function [info,description] = check_posterior_analysis_data(type,M_)

% Copyright (C) 2008-2013 Dynare Team
%
% This file is part of Dynare.
%
% Dynare 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.
%
% Dynare 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 Dynare.  If not, see <http://www.gnu.org/licenses/>.

info = 0;
if nargout>1
    description = '';
end

%% Get informations about mcmc files. 
if ~exist([ M_.dname '/metropolis'],'dir')
    disp('check_posterior_analysis_data:: Can''t find any mcmc file!')
    return
end
mhname = get_name_of_the_last_mh_file(M_);
mhdate = get_date_of_a_file(mhname);

%% Get informations about _posterior_draws files.
drawsinfo = dir([ M_.dname '/metropolis/' M_.fname '_posterior_draws*.mat']);
if isempty(drawsinfo)
    info = 1; % select_posterior_draws has to be called first.
    if nargout>1
        description = 'select_posterior_draws has to be called.';
    end
    return
else
    number_of_last_posterior_draws_file = length(drawsinfo);
    pddate = get_date_of_a_file([ M_.dname '/metropolis/' M_.fname '_posterior_draws'...
                        int2str(number_of_last_posterior_draws_file) '.mat']);
    if pddate<mhdate
        info = 2; % _posterior_draws files have to be updated.
        if nargout>1
            description = 'posterior draws files have to be updated.';
        end
        return
    else
        info = 3; % Ok!
        if nargout>1
            description = 'posterior draws files are up to date.';
        end
    end
end

%% Get informations about posterior data files.
switch type
  case 'variance'
    generic_post_data_file_name = 'Posterior2ndOrderMoments';
  case 'decomposition'
    generic_post_data_file_name = 'PosteriorVarianceDecomposition';
  case 'correlation'
    generic_post_data_file_name = 'PosteriorCorrelations';
  case 'conditional decomposition'
    generic_post_data_file_name = 'PosteriorConditionalVarianceDecomposition';
  otherwise
    disp('This feature is not yest implemented!')
end
pdfinfo = dir([ M_.dname '/metropolis/' M_.fname '_' generic_post_data_file_name '*']);
if isempty(pdfinfo)
    info = 4; % posterior draws have to be processed.
    if nargout>1
        description = 'posterior draws files have to be processed.';
    end
    return
else
    number_of_the_last_post_data_file = length(pdfinfo);
    name_of_the_last_post_data_file = ...
        [ pwd filesep M_.dname ...
          filesep 'metropolis' filesep ...
          M_.fname '_' ... 
          generic_post_data_file_name ...
          int2str(number_of_the_last_post_data_file) ...
          '.mat' ];
    pdfdate = get_date_of_a_file(name_of_the_last_post_data_file);
    if pdfdate<pddate
        info = 5; % posterior data files have to be updated.
        if nargout>1
            description = 'posterior data files have to be updated.';
        end            
    else
        info = 6; % Ok (nothing to do ;-)
        if nargout>1
            description = 'There is nothing to do';
        end        
    end
end