// In-process self-test for the WASAPI render-hook (hook/src/audio_hook.cpp).
// This process plays both "game" and "hook": it installs the audio hooks, then
// renders a sine tone through WASAPI exactly like a game would. With the hooks
// live, that render path must (1) be discovered via the COM vtables, (2) copy
// the rendered frames into the shared audio ring (non-silent), (3) silence the
// local output, and (4) report exactly one render stream. No second Steam
// account, no real game. Exits 0 on pass, 1 on failure.
//
// Requires a working default render endpoint; on a headless machine it reports
// SKIP and exits 0 (mirrors audio_loopback_test).

#include <cmath>
#include <cstdint>
#include <cstdio>
#include <vector>

#include <windows.h>

#include <audioclient.h>
#include <mmdeviceapi.h>
#include <mmreg.h>

#include "audio_hook.hpp"
#include "coop/audio_ring.hpp"
#include "coop/protocol.hpp"
#include "coop/shared_memory.hpp"
#include "ipc_client.hpp"

using namespace coop;

namespace
{

constexpr double kPi = 3.14159265358979323846;

int g_failures = 0;

void check(bool ok, const char* what)
{
	if (!ok)
	{
		std::printf("  FAIL: %s\n", what);
		++g_failures;
	}
}

template <typename T>
void release(T*& p)
{
	if (p)
	{
		p->Release();
		p = nullptr;
	}
}

} // namespace

int main()
{
	if (FAILED(CoInitializeEx(nullptr, COINIT_MULTITHREADED)))
	{
		std::printf("FAIL: CoInitializeEx\n");
		return 1;
	}

	// --- Host side: create the IPC SharedBlock (named by our pid) so the hook's
	//     IpcClient can connect, and a producer audio ring with capture enabled.
	SharedMemory shm;
	if (!shm.create(shared_memory_name(GetCurrentProcessId()), sizeof(SharedBlock)))
	{
		std::printf("FAIL: create shared memory\n");
		return 1;
	}
	auto* block = shm.as<SharedBlock>(); // mapping is zero-initialized by the OS
	block->version = kProtocolVersion;
	block->sequence.store(0, std::memory_order_relaxed);
	block->magic = kProtocolMagic;

	std::vector<std::uint8_t> ring_storage(audio_ring_total_size(kAudioRingCapacity), 0);
	auto* ring = new (ring_storage.data()) AudioRingHeader();
	audio_ring_init(*ring, kAudioRingCapacity);
	ring->capture_enabled.store(1, std::memory_order_relaxed);

	hook::IpcClient ipc;
	check(ipc.connect(10, 5), "IPC client connect");

	// --- Install the render hooks BEFORE any audio client is created. ---
	if (!hook::install_audio_hooks(ipc, ring))
	{
		std::printf("SKIP: could not install audio hooks (no default render endpoint?)\n");
		CoUninitialize();
		return 0;
	}

	// --- Game side: render a tone through WASAPI (the coop_tone render path). ---
	IMMDeviceEnumerator* enumerator = nullptr;
	IMMDevice* endpoint = nullptr;
	IAudioClient* client = nullptr;
	IAudioRenderClient* render = nullptr;
	WAVEFORMATEX* fmt = nullptr;
	HANDLE buffer_event = nullptr;
	bool rendered = false;

	do
	{
		if (FAILED(CoCreateInstance(__uuidof(MMDeviceEnumerator), nullptr, CLSCTX_ALL,
		                            __uuidof(IMMDeviceEnumerator), reinterpret_cast<void**>(&enumerator))))
		{
			break;
		}
		if (FAILED(enumerator->GetDefaultAudioEndpoint(eRender, eConsole, &endpoint)))
		{
			break;
		}
		if (FAILED(endpoint->Activate(__uuidof(IAudioClient), CLSCTX_ALL, nullptr,
		                              reinterpret_cast<void**>(&client))))
		{
			break;
		}
		if (FAILED(client->GetMixFormat(&fmt)))
		{
			break;
		}
		buffer_event = CreateEventW(nullptr, FALSE, FALSE, nullptr);
		constexpr REFERENCE_TIME kBuffer = 30 * 10000; // 30 ms
		if (FAILED(client->Initialize(AUDCLNT_SHAREMODE_SHARED, AUDCLNT_STREAMFLAGS_EVENTCALLBACK, kBuffer,
		                              0, fmt, nullptr)))
		{
			break;
		}
		client->SetEventHandle(buffer_event);
		if (FAILED(client->GetService(__uuidof(IAudioRenderClient), reinterpret_cast<void**>(&render))))
		{
			break;
		}
		UINT32 buffer_frames = 0;
		client->GetBufferSize(&buffer_frames);

		const bool is_float =
		    fmt->wFormatTag == WAVE_FORMAT_IEEE_FLOAT ||
		    (fmt->wFormatTag == WAVE_FORMAT_EXTENSIBLE &&
		     reinterpret_cast<WAVEFORMATEXTENSIBLE*>(fmt)->SubFormat == KSDATAFORMAT_SUBTYPE_IEEE_FLOAT);
		const unsigned channels = fmt->nChannels;
		const double rate = fmt->nSamplesPerSec;
		const double step = 2.0 * kPi * 440.0 / rate;

		auto write_frames = [&](UINT32 frames, double& phase) {
			BYTE* data = nullptr;
			if (frames == 0 || FAILED(render->GetBuffer(frames, &data)))
			{
				return;
			}
			for (UINT32 i = 0; i < frames; ++i)
			{
				const double s = std::sin(phase) * 0.25;
				phase += step;
				if (phase > 2.0 * kPi)
				{
					phase -= 2.0 * kPi;
				}
				for (unsigned c = 0; c < channels; ++c)
				{
					if (is_float)
					{
						reinterpret_cast<float*>(data)[i * channels + c] = static_cast<float>(s);
					}
					else
					{
						reinterpret_cast<INT16*>(data)[i * channels + c] =
						    static_cast<INT16>(s * 32767.0);
					}
				}
			}
			render->ReleaseBuffer(frames, 0);
		};

		double phase = 0.0;
		write_frames(buffer_frames, phase); // pre-roll
		client->Start();
		const DWORD end_tick = GetTickCount() + 800; // ~0.8 s of rendering
		while (GetTickCount() < end_tick)
		{
			if (WaitForSingleObject(buffer_event, 200) != WAIT_OBJECT_0)
			{
				continue;
			}
			UINT32 padding = 0;
			if (FAILED(client->GetCurrentPadding(&padding)))
			{
				break;
			}
			write_frames(buffer_frames - padding, phase);
		}
		client->Stop();
		rendered = true;
	} while (false);

	if (!rendered)
	{
		std::printf("SKIP: could not render through WASAPI on this machine\n");
		release(render);
		release(client);
		release(endpoint);
		release(enumerator);
		if (fmt)
		{
			CoTaskMemFree(fmt);
		}
		if (buffer_event)
		{
			CloseHandle(buffer_event);
		}
		hook::remove_audio_hooks();
		CoUninitialize();
		return 0;
	}

	// --- Assertions: the hook discovered and intercepted the render path. ---
	std::printf("streams_seen=%u, frames_captured=%llu, ring frames_produced=%llu\n",
	            hook::audio_streams_seen(),
	            static_cast<unsigned long long>(hook::audio_frames_captured()),
	            static_cast<unsigned long long>(ring->frames_produced.load()));

	check(hook::audio_streams_seen() == 1, "exactly one render stream observed");
	check(block->status.audio_streams_seen == 1, "stream count published to HookStatus");
	check(block->status.audio_streams[0].is_primary == 1, "slot 0 marked primary");
	check(block->status.audio_streams[0].sample_rate == fmt->nSamplesPerSec, "primary sample rate published");
	check(block->status.audio_streams[0].frames_rendered > 0, "primary frames_rendered advancing");
	check(ring->frames_produced.load() > 0, "frames pushed to the audio ring");
	check(hook::audio_frames_captured() > 0, "frames captured + silenced");

	// The ring must hold the actual (non-silent) tone we rendered.
	{
		std::vector<std::uint8_t> buf(64 * 1024, 0);
		const std::uint32_t got = audio_ring_pop(*ring, buf.data(), static_cast<std::uint32_t>(buf.size()));
		bool nonsilent = false;
		for (std::uint32_t i = 0; i < got; ++i)
		{
			if (buf[i] != 0)
			{
				nonsilent = true;
				break;
			}
		}
		check(got > 0 && nonsilent, "ring carries non-silent captured audio");
	}

	release(render);
	release(client);
	release(endpoint);
	release(enumerator);
	if (fmt)
	{
		CoTaskMemFree(fmt);
	}
	if (buffer_event)
	{
		CloseHandle(buffer_event);
	}
	hook::remove_audio_hooks();
	CoUninitialize();

	std::printf(g_failures == 0 ? "AUDIO HOOK TEST PASS\n" : "AUDIO HOOK TEST FAILED (%d)\n", g_failures);
	return g_failures == 0 ? 0 : 1;
}