%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% 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.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

function [tuning_struct, i_opt] = lqr_tuning(x0,Q,params)
    % YOUR CODE HERE
    R = eye(params.model.nu);
    size_Q = size(Q);
    param_choices = size_Q(2);
    J_array = [];
    tuning_struct = [];
    for i = 1:param_choices
        Q_mat = diag(Q(:,i));
        ctrl = LQR(Q_mat,R,params);
        [Xt, Ut, ~] = simulate(x0, ctrl, params);
        [s_max, y_max, u_max, J_u, df_max, vf_max, traj_feas] = traj_constraints(Xt,Ut,params);
        % YOUR CODE HERE
        % ctrl_feas_arr = [];
        % for k = 1:params.model.HorizonLength
        %     ctrl_feas_arr = [ctrl_feas_arr,ctrl_info(k).ctrl_feas];
        % end
        % if all(ctrl_feas_arr)
        %     J = 0;
        %     for j = 1:params.model.HorizonLength
        %         J = J + Xt(:,j)'*Q_mat*Xt(:,j);
        %         J = J + Ut(:,j)'*R*Ut(:,j);
        %     end
        %     J = J + Xt(:,end)'*Q_mat*Xt(:,end);
        %     J_array = [J_array, J];
        %     tuning_struct_item.TrajFeasible = true;
        % else
        %     tuning_struct_item.TrajFeasible = false;
        % end
        tuning_struct_item.InitialCondition = x0;
        tuning_struct_item.Qdiag = Q(:,i);
        tuning_struct_item.MaxAbsPositionXZ = s_max;
        tuning_struct_item.MaxAbsPositionY = y_max;
        tuning_struct_item.MaxAbsThrust = u_max;
        tuning_struct_item.InputCost = J_u;
        tuning_struct_item.MaxFinalPosDiff = df_max;
        tuning_struct_item.MaxFinalVelDiff = vf_max;
        tuning_struct_item.TrajFeasible = traj_feas;

        if traj_feas
            J_array = [J_array, J_u];
        end

        tuning_struct = [tuning_struct,tuning_struct_item];
    end
%     display(J_array)
    tuning_struct = tuning_struct'; 
    if isempty(J_array)
        i_opt = nan;
    else
        [~, i_opt] = min(J_array);
    end
end