classdef Polarization_Controller
    %Input can be "normal" - output will be DP!

    properties(Access=public)

        mode
        desired_angle
        desired_power

        rotation_angle
        rotation_matrix

    end

    methods (Access=public)
        function obj = Polarization_Controller(options)
            %NAME Construct an instance of this class
            %   Detailed explanation goes here

            arguments
                options.mode polarization_control_mode = polarization_control_mode.rot_power
                options.desired_angle
                options.desired_power

            end

            %
            fn = fieldnames(options);
            for n = 1:numel(fn)
                try
                    obj.(fn{n}) = options.(fn{n});
                end
            end

            % do more stuff

        end

        function signalclass_out = process(obj,signalclass_in)

            % actual processing of the signal (steps 1. - 3.)
            [signalclass_in.signal,signalclass_in.polrot] = obj.process_(signalclass_in.signal,signalclass_in.polrot);

            % append to logbook
            lbdesc = ['Logbookentry'];
            signalclass_in  = signalclass_in.logbookentry(lbdesc);

            % write to output
            signalclass_out = signalclass_in;

        end

        function [data_out, polrot_out] = process_(obj,data_in,polrot_in)
            % Rotate polarization of am opt signal

            arguments(Input)
                obj
                data_in double
                polrot_in double
            end


            if obj.mode ~= polarization_control_mode.deactivate

                switch obj.mode
                    case polarization_control_mode.random
                        obj.rotation_angle = 2*pi*rand ;

                    case polarization_control_mode.rot_angle
                        obj.rotation_angle = obj.desired_angle*pi/180 ;

                    case polarization_control_mode.rot_power
                        obj.rotation_angle = -polrot_in + acos(sqrt(obj.desired_power/100)) ;
                end

                obj.rotation_matrix = [cos(obj.rotation_angle) -sin(obj.rotation_angle) ; sin(obj.rotation_angle) cos(obj.rotation_angle)].' ;

                if min(size(data_in)) == 1
                    data_in = reshape(data_in,[],1);
                    data_in = [data_in, zeros(length(data_in),1)];
                end

                data_out = data_in * obj.rotation_matrix;

                polrot_out = polrot_in + obj.rotation_angle ;

            end


        end
    end
end