%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Copyright (c) 2023, Amon Lahr, Simon Muntwiler, Antoine Leeman & Fabian Flürenbrock Institute for Dynamic Systems and Control, ETH Zurich.
%
% All rights reserved.
%
% Please see the LICENSE file that has been included as part of this package.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

classdef MPC
    properties
        yalmip_optimizer
    end

    methods
        function obj = MPC(Q,R,N,params)
            nu = params.model.nu;
            nx = params.model.nx;

            % define optimization variables
            U = sdpvar(repmat(nu,1,N),ones(1,N),'full');
            X0 = sdpvar(nx,1,'full');

            % YOUR CODE HERE
            
            opts = sdpsettings('verbose',1,'solver','quadprog');
            obj.yalmip_optimizer = optimizer(constraints,objective,opts,X0,{U{1} objective});
        end

        function [u, ctrl_info] = eval(obj,x)
            %% evaluate control action by solving MPC problem, e.g.
            tic;
            [optimizer_out,errorcode] = obj.yalmip_optimizer(x);
            solvetime = toc;
            
            [u, objective] = optimizer_out{:};

            feasible = true;
            if (errorcode ~= 0)
                feasible = false;
            end

            ctrl_info = struct('ctrl_feas',feasible,'objective',objective,'solvetime',solvetime);
        end
    end
end