classdef PAMsource_test < IMDDTestCase
    methods (Test, TestTags = {'unit', 'fast', 'transmit', 'pamsource'})
        function constructorStoresProvidedOptions(testCase)
            src = PAMsource( ...
                "order", 5, ...
                "useprbs", false, ...
                "M", 4, ...
                "fsym", 8, ...
                "randkey", 17, ...
                "applypulseform", false, ...
                "fs_out", 8, ...
                "applyclipping", false);

            testCase.verifyEqual(src.order, 5);
            testCase.verifyFalse(src.useprbs);
            testCase.verifyEqual(src.M, 4);
            testCase.verifyEqual(src.fsym, 8);
            testCase.verifyEqual(src.randkey, 17);
            testCase.verifyFalse(src.applypulseform);
            testCase.verifyEqual(src.fs_out, 8);
            testCase.verifyFalse(src.applyclipping);
            testCase.verifyEmpty(src.pulseformer);
        end

        function deterministicProcessMatchesPamMapperAcrossOrders(testCase)
            orders = [2, 4, 8];
            sourceOrder = 5;
            fs = 8;
            seed = 17;

            for M = orders
                src = PAMsource( ...
                    "order", sourceOrder, ...
                    "useprbs", false, ...
                    "M", M, ...
                    "fsym", fs, ...
                    "randkey", seed, ...
                    "applypulseform", false, ...
                    "fs_out", fs, ...
                    "applyclipping", false);

                [digiSig, symbols, bits] = src.process();

                bitpattern = expectedBitpattern(M, sourceOrder, seed);
                expectedBits = Informationsignal(bitpattern);
                expectedSymbols = PAMmapper(M, 0).map(expectedBits);

                testCase.verifyClass(digiSig, 'Informationsignal');
                testCase.verifyClass(symbols, 'Informationsignal');
                testCase.verifyClass(bits, 'Informationsignal');
                testCase.verifyEqual(bits.signal, bitpattern);
                testCase.verifyEqual(symbols.signal, expectedSymbols.signal);
                testCase.verifyEqual(digiSig.signal, expectedSymbols.signal);
                testCase.verifyEqual(digiSig.fs, fs);
            end
        end

        function clippingLimitsAmplitudeToScaledConstellationRange(testCase)
            M = 4;
            sourceOrder = 5;
            fs = 8;
            seed = 3;

            src = PAMsource( ...
                "order", sourceOrder, ...
                "useprbs", false, ...
                "M", M, ...
                "fsym", fs, ...
                "randkey", seed, ...
                "applypulseform", false, ...
                "fs_out", fs, ...
                "applyclipping", true, ...
                "clipfactor", 0.5);

            [digiSig, symbols, bits] = src.process();

            expectedBits = expectedBitpattern(M, sourceOrder, seed);
            expectedSymbols = PAMmapper(M, 0).map(Informationsignal(expectedBits));
            lowerLimit = min(expectedSymbols.signal) * 0.5;
            upperLimit = max(expectedSymbols.signal) * 0.5;
            expectedClipped = expectedSymbols.signal;
            expectedClipped(expectedClipped < lowerLimit) = lowerLimit;
            expectedClipped(expectedClipped > upperLimit) = upperLimit;

            testCase.verifyEqual(bits.signal, expectedBits);
            testCase.verifyEqual(symbols.signal, expectedSymbols.signal);
            testCase.verifyEqual(digiSig.signal, expectedClipped);
            testCase.verifyEqual(digiSig.fs, fs);
            testCase.verifyLessThanOrEqual(max(digiSig.signal), upperLimit);
            testCase.verifyGreaterThanOrEqual(min(digiSig.signal), lowerLimit);
        end
    end
end

function bitpattern = expectedBitpattern(M, order, seed)
    bitWidth = log2(M);
    N = 2^(order - 1);
    s = RandStream('twister', 'Seed', seed);
    bitpattern = zeros(N, bitWidth);

    for idx = 1:bitWidth
        bitpattern(:, idx) = randi(s, [0 1], N, 1);
    end
end