def group_wiki_pages(request, group):
    """
    List wiki pages in group.
    """
    username = request.user.username
    try:
        repo = get_group_wiki_repo(group, username)
        pages = get_wiki_pages(repo)
    except SearpcError:
        return render_error(request, _('Internal Server Error'))
    except WikiDoesNotExist:
        return render_error(request, _('Wiki does not exists.'))

    if is_registered_user(username):
        repo_perm = seafile_api.check_permission_by_path(repo.id, '/', username)
    else:
        # when anonymous user visit public group wiki, set permission as 'r'
        repo_perm = 'r'

    mods_available = get_available_mods_by_group(group.id)
    mods_enabled = get_enabled_mods_by_group(group.id)

    return render_to_response("group/group_wiki_pages.html", {
            "group": group,
            "pages": pages,
            "is_staff": group.is_staff,
            "repo_id": repo.id,
            "search_repo_id": repo.id,
            "search_wiki": True,
            "repo_perm": repo_perm,
            "mods_enabled": mods_enabled,
            "mods_available": mods_available,
            }, context_instance=RequestContext(request))

def group_wiki_page_new(request, group, page_name="home"):
    if group.view_perm == "pub":
        raise Http404

    if request.method == "POST":
        form = MessageForm(request.POST)

        page_name = request.POST.get("page_name", "")
        if not page_name:
            return HttpResponseRedirect(request.META.get("HTTP_REFERER"))
        page_name = clean_page_name(page_name)

        try:
            repo = get_group_wiki_repo(group, request.user.username)
        except WikiDoesNotExist:
            return render_error(request, _("Wiki is not found."))

        filename = page_name + ".md"
        filepath = "/" + page_name + ".md"

        # check whether file exists
        if get_file_id_by_path(repo.id, filepath):
            return render_error(request, _('Page "%s" already exists.') % filename)

        if not post_empty_file(repo.id, "/", filename, request.user.username):
            return render_error(request, _("Failed to create wiki page. Please retry later."))

        url = "%s?p=%s&from=wiki_page_new&gid=%s" % (
            reverse("file_edit", args=[repo.id]),
            urllib2.quote(filepath.encode("utf-8")),
            group.id,
        )
        return HttpResponseRedirect(url)

def group_wiki_pages(request, group):
    """
    List wiki pages in group.
    """
    username = request.user.username
    try:
        repo = get_group_wiki_repo(group, username)
        pages = get_wiki_pages(repo)
    except SearpcError:
        return render_error(request, _("Internal Server Error"))
    except WikiDoesNotExist:
        return render_error(request, _("Wiki does not exists."))

    repo_perm = seafile_api.check_repo_access_permission(repo.id, username)
    mods_available = get_available_mods_by_group(group.id)
    mods_enabled = get_enabled_mods_by_group(group.id)

    return render_to_response(
        "group/group_wiki_pages.html",
        {
            "group": group,
            "pages": pages,
            "is_staff": group.is_staff,
            "repo_id": repo.id,
            "search_repo_id": repo.id,
            "search_wiki": True,
            "repo_perm": repo_perm,
            "mods_enabled": mods_enabled,
            "mods_available": mods_available,
        },
        context_instance=RequestContext(request),
    )

def personal_wiki_page_new(request, page_name="home"):

    if request.method == 'POST':
        page_name = request.POST.get('page_name', '')
        if not page_name:
            return HttpResponseRedirect(request.META.get('HTTP_REFERER'))
        page_name = clean_page_name(page_name)

        try:
            repo = get_personal_wiki_repo(request.user.username)
        except WikiDoesNotExist:
            return render_error(request, _('Wiki is not found.'))

        filename = page_name + ".md"
        filepath = "/" + page_name + ".md"

        # check whether file exists
        if seaserv.get_file_id_by_path(repo.id, filepath):
            return render_error(request, _('Page "%s" already exists.') % filename)

        if not seaserv.post_empty_file(repo.id, "/", filename, request.user.username):
            return render_error(request, _('Failed to create wiki page. Please retry later.'))

        url = "%s?p=%s&from=personal_wiki_page_new" % (
            reverse('file_edit', args=[repo.id]),
            urlquote(filepath.encode('utf-8')))
        return HttpResponseRedirect(url)

def render_file_revisions (request, repo_id):
    """List all history versions of a file."""

    days_str = request.GET.get('days', '')
    try:
        days = int(days_str)
    except ValueError:
        days = 7

    path = request.GET.get('p', '/')
    if path[-1] == '/':
        path = path[:-1]
    u_filename = os.path.basename(path)

    if not path:
        return render_error(request)

    repo = get_repo(repo_id)
    if not repo:
        error_msg = _(u"Library does not exist")
        return render_error(request, error_msg)

    filetype = get_file_type_and_ext(u_filename)[0].lower()
    if filetype == 'text' or filetype == 'markdown':
        can_compare = True
    else:
        can_compare = False

    try:
        commits = seafile_api.get_file_revisions(repo_id, path, -1, -1, days)
    except SearpcError, e:
        logger.error(e.msg)
        return render_error(request, e.msg)

def group_quit(request, group_id):
    try:
        group_id_int = int(group_id)
    except ValueError:
        return render_error(request, _(u"group id  is not a valid argument."))

    try:
        ccnet_threaded_rpc.quit_group(group_id_int, request.user.username)
        seafserv_threaded_rpc.remove_repo_group(group_id_int, request.user.username)
    except SearpcError, e:
        return render_error(request, e.msg)

def repo_remove_share(request):
    """
    If repo is shared from one person to another person, only these two peson
    can remove share.
    If repo is shared from one person to a group, then only the one share the
    repo and group staff can remove share.
    """
    repo_id = request.GET.get('repo_id', '')
    group_id = request.GET.get('gid', '')
    from_email = request.GET.get('from', '')
    if not is_valid_username(from_email):
        return render_error(request, _(u'Argument is not valid'))
    username = request.user.username

    # if request params don't have 'gid', then remove repos that share to
    # to other person; else, remove repos that share to groups
    if not group_id:
        to_email = request.GET.get('to', '')
        if not is_valid_username(to_email):
            return render_error(request, _(u'Argument is not valid'))

        if username != from_email and username != to_email:
            return render_permission_error(request, _(u'Failed to remove share'))

        if is_org_context(request):
            org_id = request.user.org.org_id
            org_remove_share(org_id, repo_id, from_email, to_email)
        else:
            seaserv.remove_share(repo_id, from_email, to_email)
    else:
        try:
            group_id = int(group_id)
        except:
            return render_error(request, _(u'group id is not valid'))

        group = seaserv.get_group(group_id)
        if not group:
            return render_error(request, _(u"Failed to unshare: the group doesn't exist."))

        if not seaserv.check_group_staff(group_id, username) \
                and username != from_email:
            return render_permission_error(request, _(u'Failed to remove share'))

        if is_org_group(group_id):
            org_id = get_org_id_by_group(group_id)
            del_org_group_repo(repo_id, org_id, group_id)
        else:
            seafile_api.unset_group_repo(repo_id, group_id, from_email)

    messages.success(request, _('Successfully removed share'))

    next = request.META.get('HTTP_REFERER', SITE_ROOT)
    return HttpResponseRedirect(next)

def group_share_repo(request, repo_id, group_id, from_email, permission):
    """
    Share a repo to a group.
    
    """
    # Check whether group exists
    group = get_group(group_id)
    if not group:
        return render_error(request, _(u"Failed to share: the group doesn't exist."))
    
    if seafserv_threaded_rpc.group_share_repo(repo_id, group_id, from_email, permission) != 0:
        return render_error(request, _(u"Failed to share: internal error."))

def personal_wiki_pages(request):
    """
    List personal wiki pages.
    """
    try:
        repo = get_personal_wiki_repo(request.user.username)
        pages = get_wiki_pages(repo)
    except SearpcError:
        return render_error(request, _("Internal Server Error"))
    except WikiDoesNotExist:
        return render_error(request, _("Wiki does not exists."))

    return render_to_response(
        "wiki/personal_wiki_pages.html", {"pages": pages, "repo_id": repo.id}, context_instance=RequestContext(request)
    )

def repo_remove_share(request):
    """
    If repo is shared from one person to another person, only these two peson
    can remove share.
    If repo is shared from one person to a group, then only the one share the
    repo and group staff can remove share.
    """
    repo_id = request.GET.get('repo_id', '')
    group_id = request.GET.get('gid', '')
    from_email = request.GET.get('from', '')
    if not is_valid_username(from_email):
        return render_error(request, _(u'Argument is not valid'))

    # if request params don't have 'gid', then remove repos that share to
    # to other person; else, remove repos that share to groups
    if not group_id:
        to_email = request.GET.get('to', '')
        if not is_valid_username(to_email):
            return render_error(request, _(u'Argument is not valid'))

        if request.user.username != from_email and \
                request.user.username != to_email:
            return render_permission_error(request, _(u'Failed to remove share'))
        remove_share(repo_id, from_email, to_email)
    else:
        try:
            group_id_int = int(group_id)
        except:
            return render_error(request, _(u'group id is not valid'))

        if not check_group_staff(group_id_int, request.user.username) \
                and request.user.username != from_email:
            return render_permission_error(request, _(u'Failed to remove share'))

        if is_org_group(group_id_int):
            org_id = get_org_id_by_group(group_id_int)
            del_org_group_repo(repo_id, org_id, group_id_int)
        else:
            from seahub.group.views import group_unshare_repo
            group_unshare_repo(request, repo_id, group_id_int, from_email)

    messages.success(request, _('Successfully removed share'))

    next = request.META.get('HTTP_REFERER', None)
    if not next:
        next = SITE_ROOT

    return HttpResponseRedirect(next)

def group_dismiss(request, group_id):
    """
    Dismiss a group, only group staff can perform this operation.
    """
    next = request.META.get('HTTP_REFERER', None)
    if not next:
        next = SITE_ROOT

    try:
        group_id_int = int(group_id)
    except ValueError:
        return HttpResponseRedirect(next)

    # Check whether user is group staff
    user = request.user.username
    if not ccnet_threaded_rpc.check_group_staff(group_id_int, user):
        return render_permission_error(request, _(u'Only administrators can dismiss the group'))

    try:
        ccnet_threaded_rpc.remove_group(group_id_int, user)
        seafserv_threaded_rpc.remove_repo_group(group_id_int, None)

        if request.user.org:
            org_id = request.user.org['org_id']
            url_prefix = request.user.org['url_prefix']
            ccnet_threaded_rpc.remove_org_group(org_id, group_id_int)
            return HttpResponseRedirect(reverse('org_groups',
                                                args=[url_prefix]))

    except SearpcError, e:
        return render_error(request, _(e.msg))

def repo_history_view(request, repo_id):
    """View repo in history.
    """
    repo = get_repo(repo_id)
    if not repo:
        raise Http404

    username = request.user.username
    path = get_path_from_request(request)
    user_perm = check_folder_permission(request, repo.id, '/')
    if user_perm is None:
        return render_error(request, _(u'Permission denied'))

    try:
        server_crypto = UserOptions.objects.is_server_crypto(username)
    except CryptoOptionNotSetError:
        # Assume server_crypto is ``False`` if this option is not set.
        server_crypto = False

    if repo.encrypted and \
        (repo.enc_version == 1 or (repo.enc_version == 2 and server_crypto)) \
        and not is_password_set(repo.id, username):
        return render_to_response(
            'decrypt_repo_form.html', {
                'repo':
                repo,
                'next':
                get_next_url_from_request(request)
                or reverse('repo', args=[repo.id]),
                'force_server_crypto':
                FORCE_SERVER_CRYPTO,
            },
            context_instance=RequestContext(request))

    commit_id = request.GET.get('commit_id', None)
    if commit_id is None:
        return HttpResponseRedirect(reverse('repo', args=[repo.id]))
    current_commit = get_commit(repo.id, repo.version, commit_id)
    if not current_commit:
        current_commit = get_commit(repo.id, repo.version, repo.head_cmmt_id)

    file_list, dir_list, dirent_more = get_repo_dirents(
        request, repo, current_commit, path)
    zipped = get_nav_path(path, repo.name)

    repo_owner = seafile_api.get_repo_owner(repo.id)
    is_repo_owner = True if username == repo_owner else False

    return render_to_response(
        'repo_history_view.html', {
            'repo': repo,
            "is_repo_owner": is_repo_owner,
            'user_perm': user_perm,
            'current_commit': current_commit,
            'dir_list': dir_list,
            'file_list': file_list,
            'path': path,
            'zipped': zipped,
        },
        context_instance=RequestContext(request))

def org_group_remove(request, url_prefix, group_id):
    # Request header may missing HTTP_REFERER, we need to handle that case.
    next = request.META.get("HTTP_REFERER", None)
    if not next:
        next = seahub_settings.SITE_ROOT

    try:
        group_id_int = int(group_id)
    except ValueError:
        return HttpResponseRedirect(next)

    # Check whether is the org group.
    org_id = get_org_id_by_group(group_id_int)
    if request.user.org["org_id"] != org_id:
        return render_permission_error(
            request,
            _(u"This group doesn't belong to current organazation"),
            extra_ctx={"org": request.user.org, "base_template": "org_base.html"},
        )

    try:
        ccnet_threaded_rpc.remove_group(group_id_int, request.user.username)
        seafserv_threaded_rpc.remove_repo_group(group_id_int, None)
        ccnet_threaded_rpc.remove_org_group(org_id, group_id_int)
    except SearpcError, e:
        return render_error(request, e.msg, extra_ctx={"org": request.user.org, "base_template": "org_base.html"})

def repo_history(request, repo_id):
    """
    List library modification histories.
    """
    user_perm = check_folder_permission(request, repo_id, '/')
    if not user_perm:
        return render_permission_error(request, _(u'Unable to view library modification'))

    repo = get_repo(repo_id)
    if not repo:
        raise Http404

    username = request.user.username
    try:
        server_crypto = UserOptions.objects.is_server_crypto(username)
    except CryptoOptionNotSetError:
        # Assume server_crypto is ``False`` if this option is not set.
        server_crypto = False

    password_set = False
    if repo.props.encrypted and \
            (repo.enc_version == 1 or (repo.enc_version == 2 and server_crypto)):
        try:
            ret = seafserv_rpc.is_passwd_set(repo_id, username)
            if ret == 1:
                password_set = True
        except SearpcError, e:
            return render_error(request, e.msg)

        if not password_set:
            return HttpResponseRedirect(reverse("view_common_lib_dir", args=[repo_id, '']))

    def _decorated(request):

        error = False
        if not ENABLE_OAUTH:
            logger.error('OAuth not enabled.')
            error = True
        else:
            if not CLIENT_ID or not CLIENT_SECRET or not AUTHORIZATION_URL \
                    or not REDIRECT_URL or not TOKEN_URL or not USER_INFO_URL \
                    or not SCOPE or not PROVIDER_DOMAIN:
                logger.error('OAuth relevant settings invalid.')
                logger.error('CLIENT_ID: %s' % CLIENT_ID)
                logger.error('CLIENT_SECRET: %s' % CLIENT_SECRET)
                logger.error('AUTHORIZATION_URL: %s' % AUTHORIZATION_URL)
                logger.error('REDIRECT_URL: %s' % REDIRECT_URL)
                logger.error('TOKEN_URL: %s' % TOKEN_URL)
                logger.error('USER_INFO_URL: %s' % USER_INFO_URL)
                logger.error('SCOPE: %s' % SCOPE)
                logger.error('PROVIDER_DOMAIN: %s' % PROVIDER_DOMAIN)
                error = True

        if error:
            return render_error(request,
                                _('Error, please contact administrator.'))

        return func(request)

def view_shared_file(request, token):
    """
    Preview file via shared link.
    """
    assert token is not None    # Checked by URLconf

    try:
        fileshare = FileShare.objects.get(token=token)
    except FileShare.DoesNotExist:
        raise Http404

    shared_by = fileshare.username
    repo_id = fileshare.repo_id
    repo = get_repo(repo_id)
    if not repo:
        raise Http404

    path = fileshare.path.rstrip('/') # Normalize file path 
    obj_id = seafile_api.get_file_id_by_path(repo_id, path)
    if not obj_id:
        return render_error(request, _(u'File does not exist'))
    file_size = seafile_api.get_file_size(obj_id)
    
    filename = os.path.basename(path)
    filetype, fileext = get_file_type_and_ext(filename)
    access_token = seafserv_rpc.web_get_access_token(repo.id, obj_id,
                                                     'view', '')
    raw_path = gen_file_get_url(access_token, filename)
    inner_path = gen_inner_file_get_url(access_token, filename)

    # get file content
    ret_dict = {'err': '', 'file_content': '', 'encoding': '', 'file_enc': '',
                'file_encoding_list': [], 'html_exists': False,
                'filetype': filetype}
    fsize = get_file_size(obj_id)
    exceeds_limit, err_msg = file_size_exceeds_preview_limit(fsize, filetype)
    if exceeds_limit:
        err = err_msg
    else:
        """Choose different approach when dealing with different type of file."""

        if is_textual_file(file_type=filetype):
            handle_textual_file(request, filetype, inner_path, ret_dict)
        elif filetype == DOCUMENT:
            handle_document(inner_path, obj_id, fileext, ret_dict)
        elif filetype == PDF:
            handle_pdf(inner_path, obj_id, fileext, ret_dict)

        # Increase file shared link view_cnt, this operation should be atomic
        fileshare.view_cnt = F('view_cnt') + 1
        fileshare.save()

        # send statistic messages
        if ret_dict['filetype'] != 'Unknown':
            try:
                obj_size = seafserv_threaded_rpc.get_file_size(obj_id)
                send_message('seahub.stats', 'file-view\t%s\t%s\t%s\t%s' % \
                             (repo.id, shared_by, obj_id, obj_size))
            except SearpcError, e:
                logger.error('Error when sending file-view message: %s' % str(e))

    def _decorated(request, *args, **kwargs):
        repo_id = kwargs.get("repo_id", None)
        if not repo_id:
            raise Exception, "Repo id is not found in url."
        repo = get_repo(repo_id)
        if not repo:
            raise Http404
        username = request.user.username
        if repo.encrypted:
            try:
                server_crypto = UserOptions.objects.is_server_crypto(username)
            except CryptoOptionNotSetError:
                return render_to_response("options/set_user_options.html", {}, context_instance=RequestContext(request))

            if (repo.enc_version == 1 or (repo.enc_version == 2 and server_crypto)) and not is_passwd_set(
                repo_id, username
            ):
                return render_to_response(
                    "decrypt_repo_form.html",
                    {"repo": repo, "next": request.get_full_path(), "force_server_crypto": FORCE_SERVER_CRYPTO},
                    context_instance=RequestContext(request),
                )

            if repo.enc_version == 2 and not server_crypto:
                return render_error(request, _(u"Files in this library can not be viewed online."))

        return func(request, *args, **kwargs)

    def _decorated(request, *args, **kwargs):
        repo_id = kwargs.get('repo_id', None)
        if not repo_id:
            raise Exception, 'Repo id is not found in url.'
        repo = get_repo(repo_id)
        if not repo:
            raise Http404
        username = request.user.username
        if repo.encrypted:
            try:
                server_crypto = UserOptions.objects.is_server_crypto(username)
            except CryptoOptionNotSetError:
                return render_to_response('options/set_user_options.html', {
                        }, context_instance=RequestContext(request))

            if (repo.enc_version == 1 or (repo.enc_version == 2 and server_crypto)) \
                    and not is_passwd_set(repo_id, username):
                return render_to_response('decrypt_repo_form.html', {
                        'repo': repo,
                        'next': request.get_full_path(),
                        }, context_instance=RequestContext(request))

            if repo.enc_version == 2 and not server_crypto:
                return render_error(request, _(u'Files in this library can not be viewed online.'))

        return func(request, *args, **kwargs)

def personal_wiki(request, page_name="home"):
    username = request.user.username
    wiki_exists = True
    try:
        content, repo, dirent = get_personal_wiki_page(username, page_name)
    except WikiDoesNotExist:
        wiki_exists = False
        owned_repos = seafile_api.get_owned_repo_list(username)
        owned_repos = [r for r in owned_repos if not r.encrypted]
        return render_to_response(
            "wiki/personal_wiki.html",
            {"wiki_exists": wiki_exists, "owned_repos": owned_repos},
            context_instance=RequestContext(request),
        )
    except WikiPageMissing:
        repo = get_personal_wiki_repo(username)
        filename = clean_page_name(page_name) + ".md"
        if not seaserv.post_empty_file(repo.id, "/", filename, username):
            return render_error(request, _("Failed to create wiki page. Please retry later."))
        return HttpResponseRedirect(reverse("personal_wiki", args=[page_name]))
    else:
        url_prefix = reverse("personal_wiki", args=[])
        content = convert_wiki_link(content, url_prefix, repo.id, username)

        # fetch file latest contributor and last modified
        path = "/" + dirent.obj_name
        file_path_hash = hashlib.md5(urllib2.quote(path.encode("utf-8"))).hexdigest()[:12]
        contributors, last_modified, last_commit_id = FileContributors.objects.get_file_contributors(
            repo.id, path.encode("utf-8"), file_path_hash, dirent.obj_id
        )
        latest_contributor = contributors[0] if contributors else None

        wiki_index_exists = True
        index_pagename = "index"
        index_content = None
        try:
            index_content, index_repo, index_dirent = get_personal_wiki_page(username, index_pagename)
        except (WikiDoesNotExist, WikiPageMissing) as e:
            wiki_index_exists = False
        else:
            index_content = convert_wiki_link(index_content, url_prefix, index_repo.id, username)

        return render_to_response(
            "wiki/personal_wiki.html",
            {
                "wiki_exists": wiki_exists,
                "content": content,
                "page": os.path.splitext(dirent.obj_name)[0],
                "last_modified": last_modified,
                "latest_contributor": latest_contributor,
                "path": path,
                "repo_id": repo.id,
                "search_repo_id": repo.id,
                "search_wiki": True,
                "wiki_index_exists": wiki_index_exists,
                "index_content": index_content,
            },
            context_instance=RequestContext(request),
        )

def group_unshare_repo(request, repo_id, group_id, from_email):
    """
    Unshare a repo in group.
    
    """
    # Check whether group exists
    group = get_group(group_id)
    if not group:
        return render_error(request, _(u"Failed to unshare: the group doesn't exist."))

    # Check whether user is group staff or the one share the repo
    if not check_group_staff(group_id, from_email) and \
            seafserv_threaded_rpc.get_group_repo_owner(repo_id) != from_email:
        return render_permission_error(request, _(u"Operation failed: only administrators and the owner of the library can unshare it."))
        
    if seafserv_threaded_rpc.group_unshare_repo(repo_id, group_id, from_email) != 0:
        return render_error(request, _(u"Failed to unshare: internal error."))