#include "Toolbar.hpp"

#include <cmath>

#include "Utf8Util.hpp"

namespace jdi
{

	namespace
	{
		const float kButtonHeight = 30.0f;		/**< 按钮高度（逻辑像素）。 */
		const float kButtonGap = 6.0f;			/**< 按钮间距。 */
		const float kButtonPadding = 14.0f;		/**< 按钮左右内边距。 */
		const float kGroupGap = 18.0f;			/**< 分组间距。 */
		const float kButtonRadius = 5.0f;		/**< 按钮圆角半径。 */
		const float kSidePadding = 12.0f;		/**< 工具栏左右留白。 */
		const float kTopPadding = 8.0f;			/**< 工具栏上下留白。 */
	}

	Toolbar::Toolbar() = default;

	void Toolbar::Setup(const UiFonts* fonts, const Theme* theme)
	{
		m_fonts = fonts;
		m_theme = theme;
	}

	void Toolbar::SetScale(float scale)
	{
		m_scale = (scale > 0.1f) ? scale : 1.0f;
	}

	void Toolbar::SetDocumentLoaded(bool hasDocument)
	{
		m_documentLoaded = hasDocument;
	}

	float Toolbar::DesiredHeight() const
	{
		return (kButtonHeight + kTopPadding * 2.0f) * m_scale;
	}

	bool Toolbar::IsEnabled(const Button& button) const
	{
		return button.needsDocument ? m_documentLoaded : true;
	}

	void Toolbar::Layout(const gd::RectF& area)
	{
		m_area = area;

		// 重新排布会重建全部按钮：先记下当前各 toggle 的勾选状态，
		// 否则每次因文本变化（如「光标x2」）触发的 Layout 会把按钮选中态全部清掉。
		std::vector<std::pair<ToolbarAction, bool>> previousChecked;
		for (const Button& button : m_buttons)
		{
			previousChecked.emplace_back(button.action, button.checked);
		}
		const auto inheritedChecked = [&previousChecked](ToolbarAction action)
		{
			for (const std::pair<ToolbarAction, bool>& entry : previousChecked)
			{
				if (entry.first == action)
				{
					return entry.second;
				}
			}
			return false;
		};

		m_buttons.clear();

		if (m_fonts == nullptr || m_fonts->ui == nullptr)
		{
			return;
		}

		struct Spec
		{
			ToolbarAction action;
			const wchar_t* label;
			bool primary;
			bool needsDocument;
			bool toggle;
		};

		const Spec specs[] = {
		    {ToolbarAction::OPEN_FILE, L"导入文件", true, false, false},
		    {ToolbarAction::FIT_ALL, L"适应视图", false, true, false},
		    {ToolbarAction::AUTO_FIT_Y, L"Y 轴自适应", false, true, true},
		    {ToolbarAction::ZOOM_SELECT, L"选区放大", false, true, true},
		    {ToolbarAction::CURSOR, L"光标", false, true, true},
		    {ToolbarAction::MERGE_LANES, L"合并网格", false, true, false},
		    {ToolbarAction::SPLIT_LANES, L"拆分网格", false, true, false},
		    {ToolbarAction::CLEAR_ALL, L"清空网格", false, true, false},
		};
		const std::size_t specCount = sizeof(specs) / sizeof(specs[0]);

		// 按钮宽度按实际文本像素宽 + 固定内边距计算，避免中文标签被裁切。
		const float top = area.Y + kTopPadding * m_scale;
		const float height = kButtonHeight * m_scale;
		const float horizontalPadding = kButtonPadding * 2.0f * m_scale;

		// 先建立全部按钮并测量宽度，再决定“导入文件”固定在左、其余按钮整体靠右。
		// （函数开头已经 `m_buttons.clear()` 并做过 `previousChecked` 快照，这里只需预留容量。）
		m_buttons.reserve(specCount);

		for (const Spec& spec : specs)
		{
			Button button;
			button.action = spec.action;
			button.label = spec.label;
			button.primary = spec.primary;
			button.needsDocument = spec.needsDocument;
			button.toggle = spec.toggle;
			button.checked = inheritedChecked(spec.action);

			// 动态文本覆盖（例如「光标」按当前模式显示 光标 / 光标x1 / 光标x2）。
			for (const std::pair<ToolbarAction, std::wstring>& entry : m_labelOverrides)
			{
				if (entry.first == spec.action)
				{
					button.label = entry.second;
					break;
				}
			}

			button.width = horizontalPadding + UiMeasureTextWidth(m_fonts->ui, button.label);
			m_buttons.push_back(std::move(button));
		}

		// 首按钮（导入文件）靠左；其余按钮作为整体靠右，并留出一组额外间距。
		const float leftX = area.X + kSidePadding * m_scale;
		float groupWidth = 0.0f;
		for (std::size_t index = 1; index < m_buttons.size(); ++index)
		{
			groupWidth += m_buttons[index].width;
			if (index + 1 < m_buttons.size())
			{
				groupWidth += kButtonGap * m_scale;
			}
		}

		float cursorX = leftX;
		m_buttons[0].rect = gd::RectF(cursorX, top, m_buttons[0].width, height);

		const float rightEdge = area.X + area.Width - kSidePadding * m_scale;
		cursorX = std::max(leftX + m_buttons[0].width + kGroupGap * m_scale, rightEdge - groupWidth);
		for (std::size_t index = 1; index < m_buttons.size(); ++index)
		{
			m_buttons[index].rect = gd::RectF(cursorX, top, m_buttons[index].width, height);
			cursorX += m_buttons[index].width + kButtonGap * m_scale;
		}
	}

	void Toolbar::SetToggleState(ToolbarAction action, bool checked)
	{
		for (Button& button : m_buttons)
		{
			if (button.action == action && button.toggle)
			{
				button.checked = checked;
				return;
			}
		}
	}

	bool Toolbar::SetActionLabel(ToolbarAction action, const std::wstring& label)
	{
		for (std::pair<ToolbarAction, std::wstring>& entry : m_labelOverrides)
		{
			if (entry.first == action)
			{
				if (entry.second == label)
				{
					return false;
				}
				entry.second = label;
				// 已排布过时同步更新按钮文本，宿主随后会调用 Layout() 重新计算宽度。
				for (Button& button : m_buttons)
				{
					if (button.action == action)
					{
						button.label = label;
					}
				}
				return true;
			}
		}
		m_labelOverrides.emplace_back(action, label);
		for (Button& button : m_buttons)
		{
			if (button.action == action)
			{
				button.label = label;
			}
		}
		return true;
	}

	void Toolbar::Paint(gd::Graphics& g)
	{
		if (m_theme == nullptr || m_fonts == nullptr)
		{
			return;
		}

		UiFillRect(g, m_area, m_theme->toolbarBg);

		for (std::size_t buttonIndex = 0; buttonIndex < m_buttons.size(); ++buttonIndex)
		{
			const Button& button = m_buttons[buttonIndex];
			const bool enabled = IsEnabled(button);
			// ⚠️ 悬停态的唯一来源是 `m_hoverIndex`（`Button::hover` 字段从未被赋值，
			// 旧实现读它 ⇒ 鼠标移到按钮上永远不高亮）。
			const bool hovered = (static_cast<int>(buttonIndex) == m_hoverIndex);
			std::uint32_t background = 0;
			std::uint32_t border = 0;
			std::uint32_t textColor = 0;

			if (button.primary)
			{
				background = enabled ? m_theme->accent : MixColor(m_theme->accent, m_theme->toolbarBg, 0.6);
				if (button.pressed)
				{
					background = MixColor(m_theme->accent, 0xFF000000u, 0.12);
				}
				else if (enabled && hovered)
				{
					background = MixColor(m_theme->accent, 0xFFFFFFFFu, 0.12);
				}
				border = background;
				textColor = m_theme->textOnAccent;
			}
			else
			{
				// 可切换按钮在选中时用强调色浅底 + 强调描边，与普通按钮区分。
				background = (button.toggle && button.checked) ? m_theme->accentSoft : m_theme->toolbarBg;
				if (button.pressed)
				{
					background = m_theme->pressed;
				}
				else if (enabled && hovered)
				{
					background = (button.toggle && button.checked) ? MixColor(m_theme->accentSoft, m_theme->accent,
					                                                        0.16)
					                                              : m_theme->hover;
				}
				if (!enabled)
				{
					background = m_theme->toolbarBg;
				}

				if (button.toggle && button.checked && enabled)
				{
					border = m_theme->accent;
				}
				else
				{
					border = MixColor(m_theme->border, m_theme->toolbarBg, enabled ? 0.0 : 0.5);
				}
				textColor = enabled ? ((button.toggle && button.checked) ? m_theme->textStrong : m_theme->text)
				                    : m_theme->textMuted;
			}

			if (background != m_theme->toolbarBg)
			{
				UiFillRoundRect(g, button.rect, kButtonRadius * m_scale, background);
			}
			if (!button.primary)
			{
				UiDrawRoundRect(g, button.rect, kButtonRadius * m_scale, border, 1.0f);
			}

			UiText(g, button.label, m_fonts->ui, button.rect, textColor, TextAlign::CENTER);
		}

		// 底部分隔线。
		UiDrawLine(g, m_area.X, m_area.Y + m_area.Height - 1.0f, m_area.X + m_area.Width,
		           m_area.Y + m_area.Height - 1.0f, m_theme->border, 1.0f);
	}

	bool Toolbar::HitTest(int x, int y) const
	{
		return UiPointInRect(m_area, static_cast<float>(x), static_cast<float>(y));
	}

	bool Toolbar::OnMouseMove(int x, int y)
	{
		int hoverIndex = -1;
		for (std::size_t index = 0; index < m_buttons.size(); ++index)
		{
			if (UiPointInRect(m_buttons[index].rect, static_cast<float>(x), static_cast<float>(y)))
			{
				hoverIndex = static_cast<int>(index);
				break;
			}
		}

		if (hoverIndex == m_hoverIndex)
		{
			return false;
		}
		m_hoverIndex = hoverIndex;
		return true;
	}

	bool Toolbar::OnLButtonDown(int x, int y, ToolbarAction& action)
	{
		action = ToolbarAction::NONE;

		for (std::size_t index = 0; index < m_buttons.size(); ++index)
		{
			Button& button = m_buttons[index];
			if (!UiPointInRect(button.rect, static_cast<float>(x), static_cast<float>(y)))
			{
				continue;
			}
			if (!IsEnabled(button))
			{
				return false;
			}

			m_pressedIndex = static_cast<int>(index);
			button.pressed = true;
			action = button.action;
			return true;
		}
		return false;
	}

	bool Toolbar::OnLButtonUp(int x, int y, ToolbarAction& action)
	{
		action = ToolbarAction::NONE;
		if (m_pressedIndex < 0)
		{
			return false;
		}

		const int index = m_pressedIndex;
		m_pressedIndex = -1;
		if (index >= static_cast<int>(m_buttons.size()))
		{
			return false;
		}

		Button& button = m_buttons[static_cast<std::size_t>(index)];
		button.pressed = false;

		const bool inside = UiPointInRect(button.rect, static_cast<float>(x), static_cast<float>(y));
		m_hoverIndex = inside ? index : -1;
		if (inside && IsEnabled(button))
		{
			action = button.action;
		}
		return true;
	}

	bool Toolbar::OnMouseLeave()
	{
		bool changed = false;
		if (m_hoverIndex >= 0)
		{
			m_hoverIndex = -1;
			changed = true;
		}
		if (m_pressedIndex >= 0)
		{
			if (m_pressedIndex < static_cast<int>(m_buttons.size()))
			{
				m_buttons[static_cast<std::size_t>(m_pressedIndex)].pressed = false;
			}
			m_pressedIndex = -1;
			changed = true;
		}
		return changed;
	}

} // namespace jdi