#include "stdafx.h"
#include "doctest.h"

#include "vehicle.h"

#include "vehicle/smoke.h"

// the smoke of a vehicle's engine: how many particles the smoke source of the vehicle's model spawns in an update

namespace {

// a source of 20 particles per second, with room for 100
smoke::spawn_rate const source{0.f, 20.f, 1.f, 100.f};
double const update{0.1}; // s

// a diesel at work, its engine in the state of one of the cases below
test::vehicle diesel() {
	test::vehicle vehicle{test::definition::load("wagon")};
	vehicle->MainCtrlPosNo = 1;
	vehicle->DElist[1].RPM = 1500.0;
	vehicle->enrot = 300.0;
	vehicle->EnginePower = 400.0;
	return vehicle;
}

} // namespace

TEST_CASE("smoke: a vehicle taken off the tracks puffs no more (#90)") {
	auto vehicle{diesel()};
	SUBCASE("engine starting") { vehicle->dizel_spinup = true; }
	SUBCASE("engine idling") { vehicle->DirAbsolute = 0; }
	SUBCASE("engine under load") {
		vehicle->DirAbsolute = 1;
		vehicle->Im = 400.0;
	}
	// on the tracks the engine puffs
	REQUIRE(smoke::vehicle_spawn_count(vehicle.mover(), true, source, update) >= 1.f);

	// gone through a portal, the pending particles are dropped too
	auto pending{source};
	pending.pending = 5.f;
	CHECK(smoke::vehicle_spawn_count(vehicle.mover(), false, pending, update) == 0.f);
}

TEST_CASE("smoke: a road vehicle back on the road from the pool puffs again") {
	auto vehicle{diesel()};
	// waiting in the pool, the count stays at zero update after update
	auto rate{source};
	for (auto i{0}; i < 10; ++i) {
		rate.pending = smoke::vehicle_spawn_count(vehicle.mover(), false, rate, update);
	}
	REQUIRE(rate.pending == 0.f);

	CHECK(smoke::vehicle_spawn_count(vehicle.mover(), true, rate, update) >= 1.f);
}

TEST_CASE("smoke: the engine adds to the steady rate of the source") {
	auto vehicle{diesel()};
	vehicle->DirAbsolute = 0;
	auto const steady{source.rate * update}; // the rate of a source of the scenery

	vehicle->EnginePower = 0.0;
	CHECK(smoke::vehicle_spawn_count(vehicle.mover(), true, source, update) == doctest::Approx(steady));

	vehicle->EnginePower = 400.0;
	auto const working{smoke::vehicle_spawn_count(vehicle.mover(), true, source, update)};
	CHECK(working > steady);

	// the faster the starting engine turns, the more it puffs
	vehicle->dizel_spinup = true;
	vehicle->enrot = 100.0;
	auto const slow{smoke::vehicle_spawn_count(vehicle.mover(), true, source, update)};
	vehicle->enrot = 400.0;
	CHECK(smoke::vehicle_spawn_count(vehicle.mover(), true, source, update) > slow);
}

TEST_CASE("smoke: the pending particles never outgrow the room of the source") {
	auto vehicle{diesel()};
	vehicle->dizel_spinup = true;
	vehicle->enrot = 100000.0;
	auto rate{source};
	rate.pending = 99.f;

	CHECK(smoke::vehicle_spawn_count(vehicle.mover(), true, rate, 10.0) == rate.limit);
}