classdef Optical_Demultiplex_test < IMDDTestCase
    methods (Test, TestTags = {'unit', 'fast', 'optical', 'demux'})
        function processReturnsOneCellPerChannelAndPreservesMetadata(testCase)
            fs = 32e9;
            lambdaCenterNm = 1310;
            lambdaA = 1309e-9;
            lambdaB = 1311e-9;

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

            mux = Optical_Multiplex( ...
                "fs_in", fs, ...
                "fs_out", fs, ...
                "lambda_center", lambdaCenterNm, ...
                "delta_f", 0, ...
                "random_key", 0, ...
                "attenuation", 0, ...
                "filtype", 3, ...
                "B", 200e9);
            muxOut = mux.process({sigA, sigB});

            demux = Optical_Demultiplex( ...
                "fs_in", muxOut.fs, ...
                "fs_out", muxOut.fs, ...
                "lambda_center", lambdaCenterNm, ...
                "attenuation", 0, ...
                "filtype", 3, ...
                "B", 200e9);
            out = demux.process(muxOut);

            testCase.verifyClass(out, 'cell');
            testCase.verifyNumElements(out, 2);
            testCase.verifyClass(out{1}, 'Opticalsignal');
            testCase.verifyClass(out{2}, 'Opticalsignal');
            testCase.verifyEqual(size(out{1}.signal), size(muxOut.signal));
            testCase.verifyEqual(size(out{2}.signal), size(muxOut.signal));
            testCase.verifyEqual(out{1}.fs, fs);
            testCase.verifyEqual(out{2}.fs, fs);
            testCase.verifyEqual(out{1}.lambda, muxOut.lambda(1), 'AbsTol', 1e-12);
            testCase.verifyEqual(out{2}.lambda, muxOut.lambda(2), 'AbsTol', 1e-12);
        end

        function roundTripThroughMuxAndDemuxPreservesChannelMagnitudes(testCase)
            fs = 16e9;
            lambdaCenterNm = 1310;

            sigA = makeOpticalSignal(ones(8, 2), fs, 1309.5e-9, 0.0);

            mux = Optical_Multiplex( ...
                "fs_in", fs, ...
                "fs_out", fs, ...
                "lambda_center", lambdaCenterNm, ...
                "delta_f", 0, ...
                "random_key", 0, ...
                "attenuation", 0, ...
                "filtype", 3, ...
                "B", 200e9);
            muxOut = mux.process({sigA});

            demux = Optical_Demultiplex( ...
                "fs_in", muxOut.fs, ...
                "fs_out", muxOut.fs, ...
                "lambda_center", lambdaCenterNm, ...
                "attenuation", 0, ...
                "filtype", 3, ...
                "B", 200e9);
            out = demux.process(muxOut);

            testCase.verifyNumElements(out, 1);
            testCase.verifyEqual(size(out{1}.signal), size(sigA.signal));
            testCase.verifyEqual(out{1}.fs, fs);
            testCase.verifyEqual(out{1}.lambda, muxOut.lambda(1), 'AbsTol', 1e-12);
            testCase.verifyEqual(mean(abs(out{1}.signal), 'all'), mean(abs(sigA.signal), 'all'), 'AbsTol', 1e-6);
        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