// Copyright 2019-2020 CERN and copyright holders of ALICE O2.

// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.

// All rights not expressly granted are reserved.

//

// This software is distributed under the terms of the GNU General Public

// License v3 (GPL Version 3), copied verbatim in the file "COPYING".

//

// In applying this license CERN does not waive the privileges and immunities

// granted to it by virtue of its status as an Intergovernmental Organization

// or submit itself to any jurisdiction.

#define BOOST_TEST_MODULE Test InteractionSampler class

#define BOOST_TEST_MAIN

#define BOOST_TEST_DYN_LINK

#include <algorithm>

#include <boost/test/unit_test.hpp>

#include "CommonDataFormat/InteractionRecord.h"

#include "SimulationDataFormat/InteractionSampler.h"

namespace o2

{

BOOST_AUTO_TEST_CASE(InteractionSampler)

{

using Sampler = o2::steer::InteractionSampler;

const int ntest = 100;

std::vector<o2::InteractionTimeRecord> records; // destination for records

records.reserve(ntest);

printf("Testing sampler with default settings\n");

// default sampler with BC filling like in TPC TDR, 50kHz

Sampler defSampler;

defSampler.init();

defSampler.generateCollisionTimes(records);

double t = -1.;

for (const auto& rec : records) {

BOOST_CHECK(rec.getTimeNS() >= t); // make sure time is non-decreasing

t = rec.getTimeNS();

}

printf("\nTesting sampler with custom bunch filling and low mu\n");

// configure sampler with custom bunch filling and mu per BC

Sampler sampler1;

// train of 100 bunches spaced by 25 ns (1slot) and staring at BC=0

sampler1.getBunchFilling().setBCTrain(100, 1, 0);

// train of 100 bunches spaced by 50 ns (2slots) and staring at BC=200

sampler1.getBunchFilling().setBCTrain(200, 2, 200);

// add isolated BC at slot 1600

sampler1.getBunchFilling().setBC(1600);

// add 5 trains of 20 bunches with 100ns(4slots) spacing, separated by 10 slots and

// starting at bunch 700

sampler1.getBunchFilling().setBCTrains(5, 10, 20, 4, 700);

// set total interaction rate in Hz

sampler1.setInteractionRate(40e3);

sampler1.init();

sampler1.generateCollisionTimes(records);

t = -1.;

for (const auto& rec : records) {

BOOST_CHECK(rec.getTimeNS() >= t); // make sure time is non-decreasing

t = rec.getTimeNS();

}

// make sure the IR corresponds to declared one

records.reserve((int)sampler1.getInteractionRate());

sampler1.generateCollisionTimes(records);

double dt = (records.back().getTimeNS() - records.front().getTimeNS()) * 1.e-9;

printf("\nGenerated %d collisions with time span %.3fs at IR=%e\n",

(int)records.size(), dt, sampler1.getInteractionRate());

BOOST_CHECK(std::abs(dt - 1.) < 0.1);

// reconfigure w/o modifying BC filling but setting per bunch

// mu (large -> lot of in-bunch pile-up)

printf("\nResetting/testing sampler with same bunch filling but high mu\n");

sampler1.setMuPerBC(0.5);

sampler1.init(); // this will reset all counters from previous calls

// instead of filling the vector records, we can sample one by one

t = -1.;

for (int i = 0; i < ntest; i++) {

auto rec = sampler1.generateCollisionTime();

rec.print();

// make sure time is non-decreasing and the BC is interacting

BOOST_CHECK(rec.getTimeNS() >= t && sampler1.getBunchFilling().testBC(rec.bc));

t = rec.getTimeNS();

}

sampler1.print();

sampler1.getBunchFilling().print();

}

} // namespace o2