def get(self, request, repo_id, format=None):
        repo = get_repo(repo_id)
        if not repo:
            return api_error(status.HTTP_404_NOT_FOUND, 'Repo not found.')

        # check whether user is repo owner
        if validate_owner(request, repo_id):
            owner = "self"
        else:
            owner = "share"

        last_commit = get_commits(repo.id, 0, 1)[0]
        repo.latest_modify = last_commit.ctime if last_commit else None

        # query repo infomation
        repo.size = seafserv_threaded_rpc.server_repo_size(repo_id)
        current_commit = get_commits(repo_id, 0, 1)[0]
        root_id = current_commit.root_id if current_commit else None

        repo_json = {
            "type":"repo",
            "id":repo.id,
            "owner":owner,
            "name":repo.name,
            "desc":repo.desc,
            "mtime":repo.latest_modify,
            "size":repo.size,
            "encrypted":repo.encrypted,
            "root":root_id,
            }

        return Response(repo_json)

    def get(self, request, repo_id, format=None):
        # check whether user can view repo
        repo = get_repo(repo_id)
        if not repo:
            return api_error('404')

        # if not can_access_repo(request, repo.id):
        #     return api_error('403')

        # check whether use is repo owner
        if validate_owner(request, repo_id):
            owner = "self"
        else:
            owner = "share"

        last_commit = get_commits(repo.id, 0, 1)[0].ctime
        repo.latest_modify = last_commit.ctime if last_commit else None

        # query repo infomation
        repo.size = seafserv_threaded_rpc.server_repo_size(repo_id)
        current_commit = get_commits(repo_id, 0, 1)[0]
        root_id = current_commit.root_id if current_commit else None

        # generate download url for client
        ccnet_applet_root = get_ccnetapplet_root()
        relay_id = get_session_info().id
        addr, port = get_ccnet_server_addr_port ()
        email = quote(request.user.username)
        token = get_repo_token_nonnull(repo_id, request.user.username)
        quote_repo_name = quote(repo.name.encode('utf-8'))
        enc = 1 if repo.encrypted else ''

        url = ccnet_applet_root + "/repo/download/"
        url += "?relay_id=%s&relay_addr=%s&relay_port=%s" % (relay_id, addr, port)
        url += "&email=%s&token=%s" % (email, token)
        url += "&repo_id=%s&repo_name=%s&encrypted=%s" % (repo_id, quote_repo_name, enc)
        
        repo_json = {
            "type":"repo",
            "id":repo.id,
            "owner":owner,
            "name":repo.name,
            "desc":repo.desc,
            "mtime":repo.lastest_modify,
            "size":repo.size,
            "encrypted":repo.encrypted,
            "root":root_id,
            "download_url": url,
            }

        return Response(repo_json)

def calculate_repo_last_modify(repo_list):
    """
    Get last modify time for repo. 
    
    """
    for repo in repo_list:
        repo.latest_modify = get_commits(repo.id, 0, 1)[0].ctime

def check_filename_with_rename(repo_id, parent_dir, filename):
    cmmts = get_commits(repo_id, 0, 1)
    latest_commit = cmmts[0] if cmmts else None
    if not latest_commit:
        return ''
    # TODO: what if parrent_dir does not exist?
    dirents = seafile_api.list_dir_by_commit_and_path(repo_id, latest_commit.id,
                                                      parent_dir.encode('utf-8'))

    def no_duplicate(name):
        for dirent in dirents:
            if dirent.obj_name == name:
                return False
        return True

    def make_new_name(filename, i):
        base, ext = os.path.splitext(filename)
        if ext:
            new_base = "%s (%d)" % (base, i)
            return new_base + ext
        else:
            return "%s (%d)" % (filename, i)

    if no_duplicate(filename):
        return filename
    else:
        i = 1
        while True:
            new_name = make_new_name (filename, i)
            if no_duplicate(new_name):
                return new_name
            else:
                i += 1

def calculate_repo_info(repo_list, username):
    """
    Get some info for repo.

    """
    for repo in repo_list:
        try:
            commit = get_commits(repo.id, 0, 1)[0]
            repo.latest_modify = commit.ctime
            repo.root = commit.root_id
            repo.size = seafserv_threaded_rpc.server_repo_size(repo.id)
            if not repo.size :
                repo.size = 0;

            password_need = False
            if repo.encrypted:
                try:
                    ret = seafserv_rpc.is_passwd_set(repo.id, username)
                    if ret != 1:
                        password_need = True
                except SearpcErroe, e:
                    pass
            repo.password_need = password_need
        except Exception,e:
            repo.latest_modify = 0
            repo.commit = None
            repo.size = -1
            repo.password_need = None

def check_filename_with_rename(repo_id, parent_dir, filename):
    latest_commit = get_commits(repo_id, 0, 1)[0]
    if not latest_commit:
        return ''
    dirents = seafserv_threaded_rpc.list_dir_by_path(latest_commit.id,
                                         parent_dir.encode('utf-8'))

    def no_duplicate(name):
        for dirent in dirents:
            if dirent.obj_name == name:
                return False
        return True

    def make_new_name(filename, i):
        base, ext = os.path.splitext(filename)
        if ext:
            new_base = "%s (%d)" % (base, i)
            return new_base + ext
        else:
            return "%s (%d)" % (filename, i)

    if no_duplicate(filename):
        return filename
    else:
        i = 1
        while True:
            new_name = make_new_name (filename, i)
            if no_duplicate(new_name):
                return new_name
            else:
                i += 1

def calculate_repo_last_modify(repo_list):
    """
    Get last modify time for repo. 
    
    """
    for repo in repo_list:
        cmmts = get_commits(repo.id, 0, 1)
        repo.latest_modify = cmmts[0].ctime if cmmts else 0

 def get_current_commit(self):
     commit_id = self.request.GET.get('commit_id', '')
     if not commit_id:
         return HttpResponseRedirect(reverse('repo', args=[self.repo.id]))
     current_commit = get_commit(commit_id)
     if not current_commit:
         current_commit = get_commits(self.repo.id, 0, 1)[0]
     return current_commit

def calculate_repo_info(repo_list, username):
    """
    Get some info for repo.

    """
    for repo in repo_list:
        commit = get_commits(repo.id, 0, 1)[0]
        if not commit:
            continue
        repo.latest_modify = commit.ctime
        repo.root = commit.root_id
        repo.size = server_repo_size(repo.id)

    def check_has_subdir(repo):
        latest_commit = seaserv.get_commits(repo.id, 0, 1)[0]
        if not latest_commit:
            return False
        if latest_commit.root_id == EMPTY_SHA1:
            return False

        try:
            dirs = seafile_api.list_dir_by_commit_and_path(latest_commit.id, '/')
        except Exception, e:
            logger.error(e)
            return False

def reloaddir(request, repo_id, parent_dir):
    current_commit = get_commits(repo_id, 0, 1)[0]
    if not current_commit:
        return api_error(status.HTTP_500_INTERNAL_SERVER_ERROR,
                         'Failed to get current commit of repo %s.' % repo_id)

    try:
        dir_id = seafserv_threaded_rpc.get_dirid_by_path(current_commit.id,
                                                         parent_dir.encode('utf-8'))
    except SearpcError, e:
        return api_error(HTTP_520_OPERATION_FAILED,
                         "Failed to get dir id by path")

    def check_has_subdir(repo):
        latest_commit = get_commits(repo.id, 0, 1)[0]
        if not latest_commit:
            return False
        if latest_commit.root_id == EMPTY_SHA1:
            return False

        dirs = seafserv_threaded_rpc.list_dir_by_path(latest_commit.id, '/')

        for dirent in dirs:
            if stat.S_ISDIR(dirent.props.mode):
                return True
        return False

def get_repo_last_modify(repo):
    """ Get last modification time for a repo.

    If head commit id of a repo is provided, we use that commit as last commit,
    otherwise falls back to getting last commit of a repo which is time
    consuming.
    """
    if repo.head_cmmt_id is not None:
        last_cmmt = seafserv_threaded_rpc.get_commit(repo.id, repo.version, repo.head_cmmt_id)
    else:
        logger.info('[repo %s] head_cmmt_id is missing.' % repo.id)
        last_cmmt = get_commits(repo.id, 0, 1)[0]
    return last_cmmt.ctime if last_cmmt else 0

    def get_repo_info(request, repo_id):
        # check whether user can view repo
        repo = get_repo(repo_id)
        if not repo:
            return api_error(request, '404')

        if not can_access_repo(request, repo.id):
            return api_error(request, '403')

        # check whether use is repo owner
        if validate_owner(request, repo_id):
            owner = "self"
        else:
            owner = "share"

        try:
            repo.latest_modify = get_commits(repo.id, 0, 1)[0].ctime
        except:
            repo.latest_modify = None

        # query repo infomation
        repo.size = seafserv_threaded_rpc.server_repo_size(repo_id)
        current_commit = get_commits(repo_id, 0, 1)[0]
        repo_json = {
            "type":"repo",
            "id":repo.id,
            "owner":owner,
            "name":repo.name,
            "desc":repo.desc,
            "mtime":repo.lastest_modify,
            "size":repo.size,
            "encrypted":r.encrypted,
            "root":current_commit.root_id,
            "password_need":repo.password_need,
            }

        response = Response(200, repo_json)
        return self.render(response)

def reloaddir_if_neccessary (request, repo_id, parent_dir):
    reloaddir = False
    s = request.GET.get('reloaddir', None)
    if s and s.lower() == 'true':
        reloaddir = True

    if not reloaddir:
        return HttpResponse(json.dumps('success'), status='200',
                            content_type=json_content_type)

    current_commit = get_commits(repo_id, 0, 1)[0]
    try:
        dir_id = seafserv_threaded_rpc.get_dirid_by_path(current_commit.id,
                                                         parent_dir.encode('utf-8'))
    except SearpcError, e:
        return api_error(request, "411", "SearpcError:" + e.msg)

def get_wiki_dirent(repo_id, page_name):
    file_name = page_name + ".md"
    repo = seaserv.get_repo(repo_id)
    if not repo:
        raise WikiDoesNotExist
    cmmt = seaserv.get_commits(repo.id, 0, 1)[0]
    if cmmt is None:
        raise WikiPageMissing
    dirs = list_dir_by_path(cmmt, "/")
    if dirs:
        for e in dirs:
            if stat.S_ISDIR(e.mode):
                continue  # skip directories
            if normalize_page_name(file_name) == normalize_page_name(e.obj_name):
                return e
    raise WikiPageMissing

    def get(self, request, repo_id):
        repo = get_repo(repo_id)
        resp = check_repo_access_permission(request, repo)
        if resp:
            return resp

        current_commit = get_commits(repo_id, 0, 1)[0]
        path = request.GET.get('p', '/')
        if path[-1] != '/':
            path = path + '/'

        dir_id = None
        try:
            dir_id = seafserv_threaded_rpc.get_dirid_by_path(current_commit.id,
                                                             path.encode('utf-8'))
        except SearpcError, e:
            return api_error(request, "411", "SearpcError:" + e.msg)

def reloaddir_if_neccessary (request, repo_id, parent_dir):
    reloaddir = False
    s = request.GET.get('reloaddir', None)
    if s and s.lower() == 'true':
        reloaddir = True

    if not reloaddir:
        return Response('success')

    current_commit = get_commits(repo_id, 0, 1)[0]
    if not current_commit:
        return api_error('422')

    try:
        dir_id = seafserv_threaded_rpc.get_dirid_by_path(current_commit.id,
                                                         parent_dir.encode('utf-8'))
    except SearpcError, e:
        return api_error("411", "SearpcError:" + e.msg)

def view_file_via_shared_dir(request, token):
    assert token is not None    # Checked by URLconf

    fileshare = FileShare.objects.get_valid_file_link_by_token(token)
    if fileshare is None:
        raise Http404

    shared_by = fileshare.username
    repo_id = fileshare.repo_id
    repo = get_repo(repo_id)
    if not repo:
        raise Http404
    
    path = request.GET.get('p', '').rstrip('/')
    if not path:
        raise Http404
    if not path.startswith(fileshare.path): # Can not view upper dir of shared dir
        raise Http404
    zipped = gen_path_link(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(repo.store_id, repo.version, 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)

    img_prev = None
    img_next = None

    # get file content
    ret_dict = {'err': '', 'file_content': '', 'encoding': '', 'file_enc': '',
                'file_encoding_list': [], 'html_exists': False,
                'filetype': filetype}
    exceeds_limit, err_msg = file_size_exceeds_preview_limit(file_size, filetype)
    if exceeds_limit:
        ret_dict['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 == SPREADSHEET:
            handle_spreadsheet(inner_path, obj_id, fileext, ret_dict)
        elif filetype == PDF:
            handle_pdf(inner_path, obj_id, fileext, ret_dict)
        elif filetype == IMAGE:
            current_commit = get_commits(repo_id, 0, 1)[0]
            parent_dir = os.path.dirname(path)
            dirs = seafile_api.list_dir_by_commit_and_path(current_commit.repo_id,
                                                           current_commit.id, parent_dir)
            if not dirs:
                raise Http404

            img_list = []
            for dirent in dirs:
                if not stat.S_ISDIR(dirent.props.mode):
                    fltype, flext = get_file_type_and_ext(dirent.obj_name)
                    if fltype == 'Image':
                        img_list.append(dirent.obj_name)

            if len(img_list) > 1:
                img_list.sort(lambda x, y : cmp(x.lower(), y.lower()))
                cur_img_index = img_list.index(filename) 
                if cur_img_index != 0:
                    img_prev = posixpath.join(parent_dir, img_list[cur_img_index - 1])
                if cur_img_index != len(img_list) - 1:
                    img_next = posixpath.join(parent_dir, img_list[cur_img_index + 1])

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

def view_shared_dir(request, token):
    assert token is not None    # Checked by URLconf

    fileshare = FileShare.objects.get_valid_dir_link_by_token(token)
    if fileshare is None:
        raise Http404

    if fileshare.is_encrypted():
        if not check_share_link_access(request.user.username, token):
            d = {'token': token, 'view_name': 'view_shared_dir', }
            if request.method == 'POST':
                post_values = request.POST.copy()
                post_values['enc_password'] = fileshare.password
                form = SharedLinkPasswordForm(post_values)
                d['form'] = form
                if form.is_valid():
                    # set cache for non-anonymous user
                    if request.user.is_authenticated():
                        set_share_link_access(request.user.username, token)
                else:
                    return render_to_response('share_access_validation.html', d,
                                              context_instance=RequestContext(request))
            else:
                return render_to_response('share_access_validation.html', d,
                                          context_instance=RequestContext(request))

    username = fileshare.username
    repo_id = fileshare.repo_id
    path = request.GET.get('p', '')
    path = fileshare.path if not path else path
    if path[-1] != '/':         # Normalize dir path
        path += '/'

    if not path.startswith(fileshare.path):
        path = fileshare.path   # Can not view upper dir of shared dir

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

    dir_name = os.path.basename(path[:-1])
    current_commit = seaserv.get_commits(repo_id, 0, 1)[0]
    file_list, dir_list = get_repo_dirents(request, repo, current_commit,
                                           path)
    zipped = gen_path_link(path, '')

    if path == fileshare.path:  # When user view the shared dir..
        # increase shared link view_cnt,
        fileshare = FileShare.objects.get(token=token)
        fileshare.view_cnt = F('view_cnt') + 1
        fileshare.save()

    traffic_over_limit = user_traffic_over_limit(fileshare.username)

    return render_to_response('view_shared_dir.html', {
            'repo': repo,
            'token': token,
            'path': path,
            'username': username,
            'dir_name': dir_name,
            'file_list': file_list,
            'dir_list': dir_list,
            'zipped': zipped,
            'traffic_over_limit': traffic_over_limit,
            }, context_instance=RequestContext(request))