#include <catch.hpp>
#include <alsk/alsk.h>

using namespace alsk::arg;
using namespace alsk::edsl;

static int counterDo, counterThen, counterDone;

struct Do { void operator()() { ++counterDo; } };
struct Then { void operator()() { ++counterThen; } };
struct Done { void operator()() { ++counterDone; } };

struct Produce0 { int operator()(int x) { return x+1; } };
struct Produce1 { int operator()(int x) { return x-2; } };
struct Consume { int operator()(int x, int y) { return x*y; } };

// TODO? avoid copies so it is truly stateful
struct Generate { int value; int operator()(int b) { return ++value+b; } };
struct Transform0 { int operator()(int x) { return x+1; } };
struct Transform1 { int operator()(int x) { return x-2; } };
struct Produce { int operator()(int x, int y) { return x*y; } };
struct Select {
	int mod;
	int operator()(int a, int b) { if(a%mod == b%mod) return std::min(a, b); return (a%mod > b%mod)? a : b; }
};

TEST_CASE("edsl") {
	auto aDo    = makeOperand<Do>();
	auto aThen  = makeOperand<Then>();
	auto aDone  = makeOperand<Done>();

	auto aProduce0  = makeOperand<Produce0>();
	auto aProduce1  = makeOperand<Produce1>();
	auto aConsume   = makeOperand<Consume>();

	auto e0 = aDo & (5*aThen) & aDone;
	using E0 = decltype(e0);
	using S0 = alsk::S<alsk::Serial, Do, alsk::S<alsk::Farm, Then>, Done>;
	using L0 = alsk::L<alsk::Serial, void(), void(), alsk::L<alsk::Farm, void(), void()>, void()>;

	auto e1 = 5*(aDo, 2*aThen, aDone);
	using E1 = decltype(e1);
	using S1 = alsk::S<alsk::Farm, alsk::S<alsk::Serial, Do, alsk::S<alsk::Farm, Then>, Done>>;
	using L1 = alsk::L<alsk::Farm, void(), alsk::L<alsk::Serial, void(), void(), alsk::L<alsk::Farm, void(), void()>, void()>>;

	auto e2 = link<R<2>(int)>(
		link<int(P<0>)>(aProduce0),
		link<int(P<0>)>(aProduce1),
		link<int(R<1>, R<0>)>(aConsume)
	);

	SECTION("Construction") {
		REQUIRE(std::is_same<E0::Signature, void()>{});
		REQUIRE(std::is_same<E0::Struct, S0>{});
		REQUIRE(std::is_same<E0::Links, L0>{});

		REQUIRE(std::is_same<E1::Signature, void()>{});
		REQUIRE(std::is_same<E1::Struct, S1>{});
		REQUIRE(std::is_same<E1::Links, L1>{});
	}

	SECTION("Linking") {
		{
			auto f2 = implement<alsk::exec::Sequential>(e2);

			REQUIRE(f2(0) == -2);
			REQUIRE(f2(2) == 0);
			REQUIRE(f2(5) == 18);
		}

	}

	SECTION("Setup") {
		auto f0 = implement<alsk::exec::Sequential>(e0);

		REQUIRE(f0.skeleton.task<1>().n == 5);
	}

	SECTION("Check run") {
		{
			auto f0 = implement<alsk::exec::Sequential>(e0);

			counterDo = counterThen = counterDone = 0;
			f0();

			REQUIRE(counterDo == 1);
			REQUIRE(counterThen == 5);
			REQUIRE(counterDone == 1);
		}

		{
			auto f1 = implement<alsk::exec::Sequential>(e1);

			counterDo = counterThen = counterDone = 0;
			f1();

			REQUIRE(counterDo == 5);
			REQUIRE(counterThen == 10);
			REQUIRE(counterDone == 5);
		}
	}

	SECTION("Complex case") {
		auto generate = makeOperand<Generate>();
		auto transform0 = makeOperand<Transform0>();
		auto transform1 = makeOperand<Transform1>();
		auto produce = makeOperand<Produce>();
		auto select = makeOperand<int(int, int), Select>();

		auto innerTask = link<R<3>(int)>(
			link<int(P<0>)>(generate),
			link<int(R<0>)>(transform0),
			link<int(R<0>)>(transform1),
			link<int(R<2>, R<1>)>(produce)
		);
		auto task = link<int(int)>(10 * link<R<3>(P<0>)>(innerTask)) ->* select;

		auto f = implement<alsk::exec::Sequential>(task);
		f.skeleton.select.mod = 5;

		REQUIRE(f(4) == 18);
		REQUIRE(f(5) == 28);
		REQUIRE(f(6) == 40);
		REQUIRE(f(7) == 54);
		REQUIRE(f(8) == 70);
	}
}