function filename = dccnpath(filename)

% DCCNPATH manages the filename and path for test files. It helps to locate and read

% test file from Linux, Windows or macOS computers both inside and outside the DCCN.

%

% Use as

% filename = dccnpath(filename)

% where the input filename corresponds to the test data on the DCCN cluster and the

% output filename corresponds to the local file including the full path where the

% test data is available.

%

% The test data location on the DCCN cluster is '/home/common/matlab/fieldtrip/data'

% and the specification of the input filename MUST start with this.

%

% This function will search-and-replace the location on the DCCN cluster by the

% location that applies to your computer. If needed, it will replace '/home' by 'H:'

% and will replace forward by backward slashes.

%

% In case you have a local copy of the data, or if you are inside the DCCN and have

% mounted the '/home' drive on another letter than 'H:', you should override the

% default location using

% global ft_default

% ft_default.dccnpath = '/your/copy';

%

% If you do not have a local copy and do not define ft_default.dccnpath manually,

% then dccnpath will automatically use a temporary directory and try to download the

% data.

%

% See also WHICH, WEBSAVE

% Copyright (C) 2012-2023, Donders Centre for Cognitive Neuroimaging, Nijmegen, NL

%

% This file is part of FieldTrip, see http://www.fieldtriptoolbox.org

% for the documentation and details.

%

% FieldTrip 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 3 of the License, or

% (at your option) any later version.

%

% FieldTrip 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.

%

% You should have received a copy of the GNU General Public License

% along with FieldTrip. If not, see <http://www.gnu.org/licenses/>.

%

% $Id$

global ft_default

% it must always start with this

assert(startsWith(filename, '/home/common/matlab/fieldtrip/data'));

% alternative0 applies inside the DCCN network when using the standard data location

if ispc

alternative0 = strrep(filename, '/home', 'H:');

alternative0 = strrep(alternative0, '/', '\');

else

alternative0 = strrep(filename, 'H:', '/home');

alternative0 = strrep(alternative0, '\', '/');

end

if exist(alternative0, 'file') || exist(alternative0, 'dir')

ft_notice('using default DCCN path %s', alternative0);

filename = alternative0;

return

end

% the simple alternative1 applies with a local file in the present working directory

% this is often convenient when initially setting up a new test script while the data is not yet uploaded

[p, f, x] = fileparts(alternative0);

alternative1 = [f x];

skip = {

% subdirectories like fieldtrip/xxx

'bin'

'compat'

'connectivity'

'contrib'

'external'

'fileio'

'forward'

'inverse'

'plotting'

'preproc'

'private'

'qsub'

'realtime'

'specest'

'src'

'statfun'

'template'

'test'

'trialfun'

'utilities'

% subdirectories like fieldtrip/template/xxx

'dewar'

'headmodel'

'sourcemodel'

'anatomy'

'electrode'

'layout'

'atlas'

'gradiometer'

'neighbours'

};

if any(strcmp(alternative1, skip))

% this should not be used for subdirectories underneath fieldtrip

warning('the simple alternative1 cannot be used for "%s"', alternative1)

alternative1 = '';

end

if exist(alternative1, 'file') || exist(alternative1, 'dir')

if ~isempty(x) && ~isequal(x, '.ds') % if alternative1 is a file

filenamepath = which(alternative1); % also output the path that alternative1 is located at

ft_notice('using present working directory %s', filenamepath);

filename = filenamepath;

return;

else % if alternative1 is a folder

searchPath = path; % get the MATLAB search path

directories = strsplit(searchPath, pathsep); % split the search path into individual directories

folderPath = '';

for i = 1:numel(directories)

currentFolder = directories{i};

if contains(currentFolder, alternative1)

folderPath = currentFolder;

break

end

end

warning('using present working directory %s', folderPath);

filename = folderPath;

return

end

end

% alternative2 applies when ft_default.dccnpath is specified

% see https://github.com/fieldtrip/fieldtrip/issues/1998

if ~isfield(ft_default, 'dccnpath') || isempty(ft_default.dccnpath)

ft_notice('using a temporary directory')

ft_default.dccnpath = tempdir;

end

% we do not want it to end with a '/' or '\'

ft_default.dccnpath = strip(ft_default.dccnpath, 'right', '/');

ft_default.dccnpath = strip(ft_default.dccnpath, 'right', '\');

% alternative0 is the same as the input filename, but potentially updated for windows

if ~ispc

alternative2 = strrep(alternative0, '/home/common/matlab/fieldtrip/data', ft_default.dccnpath);

else

alternative2 = strrep(alternative0, 'H:\common\matlab\fieldtrip\data', ft_default.dccnpath);

end

if exist(alternative2, 'file')

ft_notice('using local copy %s ', alternative2);

filename = alternative2;

return

elseif isfolder(alternative2) && ~isemptydir(alternative2)

ft_notice('using local copy %s ', alternative2);

filename = alternative2;

return

else

% if the file doesn't exist or the folder is empty, then download test data

% see also UNTAR, UNZIP, GUNZIP, which can download on the fly

if contains(alternative0, 'data/test') || contains(alternative0, 'data\test')

error('the test data are private and can not be downloaded from https://download.fieldtriptoolbox.org')

end

% public data are downloaded from https://download.fieldtriptoolbox.org

% so, we need to find the right path to the HTTPS download server

pattern = 'ftp(.*)';

datadir = regexp(alternative0, pattern, 'tokens', 'once');

if iscell(datadir)

datadir = datadir{1};

end

weblocation = strcat('https://download.fieldtriptoolbox.org', datadir);

weblocation = strrep(weblocation, '\', '/');

urlContent = webread(weblocation, weboptions('ContentType', 'text'));

if contains(urlContent, '<html')

% the URL corresponds to a folder

ft_notice('downloading recursively from %s', weblocation);

recursive_download(weblocation, alternative2);

filename = alternative2;

else

% the URL corresponds to a file

% create the necessary directories if they do not exist

[p, f, x] = fileparts(alternative2);

if ~isfolder(p)

mkdir(p);

end

if isfolder(alternative2)

[p, f, x] = fileparts(alternative0);

alternative2 = fullfile(alternative2, [f x]);

end

ft_notice('downloading recursively from %s', weblocation);

websave(alternative2, weblocation);

filename = alternative2;

end

end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% SUBFUNCTION

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

function bool = isemptydir(dirName)

dirContents = dir(dirName);

bool = ~isempty(dirContents(~ismember({dirContents.name}, {'.', '..'})));