//
//  KRTextureManager.cpp
//  KREngine
//
//  Copyright 2012 Kearwood Gilbert. All rights reserved.
//  
//  Redistribution and use in source and binary forms, with or without modification, are
//  permitted provided that the following conditions are met:
//  
//  1. Redistributions of source code must retain the above copyright notice, this list of
//  conditions and the following disclaimer.
//  
//  2. Redistributions in binary form must reproduce the above copyright notice, this list
//  of conditions and the following disclaimer in the documentation and/or other materials
//  provided with the distribution.
//  
//  THIS SOFTWARE IS PROVIDED BY KEARWOOD GILBERT ''AS IS'' AND ANY EXPRESS OR IMPLIED
//  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
//  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL KEARWOOD GILBERT OR
//  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
//  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
//  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
//  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
//  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
//  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//  
//  The views and conclusions contained in the software and documentation are those of the
//  authors and should not be interpreted as representing official policies, either expressed
//  or implied, of Kearwood Gilbert.
//

#include "KRTextureManager.h"
#include "KRContext.h"
#include <string.h>

KRTextureManager::KRTextureManager(KRContext &context) : KRContextObject(context) {
    m_textureMemUsed = 0;
    for(int iTexture=0; iTexture<KRENGINE_MAX_TEXTURE_UNITS; iTexture++) {
        m_activeTextures[iTexture] = NULL;
    }
}

KRTextureManager::~KRTextureManager() {
    for(map<std::string, KRTexture *>::iterator itr = m_textures.begin(); itr != m_textures.end(); ++itr){
        delete (*itr).second;
    }
}

#if TARGET_OS_IPHONE

KRTexture *KRTextureManager::loadTexture(const char *szName, KRDataBlock *data) {
    KRTexture *pTexture = new KRTexture(data, this);
    
    std::string lowerName = szName;
    std::transform(lowerName.begin(), lowerName.end(),
                   lowerName.begin(), ::tolower);
    

    
    m_textures[lowerName] = pTexture;
    return pTexture;
}

#endif

KRTexture *KRTextureManager::getTexture(const char *szName) {
    std::string lowerName = szName;
    std::transform(lowerName.begin(), lowerName.end(),
                   lowerName.begin(), ::tolower);
    
    map<std::string, KRTexture *>::iterator itr = m_textures.find(lowerName);
    if(itr == m_textures.end()) {
        // Not found
        return NULL;
    } else {
        return (*itr).second;
    }

}

void KRTextureManager::selectTexture(int iTextureUnit, KRTexture *pTexture) {
    if(m_activeTextures[iTextureUnit] != pTexture) {
        glActiveTexture(GL_TEXTURE0 + iTextureUnit);
        if(pTexture != NULL) {
            m_textureCache.erase(pTexture); // Ensure that the texture will not be deleted while it is bound to a texture unit, and return it to the top of the texture cache when it is released
            glBindTexture(GL_TEXTURE_2D, pTexture->getHandle(m_textureMemUsed));
            // TODO - These texture parameters should be assigned by the material or texture parameters
            glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, 1.0f);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
        } else {
            glBindTexture(GL_TEXTURE_2D, 0);
        }
        if(m_activeTextures[iTextureUnit] != NULL) {
            KRTexture *unloadedTexture = m_activeTextures[iTextureUnit];
            m_activeTextures[iTextureUnit] = NULL;
            bool bActive = false;
            for(int iTexture=0; iTexture < KRENGINE_MAX_TEXTURE_UNITS; iTexture++) {
                if(m_activeTextures[iTexture] == unloadedTexture) {
                    bActive = true;
                }
            }
            if(!bActive) {
                // Only return a texture to the cache when the last texture unit referencing it is re-assigned to a different texture
                if(m_textureCache.find(unloadedTexture) == m_textureCache.end()) {
                    m_textureCache.insert(unloadedTexture);
                    while(m_textureCache.size() > KRENGINE_MAX_TEXTURE_HANDLES || m_textureMemUsed > KRENGINE_MAX_TEXTURE_MEM) {
                        // Keep texture size within limits
                        KRTexture *droppedTexture = (*m_textureCache.begin());
                        droppedTexture->releaseHandle(m_textureMemUsed);
                        m_textureCache.erase(droppedTexture);
                        fprintf(stderr, "Texture Swapping...\n");
                    }
                }
            }
        }
        m_activeTextures[iTextureUnit] = pTexture;
    }
}

long KRTextureManager::getMemUsed() {
    return m_textureMemUsed;
}