classdef ML_MLSE_DUOBINARY_test < IMDDTestCase
    methods (Test, TestTags = {'unit', 'fast', 'dsp', 'ml_mlse', 'duobinary'})
        function constructorStoresDuobinaryConfiguration(testCase)
            eq = ML_MLSE_DUOBINARY();

            testCase.verifyEqual(class(eq), 'ML_MLSE_DUOBINARY');
            testCase.verifyEqual(eq.sps, 2);
            testCase.verifyEqual(eq.order, 15);
            testCase.verifyEqual(eq.ber, []);
            testCase.verifyEqual(eq.ber_dd, []);
        end

        function processReturnsPrecodeDomainAndFiniteDiagnostics(testCase)
            [~, ~, txPrecoded, txEncoded] = makePam4Fixture(512);

            eq = ML_MLSE_DUOBINARY( ...
                "sps", 1, ...
                "order", 1, ...
                "len_tr", length(txEncoded), ...
                "epochs_tr", 1, ...
                "epochs_dd", 1, ...
                "mu_tr", 0.01, ...
                "mu_dd", 0.01, ...
                "adaptive_mu", false, ...
                "L", 1);

            [detected, detectedViterbi] = eq.process(txEncoded, txPrecoded);

            testCase.verifyEqual(length(detected), length(txEncoded));
            testCase.verifyEqual(length(detectedViterbi), length(txEncoded));
            testCase.verifyTrue(all(ismembertol(detected.signal, unique(txPrecoded.signal), 1e-12)));
            testCase.verifySize(eq.ber, [1 1]);
            testCase.verifySize(eq.ber_dd, [1 1]);
            testCase.verifyTrue(isfinite(eq.ber(1)));
            testCase.verifyTrue(isfinite(eq.ber_dd(1)));

        end

        function encodeDecodeInvertsPrecodingAwayFromInitialState(testCase)
            [~, txSymbols, txPrecoded, ~] = makePam4Fixture(512);

            encoded = Duobinary().encode(txPrecoded, "M", 4);
            decoded = Duobinary().decode(encoded, "M", 4);

            testCase.verifyEqual(decoded.signal(11:end-10), ...
                txSymbols.signal(11:end-10), "AbsTol", 1e-12);
        end

        function resultWrapperReportsBothPrecodedAndOriginalBer(testCase)
            [txBits, ~, txPrecoded, txEncoded] = makePam4Fixture(32000);

            eq = ML_MLSE_DUOBINARY( ...
                "sps", 1, ...
                "order", 1, ...
                "len_tr", length(txEncoded), ...
                "epochs_tr", 1, ...
                "epochs_dd", 1, ...
                "mu_tr", 0.01, ...
                "mu_dd", 0.01, ...
                "adaptive_mu", false, ...
                "L", 1);

            results = ml_mlse(eq, 4, txEncoded, txPrecoded, txBits, ...
                "precode_mode", db_mode.db_precoded);

            testCase.verifyTrue(isfinite(results.metrics.BER));
            testCase.verifyTrue(isfinite(results.metrics.BER_precoded));
            testCase.verifyGreaterThanOrEqual(results.metrics.numBits, 0);
            testCase.verifyGreaterThanOrEqual(results.metrics.numBitErr, 0);
            testCase.verifyGreaterThanOrEqual(results.metrics.numBitErr_precoded, 0);
        end
    end
end

function [txBits, txSymbols, txPrecoded, txEncoded] = makePam4Fixture(nSymbols)
    pattern = [0 0; 0 1; 1 1; 1 0];
    bits = repmat(pattern, ceil(nSymbols / size(pattern, 1)), 1);
    bits = bits(1:nSymbols, :);

    txBits = Informationsignal(bits);
    txSymbols = PAMmapper(4, 0).map(txBits);
    txPrecoded = Duobinary().precode(txSymbols);
    txEncoded = Duobinary().encode(txPrecoded, "M", 4);
end