/**
 * @file Session.cpp
 * @brief 离屏会话实现：隐藏窗口、加载数据、逐帧渲染与抓帧。
 *
 * ⚠️ 全程不显示窗口、不移动真实鼠标、不抢焦点：所有"鼠标"都是直接调用
 * `Application::HandleMouseMove()` 注入的合成消息。
 */

#include "OffscreenSupport.hpp"

namespace jdi
{
	namespace tools
	{
		namespace
		{
			/** @brief 窄字符串（本地代码页）→ 宽字符串。 */
			std::wstring WidenLocal(const std::string& text)
			{
				if (text.empty())
				{
					return std::wstring();
				}
				// 先按 UTF-8 试一次（Agent / 终端最常见），失败再退回本地代码页。
				int length = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, text.c_str(), -1, nullptr, 0);
				UINT codePage = CP_UTF8;
				if (length <= 1)
				{
					codePage = CP_ACP;
					length = MultiByteToWideChar(CP_ACP, 0, text.c_str(), -1, nullptr, 0);
				}
				if (length <= 1)
				{
					return std::wstring();
				}
				std::wstring wide(static_cast<std::size_t>(length - 1), L'\0');
				MultiByteToWideChar(codePage, 0, text.c_str(), -1, &wide[0], length);
				return wide;
			}
		} // namespace

		bool Session::Start()
		{
			if (m_started)
			{
				return true;
			}
			m_app = &Application::Instance();
			if (!m_app->Initialize(GetModuleHandleW(nullptr), SW_HIDE))
			{
				m_app = nullptr;
				return false;
			}
			m_started = true;
			return true;
		}

		void Session::Stop()
		{
			if (m_app != nullptr && m_started)
			{
				m_app->Shutdown();
				m_started = false;
			}
		}

		bool Session::Load(const std::string& path)
		{
			if (m_app == nullptr)
			{
				return false;
			}
			const std::wstring wide = WidenLocal(path);
			if (wide.empty())
			{
				return false;
			}
			if (!m_app->LoadFile(wide))
			{
				return false;
			}
			m_loadedPath = path;
			m_app->SynchronizeView(true);
			m_app->Relayout();
			return true;
		}

		bool Session::RenderFrame()
		{
			if (m_app == nullptr)
			{
				return false;
			}
			// 强制整帧：`m_chromeDirty` 为真时标签栏/工具栏/面板/绘图区都会重绘，
			// 否则 `Render()` 可能走"只重绘绘图区"的快路径，抓到的不是完整画面。
			m_app->m_chromeDirty = true;

			LARGE_INTEGER frequency = {};
			LARGE_INTEGER start = {};
			LARGE_INTEGER stop = {};
			QueryPerformanceFrequency(&frequency);
			QueryPerformanceCounter(&start);
			m_app->Render();
			QueryPerformanceCounter(&stop);
			m_lastRenderMs = static_cast<double>(stop.QuadPart - start.QuadPart) * 1000.0 /
			                 static_cast<double>(frequency.QuadPart);

			return CaptureFrame(*m_app, m_lastFrame);
		}

		void Session::ShowSignals(const std::vector<SignalRef>& refs)
		{
			if (m_app == nullptr)
			{
				return;
			}
			TabConfig& tab = m_app->ActiveTab();
			tab.SetAllVisible(false);
			for (const SignalRef& ref : refs)
			{
				tab.SetVisible(ref, true);
			}
			m_app->SynchronizeView(true);
			m_app->Relayout();
		}

		void Session::ShowFirstSignals(const int limit)
		{
			if (m_app == nullptr)
			{
				return;
			}
			const DataSet& dataSet = m_app->m_dataSet;
			std::vector<SignalRef> refs;
			for (int groupIndex = 0; groupIndex < static_cast<int>(dataSet.GroupCount()); ++groupIndex)
			{
				const SignalGroup* group = dataSet.GroupAt(groupIndex);
				if (group == nullptr)
				{
					continue;
				}
				for (int signalIndex = 0; signalIndex < static_cast<int>(group->signals.size()); ++signalIndex)
				{
					if (limit > 0 && static_cast<int>(refs.size()) >= limit)
					{
						break;
					}
					refs.push_back(SignalRef{groupIndex, signalIndex});
				}
				if (limit > 0 && static_cast<int>(refs.size()) >= limit)
				{
					break;
				}
			}
			ShowSignals(refs);
		}

		void Session::HideAll()
		{
			if (m_app == nullptr)
			{
				return;
			}
			m_app->ActiveTab().SetAllVisible(false);
			m_app->SynchronizeView(true);
			m_app->Relayout();
		}

		bool Session::MouseMove(const int x, const int y)
		{
			if (m_app == nullptr)
			{
				return false;
			}
			return m_app->HandleMouseMove(x, y, false);
		}

		gd::RectF Session::PlotArea() const
		{
			if (m_app == nullptr)
			{
				return gd::RectF(0.0f, 0.0f, 0.0f, 0.0f);
			}
			return m_app->m_plot.Area();
		}

		gd::RectF Session::LaneRect(const int index) const
		{
			if (m_app == nullptr || index < 0)
			{
				return gd::RectF(0.0f, 0.0f, 0.0f, 0.0f);
			}
			const std::vector<PlotView::LaneVisual>& lanes = m_app->m_plot.m_lanes;
			if (index >= static_cast<int>(lanes.size()))
			{
				return gd::RectF(0.0f, 0.0f, 0.0f, 0.0f);
			}
			return lanes[static_cast<std::size_t>(index)].rect;
		}

		int Session::LaneCount() const
		{
			if (m_app == nullptr)
			{
				return 0;
			}
			return static_cast<int>(m_app->m_plot.m_lanes.size());
		}

		void Session::ClientSize(int& width, int& height) const
		{
			width = 0;
			height = 0;
			if (m_app == nullptr || m_app->m_hwnd == nullptr)
			{
				return;
			}
			RECT rect = {};
			GetClientRect(m_app->m_hwnd, &rect);
			width = rect.right - rect.left;
			height = rect.bottom - rect.top;
			if (width <= 0 || height <= 0)
			{
				// 隐藏窗口在某些 DPI 路径下可能还没有客户区尺寸，退回后备缓冲区尺寸。
				const Frame& frame = m_lastFrame;
				width = frame.width;
				height = frame.height;
			}
		}
	} // namespace tools
} // namespace jdi