dry_run:
        shutil.copy(src, dst)


def shell_rm(path):
    if not os.path.exists(path):
        return
    verbose('deleting %s' % path)
    if not OPTIONS.dry_run:
        os.unlink(path)


def shell_rmtree(path):
    if not os.path.isdir(path):
        return
    verbose('deleting %s' % path)
    if not OPTIONS.dry_run:
        shutil.rmtree(path)


def shell(cmd, raise_error=True):
    '''
    Execute command cmd in shell and return tuple
    (stdoutdata, stderrdata, returncode).
    If raise_error is True then a non-zero return terminates the application.
    '''
    if os.name == 'nt':
        # TODO: this is probably unnecessary, see:
        # http://groups.google.com/group/asciidoc/browse_frm/thread/9442ee0c419f1242
        # Windows doesn't like running scripts directly so explicitly
        # specify python interpreter.
        # Extract first (quoted or unquoted) argument.
        mo = re.match(r'^\s*"\s*(?P<arg0>[^"]+)\s*"', cmd)
        if not mo:
            mo = re.match(r'^\s*(?P<arg0>[^ ]+)', cmd)
        if mo.group('arg0').endswith('.py'):
            cmd = 'python ' + cmd
        # Remove redundant quoting -- this is not just cosmetic,
        # quoting seems to dramatically decrease the allowed command
        # length in Windows XP.
        cmd = re.sub(r'"([^ ]+?)"', r'\1', cmd)
    verbose('executing: %s' % cmd)
    if OPTIONS.dry_run:
        return
    stdout = stderr = subprocess.PIPE
    try:
        popen = subprocess.Popen(cmd, stdout=stdout, stderr=stderr,
                                 shell=True, env=ENV, universal_newlines=True)
    except OSError as e:
        die('failed: %s: %s' % (cmd, e))
    stdoutdata, stderrdata = popen.communicate()
    if OPTIONS.verbose:
        print(stdoutdata)
        print(stderrdata)
    if popen.returncode != 0 and raise_error:
        die('%s returned non-zero exit status %d' % (cmd, popen.returncode))
    return (stdoutdata, stderrdata, popen.returncode)


def get_encoding(string: bytes) -> str:
    """
    Given a byte representation of a XML or HTML document, find and return the encoding set
    as an attribute, or return utf-8 if none could be found.
    """
    mo = re.search(br'^<\?xml.* encoding="(.*?)"', string)
    if mo is None:
        mo = re.search(br'<meta http\-equiv="Content\-Type" content="text\/html; charset=(.*?)">', string)
    return mo.group(1).decode('utf-8') if mo else 'utf-8'


def find_resources(files, tagname, attrname, filter=None):
    '''
    Search all files and return a list of local URIs from attrname attribute
    values in tagname tags.
    Handles HTML open and XHTML closed tags.
    Non-local URIs are skipped.
    files can be a file name or a list of file names.
    The filter function takes a dictionary of tag attributes and returns True
    if the URI is to be included.
    '''
    class FindResources(HTMLParser):
        # Nested parser class shares locals with enclosing function.
        def handle_startendtag(self, tag, attrs):
            self.handle_starttag(tag, attrs)

        def handle_starttag(self, tag, attrs):
            attrs = dict(attrs)
            if tag == tagname and (filter is None or filter(attrs)):
                # Accept only local URIs.
                uri = urlparse(attrs[attrname])
                if uri[0] in ('', 'file') and not uri[1] and uri[2]:
                    result.append(uri[2])

    if isinstance(files, str):
        files = [files]
    result = []
    for filename in files:
        verbose('finding resources in: %s' % filename)
        if OPTIONS.dry_run:
            continue
        parser = FindResources()
        with open(filename, 'rb') as open_file:
            contents = open_file.read()
        contents = contents.decode(get_encoding(contents))
        parser.feed(contents)
        parser.close()
    result = list(set(result))   # Drop duplicate values.
    result.sort()
    return result


def find_files(path, pattern):
    '''
    Return list of file names matching pattern in directory path.
    '''
    result = []
    for (p, dirs, files) in os.walk(path):
        for f in files:
            if fnmatch.fnmatch(f, pattern):
                result.append(os.path.normpath(os.path.join(p, f)))
    return result


def exec_xsltproc(xsl_file, xml_file, dst_dir, opts=''):
    cwd = os.getcwd()
    shell_cd(dst_dir)
    try:
        shell('"%s" %s "%s" "%s"' % (XSLTPROC, opts, xsl_file, xml_file))
    finally:
        shell_cd(cwd)


def get_source_options(asciidoc_file: str) -> List[str]:
    '''
    Look for a2x command options in AsciiDoc source file.
    Limitation: options cannot contain double-quote characters.
    '''
    result = []

    if not os.path.isfile(asciidoc_file):
        return result

    options = ''
    with open(asciidoc_file, 'rb') as f:
        line_number = 0
        for line in f:
            line_number += 1
            mo = re.search(br'^//\s*a2x:', line)
            if mo:
                try:
                    options += ' ' + line[mo.end():].strip().decode('ascii')
                except UnicodeDecodeError as e:
                    warning(
                        "Could not decode option to %s " % e.encoding +
                        "on line %s in %s" % (line_number, asciidoc_file)
                    )

    # Parse options to result sequence.
    inquotes = False
    opt = ''
    for c in options:
        if c == '"':
            if inquotes:
                result.append(opt)
                opt = ''
                inquotes = False
            else:
                inquotes = True
        elif c == ' ':
            if inquotes:
                opt += c
            elif opt:
                result.append(opt)
                opt = ''
        else:
            opt += c
    if opt:
        result.append(opt)

    return result


#####################################################################
# Application class
#####################################################################

class A2X(AttrDict):
    '''
    a2x options and conversion functions.
    '''

    def execute(self):
        '''
        Process a2x command.
        '''
        self.process_options()
        # Append configuration file options.
        self.asciidoc_opts += ASCIIDOC_OPTS
        self.dblatex_opts += ' ' + DBLATEX_OPTS
        self.fop_opts += ' ' + FOP_OPTS
        self.xsltproc_opts += ' ' + XSLTPROC_OPTS
        self.backend_opts += ' ' + BACKEND_OPTS
        # Execute to_* functions.
        if self.backend:
            self.to_backend()
        else:
            self.__getattribute__('to_'+self.format)()
        if not (self.keep_artifacts or self.format == 'docbook' or self.skip_asciidoc):
            shell_rm(self.dst_path('.xml'))

    def load_conf(self):
        '''
        Load a2x configuration file from default locations and --conf-file
        option.
        '''
        CONF_FILE = 'a2x.conf'
        a2xdir = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'resources')
        conf_files = []
        # From a2x.py directory.
        conf_files.append(os.path.join(a2xdir, CONF_FILE))
        # If the asciidoc executable and conf files are in the a2x directory
        # then use the local copy of asciidoc and skip the global a2x conf.
        asciidoc_conf = os.path.join(a2xdir, 'asciidoc.conf')

        # TODO: CONF_DIR work
        # From global conf directory.
        # conf_files.append(os.path.join(CONF_DIR, CONF_FILE))

        # From $HOME directory.
        home_dir = os.environ.get('HOME')
        if home_dir is not None:
            conf_files.append(os.path.join(home_dir, '.asciidoc', CONF_FILE))

        # From backend plugin directory.
        if self.backend is not None:
            outfile = io.StringIO()
            asciidoc.execute('asciidoc', [('--backend', 'list'), ('--out-file', outfile)], [])
            backends = [(i, os.path.split(i)[1]) for i in outfile.getvalue().splitlines()]
            backend_dir = [i[0] for i in backends if i[1] == self.backend]
            if len(backend_dir) == 0:
                die('missing %s backend' % self.backend)
            if len(backend_dir) > 1:
                die('more than one %s backend' % self.backend)
            verbose('found %s backend directory: %s' %
                    (self.backend, backend_dir[0]))
            conf_files.append(os.path.join(backend_dir[0], 'a2x-backend.py'))
        # From --conf-file option.
        if self.conf_file is not None:
            if not os.path.isfile(self.conf_file):
                die('missing configuration file: %s' % self.conf_file)
            conf_files.append(self.conf_file)
        # From --xsl-file option.
        if self.xsl_file is not None:
            if not os.path.isfile(self.xsl_file):
                die('missing XSL file: %s' % self.xsl_file)
            self.xsl_file = os.path.abspath(self.xsl_file)
        # Load ordered files.
        for f in conf_files:
            if os.path.isfile(f):
                verbose('loading configuration file: %s' % f)
                exec(open(f).read(), globals())

    def process_options(self):
        '''
        Validate and command options and set defaults.
        '''
        if not os.path.isfile(self.asciidoc_file):
            die('missing ASCIIDOC_FILE: %s' % self.asciidoc_file)
        self.asciidoc_file = os.path.abspath(self.asciidoc_file)
        if os.path.splitext(self.asciidoc_file)[1].lower() == '.xml':
            self.skip_asciidoc = True
        else:
            self.skip_asciidoc = False
        if not self.destination_dir:
            self.destination_dir = os.path.dirname(self.asciidoc_file)
        else:
            if not os.path.isdir(self.destination_dir):
                die('missing --destination-dir: %s' % self.destination_dir)
            self.destination_dir = os.path.abspath(self.destination_dir)
            if self.format not in ('chunked', 'epub', 'htmlhelp', 'xhtml', 'manpage'):
                warning('--destination-dir option is only applicable to HTML and manpage based outputs')
        self.resource_dirs = []
        self.resource_files = []
        if self.resource_manifest:
            if not os.path.isfile(self.resource_manifest):
                die('missing --resource-manifest: %s' % self.resource_manifest)
            with open(self.resource_manifest) as f:
                for r in f:
                    self.resources.append(r.strip())
        for r in self.resources:
            r = os.path.expanduser(r)
            r = os.path.expandvars(r)
            if r.endswith('/') or r.endswith('\\'):
                if os.path.isdir(r):
                    self.resource_dirs.append(r)
                else:
                    die('missing resource directory: %s' % r)
            elif os.path.isdir(r):
                self.resource_dirs.append(r)
            elif r.startswith('.') and '=' in r:
                ext, mimetype = r.split('=')
                mimetypes.add_type(mimetype, ext)
            else:
                self.resource_files.append(r)
        for d in ('images', 'stylesheets'):
            d = os.path.join(CONF_DIR, d)
            if os.path.isdir(d):
                self.resource_dirs.append(d)
        verbose('resource files: %s' % self.resource_files)
        verbose('resource directories: %s' % self.resource_dirs)
        if not self.doctype and self.format == 'manpage':
            self.doctype = 'manpage'
        if self.doctype:
            self.asciidoc_opts.append(('--doctype', self.doctype))
        for attr in self.attributes:
            self.asciidoc_opts.append(('--attribute', attr))
#        self.xsltproc_opts += ' --nonet'
        if self.verbose:
            self.asciidoc_opts.append(('--verbose',))
            self.dblatex_opts += ' -V'
        if self.icons or self.icons_dir:
            params = [
                'callout.graphics 1',
                'navig.graphics 1',
                'admon.textlabel 0',
                'admon.graphics 1',
            ]
            if self.icons_dir:
                params += [
                    'admon.graphics.path "%s/"' % self.icons_dir,
                    'callout.graphics.path "%s/callouts/"' % self.icons_dir,
                    'navig.graphics.path "%s/"' % self.icons_dir,
                ]
        else:
            params = [
                'callout.graphics 0',
                'navig.graphics 0',
                'admon.textlabel 1',
                'admon.graphics 0',
            ]
        if self.stylesheet:
            params += ['html.stylesheet "%s"' % self.stylesheet]
        if self.format == 'htmlhelp':
            params += ['htmlhelp.chm "%s"' % self.basename('.chm'),
                       'htmlhelp.hhp "%s"' % self.basename('.hhp'),
                       'htmlhelp.hhk "%s"' % self.basename('.hhk'),
                       'htmlhelp.hhc "%s"' % self.basename('.hhc')]
        if self.doctype == 'book':
            params += ['toc.section.depth 1']
            # Books are chunked at chapter level.
            params += ['chunk.section.depth 0']
        for o in params:
            if o.split()[0]+' ' not in self.xsltproc_opts:
                self.xsltproc_opts += ' --stringparam ' + o
        if self.fop_opts:
            self.fop = True

    def dst_path(self, ext):
        '''
        Return name of file or directory in the destination directory with
        the same name as the asciidoc source file but with extension ext.
        '''
        return os.path.join(self.destination_dir, self.basename(ext))

    def basename(self, ext):
        '''
        Return the base name of the asciidoc source file but with extension
        ext.
        '''
        return os.path.basename(os.path.splitext(self.asciidoc_file)[0]) + ext

    @staticmethod
    def asciidoc_conf_file(path):
        '''
        Return full path name of file in asciidoc configuration files directory.
        Search first the directory containing the asciidoc executable then
        the global configuration file directory.
        '''
        f = os.path.join(CONF_DIR, path)
        if not os.path.isfile(f):
            die('missing configuration file: %s' % f)
        return os.path.normpath(f)

    def xsl_stylesheet(self, file_name=None):
        '''
        Return full path name of file in asciidoc docbook-xsl configuration
        directory.
        If an XSL file was specified with the --xsl-file option then it is
        returned.
        '''
        if self.xsl_file is not None:
            return self.xsl_file
        if not file_name:
            file_name = self.format + '.xsl'
        return self.asciidoc_conf_file(os.path.join('docbook-xsl', file_name))

    def copy_resources(self, html_files, src_dir, dst_dir, resources=[]):
        '''
        Search html_files for images and CSS resource URIs (html_files can
        be a list of file names or a single file name).
        Copy them from the src_dir to the dst_dir.
        If not found in src_dir then recursively search all specified
        resource directories.
        Optional additional resources files can be passed in the resources
        list.
        '''
        resources = resources[:]
        resources += find_resources(
            html_files,
            'link',
            'href',
            lambda attrs: attrs.get('type') == 'text/css'
        )
        resources += find_resources(html_files, 'img', 'src')
        resources += self.resource_files
        resources = list(set(resources))    # Drop duplicates.
        resources.sort()
        for f in resources:
            if '=' in f:
                src, dst = f.split('=')
                if not dst:
                    dst = src
            else:
                src = dst = f
            src = os.path.normpath(src)
            dst = os.path.normpath(dst)
            if os.path.isabs(dst):
                die('absolute resource file name: %s' % dst)
            if dst.startswith(os.pardir):
                die('resource file outside destination directory: %s' % dst)
            src = os.path.join(src_dir, src)
            dst = os.path.join(dst_dir, dst)
            if not os.path.isfile(src):
                for d in self.resource_dirs:
                    d = os.path.join(src_dir, d)
                    found = find_files(d, os.path.basename(src))
                    if found:
                        src = found[0]
                        break
                else:
                    if not os.path.isfile(dst):
                        die('missing resource: %s' % src)
                    continue
            # Arrive here if resource file has been found.
            if os.path.normpath(src) != os.path.normpath(dst):
                dstdir = os.path.dirname(dst)
                shell_makedirs(dstdir)
                shell_copy(src, dst)

    def to_backend(self):
        '''
        Convert AsciiDoc source file to a backend output file using the global
        'to_<backend name>' function (loaded from backend plugin a2x-backend.py
        file).
        Executes the global function in an A2X class instance context.
        '''
        eval('to_%s(self)' % self.backend)

    def to_docbook(self):
        '''
        Use asciidoc to convert asciidoc_file to DocBook.
        args is a string containing additional asciidoc arguments.
        '''
        docbook_file = self.dst_path('.xml')
        if self.skip_asciidoc:
            if not os.path.isfile(docbook_file):
                die('missing docbook file: %s' % docbook_file)
            return
        options = self.asciidoc_opts[:]
        options.append(('--backend', 'docbook'))
        options.append(('-a', 'a2x-format=%s' % self.format))
        options.append(('--out-file', docbook_file))

        verbose("executing: asciidoc {}".format(options))

        asciidoc.cli(flatten(['asciidoc'] + options + [self.asciidoc_file]))
        if not self.no_xmllint and XMLLINT:
            xmllint_options = ['--nonet', '--noout', '--valid']
            if 'SGML_CATALOG_FILES' in os.environ:
                xmllint_options.append('--catalogs')
            shell('"%s" %s "%s"' % (XMLLINT, " ".join(xmllint_options), docbook_file))

    def to_xhtml(self):
        self.to_docbook()
        docbook_file = self.dst_path('.xml')
        xhtml_file = self.dst_path('.html')
        opts = '%s --output "%s"' % (self.xsltproc_opts, xhtml_file)
        exec_xsltproc(self.xsl_stylesheet(), docbook_file, self.destination_dir, opts)
        src_dir = os.path.dirname(self.asciidoc_file)
        self.copy_resources(xhtml_file, src_dir, self.destination_dir)

    def to_manpage(self):
        self.to_docbook()
        docbook_file = self.dst_path('.xml')
        opts = self.xsltproc_opts
        exec_xsltproc(self.xsl_stylesheet(), docbook_file, self.destination_dir, opts)

    def to_pdf(self):
        if self.fop:
            self.exec_fop()
        else:
            self.exec_dblatex()

    def exec_fop(self):
        self.to_docbook()
        docbook_file = self.dst_path('.xml')
        xsl = self.xsl_stylesheet('fo.xsl')
        fo = self.dst_path('.fo')
        pdf = self.dst_path('.pdf')
        opts = '%s --output "%s"' % (self.xsltproc_opts, fo)
        exec_xsltproc(xsl, docbook_file, self.destination_dir, opts)
        shell('"%s" %s -fo "%s" -pdf "%s"' % (FOP, self.fop_opts, fo, pdf))
        if not self.keep_artifacts:
            shell_rm(fo)

    def exec_dblatex(self):
        self.to_docbook()
        docbook_file = self.dst_path('.xml')
        xsl = self.asciidoc_conf_file(os.path.join('dblatex','asciidoc-dblatex.xsl'))
        sty = self.asciidoc_conf_file(os.path.join('dblatex','asciidoc-dblatex.sty'))
        shell('"%s" -t %s -p "%s" -s "%s" %s "%s"' %
             (DBLATEX, self.format, xsl, sty, self.dblatex_opts, docbook_file))

    def to_dvi(self):
        self.exec_dblatex()

    def to_ps(self):
        self.exec_dblatex()

    def to_tex(self):
        self.exec_dblatex()

    def to_htmlhelp(self):
        self.to_chunked()

    def to_chunked(self):
        self.to_docbook()
        docbook_file = self.dst_path('.xml')
        opts = self.xsltproc_opts
        xsl_file = self.xsl_stylesheet()
        if self.format == 'chunked':
            dst_dir = self.dst_path('.chunked')
        elif self.format == 'htmlhelp':
            dst_dir = self.dst_path('.htmlhelp')
        if 'base.dir ' not in opts:
            opts += ' --stringparam base.dir "%s/"' % os.path.basename(dst_dir)
        # Create content.
        shell_rmtree(dst_dir)
        shell_makedirs(dst_dir)
        exec_xsltproc(xsl_file, docbook_file, self.destination_dir, opts)
        html_files = find_files(dst_dir, '*.html')
        src_dir = os.path.dirname(self.asciidoc_file)
        self.copy_resources(html_files, src_dir, dst_dir)

    def update_epub_manifest(self, opf_file):
        '''
        Scan the OEBPS directory for any files that have not been registered in
        the OPF manifest then add them to the manifest.
        '''
        opf_dir = os.path.dirname(opf_file)
        resource_files = []
        for (p, dirs, files) in os.walk(os.path.dirname(opf_file)):
            for f in files:
                f = os.path.join(p, f)
                if os.path.isfile(f):
                    assert f.startswith(opf_dir)
                    f = '.' + f[len(opf_dir):]
                    f = os.path.normpath(f)
                    if f not in ['content.opf']:
                        resource_files.append(f)
        opf = xml.dom.minidom.parseString(read_file(opf_file))
        manifest_files = []
        manifest = opf.getElementsByTagName('manifest')[0]
        for el in manifest.getElementsByTagName('item'):
            f = el.getAttribute('href')
            f = os.path.normpath(f)
            manifest_files.append(f)
        count = 0
        for f in resource_files:
            if f not in manifest_files:
                count += 1
                verbose('adding to manifest: %s' % f)
                item = opf.createElement('item')
                item.setAttribute('href', f.replace(os.path.sep, '/'))
                item.setAttribute('id', 'a2x-%d' % count)
                mimetype = mimetypes.guess_type(f)[0]
                if mimetype is None:
                    die('unknown mimetype: %s' % f)
                item.setAttribute('media-type', mimetype)
                manifest.appendChild(item)
        if count > 0:
            write_file(opf_file, opf.toxml())

    def to_epub(self):
        self.to_docbook()
        xsl_file = self.xsl_stylesheet()
        docbook_file = self.dst_path('.xml')
        epub_file = self.dst_path('.epub')
        build_dir = epub_file + '.d'
        shell_rmtree(build_dir)
        shell_makedirs(build_dir)
        # Create content.
        exec_xsltproc(xsl_file, docbook_file, build_dir, self.xsltproc_opts)
        # Copy resources referenced in the OPF and resources referenced by the
        # generated HTML (in theory DocBook XSL should ensure they are
        # identical but this is not always the case).
        src_dir = os.path.dirname(self.asciidoc_file)
        dst_dir = os.path.join(build_dir, 'OEBPS')
        opf_file = os.path.join(dst_dir, 'content.opf')
        opf_resources = find_resources(opf_file, 'item', 'href')
        html_files = find_files(dst_dir, '*.html')
        self.copy_resources(html_files, src_dir, dst_dir, opf_resources)
        # Register any unregistered resources.
        self.update_epub_manifest(opf_file)
        # Build epub archive.
        cwd = os.getcwd()
        shell_cd(build_dir)
        try:
            if not self.dry_run:
                zip_archive = zipfile.ZipFile(epub_file, 'w')
                try:
                    # Create and add uncompressed mimetype file.
                    verbose('archiving: mimetype')
                    write_file('mimetype', 'application/epub+zip')
                    zip_archive.write('mimetype', compress_type=zipfile.ZIP_STORED)
                    # Compress all remaining files.
                    for (p, dirs, files) in os.walk('.'):
                        for f in files:
                            f = os.path.normpath(os.path.join(p,f))
                            if f != 'mimetype':
                                verbose('archiving: %s' % f)
                                zip_archive.write(f, compress_type=zipfile.ZIP_DEFLATED)
                finally:
                    zip_archive.close()
            verbose('created archive: %s' % epub_file)
        finally:
            shell_cd(cwd)
        if not self.keep_artifacts:
            shell_rmtree(build_dir)
        if self.epubcheck and EPUBCHECK:
            if not find_executable(EPUBCHECK):
                warning('epubcheck skipped: unable to find executable: %s' % EPUBCHECK)
            else:
                shell('"%s" "%s"' % (EPUBCHECK, epub_file))

    def to_text(self):
        text_file = self.dst_path('.text')
        html_file = self.dst_path('.text.html')
        if self.lynx:
            options = self.asciidoc_opts[:]
            options.append(('--conf-file', self.asciidoc_conf_file('text.conf')))
            options.append(('-b', 'html4'))
            options.append(('-a', 'a2x-format=%s' % self.format))
            options.append(('-o', html_file))
            asciidoc.cli(flatten(['asciidoc'] + options + [self.asciidoc_file]))
            cmd = '"%s" %s "%s" > "%s"' % (LYNX, LYNX_OPTS, html_file, text_file)
            shell(cmd)
        else:
            # Use w3m(1).
            self.to_docbook()
            docbook_file = self.dst_path('.xml')
            opts = '%s --output "%s"' % (self.xsltproc_opts, html_file)
            exec_xsltproc(self.xsl_stylesheet(), docbook_file,
                    self.destination_dir, opts)
            cmd = '"%s" %s "%s" > "%s"' % (W3M, W3M_OPTS, html_file, text_file)
            shell(cmd)
        if not self.keep_artifacts:
            shell_rm(html_file)


def parse_args(argv):
    description = '''A toolchain manager for AsciiDoc (converts Asciidoc text files to other file formats)'''
    from optparse import OptionParser
    import shlex
    parser = OptionParser(usage='usage: %prog [OPTIONS] SOURCE_FILE',
        version='%s %s' % (PROG,VERSION),
        description=description)
    parser.add_option('-a', '--attribute',
        action='append', dest='attributes', default=[], metavar='ATTRIBUTE',
        help='set asciidoc attribute value')
    parser.add_option('--asciidoc-opts',
        action='append', dest='asciidoc_opts', default=[],
        metavar='ASCIIDOC_OPTS', help='asciidoc options')
    #DEPRECATED
    parser.add_option('--copy',
        action='store_true', dest='copy', default=False,
        help='DEPRECATED: does nothing')
    parser.add_option('--conf-file',
        dest='conf_file', default=None, metavar='CONF_FILE',
        help='configuration file')
    parser.add_option('-D', '--destination-dir',
        action='store', dest='destination_dir', default=None, metavar='PATH',
        help='output directory (defaults to SOURCE_FILE directory)')
    parser.add_option('-d','--doctype',
        action='store', dest='doctype', metavar='DOCTYPE',
        choices=('article','manpage','book'),
        help='article, manpage, book')
    parser.add_option('-b','--backend',
        action='store', dest='backend', metavar='BACKEND',
        help='name of backend plugin')
    parser.add_option('--epubcheck',
        action='store_true', dest='epubcheck', default=False,
        help='check EPUB output with epubcheck')
    parser.add_option('-f','--format',
        action='store', dest='format', metavar='FORMAT', default = 'pdf',
        choices=('chunked','epub','htmlhelp','manpage','pdf', 'text',
                 'xhtml','dvi','ps','tex','docbook'),
        help='chunked, epub, htmlhelp, manpage, pdf, text, xhtml, dvi, ps, tex, docbook')
    parser.add_option('--icons',
        action='store_true', dest='icons', default=False,
        help='use admonition, callout and navigation icons')
    parser.add_option('--icons-dir',
        action='store', dest='icons_dir',
        default=None, metavar='PATH',
        help='admonition and navigation icon directory')
    parser.add_option('-k', '--keep-artifacts',
        action='store_true', dest='keep_artifacts', default=False,
        help='do not delete temporary build files')
    parser.add_option('--lynx',
        action='store_true', dest='lynx', default=False,
        help='use lynx to generate text files')
    parser.add_option('-L', '--no-xmllint',
        action='store_true', dest='no_xmllint', default=False,
        help='do not check asciidoc output with xmllint')
    parser.add_option('-n','--dry-run',
        action='store_true', dest='dry_run', default=False,
        help='just print the commands that would have been executed')
    parser.add_option('-r','--resource',
        action='append', dest='resources', default=[],
        metavar='PATH',
        help='resource file or directory containing resource files')
    parser.add_option('-m', '--resource-manifest',
        action='store', dest='resource_manifest', default=None, metavar='FILE',
        help='read resources from FILE')
    #DEPRECATED
    parser.add_option('--resource-dir',
        action='append', dest='resources', default=[],
        metavar='PATH',
        help='DEPRECATED: use --resource')
    #DEPRECATED
    parser.add_option('-s','--skip-asciidoc',
        action='store_true', dest='skip_asciidoc', default=False,
        help='DEPRECATED: redundant')
    parser.add_option('--stylesheet',
        action='store', dest='stylesheet', default=None,
        metavar='STYLESHEET',
        help='HTML CSS stylesheet file name')
    #DEPRECATED
    parser.add_option('--safe',
        action='store_true', dest='safe', default=False,
        help='DEPRECATED: does nothing')
    parser.add_option('--dblatex-opts',
        action='append', dest='dblatex_opts', default=[],
        metavar='DBLATEX_OPTS', help='dblatex options')
    parser.add_option('--backend-opts',
        action='append', dest='backend_opts', default=[],
        metavar='BACKEND_OPTS', help='backend plugin options')
    parser.add_option('--fop',
        action='store_true', dest='fop', default=False,
        help='use FOP to generate PDF files')
    parser.add_option('--fop-opts',
        action='append', dest='fop_opts', default=[],
        metavar='FOP_OPTS', help='options for FOP pdf generation')
    parser.add_option('--xsltproc-opts',
        action='append', dest='xsltproc_opts', default=[],
        metavar='XSLTPROC_OPTS', help='xsltproc options for XSL stylesheets')
    parser.add_option('--xsl-file',
        action='store', dest='xsl_file', metavar='XSL_FILE',
        help='custom XSL stylesheet')
    parser.add_option('-v', '--verbose',
        action='count', dest='verbose', default=0,
        help='increase verbosity')
    if len(argv) == 1:
        parser.parse_args(['--help'])
    source_options = get_source_options(argv[-1])
    new_argv = source_options + argv[1:]
    opts, args = parser.parse_args(new_argv)
    if len(args) != 1:
        parser.error('incorrect number of arguments')
    opts.asciidoc_opts = shlex.split(' ' .join(opts.asciidoc_opts))
    opts.dblatex_opts = ' '.join(opts.dblatex_opts)
    opts.fop_opts = ' '.join(opts.fop_opts)
    opts.xsltproc_opts = ' '.join(opts.xsltproc_opts)
    opts.backend_opts = ' '.join(opts.backend_opts)
    return (new_argv, opts, args)


def cli():
    global OPTIONS
    asciidoc.set_caller("__main__")
    argv, opts, args = parse_args(sys.argv)
    opts = eval(str(opts))  # Convert optparse.Values to dict.
    a2x = A2X(opts)
    OPTIONS = a2x           # verbose and dry_run used by utility functions.
    verbose('args: %r' % argv)
    a2x.asciidoc_file = args[0]
    try:
        a2x.load_conf()
        a2x.execute()
    except KeyboardInterrupt:
        sys.exit(1)

#####################################################################
# Script main line.
#####################################################################

if __name__ == "__main__":
    cli()