// Copyright (C) 2016 - IIT Bombay - FOSSEE
//
// 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-en.txt
// Author: Pranav Deshpande and Akshay Miterani
// Organization: FOSSEE, IIT Bombay
// Email: toolbox@scilab.in

function [xopt,fopt,status,output] = cbcmatrixintlinprog (varargin)
    // Sci file wrapper for the matrix_cbcintlinprog.cpp file
        
    // To check the number of input and output argument
    [lhs , rhs] = argn();
    
    // To check the number of argument given by user
    if ( rhs < 4 | rhs == 5 | rhs == 7 | rhs > 9 ) then
        errmsg = msprintf(gettext("%s: Unexpected number of input arguments : %d provided while should be in the set [4 6 8 9]"), "cbcintlinprog", rhs);
        error(errmsg);
    end
   
    c = [];
    intcon = [];
    A = [];
    b = [];
    Aeq = [];
    beq = [];
    lb = [];
    ub = [];
    options = list();
    
    c = varargin(1)
    intcon = varargin(2)
    A = varargin(3)
    b = varargin(4)

    if(size(c,2) == 0) then
        errmsg = msprintf(gettext("%s: Cannot determine the number of variables because input objective coefficients is empty"),"cbcintlinprog");
        error(errmsg);
    end

   if (size(c,2)~=1) then
    errmsg = msprintf(gettext("%s: Objective Coefficients should be a column matrix"), "cbcintlinprog");
    error(errmsg);
   end

   nbVar = size(c,1);

   if ( rhs<5 ) then
      Aeq = []
      beq = []
   else
      Aeq = varargin(5);
      beq = varargin(6);
   end
   
   if ( rhs<7 ) then
      lb = repmat(-%inf,1,nbVar);
      ub = repmat(%inf,1,nbVar);
   else
      lb = varargin(7);
      ub = varargin(8);
   end
   
   if (rhs<9|size(varargin(9))==0) then
      options = list();
   else
      options = varargin(9);
   end

    //Check type of variables
    Checktype("cbcintlinprog", c, "c", 1, "constant")
    Checktype("cbcintlinprog", intcon, "intcon", 2, "constant")
    Checktype("cbcintlinprog", A, "A", 3, "constant")
    Checktype("cbcintlinprog", b, "b", 4, "constant")
    Checktype("cbcintlinprog", Aeq, "Aeq", 5, "constant")
    Checktype("cbcintlinprog", beq, "beq", 6, "constant")
    Checktype("cbcintlinprog", lb, "lb", 7, "constant")
    Checktype("cbcintlinprog", ub, "ub", 8, "constant")

    // Check if the user gives empty matrix
    if (size(lb,2)==0) then
        lb = repmat(-%inf,nbVar,1);
    end
    
    if (size(intcon,2)==0) then
        intcon = [];
    end
    
    if (size(ub,2)==0) then
        ub = repmat(%inf,nbVar,1);
    end

    // Calculating the size of equality and inequality constraints
    nbConInEq = size(A,1);
    nbConEq = size(Aeq,1);

    // Check if the user gives row vector 
    // and Changing it to a column matrix

    if (size(lb,2)== [nbVar]) then
        lb = lb';
    end

    if (size(ub,2)== [nbVar]) then
        ub = ub';
    end

    if (size(b,2)== [nbConInEq]) then
        b = b';
    end

    if (size(beq,2)== [nbConEq]) then
        beq = beq';
    end

    for i=1:size(intcon,2)
        if(intcon(i)>nbVar) then
            errmsg = msprintf(gettext("%s: The values inside intcon should be less than the number of variables"), "cbcintlinprog");
            error(errmsg);
        end

        if (intcon(i)<0) then
            errmsg = msprintf(gettext("%s: The values inside intcon should be greater than 0 "), "cbcintlinprog");
            error(errmsg);
        end

        if(modulo(intcon(i),1)) then
            errmsg = msprintf(gettext("%s: The values inside intcon should be an integer "), "cbcintlinprog");
            error(errmsg);
        end
    end

   //Check the size of inequality constraint which should equal to the number of inequality constraints
    if ( size(A,2) ~= nbVar & size(A,2) ~= 0) then
        errmsg = msprintf(gettext("%s: The size of inequality constraint is not equal to the number of variables"), "cbcintlinprog");
        error(errmsg);
    end


   //Check the size of lower bound of inequality constraint which should equal to the number of constraints
    if ( size(b,1) ~= size(A,1)) then
        errmsg = msprintf(gettext("%s: The Lower Bound of inequality constraint is not equal to the number of constraint"), "cbcintlinprog");
        error(errmsg);
    end

   //Check the size of equality constraint which should equal to the number of inequality constraints
    if ( size(Aeq,2) ~= nbVar & size(Aeq,2) ~= 0) then
        errmsg = msprintf(gettext("%s: The size of equality constraint is not equal to the number of variables"), "cbcintlinprog");
        error(errmsg);
    end

   //Check the size of upper bound of equality constraint which should equal to the number of constraints
    if ( size(beq,1) ~= size(Aeq,1)) then
        errmsg = msprintf(gettext("%s: The equality constraint upper bound is not equal to the number of equality constraint"), "cbcintlinprog");
        error(errmsg);
    end

   //Check the size of Lower Bound which should equal to the number of variables
   if ( size(lb,1) ~= nbVar) then
      errmsg = msprintf(gettext("%s: The Lower Bound is not equal to the number of variables"), "cbcintlinprog");
      error(errmsg);
   end

   //Check the size of Upper Bound which should equal to the number of variables
   if ( size(ub,1) ~= nbVar) then
      errmsg = msprintf(gettext("%s: The Upper Bound is not equal to the number of variables"), "cbcintlinprog");
      error(errmsg);
   end
   
   if (type(options) ~= 15) then
      errmsg = msprintf(gettext("%s: Options should be a list "), "cbcintlinprog");
      error(errmsg);
   end
   

   if (modulo(size(options),2)) then
    errmsg = msprintf(gettext("%s: Size of parameters should be even"), "cbcintlinprog");
    error(errmsg);
   end

   //Check if the user gives a matrix instead of a vector
   
   if (((size(intcon,1)~=1)& (size(intcon,2)~=1))&(size(intcon,2)~=0)) then
      errmsg = msprintf(gettext("%s: intcon should be a vector"), "cbcintlinprog");
      error(errmsg); 
   end
   
   if (size(lb,1)~=1)& (size(lb,2)~=1) then
      errmsg = msprintf(gettext("%s: Lower Bound should be a vector"), "cbcintlinprog");
      error(errmsg); 
   end
   
   if (size(ub,1)~=1)& (size(ub,2)~=1) then
      errmsg = msprintf(gettext("%s: Upper Bound should be a vector"), "cbcintlinprog");
      error(errmsg); 
   end
   
   if (nbConInEq) then
        if ((size(b,1)~=1)& (size(b,2)~=1)) then
            errmsg = msprintf(gettext("%s: Constraint Lower Bound should be a vector"), "cbcintlinprog");
            error(errmsg); 
        end
    end
    
    if (nbConEq) then
        if (size(beq,1)~=1)& (size(beq,2)~=1) then
            errmsg = msprintf(gettext("%s: Constraint Upper Bound should be a vector"), "cbcintlinprog");
            error(errmsg); 
        end
   end
  

    //Changing the inputs in symphony's format 
    conMatrix = [A;Aeq]
    nbCon = size(conMatrix,1);
    conLB = [repmat(-%inf,size(A,1),1);beq];
    conUB = [b;beq] ;
    
    isInt = repmat(%f,1,nbVar);
    // Changing intcon into column vector
    intcon = intcon(:);
    for i=1:size(intcon,1)
        isInt(intcon(i)) = %t
    end
    
    objSense = 1.0;

    //Changing into row vector
    lb = lb';
    ub = ub';
    c = c';
    
    //Pusing options as required to a double array
    optval = [];
    if length(options) == 0 then
        optval = [0 0 0 0];
    else
        optval = [0 0 0 0];
        for i=1:2:length(options)
            select options(i)
                case 'IntegerTolerance' then
                    optval(1) = options(i+1);
                case 'MaxNodes' then
                    optval(2) = options(i+1);
                case 'MaxTime' then
                    optval(3) = options(i+1);
                case 'AllowableGap' then
                    optval(4) = options(i+1);
                else
                    error(999, 'Unknown string argument passed.');
                end
        end
    end
	
    [xopt,fopt,status,nodes,nfpoints,L,U,niter] = sci_matrix_intlinprog(nbVar,nbCon,c,intcon,conMatrix,conLB,conUB,lb,ub,objSense,optval);

    //Debugging Prints
    //disp(c);disp(intcon);disp(conMatrix);disp(conLB);disp(conUB);disp(lb);disp(ub);disp(Aeq);disp(beq);disp(xopt);
    //disp(L);disp(U);
    //disp(options);
    
    output = struct("relativegap"       , [],..
                    "absolutegap"       , [],..
                    "numnodes"          , [],..
                    "numfeaspoints"     , [],..
                    "numiterations"		, [],..
                    "constrviolation"   , [],..
                    "message"           , '');
                    
    output.numnodes=[nodes];
    output.numfeaspoints=[nfpoints];
    output.numiterations=[niter];
    output.relativegap=(U-L)/(abs(U)+1);
    output.absolutegap=(U-L);
    output.constrviolation = max([0;norm(Aeq*xopt-beq, 'inf');(lb'-xopt);(xopt-ub');(A*xopt-b)]);
    
    select status

    case 0 then
        output.message="Optimal Solution"
    case 1 then 
        output.message="Primal Infeasible"
    case 2 then 
        output.message="Solution Limit is reached"
    case 3 then
        output.message="Node Limit is reached"
    case 4 then 
        output.message="Numerical Difficulties"
    case 5 then 
        output.message="Time Limit Reached"
    case 6 then 
        output.message="Continuous Solution Unbounded"
    case 7 then 
        output.message="Dual Infeasible"
    else
        output.message="Invalid status returned. Notify the Toolbox authors"
        break;
    end

endfunction