classdef Optical_Multiplex_test < IMDDTestCase
    methods (Test, TestTags = {'unit', 'fast', 'optical', 'mux'})
        function processCombinesChannelsAndPreservesMetadata(testCase)
            fs = 32e9;
            lambdaCenter = 1550;
            lambdaA = 1550e-9;
            lambdaB = 1550e-9;

            sigA = makeOpticalSignal( ...
                [1 2; 1 2; 1 2], ...
                fs, ...
                lambdaA, ...
                0.10);
            sigB = makeOpticalSignal( ...
                [3 4; 3 4; 3 4], ...
                fs, ...
                lambdaB, ...
                0.90);

            mux = Optical_Multiplex( ...
                "fs_in", fs, ...
                "fs_out", fs, ...
                "lambda_center", lambdaCenter, ...
                "delta_f", 0, ...
                "random_key", 0, ...
                "attenuation", 0, ...
                "filtype", 3);

            out = mux.process({sigA, sigB});
            expected = combineSingleChannelMuxOutputs({sigA, sigB}, mux);

            testCase.verifyClass(out, 'Opticalsignal');
            testCase.verifyEqual(size(out.signal), [3 2]);
            testCase.verifyEqual(out.signal, expected, 'AbsTol', 1e-12);
            testCase.verifyEqual(out.fs, fs);
            testCase.verifyEqual(out.lambda, [lambdaA, lambdaB], 'AbsTol', 1e-9);
            testCase.verifyEqual(out.polrot, [0.10, 0.90], 'AbsTol', 1e-12);
            testCase.verifyEqual(height(out.logbook), 2);
            testCase.verifyEqual(string(out.logbook.Description(end)), "Opt. Mux. ");
        end

        function processSupportsMoreThanOneInputChannel(testCase)
            fs = 16e9;
            lambdaCenter = 1310;

            sig1 = makeOpticalSignal(ones(4, 2), fs, lambdaCenter * 1e-9, 0.0);
            sig2 = makeOpticalSignal(2 * ones(4, 2), fs, lambdaCenter * 1e-9, 0.5);
            sig3 = makeOpticalSignal(3 * ones(4, 2), fs, lambdaCenter * 1e-9, 1.0);

            mux = Optical_Multiplex( ...
                "fs_in", fs, ...
                "fs_out", fs, ...
                "lambda_center", lambdaCenter, ...
                "delta_f", 0, ...
                "random_key", 0, ...
                "attenuation", 0, ...
                "filtype", 3);

            out = mux.process({sig1, sig2, sig3});
            expected = combineSingleChannelMuxOutputs({sig1, sig2, sig3}, mux);

            testCase.verifySize(out.signal, [4, 2]);
            testCase.verifyEqual(out.signal, expected, 'AbsTol', 1e-12);
            testCase.verifyEqual(numel(out.lambda), 3);
            testCase.verifyEqual(numel(out.polrot), 3);
        end
    end
end

function sig = makeOpticalSignal(signal, fs, lambda, polrot)
    base = Signal(signal, "fs", fs);
    sig = Opticalsignal( ...
        signal, ...
        "fs", fs, ...
        "logbook", base.logbook, ...
        "lambda", lambda, ...
        "nase", 0, ...
        "polrot", polrot);
end

function expected = combineSingleChannelMuxOutputs(signals, muxPrototype)
    expected = [];

    for idx = 1:numel(signals)
        mux = Optical_Multiplex( ...
            "fs_in", muxPrototype.fs_in, ...
            "fs_out", muxPrototype.fs_out, ...
            "lambda_center", muxPrototype.lambda_center, ...
            "delta_f", muxPrototype.delta_f, ...
            "random_key", muxPrototype.random_key, ...
            "attenuation", muxPrototype.attenuation, ...
            "filtype", muxPrototype.filtype);
        singleOut = mux.process({signals{idx}});

        if isempty(expected)
            expected = zeros(size(singleOut.signal));
        end

        expected = expected + singleOut.signal;
    end
end