% FFTFILT overrides the fft filter function for analysis objects.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% DESCRIPTION: FFTFILT overrides the fft filter function for analysis objects.
%              Applies the input filter to the input analysis
%              object in the frequency domain. 
% 
%
% CALL:        >> b = fftfilt(a,smodel); b = fftfilt(a,plist('filter',smodel)) 
%              >> b = fftfilt(a,mfir); b = fftfilt(a,plist('filter',mfir))
%              >> b = fftfilt(a,miir); b = fftfilt(a,plist('filter',miir))
%              >> b = fftfilt(a,ltpda_tf); b = fftfilt(a,plist('filter',ltpda_tf))
%              >> b = fftfilt(a,plist('filter',c)) % c is an AO used as a
%                 filter
%
% INPUTS:      
%                   a - input analysis object
%      one of
%              smodel - a model to filter with. The x-dependency must
%                           be on frequency ('f').
%                mfir - an FIR filter
%                miir - an IIR filter
%                tf   - an ltpda_tf object
%                       including:
%                         - pzmodel
%                         - rational
%                         - parfrac
%                  ao - a frequency-series AO. This must have the
%                       correct frequency base to match the FFT'd input
%                       data. You must input it in a plist
%
% OUTPUTS:
%              b    - output analysis object containing the filtered data.
%
% <a href="matlab:utils.helper.displayMethodInfo('ao', 'fftfilt')">Parameters Description</a>
% 
% VERSION:     $Id: fftfilt.m,v 1.35 2011/05/28 05:42:15 mauro Exp $
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

function varargout = fftfilt(varargin)
  
  % Check if this is a call for parameters
  if utils.helper.isinfocall(varargin{:})
    varargout{1} = getInfo(varargin{3});
    return
  end

  import utils.const.*
  utils.helper.msg(msg.PROC3, 'running %s/%s', mfilename('class'), mfilename);

  % Collect input variable names
  in_names = cell(size(varargin));
  for ii = 1:nargin,in_names{ii} = inputname(ii);end
  
  % Collect all AOs and plists
  [as, ao_invars]     = utils.helper.collect_objects(varargin(:), 'ao', in_names);
  [filt, f_invars]    = utils.helper.collect_objects(varargin(:), 'ltpda_filter', in_names);
  [mobjs, md_invars]  = utils.helper.collect_objects(varargin(:), 'smodel', in_names);
  [tfobjs, tf_invars] = utils.helper.collect_objects(varargin(:), 'ltpda_tf', in_names);
  
  % Make copies or handles to inputs
  bs   = copy(as, nargout);

  % Apply defaults to plist
  pl = applyDefaults(getDefaultPlist, varargin{:});
  
  % Filter with a smodel object
  if ~isempty(mobjs)
    filt = mobjs;
  elseif ~isempty(tfobjs)
    filt = tfobjs;
  end

  if isempty(filt)
    filt = find(pl, 'filter');
  end
  
  if isempty(filt)
    error('### A filter must be provided ###')
  end

  % get number of Bins for zero padding
  Npad = find(pl,'Npad');
  
  % get initial conditions
  inConds = find(pl,'Initial Conditions');
  
  % check initial conditions
  if ~isempty(inConds)
    if iscell(inConds) && numel(inConds) ~= numel(bs)
      error('### Please give the proper number of initial conditions')
    end
    if ~iscell(inConds) && numel(bs)>1
      error('### Please give the initial conditions in a cell-array')
    else
      inConds = {inConds};
    end
  end
  
  inCondsMdl = repmat(smodel(), numel(bs), 1);
  for ii = 1:numel(bs)
    if ~isempty(inConds)
      N = numel(inConds{ii});
      expr = '';
      ix = 1;
      for jj = N-1:-1:0
        expr = [expr,sprintf('+(2*pi*i*f).^%i*%g',jj,inConds{ii}(ix))];
        ix = ix+1;
      end
      inCondsMdl(ii) = smodel(plist('expression', expr, 'xvar', 'f'));      
    end
  end
  
  for ii = 1:numel(bs)
    % keep the history to suppress the history of the intermediate steps
    inhist = bs(ii).hist;

    % make sure we operate on physical frequencies   
    switch class(filt)
      case 'smodel'
        switch filt.xvar{1}
          case 'f'
            % Nothing to do
          case 's'
            % I need to map from 's' to 'f'
            filt.setTrans('2*pi*i');
          otherwise
            error('### The filter smodel must have xvar = ''s'' or ''f''');
        end
      otherwise
    end
      
    % call core method of the fftfilt
    bs(ii).fftfilt_core(filt, Npad, inCondsMdl(ii));    
    
    % Set name
    bs(ii).setName(sprintf('fftfilt(%s)', ao_invars{ii}));
    % Add history
    bs(ii).addHistory(getInfo('None'), pl, ao_invars(ii), [inhist filt(:).hist]);
    
  end
  
  % Set output
  varargout = utils.helper.setoutputs(nargout, bs);
end


%--------------------------------------------------------------------------
% Get Info Object
%--------------------------------------------------------------------------
function ii = getInfo(varargin)
  if nargin == 1 && strcmpi(varargin{1}, 'None')
    sets = {};
    pl   = [];
  else
    sets = {'Default'};
    pl   = getDefaultPlist();
  end
  % Build info object
  ii = minfo(mfilename, 'ao', 'ltpda', utils.const.categories.sigproc, '$Id: fftfilt.m,v 1.35 2011/05/28 05:42:15 mauro Exp $', sets, pl);
end

%--------------------------------------------------------------------------
% Get Default Plist
%--------------------------------------------------------------------------
function plout = getDefaultPlist()
  persistent pl;  
  if ~exist('pl', 'var') || isempty(pl)
    pl = buildplist();
  end
  plout = pl;  
end

function pl = buildplist()

  pl = plist();
  
  % Filter
  p = param({'filter', 'The filter to apply to the data.'}, paramValue.EMPTY_STRING);
  pl.append(p);
  
  % Number of bins for zero padding
  p = param({'Npad', 'Number of bins for zero padding.'}, paramValue.EMPTY_DOUBLE);
  pl.append(p);
  
  % Initial conditions
  p = param({'Initial Conditions', ['A cell containing the arrays of initial conditions, one '...
      'for each system being solved, '...
      'starting from the lower order to the maximum allowed. '...
      'It assumed that the underlying system follows a linear differential equation with constant coefficients. '...
      'For example, if the system is the Newton '...
      '2nd-order equation of motion, than the array contains the initial position and the '...
      'initial velocity.']}, paramValue.EMPTY_CELL);
  pl.append(p);
  
end