// Mirrors a target window into a D3D11 texture using Windows.Graphics.Capture
// (no injection). Frames arrive on a WGC thread; the newest is handed to the
// render thread, which copies and draws it -- so all D3D11 context use stays on
// one thread.
#pragma once

#include <cstdint>
#include <mutex>

#include <d3d11.h>
#include <windows.h>
#include <wrl/client.h>

#include <winrt/Windows.Graphics.Capture.h>
#include <winrt/Windows.Graphics.DirectX.Direct3D11.h>

namespace coop
{

class FrameRenderer;

class WindowCapture
{
public:
	~WindowCapture();

	// Begins capturing `target`. Returns false if WGC is unavailable or the
	// window can't be captured.
	bool start(HWND target, ID3D11Device* device);
	void stop();

	[[nodiscard]] bool running() const
	{
		return session_ != nullptr;
	}
	[[nodiscard]] HWND target() const
	{
		return target_;
	}
	[[nodiscard]] std::uint32_t frame_width() const
	{
		return width_;
	}
	[[nodiscard]] std::uint32_t frame_height() const
	{
		return height_;
	}

	// Cumulative frames WGC has delivered (for the capture-rate metric).
	[[nodiscard]] std::uint64_t frames_arrived() const
	{
		return frames_arrived_;
	}

	// Render thread: consume the newest frame (if any) and draw it letterboxed
	// into a dst_w x dst_h target via `renderer`.
	void draw_latest(FrameRenderer& renderer, ID3D11DeviceContext* ctx, std::uint32_t dst_w, std::uint32_t dst_h);

private:
	void on_frame_arrived(winrt::Windows::Graphics::Capture::Direct3D11CaptureFramePool const& pool,
	                      winrt::Windows::Foundation::IInspectable const&);

	HWND target_ = nullptr;
	Microsoft::WRL::ComPtr<ID3D11Device> device_;
	Microsoft::WRL::ComPtr<ID3D11Texture2D> latest_;
	Microsoft::WRL::ComPtr<ID3D11ShaderResourceView> latest_srv_;
	std::uint32_t width_ = 0;
	std::uint32_t height_ = 0;
	std::uint64_t frames_arrived_ = 0; // incremented in on_frame_arrived

	std::mutex mutex_; // guards pending_ handoff only (no context work under it)
	winrt::Windows::Graphics::Capture::Direct3D11CaptureFrame pending_{nullptr};

	winrt::Windows::Graphics::DirectX::Direct3D11::IDirect3DDevice winrt_device_{nullptr};
	winrt::Windows::Graphics::Capture::GraphicsCaptureItem item_{nullptr};
	winrt::Windows::Graphics::Capture::Direct3D11CaptureFramePool frame_pool_{nullptr};
	winrt::Windows::Graphics::Capture::GraphicsCaptureSession session_{nullptr};
	winrt::event_token frame_token_{};
	winrt::Windows::Graphics::SizeInt32 pool_size_{0, 0};
};

} // namespace coop