% EEG_READOPTIONS - Read EEGLAB memory options file (eeg_options) into a

%                     structure variable (opt).

%

% Usage:

%   [ header, opt ] = eeg_readoptions( filename, opt );

%

% Input:

%   filename    - [string] name of the option file

%   opt         - [struct] option structure containing backup values

%

% Outputs:

%   header      - [string] file header.

%   opt         - [struct] option structure containing an array of 3 fields

%                 varname     -> all variable names.

%                 value       -> value for each variable name

%                 description -> all description associated with each variable

%

% Author: Arnaud Delorme, SCCN, INC, UCSD, 2006-

%

% See also: EEG_OPTIONS, EEG_EDITOPTIONS

% Copyright (C) Arnaud Delorme, SCCN, INC, UCSD, 2006-

%

% This file is part of EEGLAB, see http://www.eeglab.org

% for the documentation and details.

%

% Redistribution and use in source and binary forms, with or without

% modification, are permitted provided that the following conditions are met:

%

% 1. Redistributions of source code must retain the above copyright notice,

% this list of conditions and the following disclaimer.

%

% 2. Redistributions in binary form must reproduce the above copyright notice,

% this list of conditions and the following disclaimer in the documentation

% and/or other materials provided with the distribution.

%

% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

% AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

% IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

% ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

% LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

% CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

% SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

% INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

% CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

% ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF

% THE POSSIBILITY OF SUCH DAMAGE.

function [ header, opt ] = eeg_readoptions( filename, opt_backup );

    if nargin < 1

        help eeg_readoptions;

        return;

    end

    if nargin < 2

        opt_backup = [];

    end

    if ischar(filename)

         fid = fopen(filename, 'r');

    else fid = filename;

    end

    % skip header

    % -----------

    header = '';

    str = fgets( fid );

    while (str(1) == '%')

        header = [ header str];

        str = fgets( fid );

    end

    % read variables values and description

    % --------------------------------------

    str = fgetl( fid ); % jump a line

    index = 1;

    opt = [];

    while (str(1) ~= -1)

        if str(1) == '%'

            opt(index).description = str(3:end-1);

            opt(index).value       = [];

            opt(index).varname     = '';

        else

            [ opt(index).varname str ] = strtok(str); % variable name

            [ equal              str ] = strtok(str); % =

            [ opt(index).value   str ] = strtok(str); % value

            [ tmp                str ] = strtok(str); % ;

            [ tmp                dsc ] = strtok(str); % comment

            dsc = deblank( dsc(end:-1:1) );

            opt(index).description = deblank( dsc(end:-1:1) );

            opt(index).value       = str2num(  opt(index).value );

        end

        str = fgets( fid ); % jump a line

        index = index+1;

    end

    fclose(fid);

    % replace in backup structure if any

    % ----------------------------------

    if ~isempty(opt_backup)

        if ~isempty(opt)

            for index = 1:length(opt_backup)

                ind = strmatch(opt_backup(index).varname, { opt.varname }, 'exact');

                if ~isempty(ind) && ~isempty(opt_backup(index).varname)

                    opt_backup(index).value = opt(ind).value;

                end

            end

        end

        opt = opt_backup;

    end