/* Copyright (C) 2016 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 <algorithm>
#include <vector>

#include "TerrainTextureManager.h"
#include "TerrainTextureEntry.h"
#include "TerrainProperties.h"

#include "lib/res/graphics/ogl_tex.h"
#include "lib/ogl.h"
#include "lib/timer.h"

#include "ps/CLogger.h"
#include "ps/Filesystem.h"
#include "ps/XML/Xeromyces.h"

#include <boost/algorithm/string.hpp>


CTerrainTextureManager::CTerrainTextureManager()
	: m_LastGroupIndex(0)
{
	if (!VfsDirectoryExists(L"art/terrains/"))
		return;
	if (!CXeromyces::AddValidator(g_VFS, "terrain", "art/terrains/terrain.rng"))
		LOGERROR("CTerrainTextureManager: failed to load grammar file 'art/terrains/terrain.rng'");
	if (!CXeromyces::AddValidator(g_VFS, "terrain_texture", "art/terrains/terrain_texture.rng"))
		LOGERROR("CTerrainTextureManager: failed to load grammar file 'art/terrains/terrain_texture.rng'");
}

CTerrainTextureManager::~CTerrainTextureManager()
{
	UnloadTerrainTextures();

	for (std::pair<const VfsPath, TerrainAlpha>& ta : m_TerrainAlphas)
	{
		ogl_tex_free(ta.second.m_hCompositeAlphaMap);
		ta.second.m_hCompositeAlphaMap = 0;
	}
}

void CTerrainTextureManager::UnloadTerrainTextures()
{
	for (CTerrainTextureEntry* const& te : m_TextureEntries)
		delete te;
	m_TextureEntries.clear();

	for (const std::pair<CStr, CTerrainGroup*>& tg : m_TerrainGroups)
		delete tg.second;
	m_TerrainGroups.clear();

	m_LastGroupIndex = 0;
}

CTerrainTextureEntry* CTerrainTextureManager::FindTexture(const CStr& tag_) const
{
	CStr tag = tag_.BeforeLast("."); // Strip extension

	for (CTerrainTextureEntry* const& te : m_TextureEntries)
		if (te->GetTag() == tag)
			return te;

	LOGWARNING("CTerrainTextureManager: Couldn't find terrain %s", tag.c_str());
	return 0;
}

CTerrainTextureEntry* CTerrainTextureManager::AddTexture(const CTerrainPropertiesPtr& props, const VfsPath& path)
{
	CTerrainTextureEntry* entry = new CTerrainTextureEntry(props, path);
	m_TextureEntries.push_back(entry);
	return entry;
}

void CTerrainTextureManager::DeleteTexture(CTerrainTextureEntry* entry)
{
	std::vector<CTerrainTextureEntry*>::iterator it = std::find(m_TextureEntries.begin(), m_TextureEntries.end(), entry);
	if (it != m_TextureEntries.end())
		m_TextureEntries.erase(it);

	delete entry;
}

struct AddTextureCallbackData
{
	CTerrainTextureManager* self;
	CTerrainPropertiesPtr props;
};

static Status AddTextureDirCallback(const VfsPath& pathname, const uintptr_t cbData)
{
	AddTextureCallbackData& data = *(AddTextureCallbackData*)cbData;
	VfsPath path = pathname / L"terrains.xml";
	if (!VfsFileExists(path))
		LOGMESSAGE("'%s' does not exist. Using previous properties.", path.string8());
	else
		data.props = CTerrainProperties::FromXML(data.props, path);

	return INFO::OK;
}

static Status AddTextureCallback(const VfsPath& pathname, const CFileInfo& UNUSED(fileInfo), const uintptr_t cbData)
{
	AddTextureCallbackData& data = *(AddTextureCallbackData*)cbData;
	if (pathname.Basename() != L"terrains")
		data.self->AddTexture(data.props, pathname);

	return INFO::OK;
}

int CTerrainTextureManager::LoadTerrainTextures()
{
	AddTextureCallbackData data = {this, CTerrainPropertiesPtr(new CTerrainProperties(CTerrainPropertiesPtr()))};
	vfs::ForEachFile(g_VFS, L"art/terrains/", AddTextureCallback, (uintptr_t)&data, L"*.xml", vfs::DIR_RECURSIVE, AddTextureDirCallback, (uintptr_t)&data);
	return 0;
}

CTerrainGroup* CTerrainTextureManager::FindGroup(const CStr& name)
{
	TerrainGroupMap::const_iterator it = m_TerrainGroups.find(name);
	if (it != m_TerrainGroups.end())
		return it->second;
	else
		return m_TerrainGroups[name] = new CTerrainGroup(name, ++m_LastGroupIndex);
}

void CTerrainGroup::AddTerrain(CTerrainTextureEntry* pTerrain)
{
	m_Terrains.push_back(pTerrain);
}

void CTerrainGroup::RemoveTerrain(CTerrainTextureEntry* pTerrain)
{
	std::vector<CTerrainTextureEntry*>::iterator it = find(m_Terrains.begin(), m_Terrains.end(), pTerrain);
	if (it != m_Terrains.end())
		m_Terrains.erase(it);
}