/*
 * 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)
#else
#include "tuscany_sca_config.h"
#endif

#include <sstream>

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

using namespace std;

namespace tuscany
{
    namespace sca
    {
        namespace util
        {
            Library::Library()
                : hDLL(NULL)
            {
            }
            
            Library::Library(const string& libraryName)
                : name(libraryName), hDLL(NULL)
            {
                logentry();
                load();
            }
    
            Library::Library(const Library& lib)
                : name(lib.name), hDLL(NULL)
            {
                logentry();
                if (lib.hDLL)
                {
                    load();
                }
            }
            
            Library& Library::operator=(const Library& lib)
            {
                logentry();
                if (&lib != this)
                {
                    unload();
                    name = lib.name;
                    load();
                }
                return *this;
            }
            
            Library::~Library()
            {
                logentry();
                unload();
            }
            
            
            void Library::load()
            {
                logentry();
                loginfo("Library: %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";
                }
                SetErrorMode(SEM_FAILCRITICALERRORS);
                hDLL = LoadLibrary(dllName.c_str());
                if (hDLL == NULL)
                {
                    ostringstream msgs;
                    msgs << "Unable to load library: " + dllName << ", error: ";
                    Utils::printLastError(msgs);
                    msg = msgs.str();
                }
#else
                int l = name.length();
                string libName;
#ifdef IS_DARWIN
                string suffix = ".dylib";
#else
                string suffix = ".so";
#endif
                unsigned int suffixLength = suffix.length();
                if (l>=suffixLength && name.substr(l-suffixLength, suffixLength)==suffix)
                {
                    libName = name;
                }
               else
               {
                    int s = name.rfind("/");
                    if (s == name.length())
                    {
                        libName = name + suffix;
                    }
                    else
                    {
                        s++;
                        libName = name.substr(0, s) + "lib" + name.substr(s, name.length()-s) + suffix;
                    }
                }
                hDLL = dlopen(libName.c_str(), RTLD_NOW);
                if (hDLL == NULL)
                {
                    msg = "Unable to load library: " + libName + ": " + dlerror();
                }
#endif
                if (hDLL == NULL)
                {
                    throwException(SystemConfigurationException, msg.c_str());
                }    
            }
            
            void Library::unload()
            {
                logentry();
                loginfo("Library: %s", name.c_str()); 
                
                if (hDLL != NULL)
                {
#if defined(WIN32)  || defined (_WINDOWS)
                    FreeLibrary(hDLL);
#else
                    dlclose(hDLL);
#endif
                    hDLL = NULL;
                }
            }
        
            void* Library::getSymbol(const string& symbol)
            {
                logentry();
                loginfo("Symbol: %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 util
    } // End namespace sca
} // End namespace tuscany