// Unit test for the MKB event ring (SPSC push/pop, wrap-around, full/empty).
#include <cstdio>

#include "coop/protocol.hpp"

using namespace coop;

namespace
{
int g_failures = 0;
void check(bool cond, const char* what)
{
	if (!cond)
	{
		std::printf("FAIL: %s\n", what);
		++g_failures;
	}
}
} // namespace

int main()
{
	MkbRing ring{};

	// Empty pop fails.
	MkbEvent out{};
	check(!pop_mkb_event(ring, out), "pop on empty ring returns false");

	// Push then pop returns the same event, FIFO.
	for (std::uint32_t i = 0; i < 10; ++i)
	{
		MkbEvent ev{Mkb_KeyDown, i, static_cast<int>(i) * 2, static_cast<int>(i) * 3};
		check(push_mkb_event(ring, ev), "push succeeds with room");
	}
	for (std::uint32_t i = 0; i < 10; ++i)
	{
		check(pop_mkb_event(ring, out), "pop succeeds with data");
		check(out.code == i && out.x == static_cast<int>(i) * 2 && out.y == static_cast<int>(i) * 3,
		      "popped event matches pushed (FIFO)");
	}
	check(!pop_mkb_event(ring, out), "ring empty again after draining");

	// Fill to capacity, then one more push is dropped.
	for (std::uint32_t i = 0; i < kMkbQueueSize; ++i)
	{
		check(push_mkb_event(ring, MkbEvent{Mkb_Char, i, 0, 0}), "push fills to capacity");
	}
	check(!push_mkb_event(ring, MkbEvent{Mkb_Char, 999, 0, 0}), "push on full ring is dropped");

	// Drain and verify order survived a full buffer.
	for (std::uint32_t i = 0; i < kMkbQueueSize; ++i)
	{
		check(pop_mkb_event(ring, out) && out.code == i, "full-buffer drain is in order");
	}

	// Wrap-around: indices are free-running, so many cycles must keep working.
	std::uint32_t produced = 0, consumed = 0;
	for (int cycle = 0; cycle < 1000; ++cycle)
	{
		for (int k = 0; k < 50; ++k)
		{
			if (push_mkb_event(ring, MkbEvent{Mkb_MouseDown, produced, 0, 0}))
			{
				++produced;
			}
		}
		while (pop_mkb_event(ring, out))
		{
			check(out.code == consumed, "wrap-around preserves FIFO order");
			++consumed;
		}
	}
	check(produced == consumed, "all wrap-around events consumed");

	if (g_failures == 0)
	{
		std::printf("PASS: mkb_ring_test\n");
		return 0;
	}
	std::printf("FAIL: %d checks failed\n", g_failures);
	return 1;
}