classdef FFE_test < IMDDTestCase
    methods (Test, TestTags = {'unit', 'fast', 'dsp', 'ffe'})
        function constructorStoresDefaultsAndInitialState(testCase)
            ffe = FFE();

            testCase.verifyEqual(ffe.sps, 2);
            testCase.verifyEqual(ffe.order, 15);
            testCase.verifyEqual(ffe.len_tr, 4096);
            testCase.verifyEqual(ffe.mu_tr, 0);
            testCase.verifyEqual(ffe.epochs_tr, 5);
            testCase.verifyEqual(ffe.adaption_technique, adaption_method.lms);
            testCase.verifyEqual(ffe.dd_mode, 1);
            testCase.verifyEqual(ffe.mu_dd, 1e-5);
            testCase.verifyEqual(ffe.epochs_dd, 5);
            testCase.verifyFalse(logical(ffe.optimize_dc_params));
            testCase.verifyEqual(ffe.dc_optimization_delay_weight, 1e-3);
            testCase.verifyFalse(ffe.decide);
            testCase.verifyEqual(ffe.e, zeros(ffe.order, 1));
            testCase.verifyEqual(ffe.error, 0);
        end

        function noUpdateModeKeepsWeightsAtZeroAndPreservesSamplingRate(testCase)
            x = makeSignal([-1; 1; -1; 1], 32e9);
            d = makeSignal([-1; 1; -1; 1], 8e9);

            ffe = FFE( ...
                "sps", 1, ...
                "order", 1, ...
                "len_tr", length(x), ...
                "mu_tr", 0, ...
                "epochs_tr", 1, ...
                "mu_dd", 0, ...
                "epochs_dd", 1, ...
                "dd_mode", 0, ...
                "decide", false, ...
                "adaption_technique", adaption_method.lms);

            [y, noi] = ffe.process(x, d);

            testCase.verifyEqual(ffe.e, 0);
            testCase.verifyEqual(ffe.e_tr, 0);
            testCase.verifyEqual(y.signal, zeros(size(x.signal)), "AbsTol", 1e-12);
            testCase.verifyEqual(y.fs, d.fs);
            testCase.verifyEqual(noi.signal, -d.signal, "AbsTol", 1e-12);
            testCase.verifyEqual(length(y.signal), length(x.signal));
        end

        function trainingModeLearnsFromTinySyntheticChannel(testCase)
            x = makeSignal([1; -1; 1; -1], 16e9);
            d = makeSignal([1; -1; 1; -1], 4e9);

            ffe = FFE( ...
                "sps", 1, ...
                "order", 1, ...
                "len_tr", length(x), ...
                "mu_tr", 0.5, ...
                "epochs_tr", 1, ...
                "mu_dd", 0, ...
                "epochs_dd", 1, ...
                "dd_mode", 0, ...
                "decide", false, ...
                "adaption_technique", adaption_method.lms);

            [y, noi] = ffe.process(x, d);

            testCase.verifyEqual(y.fs, d.fs);
            testCase.verifyClass(y, 'Informationsignal');
            testCase.verifyClass(noi, 'Informationsignal');
            testCase.verifyNotEqual(ffe.e, 0);
            testCase.verifyNotEqual(ffe.e_tr, 0);
            testCase.verifyNotEqual(y.signal, zeros(size(x.signal)));
            testCase.verifyEqual(length(y.signal), length(x.signal));
        end
    end
end

function sig = makeSignal(values, fs)
    base = Signal(values);
    sig = Informationsignal(values, "fs", fs, "logbook", base.logbook);
end