function ArgStruct=parseArgs(args,ArgStruct,varargin)
% Helper function for parsing varargin.
%
%
% ArgStruct=parseArgs(varargin,ArgStruct[,FlagtypeParams[,Aliases]])
%
% * ArgStruct is the structure full of named arguments with default values.
% * Flagtype params is params that don't require a value. (the value will be set to 1 if it is present)
% * Aliases can be used to map one argument-name to several argstruct fields
%
%
% example usage:
% --------------
% function parseargtest(varargin)
%
% %define the acceptable named arguments and assign default values
% Args=struct('Holdaxis',0, ...
%        'SpacingVertical',0.05,'SpacingHorizontal',0.05, ...
%        'PaddingLeft',0,'PaddingRight',0,'PaddingTop',0,'PaddingBottom',0, ...
%        'MarginLeft',.1,'MarginRight',.1,'MarginTop',.1,'MarginBottom',.1, ...
%        'rows',[],'cols',[]);
%
% %The capital letters define abrreviations.
% %  Eg. parseargtest('spacingvertical',0) is equivalent to  parseargtest('sv',0)
%
% Args=parseArgs(varargin,Args, ... % fill the arg-struct with values entered by the user
%           {'Holdaxis'}, ... %this argument has no value (flag-type)
%           {'Spacing' {'sh','sv'}; 'Padding' {'pl','pr','pt','pb'}; 'Margin' {'ml','mr','mt','mb'}});
%
% disp(Args)
%
%
%
%
% Aslak Grinsted 2014

% -------------------------------------------------------------------------
%The MIT License (MIT)
%
%Copyright (c) 2002-2014 Aslak Grinsted
%
%Permission is hereby granted, free of charge, to any person obtaining a copy
%of this software and associated documentation files (the "Software"), to deal
%in the Software without restriction, including without limitation the rights
%to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
%copies of the Software, and to permit persons to whom the Software is
%furnished to do so, subject to the following conditions:
%
%The above copyright notice and this permission notice shall be included in
%all copies or substantial portions of the Software.
%
%THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
%IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
%FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
%AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
%LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
%OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
%THE SOFTWARE.
%---------------------------------------------------------------------------


persistent matlabver

if isempty(matlabver)
    matlabver=ver('MATLAB');
    matlabver=str2double(matlabver.Version);
end

Aliases={};
FlagTypeParams='';

if (length(varargin)>0)
    FlagTypeParams=lower(strvcat(varargin{1}));  %#ok
    if length(varargin)>1
        Aliases=varargin{2};
    end
end


%---------------Get "numeric" arguments
NumArgCount=1;
while (NumArgCount<=size(args,2))&&(~ischar(args{NumArgCount}))
    NumArgCount=NumArgCount+1;
end
NumArgCount=NumArgCount-1;
if (NumArgCount>0)
    ArgStruct.NumericArguments={args{1:NumArgCount}};
else
    ArgStruct.NumericArguments={};
end


%--------------Make an accepted fieldname matrix (case insensitive)
Fnames=fieldnames(ArgStruct);
for i=1:length(Fnames)
    name=lower(Fnames{i,1});
    Fnames{i,2}=name; %col2=lower
    Fnames{i,3}=[name(Fnames{i,1}~=name) ' ']; %col3=abreviation letters (those that are uppercase in the ArgStruct) e.g. SpacingHoriz->sh
    %the space prevents strvcat from removing empty lines
    Fnames{i,4}=isempty(strmatch(Fnames{i,2},FlagTypeParams)); %Does this parameter have a value?
end
FnamesFull=strvcat(Fnames{:,2}); %#ok
FnamesAbbr=strvcat(Fnames{:,3}); %#ok

if length(Aliases)>0
    for i=1:length(Aliases)
        name=lower(Aliases{i,1});
        FieldIdx=strmatch(name,FnamesAbbr,'exact'); %try abbreviations (must be exact)
        if isempty(FieldIdx)
            FieldIdx=strmatch(name,FnamesFull); %&??????? exact or not?
        end
        Aliases{i,2}=FieldIdx;
        Aliases{i,3}=[name(Aliases{i,1}~=name) ' ']; %the space prevents strvcat from removing empty lines
        Aliases{i,1}=name; %dont need the name in uppercase anymore for aliases
    end
    %Append aliases to the end of FnamesFull and FnamesAbbr
    FnamesFull=strvcat(FnamesFull,strvcat(Aliases{:,1})); %#ok
    FnamesAbbr=strvcat(FnamesAbbr,strvcat(Aliases{:,3})); %#ok
end

%--------------get parameters--------------------
l=NumArgCount+1;
while (l<=length(args))
    a=args{l};
    if ischar(a)
        paramHasValue=1; % assume that the parameter has is of type 'param',value
        a=lower(a);
        FieldIdx=strmatch(a,FnamesAbbr,'exact'); %try abbreviations (must be exact)
        if isempty(FieldIdx)
            FieldIdx=strmatch(a,FnamesFull);
        end
        if (length(FieldIdx)>1) %shortest fieldname should win
            [mx,mxi]=max(sum(FnamesFull(FieldIdx,:)==' ',2));%#ok
            FieldIdx=FieldIdx(mxi);
        end
        if FieldIdx>length(Fnames) %then it's an alias type.
            FieldIdx=Aliases{FieldIdx-length(Fnames),2};
        end

        if isempty(FieldIdx)
            error(['Unknown named parameter: ' a])
        end
        for curField=FieldIdx' %if it is an alias it could be more than one.
            if (Fnames{curField,4})
                if (l+1>length(args))
                    error(['Expected a value for parameter: ' Fnames{curField,1}])
                end
                val=args{l+1};
            else %FLAG PARAMETER
                if (l<length(args)) %there might be a explicitly specified value for the flag
                    val=args{l+1};
                    if isnumeric(val)
                        if (numel(val)==1)
                            val=logical(val);
                        else
                            error(['Invalid value for flag-parameter: ' Fnames{curField,1}])
                        end
                    else
                        val=true;
                        paramHasValue=0;
                    end
                else
                    val=true;
                    paramHasValue=0;
                end
            end
            if matlabver>=6
                ArgStruct.(Fnames{curField,1})=val; %try the line below if you get an error here
            else
                ArgStruct=setfield(ArgStruct,Fnames{curField,1},val); %#ok <-works in old matlab versions
            end
        end
        l=l+1+paramHasValue; %if a wildcard matches more than one
    else
        error(['Expected a named parameter: ' num2str(a)])
    end
end
