// Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
// Copyright (C) INRIA -
//
// This file must be used under the terms of the CeCILL.
// This source file is licensed as described in the file COPYING, which
// you should have received as part of this distribution.  The terms
// are also available at
// http://www.cecill.info/licences/Licence_CeCILL_V2.1-en.txt


function [h,name]=bloc2exp(syst,sexp)

    [lhs,rhs]=argn(0)

    if type(syst)<>15 then
        error(msprintf(gettext("%s: Wrong type for input argument #%d: A list expected.\n"),"bloc2exp",1));
    end;
    if syst(1)<>"blocd" then
        error(msprintf(gettext("%s: Wrong type for input argument #%d: A list expected.\n"),"bloc2exp",1));
    end;
    //inter%connection matrix
    nsyst=size(syst)
    for l=2:nsyst
        sys=syst(l)
        if sys(1)=="blocd" then
            if rhs==1 then  sys=bloc2exp(sys)
                syst(l)=list("transfer",sys)
            else  [sys]=bloc2exp(sys,sexp)
                syst(l)=list("transfer",sys(1))
                sexp=sys(2)
            end;
        end;
    end;
    if lhs==2 then [t,nio,name]=construct(syst)
    else [t,nio]=construct(syst)
    end;
    //linear equation
    if rhs==1 then
        t=trianfml(t)
    else
        [t,sexp]=trianfml(t,sexp)
    end
    [nt,mt]=size(t)
    h=t(nt-nio(2)+1:nt,nt+1:mt)
    for kt=1:nio(1),for lt=1:nio(2),
            h(lt,kt)=mulf("-1",h(lt,kt))
    end,end,
    if rhs==1 then h=trisolve(t(nt-nio(2)+1:nt,nt-nio(2)+1:nt),h)
    else [h,sexp]=trisolve(t(nt-nio(2)+1:nt,nt-nio(2)+1:nt),h,sexp)
        h=list(h,sexp)
    end;
    if lhs==2 then name=list(name(nt+1:mt)',name(nt-nio(2)+1:nt)'),end,

endfunction
function [ab,nio,name]=construct(syst)
    //!
    [lhs,rhs]=argn(0)

    [lboites,lliens,lentrees,lsorties]=blocdext(syst)
    nio=[prod(size(lentrees)),prod(size(lsorties))]
    lliens=[lliens,lsorties]
    nlignes=prod(size(lliens))
    ncols=nlignes+nio(1)
    //
    ab=string(0*ones(nlignes,ncols))
    l=1;
    for numero=lboites
        //on ecrit les equations relatives a la boite "bloc" --> une ligne bloc de la
        //matrice ab
        bloc=syst(numero)
        transfert=bloc(2);[no,ni]=size(transfert);
        l1=l+no-1;
        outint=out1(numero,lliens)
        internes=%connect(numero,lliens);
        externes=%connect(numero,lentrees);
        for inti=internes
            ni=prod(size(inti))
            ab(l:l1,inti(1))=transfert(:,inti(2:ni))
            ll=0;for iout=outint
                ab(l-1+iout(2),iout(1))="-eye()"
                ll=ll+1
            end;
        end;
        for ext=externes
            ne=prod(size(ext))
            ab(l:l1,nlignes+ext(1))=transfert(:,ext(2:ne))
            ll=0;for iout=outint
                ab(l-1+iout(2),iout(1))="-eye()"
                ll=ll+1
            end;
        end;
        l=l1+1
    end;
    if lhs==1 then  return,end
    name=[]
    for kvar=[lliens,lentrees],
        obj=syst(kvar)
        name=[name,obj(2)]
    end;

endfunction
function [lboites,lliens,lentrees,lsorties]=blocdext(syst)
    //!
    //
    lboites=[]
    lliens=[]
    lentrees=[]
    lsorties=[]
    nsyst=size(syst)
    for k=2:nsyst
        obj=syst(k)
        if type(obj)==15, if size(obj)>1 then
                select obj(1)
                case "transfer",
                    lboites=[lboites,k]
                case "link"
                    obj2=obj(3)
                    if obj2(1)>0 then
                        nobj=size(obj)
                        is_sortie=[]
                        for ko=3:nobj
                            objk=obj(ko)
                            if objk(1)<0 then is_sortie=[is_sortie,-objk(1)],end
                        end;
                        if is_sortie==[] then lliens=[lliens,k],
                        else lsorties(1,is_sortie)=k
                        end;
                    else lentrees(1,-obj2(1))=k,
                    end;
                else  error(msprintf(gettext("%s: Undefined type ''%s''.\n"),"bloc2exp",obj(1)))
                end;
        end,end
    end;
    if min(lsorties)==0 then
        error(msprintf(gettext("%s: Some output(s) are undefined.\n"),"bloc2exp")),
    end
    if min(lentrees)==0 then
        error(msprintf(gettext("%s: Some input(s) are undefined.\n"),"bloc2exp")),
    end

endfunction
function [where_x]=%connect(bloc,lliens,syst)
    where_x=list();nw=0
    nliens=prod(size(lliens))
    for l=1:nliens,
        lien=syst(lliens(l));
        nb=size(lien);
        whi=l
        for k=4:nb,
            output=lien(k),
            if bloc==output(1) then whi=[whi,output(2)],end;
        end;
        if prod(size(whi))>1 then nw=nw+1,where_x(nw)=whi,end
    end;

endfunction
function [where_x]=out1(bloc,lliens,syst)
    where_x=[];l=0;
    for li=lliens
        lien=syst(li)
        nb=size(lien);l=l+1;
        output=lien(3),
        if bloc==output(1) then where_x=[where_x,[l;output(2)]],end;
    end;
endfunction