/* Copyright (C) 2022 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 "lib/self_test.h"

#include "graphics/FontManager.h"
#include "graphics/FontMetrics.h"
#include "gui/CGUI.h"
#include "gui/CGUIText.h"
#include "gui/SettingTypes/CGUIString.h"
#include "ps/CLogger.h"
#include "ps/ConfigDB.h"
#include "ps/Filesystem.h"
#include "ps/ProfileViewer.h"
#include "ps/VideoMode.h"
#include "renderer/Renderer.h"
#include "scriptinterface/ScriptInterface.h"

#include <algorithm>
#include <array>

class TestCGUIText : public CxxTest::TestSuite
{
	CProfileViewer* m_Viewer = nullptr;
	CRenderer* m_Renderer = nullptr;

public:
	void setUp()
	{
		g_VFS = CreateVfs();
		TS_ASSERT_OK(g_VFS->Mount(L"", DataDir() / "mods" / "_test.minimal" / "", VFS_MOUNT_MUST_EXIST));
		TS_ASSERT_OK(g_VFS->Mount(L"cache", DataDir() / "_testcache" / "", 0, VFS_MAX_PRIORITY));

		CXeromyces::Startup();

		// The renderer spews messages.
		TestLogger logger;

		// We need to initialise the renderer to initialise the font manager.
		// TODO: decouple this.
		CConfigDB::Initialise();
		CConfigDB::Instance()->SetValueString(CFG_SYSTEM, "rendererbackend", "dummy");
		g_VideoMode.InitNonSDL();
		g_VideoMode.CreateBackendDevice(false);
		m_Viewer = new CProfileViewer;
		m_Renderer = new CRenderer;
	}

	void tearDown()
	{
		delete m_Renderer;
		delete m_Viewer;
		g_VideoMode.Shutdown();
		CConfigDB::Shutdown();
		CXeromyces::Terminate();
		g_VFS.reset();
		DeleteDirectory(DataDir() / "_testcache");
	}

	void test_empty()
	{
		CGUI gui(g_ScriptContext);
		CGUIText empty;
	}

	void test_wrapping()
	{
		CGUI gui(g_ScriptContext);

		const CStrW font = L"console";
		// Make sure this matches the value of the file.
		// TODO: load dynamically.
		const float lineHeight = 12.f;
		const float lineSpacing = 15.f;

		CGUIString string;
		CGUIText text;
		float width = 0.f;
		float renderedWidth = 0.f;
		float padding = 0.f;
		EAlign align = EAlign::LEFT;

		// Thing to note: the space before the newline should collapse in right-alignment.
		string.SetValue(L"Some long text that will wrap-around. \n New line.");
		text = CGUIText(gui, string, font, width, padding, align, nullptr);

		// Width 0 means no wrapping, so we should be getting one render call & one line.
		// TODO: is it wanted that \n doesn't wrap in that case?
		// We have 11 calls: the 9 words (wrap-around is split in two), the space after the newline, and the newline itself.
		TS_ASSERT_EQUALS(text.GetTextCalls().size(), 11);
		TS_ASSERT_EQUALS(text.GetSize().Height, lineHeight);

		width = 100.f;
		padding = 2.0f;
		align = EAlign::LEFT;
		text = CGUIText(gui, string, font, width, padding, align, nullptr);
		renderedWidth = text.GetSize().Width;
		// We have 10 calls: the 9 words (wrap-around is split in two), the space after the newline.
		TS_ASSERT_EQUALS(text.GetTextCalls().size(), 10);
		TS_ASSERT_LESS_THAN(text.GetSize().Width, width);
		TS_ASSERT_EQUALS(text.GetSize().Height, padding * 2 + lineHeight + lineSpacing * 4);

		align = EAlign::RIGHT;
		text = CGUIText(gui, string, font, width, padding, align, nullptr);
		TS_ASSERT_EQUALS(text.GetTextCalls().size(), 10);
		TS_ASSERT_EQUALS(text.GetSize().Width, renderedWidth); // Should be the same width as the left-case.
		TS_ASSERT_EQUALS(text.GetSize().Height, padding * 2 + lineHeight + lineSpacing * 4);

		width = 400.f;
		padding = 3.0f;
		align = EAlign::LEFT;
		text = CGUIText(gui, string, font, width, padding, align, nullptr);
		TS_ASSERT_EQUALS(text.GetTextCalls().size(), 10);
		TS_ASSERT_LESS_THAN(text.GetSize().Width, width);
		TS_ASSERT_EQUALS(text.GetSize().Height, padding * 2 + lineHeight + lineSpacing);

		width = 400.f;
		padding = 5.0f;
		align = EAlign::CENTER;
		text = CGUIText(gui, string, font, width, padding, align, nullptr);
		renderedWidth = text.GetSize().Width;
		TS_ASSERT_LESS_THAN(text.GetSize().Width, width);
		TS_ASSERT_EQUALS(text.GetSize().Height, padding * 2 + lineHeight + lineSpacing);

		align = EAlign::RIGHT;
		text = CGUIText(gui, string, font, width, padding, align, nullptr);
		TS_ASSERT_EQUALS(text.GetSize().Width, renderedWidth); // Should be the same width as the center-case.
		TS_ASSERT_EQUALS(text.GetSize().Height, padding * 2 + lineHeight + lineSpacing);

		align = EAlign::LEFT;
		text = CGUIText(gui, string, font, width, padding, align, nullptr);
		TS_ASSERT_EQUALS(text.GetSize().Width, renderedWidth); // Should be the same width as the center-case.
		TS_ASSERT_EQUALS(text.GetSize().Height, padding * 2 + lineHeight + lineSpacing);

		width = 400.f;
		padding = 100.0f;
		align = EAlign::LEFT;
		text = CGUIText(gui, string, font, width, padding, align, nullptr);
		renderedWidth = text.GetSize().Width;
		TS_ASSERT_LESS_THAN(text.GetSize().Width, width);
		TS_ASSERT_EQUALS(text.GetSize().Height, padding * 2 + lineHeight + lineSpacing * 2);

		align = EAlign::RIGHT;
		text = CGUIText(gui, string, font, width, padding, align, nullptr);
		TS_ASSERT_EQUALS(text.GetSize().Width, renderedWidth); // Should be the same width as the left-case.
		TS_ASSERT_EQUALS(text.GetSize().Height, padding * 2 + lineHeight + lineSpacing * 2);
	}

	void test_layout_wrapping_center()
	{
		// The short word should be layouted the same as when there is no
		// second word, because it's the only one word in the first line until
		// the width is enough to fit both. So we need to check that for
		// increasing width X positions of both words are also increasing until
		// they fit into a single line.
		//
		// Width is too small for both:
		// +--------------------+
		// |     Shortword      |
		// | (Veryverylongword) |
		// +--------------------+
		//
		// Right before the big enough width:
		// +---------------------------+
		// |         Shortword         |
		// |    (Veryverylongword)     |
		// +---------------------------+
		//
		// Width is enough to fit both:
		// +------------------------------+
		// | Shortword (Veryverylongword) |
		// +------------------------------+
		//

		CGUI gui(g_ScriptContext);
		const CStrW firstWord = L"Shortword";
		const CStrW secondWord = L"(Veryverylongword)";
		const CStrW text = firstWord + L" " + secondWord;
		CGUIString string;
		string.SetValue(text);
		const CStrW font = L"console";
		CFontMetrics fontMetrics{CStrIntern(font.ToUTF8())};

		int firstWordWidth = 0, firstWordHeight = 0;
		fontMetrics.CalculateStringSize(firstWord.c_str(), firstWordWidth, firstWordHeight);
		TS_ASSERT(firstWordWidth > 0);
		int secondWordWidth = 0, secondWordHeight = 0;
		fontMetrics.CalculateStringSize(secondWord.c_str(), secondWordWidth, secondWordHeight);
		TS_ASSERT(secondWordWidth > 0);
		TS_ASSERT(firstWordWidth < secondWordWidth);
		const float spaceWidth = fontMetrics.GetCharacterWidth(L' ');

		const float lineHeight = fontMetrics.GetHeight();
		const float lineSpacing = fontMetrics.GetLineSpacing();

		auto layoutText = [&gui, &string, &font, lineHeight, firstWordWidth](const float width)
		{
			const float padding = 0.0f;
			const CGUIText text(gui, string, font, width, padding, EAlign::CENTER, nullptr);

			std::array<CVector2D, 2> positions;
			TS_ASSERT_EQUALS(text.GetTextCalls().size(), positions.size());

			// If the second word is on the next line then the first word should be
			// centered alone.
			if (text.GetTextCalls()[0].m_Pos.Y + lineHeight <= text.GetTextCalls()[1].m_Pos.Y)
			{
				const float expectedX = (width - firstWordWidth) / 2.0f;
				TS_ASSERT_EQUALS(text.GetTextCalls()[0].m_Pos.X, expectedX);
			}

			std::transform(
				text.GetTextCalls().begin(), text.GetTextCalls().end(), positions.begin(),
				[](const CGUIText::STextCall& textCall) { return textCall.m_Pos; });
			return positions;
		};

		const float testPadding = 2;
		const float beginWidth = firstWordWidth - testPadding;
		const float endWidth = firstWordWidth + spaceWidth + secondWordWidth + testPadding;
		std::array<CVector2D, 2> previousPositions = layoutText(beginWidth);
		TS_ASSERT_EQUALS(std::get<0>(previousPositions).Y, lineHeight);
		TS_ASSERT_EQUALS(std::get<1>(previousPositions).Y, lineHeight + lineSpacing);
		bool firstFit = false;
		for (float width = beginWidth; width <= endWidth; width += 1.0f)
		{
			std::array<CVector2D, 2> positions = layoutText(width);
			TS_ASSERT_EQUALS(std::get<0>(positions).Y, lineHeight);
			if (std::get<0>(positions).X >= std::get<0>(previousPositions).X)
			{
				if (firstFit)
				{
					TS_ASSERT_EQUALS(std::get<0>(positions).Y, std::get<1>(positions).Y);
				}
				else
				{
					TS_ASSERT_EQUALS(std::get<1>(positions).Y, lineHeight + lineSpacing);
				}
				TS_ASSERT(std::get<1>(positions).X >= std::get<1>(previousPositions).X);
			}
			else
			{
				TS_ASSERT(!firstFit);
				firstFit = true;
				TS_ASSERT_EQUALS(std::get<0>(positions).Y, std::get<1>(positions).Y);
				TS_ASSERT(std::get<0>(positions).X < std::get<1>(positions).X);
			}
			previousPositions = positions;
		}
		TS_ASSERT(firstFit);
	}

	void test_overflow()
	{
		CGUI gui(g_ScriptContext);

		const CStrW font = L"console";
		// Make sure this matches the value of the file.
		// TODO: load dynamically.
		const float lineHeight = 12.f;
		const float lineSpacing = 15.f;

		float renderedWidth = 0.f;
		const float width = 200.f;
		const float padding = 20.f;

		CGUIString string;
		CGUIText text;
		string.SetValue(L"wordthatisverylonganddefinitelywontfitinaline and other words");
		text = CGUIText(gui, string, font, width, padding, EAlign::LEFT, nullptr);
		renderedWidth = text.GetSize().Width;
		TS_ASSERT_EQUALS(text.GetSize().Height, lineHeight + lineSpacing * 1 + padding * 2);
		text = CGUIText(gui, string, font, width, padding, EAlign::CENTER, nullptr);
		TS_ASSERT_EQUALS(renderedWidth, text.GetSize().Width);
		TS_ASSERT_EQUALS(text.GetSize().Height, lineHeight + lineSpacing * 1 + padding * 2);
		text = CGUIText(gui, string, font, width, padding, EAlign::RIGHT, nullptr);
		TS_ASSERT_EQUALS(renderedWidth, text.GetSize().Width);
		TS_ASSERT_EQUALS(text.GetSize().Height, lineHeight + lineSpacing * 1 + padding * 2);

		string.SetValue(L"other words and wordthatisverylonganddefinitelywontfitinaline");
		text = CGUIText(gui, string, font, width, padding, EAlign::LEFT, nullptr);
		renderedWidth = text.GetSize().Width;
		TS_ASSERT_EQUALS(text.GetSize().Height, lineHeight + lineSpacing * 1 + padding * 2);
		text = CGUIText(gui, string, font, width, padding, EAlign::CENTER, nullptr);
		TS_ASSERT_EQUALS(renderedWidth, text.GetSize().Width);
		TS_ASSERT_EQUALS(text.GetSize().Height, lineHeight + lineSpacing * 1 + padding * 2);
		text = CGUIText(gui, string, font, width, padding, EAlign::RIGHT, nullptr);
		TS_ASSERT_EQUALS(renderedWidth, text.GetSize().Width);
		TS_ASSERT_EQUALS(text.GetSize().Height, lineHeight + lineSpacing * 1 + padding * 2);

		string.SetValue(L"wordthatisverylonganddefinitelywontfitinaline");
		text = CGUIText(gui, string, font, width, padding, EAlign::LEFT, nullptr);
		renderedWidth = text.GetSize().Width;
		TS_ASSERT_EQUALS(text.GetSize().Height, lineHeight + padding * 2);
		text = CGUIText(gui, string, font, width, padding, EAlign::CENTER, nullptr);
		TS_ASSERT_EQUALS(renderedWidth, text.GetSize().Width);
		TS_ASSERT_EQUALS(text.GetSize().Height, lineHeight + padding * 2);
		text = CGUIText(gui, string, font, width, padding, EAlign::RIGHT, nullptr);
		TS_ASSERT_EQUALS(renderedWidth, text.GetSize().Width);
		TS_ASSERT_EQUALS(text.GetSize().Height, lineHeight + padding * 2);
	}

	void test_multiple_blank_spaces()
	{
		CGUI gui(g_ScriptContext);

		const CStrW font = L"console";
		// Make sure this matches the value of the file.
		// TODO: load dynamically.
		const float lineHeight = 12.f;
		const float lineSpacing = 15.f;

		CGUIString string;
		CGUIText text;
		float width = 100.f;
		float renderedWidth = 0.f;
		float padding = 0.f;
		EAlign align = EAlign::LEFT;

		string.SetValue(L"   word    another    \n    spaces   \n   \n  word   ");
		text = CGUIText(gui, string, font, width, padding, align, nullptr);

		// Blank spaces are treated as a word.
		TS_ASSERT_EQUALS(text.GetTextCalls().size(), 26);
		TS_ASSERT_EQUALS(text.GetSize().Height, lineHeight + lineSpacing * 4);
		TS_ASSERT_EQUALS(text.GetSize().Width, 89.f);
		renderedWidth = text.GetSize().Width;

		align = EAlign::RIGHT;
		text = CGUIText(gui, string, font, width, padding, align, nullptr);
		TS_ASSERT_EQUALS(text.GetSize().Width, renderedWidth);
	}
};