using Plots;
using FFTW;
using DSP;

# read I/Q samples
function gimme()
    data = reinterpret(Complex{Float32}, read("/home/domagoj/gqrx_20181207_153804_437485000_1800000_fc.raw"));
    dataLength = floor(Int, size(data,1));

    # multiply by complex exponential -> frequency shift; desired carrier frequency is shifted to origin
    T = 1/1800000;
    shiftFreq = 23000;
    shiftExp = [exp(-im*2*pi*shiftFreq*n*T) for n in 1:dataLength];
    data = data.*shiftExp;

    # create Butterworth lowpass filter
    responsetype = Lowpass(1500; fs=1800000);
    prototype = Butterworth(40);

    # apply created filter to sample array
    db = filt(digitalfilter(responsetype, prototype), data);
end
try
    db;
catch
    db = gimme();
end
#=
# generate and plot 32768-FFT results
windowSize = 32768;
n = floor(Int, size(dbdAvg,1)/windowSize);
for i in 1:n
    F = fft(dbdAvg[(i-1)*windowSize+1:i*windowSize]);
    F = fftshift(F);
    Fr = [20*log10(abs(i)) for i in F];
    plot(Fr[15000:17500])
    #ylims!(-30, 60);
    gui();
    sleep(0.04)
end
=#
function unweraper(x)
    state = 0;
    retArr = Array{Float32}(length(x));

    for i=1:length(x)
        w = x[i];
        if (pi - w < 0.01)
            state--;
        end
        if (w + pi < -0.0)
            state++;
        end
        ret[i] = x[i] + pi*state;
    end
    retArr
end

angularv = (x, i) -> i> 1 && i <= length(x) ? angle(x[i]/x[i-1]) : 0
dbAng = angle.(db) |> unwrap;
#dbd = [diffNaiv(dbAng, i) for i=1:length(dbAng)];
#dbav = [angularv(dbAng, i) for i=1:length(dbAng)];
#dbdAvg = [Statistics.median((dbd[i-30:i])) for i=31:30:length(dbd)];
diffNaiv = (x, i) -> i> 1 && i <= length(x) ? x[i] - x[i-1] : typeof(x[1])(0);
Q = imag.(data) - real.(data) .|> sign ;
Qd = [diffNaiv(dbAng, i) for i=2:length(dbAng)];
dbd = sign.(dbd);
# plot d_phi / dt
windowSize = 1024;
n = floor(Int, size(Q,1)/windowSize);
b = true;
function a(arrr, amp, frame, ws)
    for i in (18 * ws):(20 * ws)
        currr = arrr[(i-1)*windowSize+1:i*windowSize];
#       if (currr |> findmin)[1] >  | true
            plot(currr)
            if (amp > 0)
                ylims!(-amp,amp)
            end
            #xlims!(-.01,.01)
            gui()
            sleep(frame)
            if !b
                break;
            end
            println(i);
#       end
    endcd
    println("Stopped");
end
@async a(Qd, 0.01, 0.04, windowSize)
#=
# plot "live" constellation diagram
windowSize = 10240;
n = floor(Int, size(db,1)/windowSize);
for i in 1:n
    plot(db[(i-1)*windowSize+1:i*windowSize])
    ylims!(-.01u,.01)
    xlims!(-.01,.01)
    gui();
    sleep(0.04)
end
=#

# EOF