function [ids_struct_out,ids_struct_out_description] =  tcv_ids_coil(shot, ids_structures, gdat_params, varargin)
%
% [ids_struct_out,ids_struct_out_desccription] =  tcv_get_ids_coil(shot, ids_structures, gdat_params, varargin)
%
%  pf_active coils
%
% error_bar: from gdat_params.error_bar
%            'delta' (default): error_bar to be added inserted in "upper" only as mentioned in description
%            'delta_with_lower' : error_bar (abs) inserted in both lower and upper
%            'added': value already added to data: upper/lower = data +/- error_bar
%

% TODO add logic to get the current in the coils only once.

error_bar = 'delta';
if exist('gdat_params','var') && isfield(gdat_params,'error_bar') && ~isempty(gdat_params.error_bar)
  error_bar = gdat_params.error_bar;
end
params_eff_ref = gdat_params; params_eff_ref.doplot=0;
try params_eff_ref=rmfield(params_eff_ref,'source');catch;end % make sure no source (from ids def)

% Coils that can be characterized by R, Z and a
% crosssectional area are described as distinct coils with a single element, this also corresponds to coils with distinct TCV names).
% Elements can be used in the future to refine the spatial
% description of each coil.
% The circular conductor of G-coils approximated by a square of equal
% crosssectional area.
% Each coil has a positive turnsign. The return current in T_003 is
% dealt with in the circuit description and in the machine mapping.
% In practice the dissipated energy in the pf '
% coils is not a relevant limit.

%% Get power supply/coils names for each circuit.
[pf_def] =  tcv_ids_pf_active_definition();
coil_names2ids = pf_def.coil_names;
mds_paths2ids = pf_def.mds_paths;

ncircuits2ids = numel(coil_names2ids);

%% Get geometrical data from the static tree
% Information from the static tree - Z-zeroed with respect to coils
mdsopen(shot)
r_c     = mdsvalue('_r_c=static(''r_c'')'); % R position
z_c     = mdsvalue('_z_c=static(''z_c'')'); % Z position
w_c     = mdsvalue('static(''w_c'')'); % width rectangular description
h_c     = mdsvalue('static(''h_c'')'); % height rectangular description
% a_c     = mdsvalue('static(''a_c'')'); % tilt angle for parallelogram representation ( deprecated representation in IDS)
nt_c    = mdsvalue('static(''nt_c'')'); % number of turns
xsect_c = mdsvalue('static(''xsect_c'')');
res_c   = mdsvalue('static(''res_c'')'); % resistence of the coil
sizepfc = numel(r_c);
namepfc = mdsvalue('static(''dim_c'')');

% Set effective turns in T1 and T2 (see J.-M. Moret, et al., RSI 69 (1998) 2333)
iT = strcmp('T_001',namepfc);
nt_c(iT)=26/68;
iT = strcmp('T_002',namepfc);
nt_c(iT)=42/68;
iT = strcmp('T_003',namepfc);      % Return current
nt_c(iT)=1;

% Approximate circular G-coil conductor with a square of the same crosssection
iG=strncmp('G_00',namepfc,4);
w_c(iG)=sqrt(xsect_c(iG));
h_c(iG)=sqrt(xsect_c(iG));

%% Put data to ids structure
ids_struct_out(1:sizepfc) = ids_structures;
ids_struct_out_description = cell(1,sizepfc);
ind_coil_ids = 0;
params_eff = params_eff_ref;
for ii=1:ncircuits2ids
  ncoil2ids = numel(coil_names2ids{ii}); % number of coils for a given circuit
  
  for jj = 1:ncoil2ids
    ind_coil_ids = ind_coil_ids +1;
    ids_struct_out{ind_coil_ids}.name = coil_names2ids{ii}{jj};
    ids_struct_out_description{ind_coil_ids}.name = 'through aa=tcv_ids_pf_active_definition from aa.coil_names  ';
    
    % time-varying data
    if shot == -1
      tmpdata.dim{1} = [];
      tmpdata.data = [];
      warning('no time data loaded for shot %d',shot);
    else
      params_eff.data_request = mds_paths2ids{ii};
      tmpdata = gdat_tcv(shot,params_eff);
    end
    % $$$       ids_struct_out{ind_coil_ids}.current.data = tmpdata.data;
    % $$$       ids_struct_out_description{ind_coil_ids}.current.data = ['from ' mds_paths2ids{ii}];
    ids_struct_out{ind_coil_ids}.current.data = pf_def.coil_current_signs{ii}(jj) .* tmpdata.data;
    ids_struct_out_description{ind_coil_ids}.current.data = ['from ' num2str(pf_def.coil_current_signs{ii}(jj)) ' * ' mds_paths2ids{ii}];
    try
      ids_struct_out{ind_coil_ids}.current.time = tmpdata.dim{1};
    catch
      keyboard
    end
    
    % Find index on static tree
    tmpind = find(strcmp(ids_struct_out{ind_coil_ids}.name, namepfc));
    ids_struct_out{ind_coil_ids}.element{1}.geometry.rectangle.r = r_c(tmpind);
    ids_struct_out_description{ind_coil_ids}.element{1}.geometry.rectangle_r = 'from static(''r_c'')';
    ids_struct_out{ind_coil_ids}.element{1}.geometry.rectangle.z = z_c(tmpind);
    ids_struct_out_description{ind_coil_ids}.element{1}.geometry.rectangle_z = 'from static(''z_c'')';
    ids_struct_out{ind_coil_ids}.element{1}.geometry.rectangle.width = w_c(tmpind);
    ids_struct_out_description{ind_coil_ids}.element{1}.geometry.rectangle_width = 'from static(''w_c'')';
    ids_struct_out{ind_coil_ids}.element{1}.geometry.rectangle.height = h_c(tmpind);
    ids_struct_out_description{ind_coil_ids}.element{1}.geometry.rectangle_height = 'from static(''h_c'')';
    ids_struct_out{ind_coil_ids}.element{1}.turns_with_sign = nt_c(tmpind);
    ids_struct_out_description{ind_coil_ids}.element{1}.turns_with_sign = 'from static(''nt_c'')';
    ids_struct_out{ind_coil_ids}.element{1}.geometry.geometry_type = 2; % 1 outline, 2 rectangle, 4 arc of circle
    ids_struct_out_description{ind_coil_ids}.element{1}.geometry.geometry_type = 'rectangle';
    
    ids_struct_out{ind_coil_ids}.resistance = res_c(tmpind);
    ids_struct_out_description{ind_coil_ids}.resistance = 'from static(''res_c'')';
  end
end

% fixed_error = 200.;
ind_coil_ids = 0;
switch error_bar
  case 'delta'
    for ii=1:ncircuits2ids
      ncoil2ids = numel(coil_names2ids{ii}); % number of coils for a given circuit
      for jj = 1:ncoil2ids
        fixed_error = pf_def.coil_current_error{ii}(jj);
        ind_coil_ids = ind_coil_ids +1;
        ids_struct_out{ind_coil_ids}.current.data_error_upper = fixed_error.*ones(size(ids_struct_out{ind_coil_ids}.current.data));
        ids_struct_out_description{ind_coil_ids}.current_data_error_upper = fixed_error.*ones(size(ids_struct_out{ind_coil_ids}.current.data));
        ids_struct_out_description{ind_coil_ids}.current_data_error_lower = 'not provided since symmetric';
      end
    end
  case 'delta_with_lower'
    for ii=1:ncircuits2ids
      ncoil2ids = numel(coil_names2ids{ii}); % number of coils for a given circuit
      for jj = 1:ncoil2ids
        fixed_error = pf_def.coil_current_error{ii}(jj);
        ind_coil_ids = ind_coil_ids +1;
        ids_struct_out{ind_coil_ids}.current.data_error_upper = fixed_error.*ones(size(ids_struct_out{ind_coil_ids}.current.data));
        ids_struct_out{ind_coil_ids}.current.data_error_lower = ids_struct_out{ind_coil_ids}.current.data_error_upper;
        ids_struct_out_description{ind_coil_ids}.current_data_error_upper = ['from fixed error value in case ' error_bar];
        ids_struct_out_description{ind_coil_ids}.current_data_error_lower = ['from fixed error value in case ' error_bar];
      end
    end
  case 'added'
    for ii=1:ncircuits2ids
      ncoil2ids = numel(coil_names2ids{ii}); % number of coils for a given circuit
      for jj = 1:ncoil2ids
        fixed_error = pf_def.coil_current_error{ii}(jj);
        ind_coil_ids = ind_coil_ids +1;
        ids_struct_out{ind_coil_ids}.current.data_error_upper = ids_struct_out{ind_coil_ids}.current.data ...
          + fixed_error.*ones(size(ids_struct_out{ind_coil_ids}.current.data));
        ids_struct_out{ind_coil_ids}.current.data_error_lower = ids_struct_out{ind_coil_ids}.current.data ...
          - fixed_error.*ones(size(ids_struct_out{ind_coil_ids}.current.data));
        ids_struct_out_description{ind_coil_ids}.current_data_error_upper = ['from data + fixed error value in case ' error_bar];
        ids_struct_out_description{ind_coil_ids}.current_data_error_lower = ['from data - fixed error value in case ' error_bar];
      end
    end
  otherwise
    error(['tcv_ids_bpol_loop: error_bar option not known: ' error_bar])
end