/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 *   
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

/* $Rev$ $Date$ */

#if defined(WIN32)  || defined (_WINDOWS)
#pragma warning(disable: 4786)
#endif

#include "tuscany/sca/util/Library.h"
#include "tuscany/sca/util/Utils.h"
#include "tuscany/sca/util/Exceptions.h"
#include "tuscany/sca/util/Logging.h"

namespace tuscany
{
    namespace sca
    {
        Library::Library()
            : hDLL(NULL)
        {
        }
        
        Library::Library(const string& libraryName)
            : name(libraryName), hDLL(NULL)
        {
            LOGINFO_1(3, "Library::construcor : %s", name.c_str()); 
            load();
        }

        Library::Library(const Library& lib)
            : name(lib.name), hDLL(NULL)
        {
            LOGINFO_1(3, "Library::copy constructor : %s", name.c_str()); 
            if (lib.hDLL)
            {
                load();
            }
        }
        
        Library& Library::operator=(const Library& lib)
        {
            LOGINFO_1(3, "Library::operator= : %s", name.c_str()); 
            if (&lib != this)
            {
                unload();
                name = lib.name;
                load();
            }
            return *this;
        }
        
        Library::~Library()
        {
            LOGINFO_1(3, "Library::destructor: %s", name.c_str()); 
            unload();
        }
        
        
        void Library::load()
        {
            LOGINFO_1(3, "Library::load : %s", name.c_str()); 
            string msg;
#if defined(WIN32)  || defined (_WINDOWS)
            int l = name.length();
            string dllName;
            if (l>=4 && name.substr(l-4, 4)==".dll")
            {
                dllName = name;
            }
            else
            {
                dllName = name+".dll";
            }
            hDLL = LoadLibrary(dllName.c_str());
            if (hDLL == NULL)
            {
                msg = "Unable to load library: " + dllName;
            }
#else
            int l = name.length();
            string soName;
            if (l>=3 && name.substr(l-3, 3)==".so")
            {
                soName = name;
            }
            else
            {
                int s = name.rfind("/");
                if (s == name.length())
                {
                    soName = name + ".so";
                }
                else
                {
                    s++;
                    soName = name.substr(0, s) + "lib" + name.substr(s, name.length()-s) + ".so";
                }
            }
            hDLL = dlopen(soName.c_str(), RTLD_NOW);
            if (hDLL == NULL)
            {
                msg = "Unable to load library: " + soName + ": " + dlerror();
            }
#endif
            if (hDLL == NULL)
            {
                LOGERROR(1, msg.c_str());
                throw SystemConfigurationException(msg.c_str());
            }    
        }
        
        void Library::unload()
        {
            if (hDLL != NULL)
            {
            LOGINFO_1(3, "Library::unload : %s", name.c_str()); 
#if defined(WIN32)  || defined (_WINDOWS)
                FreeLibrary(hDLL);
#else
                dlclose(hDLL);
#endif
                hDLL = NULL;
            }
        }
    
        void* Library::getSymbol(const string& symbol)
        {
            LOGINFO_1(3, "Library::getSymbol : %s", symbol.c_str()); 
            if (!hDLL)
            {
                return 0;
            }
#if defined(WIN32)  || defined (_WINDOWS)
            return GetProcAddress(hDLL, symbol.c_str());        
#else
            return dlsym(hDLL, symbol.c_str());    
#endif            
        }    
        
    } // End namespace sca
} // End namespace tuscany