/* Copyright (C) 2021 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * 0 A.D. is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "precompiled.h"

#include "CText.h"

#include "gui/CGUI.h"
#include "gui/CGUIScrollBarVertical.h"
#include "gui/CGUIText.h"

CText::CText(CGUI& pGUI)
	: IGUIObject(pGUI),
	  IGUIScrollBarOwner(*static_cast<IGUIObject*>(this)),
	  IGUITextOwner(*static_cast<IGUIObject*>(this)),
	  m_BufferZone(this, "buffer_zone"),
	  m_Caption(this, "caption"),
	  m_Clip(this, "clip", true),
	  m_Font(this, "font"),
	  m_ScrollBar(this, "scrollbar", false),
	  m_ScrollBarStyle(this, "scrollbar_style"),
	  m_ScrollBottom(this, "scroll_bottom"),
	  m_ScrollTop(this, "scroll_top"),
	  m_Sprite(this, "sprite"),
	  m_SpriteOverlay(this, "sprite_overlay"),
	  m_TextColor(this, "textcolor"),
	  m_TextColorDisabled(this, "textcolor_disabled")
{
	// Add scroll-bar
	auto bar = std::make_unique<CGUIScrollBarVertical>(pGUI);
	bar->SetRightAligned(true);
	AddScrollBar(std::move(bar));

	// Add text
	AddText();
}

CText::~CText()
{
}

void CText::SetupText()
{
	if (m_GeneratedTexts.empty())
		return;

	float width = m_CachedActualSize.GetWidth();
	// remove scrollbar if applicable
	if (m_ScrollBar && GetScrollBar(0).GetStyle())
		width -= GetScrollBar(0).GetStyle()->m_Width;

	m_GeneratedTexts[0] = CGUIText(m_pGUI, m_Caption, m_Font, width, m_BufferZone, m_TextAlign, this);

	if (!m_ScrollBar)
		CalculateTextPosition(m_CachedActualSize, m_TextPos, m_GeneratedTexts[0]);

	// Setup scrollbar
	if (m_ScrollBar)
	{
		// If we are currently scrolled to the bottom of the text,
		// then add more lines of text, update the scrollbar so we
		// stick to the bottom.
		// (Use 1.5px delta so this triggers the first time caption is set)
		bool bottom = false;
		if (m_ScrollBottom && GetScrollBar(0).GetPos() > GetScrollBar(0).GetMaxPos() - 1.5f)
			bottom = true;

		GetScrollBar(0).SetScrollRange(m_GeneratedTexts[0].GetSize().Height);
		GetScrollBar(0).SetScrollSpace(m_CachedActualSize.GetHeight());

		GetScrollBar(0).SetX(m_CachedActualSize.right);
		GetScrollBar(0).SetY(m_CachedActualSize.top);
		GetScrollBar(0).SetZ(GetBufferedZ());
		GetScrollBar(0).SetLength(m_CachedActualSize.bottom - m_CachedActualSize.top);

		if (bottom)
			GetScrollBar(0).SetPos(GetScrollBar(0).GetMaxPos());

		if (m_ScrollTop)
			GetScrollBar(0).SetPos(0.0f);
	}
}

void CText::ResetStates()
{
	IGUIObject::ResetStates();
	IGUIScrollBarOwner::ResetStates();
}

void CText::UpdateCachedSize()
{
	IGUIObject::UpdateCachedSize();
	IGUITextOwner::UpdateCachedSize();
}

CSize2D CText::GetTextSize()
{
	UpdateText();
	return m_GeneratedTexts[0].GetSize();
}

const CStrW& CText::GetTooltipText() const
{
	for (const CGUIText& text : m_GeneratedTexts)
		for (const CGUIText::STextCall& textChunk : text.GetTextCalls())
		{
			if (textChunk.m_Tooltip.empty())
				continue;
			CRect area(textChunk.m_Pos - CVector2D(0.f, textChunk.m_Size.Height), textChunk.m_Size);
			if (area.PointInside(m_pGUI.GetMousePos() - m_CachedActualSize.TopLeft()))
				return textChunk.m_Tooltip;
		}
	return m_Tooltip;
}

void CText::HandleMessage(SGUIMessage& Message)
{
	IGUIObject::HandleMessage(Message);
	IGUIScrollBarOwner::HandleMessage(Message);
	//IGUITextOwner::HandleMessage(Message); <== placed it after the switch instead!

	switch (Message.type)
	{
	case GUIM_SETTINGS_UPDATED:
		if (Message.value == "scrollbar")
			SetupText();

		// Update scrollbar
		if (Message.value == "scrollbar_style")
		{
			GetScrollBar(0).SetScrollBarStyle(m_ScrollBarStyle);
			SetupText();
		}

		break;

	case GUIM_MOUSE_WHEEL_DOWN:
	{
		GetScrollBar(0).ScrollPlus();
		// Since the scroll was changed, let's simulate a mouse movement
		//  to check if scrollbar now is hovered
		SGUIMessage msg(GUIM_MOUSE_MOTION);
		HandleMessage(msg);
		break;
	}
	case GUIM_MOUSE_WHEEL_UP:
	{
		GetScrollBar(0).ScrollMinus();
		// Since the scroll was changed, let's simulate a mouse movement
		//  to check if scrollbar now is hovered
		SGUIMessage msg(GUIM_MOUSE_MOTION);
		HandleMessage(msg);
		break;
	}
	case GUIM_LOAD:
	{
		GetScrollBar(0).SetX(m_CachedActualSize.right);
		GetScrollBar(0).SetY(m_CachedActualSize.top);
		GetScrollBar(0).SetZ(GetBufferedZ());
		GetScrollBar(0).SetLength(m_CachedActualSize.bottom - m_CachedActualSize.top);
		GetScrollBar(0).SetScrollBarStyle(m_ScrollBarStyle);
		break;
	}

	default:
		break;
	}

	IGUITextOwner::HandleMessage(Message);
}

void CText::Draw(CCanvas2D& canvas)
{
	m_pGUI.DrawSprite(m_Sprite, canvas, m_CachedActualSize);

	float scroll = 0.f;
	if (m_ScrollBar)
		scroll = GetScrollBar(0).GetPos();

	// Clipping area (we'll have to subtract the scrollbar)
	CRect cliparea;
	if (m_Clip)
	{
		cliparea = m_CachedActualSize;

		if (m_ScrollBar)
		{
			// subtract scrollbar from cliparea
			if (cliparea.right > GetScrollBar(0).GetOuterRect().left &&
			    cliparea.right <= GetScrollBar(0).GetOuterRect().right)
				cliparea.right = GetScrollBar(0).GetOuterRect().left;

			if (cliparea.left >= GetScrollBar(0).GetOuterRect().left &&
			    cliparea.left < GetScrollBar(0).GetOuterRect().right)
				cliparea.left = GetScrollBar(0).GetOuterRect().right;
		}
	}

	const CGUIColor& color = m_Enabled ? m_TextColor : m_TextColorDisabled;

	if (m_ScrollBar)
		DrawText(canvas, 0, color, m_CachedActualSize.TopLeft() - CVector2D(0.f, scroll), cliparea);
	else
		DrawText(canvas, 0, color, m_TextPos, cliparea);

	// Draw scrollbars on top of the content
	if (m_ScrollBar)
		IGUIScrollBarOwner::Draw(canvas);

	// Draw the overlays last
	m_pGUI.DrawSprite(m_SpriteOverlay, canvas, m_CachedActualSize);
}