def _makeintro(repo, sender, patches, **opts):
    """make an introduction email, asking the user for content if needed

    email is returned as (subject, body, cumulative-diffstat)"""
    ui = repo.ui
    _charsets = mail._charsets(ui)
    tlen = len(str(len(patches)))

    flag = opts.get('flag') or ''
    if flag:
        flag = ' ' + ' '.join(flag)
    prefix = '[PATCH %0*d of %d%s]' % (tlen, 0, len(patches), flag)

    subj = (opts.get('subject') or
            prompt(ui, '(optional) Subject: ', rest=prefix, default=''))
    if not subj:
        return None         # skip intro if the user doesn't bother

    subj = prefix + ' ' + subj

    body = ''
    if opts.get('diffstat'):
        # generate a cumulative diffstat of the whole patch series
        diffstat = patch.diffstat(sum(patches, []))
        body = '\n' + diffstat
    else:
        diffstat = None

    body = _getdescription(repo, body, sender, **opts)
    msg = mail.mimeencode(ui, body, _charsets, opts.get('test'))
    msg['Subject'] = mail.headencode(ui, subj, _charsets,
                                     opts.get('test'))
    return (msg, subj, diffstat)

    def makeintro(patches):
        tlen = len(str(len(patches)))

        flag = opts.get('flag') or ''
        if flag:
            flag = ' ' + ' '.join(flag)
        prefix = '[PATCH %0*d of %d%s]' % (tlen, 0, len(patches), flag)

        subj = (opts.get('subject') or
                prompt(ui, 'Subject: ', rest=prefix, default=''))
        if not subj:
            return None         # skip intro if the user doesn't bother

        subj = prefix + ' ' + subj

        body = ''
        if opts.get('diffstat'):
            # generate a cumulative diffstat of the whole patch series
            diffstat = patch.diffstat(sum(patches, []))
            body = '\n' + diffstat
        else:
            diffstat = None

        body = getdescription(body, sender)
        msg = mail.mimeencode(ui, body, _charsets, opts.get('test'))
        msg['Subject'] = mail.headencode(ui, subj, _charsets,
                                         opts.get('test'))
        return (msg, subj, diffstat)

    def diff(self, ctx, ref=None):

        maxdiff = int(self.ui.config('notify', 'maxdiff', 300))
        prev = ctx.p1().node()
        if ref:
            ref = ref.node()
        else:
            ref = ctx.node()
        chunks = patch.diff(self.repo, prev, ref,
                            opts=patch.diffallopts(self.ui))
        difflines = ''.join(chunks).splitlines()

        if self.ui.configbool('notify', 'diffstat', True):
            s = patch.diffstat(difflines)
            # s may be nil, don't include the header if it is
            if s:
                self.ui.write('\ndiffstat:\n\n%s' % s)

        if maxdiff == 0:
            return
        elif maxdiff > 0 and len(difflines) > maxdiff:
            msg = _('\ndiffs (truncated from %d to %d lines):\n\n')
            self.ui.write(msg % (len(difflines), maxdiff))
            difflines = difflines[:maxdiff]
        elif difflines:
            self.ui.write(_('\ndiffs (%d lines):\n\n') % len(difflines))

        self.ui.write("\n".join(difflines))

def cdiffstat(ui, summary, patchlines):
    s = patch.diffstat(patchlines)
    if summary:
        ui.write(summary, '\n')
        ui.write(s, '\n')
    ans = prompt(ui, _('does the diffstat above look okay?'), 'y')
    if not ans.lower().startswith('y'):
        raise util.Abort(_('diffstat rejected'))
    return s

 def cdiffstat(summary, patchlines):
     s = patch.diffstat(patchlines)
     if s:
         if summary:
             ui.write(summary, '\n')
             ui.write(s, '\n')
         confirm(_('Does the diffstat above look okay'),
                 _('diffstat rejected'))
     elif s is None:
         ui.warn(_('No diffstat information available.\n'))
         s = ''
     return s

    def diffstat(self):
        class patchbuf(object):
            def __init__(self):
                self.lines = []
                # diffstat is stupid
                self.name = 'cia'
            def write(self, data):
                self.lines.append(data)
            def close(self):
                pass

        n = self.ctx.node()
        pbuf = patchbuf()
        cmdutil.export(self.cia.repo, [n], fp=pbuf)
        return patch.diffstat(pbuf.lines) or ''

    def diffstat(self):
        class patchbuf(object):
            def __init__(self):
                self.lines = []
                # diffstat is stupid
                self.name = "cia"

            def write(self, data):
                self.lines += data.splitlines(True)

            def close(self):
                pass

        n = self.ctx.node()
        pbuf = patchbuf()
        cmdutil.export(self.cia.repo, [n], fp=pbuf)
        return patch.diffstat(pbuf.lines) or ""

def diffstat(ui, repo, **kwargs):
    '''Example usage:

    [hooks]
    commit.diffstat = python:/path/to/this/file.py:diffstat
    changegroup.diffstat = python:/path/to/this/file.py:diffstat
    '''
    if kwargs.get('parent2'):
        return
    node = kwargs['node']
    first = repo[node].p1().node()
    if 'url' in kwargs:
        last = repo['tip'].node()
    else:
        last = node
    diff = patch.diff(repo, first, last)
    ui.write(patch.diffstat(util.iterlines(diff)))

 def diff(self, node, ref):
     maxdiff = int(self.ui.config('notify', 'maxdiff', 300))
     prev = self.repo.changelog.parents(node)[0]
     self.ui.pushbuffer()
     patch.diff(self.repo, prev, ref)
     difflines = self.ui.popbuffer().splitlines(1)
     if self.ui.configbool('notify', 'diffstat', True):
         s = patch.diffstat(difflines)
         # s may be nil, don't include the header if it is
         if s:
             self.ui.write('\ndiffstat:\n\n%s' % s)
     if maxdiff == 0:
         return
     if maxdiff > 0 and len(difflines) > maxdiff:
         self.ui.write(_('\ndiffs (truncated from %d to %d lines):\n\n') %
                       (len(difflines), maxdiff))
         difflines = difflines[:maxdiff]
     elif difflines:
         self.ui.write(_('\ndiffs (%d lines):\n\n') % len(difflines))
     self.ui.write(*difflines)

    def getpatchmsgs(patches, patchnames=None):
        jumbo = []
        msgs = []

        ui.write(_('This patch series consists of %d patches.\n\n')
                 % len(patches))

        name = None
        for i, p in enumerate(patches):
            jumbo.extend(p)
            if patchnames:
                name = patchnames[i]
            msg = makepatch(ui, repo, p, opts, _charsets, i + 1,
                            len(patches), name)
            msgs.append(msg)

        if introneeded(opts, len(patches)):
            tlen = len(str(len(patches)))

            flag = ' '.join(opts.get('flag'))
            if flag:
                subj = '[PATCH %0*d of %d %s]' % (tlen, 0, len(patches), flag)
            else:
                subj = '[PATCH %0*d of %d]' % (tlen, 0, len(patches))
            subj += ' ' + (opts.get('subject') or
                           prompt(ui, 'Subject: ', rest=subj))

            body = ''
            ds = patch.diffstat(jumbo)
            if ds and opts.get('diffstat'):
                body = '\n' + ds

            body = getdescription(body, sender)
            msg = mail.mimeencode(ui, body, _charsets, opts.get('test'))
            msg['Subject'] = mail.headencode(ui, subj, _charsets,
                                             opts.get('test'))

            msgs.insert(0, (msg, subj, ds))
        return msgs

def makepatch(ui, repo, patchlines, opts, _charsets, idx, total, numbered,
              patchname=None):

    desc = []
    node = None
    body = ''

    for line in patchlines:
        if line.startswith('#'):
            if line.startswith('# Node ID'):
                node = line.split()[-1]
            continue
        if line.startswith('diff -r') or line.startswith('diff --git'):
            break
        desc.append(line)

    if not patchname and not node:
        raise ValueError

    if opts.get('attach') and not opts.get('body'):
        body = ('\n'.join(desc[1:]).strip() or
                'Patch subject is complete summary.')
        body += '\n\n\n'

    if opts.get('plain'):
        while patchlines and patchlines[0].startswith('# '):
            patchlines.pop(0)
        if patchlines:
            patchlines.pop(0)
        while patchlines and not patchlines[0].strip():
            patchlines.pop(0)

    ds = patch.diffstat(patchlines, git=opts.get('git'))
    if opts.get('diffstat'):
        body += ds + '\n\n'

    addattachment = opts.get('attach') or opts.get('inline')
    if not addattachment or opts.get('body'):
        body += '\n'.join(patchlines)

    if addattachment:
        msg = email.MIMEMultipart.MIMEMultipart()
        if body:
            msg.attach(mail.mimeencode(ui, body, _charsets, opts.get('test')))
        p = mail.mimetextpatch('\n'.join(patchlines), 'x-patch',
                               opts.get('test'))
        binnode = bin(node)
        # if node is mq patch, it will have the patch file's name as a tag
        if not patchname:
            patchtags = [t for t in repo.nodetags(binnode)
                         if t.endswith('.patch') or t.endswith('.diff')]
            if patchtags:
                patchname = patchtags[0]
            elif total > 1:
                patchname = cmdutil.makefilename(repo, '%b-%n.patch',
                                                 binnode, seqno=idx,
                                                 total=total)
            else:
                patchname = cmdutil.makefilename(repo, '%b.patch', binnode)
        disposition = 'inline'
        if opts.get('attach'):
            disposition = 'attachment'
        p['Content-Disposition'] = disposition + '; filename=' + patchname
        msg.attach(p)
    else:
        msg = mail.mimetextpatch(body, display=opts.get('test'))

    flag = ' '.join(opts.get('flag'))
    if flag:
        flag = ' ' + flag

    subj = desc[0].strip().rstrip('. ')
    if not numbered:
        subj = '[PATCH%s] %s' % (flag, opts.get('subject') or subj)
    else:
        tlen = len(str(total))
        subj = '[PATCH %0*d of %d%s] %s' % (tlen, idx, total, flag, subj)
    msg['Subject'] = mail.headencode(ui, subj, _charsets, opts.get('test'))
    msg['X-Mercurial-Node'] = node
    msg['X-Mercurial-Series-Index'] = '%i' % idx
    msg['X-Mercurial-Series-Total'] = '%i' % total
    return msg, subj, ds

def _incoming(ui, repo, **kwargs):
    # Ensure that no fancying of output is enabled (e.g. coloring)
    os.environ['TERM'] = 'dumb'
    ui.setconfig('ui', 'interactive', 'False')
    ui.setconfig('ui', 'formatted', 'False')
    try:
        colormod = sys.modules['hgext.color']
    except KeyError:
        pass
    else:
        colormod._styles.clear()

    blacklisted = ui.config('mail', 'diff-blacklist', '').split()

    displayer = cmdutil.changeset_printer(ui, repo, False, False, True)
    ctx = repo[kwargs['node']]
    displayer.show(ctx)
    log = displayer.hunk[ctx.rev()]
    user = os.environ.get('HGPUSHER', 'local')
    path = '/'.join(repo.root.split('/')[4:])

    body = []
    #body += ['%s pushed %s to %s:' % (user, str(ctx), path), '']
    body += [CSET_URL % (path, ctx)]
    body += [line for line in log.splitlines()[:-2]
             if line != 'tag:         tip']
    body += ['summary:\n  ' + fromlocal(ctx.description())]
    # ctx.files() gives us misleading info on merges, we use a diffstat instead
    body += ['', 'files:']

    diffopts = patch.diffopts(repo.ui, {'git': True, 'showfunc': True})
    parents = ctx.parents()
    node1 = parents and parents[0].node() or nullid
    node2 = ctx.node()
    diffchunks = list(patch.diff(repo, node1, node2, opts=diffopts))
    diffstat = patch.diffstat(iterlines(diffchunks), width=60, git=True)
    for line in iterlines([''.join(diffstat)]):
        body.append(' ' + line)
    body += ['', '']
    diffchunks = strip_bin_diffs(diffchunks)
    diffchunks = strip_blacklisted_files(diffchunks, blacklisted)
    body.append(''.join(chunk for chunk in diffchunks))

    body.append('-- ')
    body.append('Repository URL: %s%s' % (BASE, path))

    to = ui.config('mail', 'notify', None)
    if to is None:
        print 'no email address configured'
        return False
    from_ = ui.config('mail', 'sender', None)
    if from_ is None:
        from_ = to
    sender = '%s <%s>' % (user, from_)

    prefixes = [path]

    if len(parents) == 2:
        b1, b2, b = parents[0].branch(), parents[1].branch(), ctx.branch()
        if b in (b1, b2):
            bp = b2 if b == b1 else b1
            # normal case
            prefixes.append('(merge %s -> %s)' % (bp, b))
        else:
            # XXX really??
            prefixes.append('(merge %s + %s -> %s)' % (b1, b2, b))
    else:
        branch = ctx.branch()
        if branch != 'default':
            prefixes.append('(%s)' % branch)

    desc = ctx.description().splitlines()[0]
    if len(desc) > 80:
        desc = desc[:80]
        if ' ' in desc:
            desc = desc.rsplit(' ', 1)[0]

    if prefixes:
        prefixes = ' '.join(prefixes) + ': '
    else:
        prefixes = ''

    subj = prefixes + desc

    host = ui.config('smtp', 'host', '')
    port = int(ui.config('smtp', 'port', 0))
    smtp = smtplib.SMTP(host, port)
    username = ui.config('smtp', 'username', '')
    if username:
        smtp.login(username, ui.config('smtp', 'password', ''))
    send(smtp, subj, sender, to, '\n'.join(body) + '\n')
    smtp.close()

    ui.status('notified %s of incoming changeset %s\n' % (to, ctx))
    return False

def showdiffstat(repo, ctx, templ, **args):
    """String. Return diffstat-style summary of changes."""
    width = repo.ui.termwidth()
    return patch.diffstat(util.iterlines(ctx.diff(noprefix=False)), width=width)