// ServerFunctionsList.cc

// This file is part of bes, A C++ back-end server implementation framework

// for the OPeNDAP Data Access Protocol.

// Copyright (c) 2013 OPeNDAP, Inc.

// Author: James Gallagher <jgallagher@opendap.org>

//

// This library is free software; you can redistribute it and/or

// modify it under the terms of the GNU Lesser General Public

// License as published by the Free Software Foundation; either

// version 2.1 of the License, or (at your option) any later version.

//

// This library 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

// Lesser General Public License for more details.

//

// You should have received a copy of the GNU Lesser General Public

// License along with this library; if not, write to the Free Software

// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

//

// You can contact OPeNDAP, Inc. at PO Box 112, Saunderstown, RI. 02874-0112.

#include "config.h"

#ifdef HAVE_STDLIB_H

#include <stdlib.h>

#endif

#include <pthread.h>

#include <iostream>

#include <algorithm>

//#define DODS_DEBUG

#include <expr.h>

#include "debug.h"

#include "ServerFunctionsList.h"

using namespace std;

using namespace libdap;

namespace libdap {

static pthread_once_t ServerFunctionsList_instance_control = PTHREAD_ONCE_INIT;

ServerFunctionsList *ServerFunctionsList::d_instance = 0 ;

/**

 * private static that only gets called once in the life cycle of the process.

 */

void ServerFunctionsList::initialize_instance() {

    if (d_instance == 0) {

        DBG(cerr << "ServerFunctionsList::initialize_instance() - Creating singleton ServerFunctionList instance." << endl);

        d_instance = new ServerFunctionsList;

        #if HAVE_ATEXIT

            atexit(delete_instance);

        #endif

    }

}

/**

 * Private static function can only be called by friends andf pThreads code.

 */

void ServerFunctionsList::delete_instance() {

    DBG(cerr << "ServerFunctionsList::delete_instance() - Deleting singleton ServerFunctionList instance." << endl);

    delete d_instance;

    d_instance = 0;

}

/**

 * Private method insures that nobody can try to delete the singleton class.

 */

ServerFunctionsList::~ServerFunctionsList() {

    SFLIter fit;

    for(fit=d_func_list.begin(); fit!=d_func_list.end() ; fit++){

        ServerFunction *func = fit->second;

        DBG(cerr << "ServerFunctionsList::~ServerFunctionsList() - Deleting ServerFunction " << func->getName() << " from ServerFunctionsList." << endl);

        delete func;

    }

    d_func_list.clear();

}

ServerFunctionsList * ServerFunctionsList::TheList() {

    pthread_once(&ServerFunctionsList_instance_control, initialize_instance);

    DBG(cerr << "ServerFunctionsList::TheList() - Returning singleton ServerFunctionList instance." << endl);

    return d_instance;

}

/**

 * Adds the passed ServerFunction pointer to the list of ServerFunctions using

 * the value of ServerFunction.getName() as the key in the list.

 *

 * @brief Adds the passed ServerFunction pointer to the list of ServerFunctions.

 * @param *func A pointer to the ServerFunction object to add to the ServerFunctionList.

 * The pointer is copied, not the object referenced; this class does not

 * delete the pointer.

 */

void ServerFunctionsList::add_function(ServerFunction *func )

{

    DBG(cerr << "ServerFunctionsList::add_function() - Adding ServerFunction " << func->getName() << endl);

    d_func_list.insert(std::make_pair(func->getName(),func));

}

/**

 * Returns the first boolean function in the list whose key value matches the passed string name.

 * When a match is found the function returns true and sets returned value parameter *f to

 * the boolean function held by the ServerFunction object extracted from the list.

 *

 * Method:

 * Looks through the list of ServerFunctions and compares each function's key value (which

 * would be the value of SurverFunction.getName()) with the value of the string parameter

 * 'name'. When they match then the returned value parameter is set to the value returned

 * by ServerFunction.get_btp_func(). If the ServerFunction _is not_  a instance of a boolean

 * function then the return value will be 0 (null) and the search for matching function will continue.

 * If the ServerFunction _is_ a boolean function then the returned value will be non-zero and

 * the search will return true (it found the thing) and the returned value parameter *f will have

 * it's value set to the boolean function.

 *

 *  @brief Find a boolean function with a given name in the function list.

 *  @param name A string containing the name of the function to find.

 *  @param *f   A returned value parameter through which a point to the desired function is returned.

 *

 */

bool ServerFunctionsList::find_function(const std::string &name, bool_func *f) const

{

    if (d_func_list.empty())

        return false;

    std::pair <SFLCIter, SFLCIter> ret;

    ret = d_func_list.equal_range(name);

    for (SFLCIter it = ret.first; it != ret.second; ++it) {

        if (name == it->first && (*f = it->second->get_bool_func())){

            DBG(cerr << "ServerFunctionsList::find_function() - Found boolean function " << it->second->getName() << endl);

            return true;

        }

    }

    return false;

}

/**

 * Returns the first BaseType function in the list whose key value matches the passed string name.

 * When a match is found the function returns true and sets returned value parameter *f to

 * the BaseType function held by the ServerFunction object extracted from the list.

 *

 * Method:

 * Looks through the list of ServerFunctions and compares each function's key value (which

 * would be the value of SurverFunction.getName()) with the value of the string parameter

 * 'name'. When they match then the returned value parameter is set to the value returned

 * by ServerFunction.get_btp_func(). If the ServerFunction _is not_  a instance of a BaseType

 * function then the return value will be 0 (null) and the search for matching function will continue.

 * If the ServerFunction _is_ a BaseType function then the returned value will be non-zero and

 * the search will return true (it found the thing) and the returned value parameter *f will have

 * it's value set to the BaseType function.

 *

 *  @brief Find a BaseType function with a given name in the function list.

 *  @param name A string containing the name of the function to find.

 *  @param *f   A returned value parameter through which a point to the desired function is returned.

 *

 */

bool ServerFunctionsList::find_function(const string &name, btp_func *f) const

{

    if (d_func_list.empty())

        return false;

    DBG(cerr << "ServerFunctionsList::find_function() - Looking for ServerFunction '" << name << "'" << endl);

    std::pair <SFLCIter, SFLCIter> ret;

    ret = d_func_list.equal_range(name);

    for (SFLCIter it = ret.first; it != ret.second; ++it) {

        if (name == it->first && (*f = it->second->get_btp_func())){

            DBG(cerr << "ServerFunctionsList::find_function() - Found basetype function " << it->second->getName() << endl);

            return true;

        }

    }

    return false;

}

/**

 * Returns the first projection function in the list whose key value matches the passed string name.

 * When a match is found the function returns true and sets returned value parameter *f to

 * the projection function held by the ServerFunction object extracted from the list.

 *

 * Method:

 * Looks through the list of ServerFunctions and looks at each function's key value (which

 * would be the value of SurverFunction.getName() for each function). When a function has the same

 * key name as the value of the string parameter 'name', then the returned value parameter is set

 * the value returned by ServerFunction.get_proj_func(). If the ServerFunction _is not_  a projection

 * function then the return value will be 0 (null) and the search for matching function will continue.

 * If the ServerFunction _is_ a projection then the returned value will be non-zero and the search will

 * return true (it found the thing) and the returned value parameter *f will have it's value set

 * to the projection function.

 *

 *  @brief Find a projection function with a given name in the function list.

 *  @param name A string containing the name of the function to find.

 *  @param *f   A returned value parameter through which a point to the desired function is returned.

 *

 */

bool ServerFunctionsList::find_function(const string &name, proj_func *f) const

{

    if (d_func_list.empty())

        return false;

    std::pair <SFLCIter, SFLCIter> ret;

    ret = d_func_list.equal_range(name);

    for (SFLCIter it = ret.first; it != ret.second; ++it) {

        if (name == it->first && (*f = it->second->get_proj_func())){

            DBG(cerr << "ServerFunctionsList::find_function() - Found projection function " << it->second->getName() << endl);

           return true;

        }

    }

    return false;

}

/**

 * Find a DAP4 function in the Server Functions List.

 *

 * @param name Look for this function name

 * @param f Value-result parameter. NULL if the function is not found

 * @return True if the function was found, otherwise false.

 */

bool ServerFunctionsList::find_function(const string &name, D4Function *f) const

{

    if (d_func_list.empty())

        return false;

    std::pair <SFLCIter, SFLCIter> ret;

    ret = d_func_list.equal_range(name);

    for (SFLCIter it = ret.first; it != ret.second; ++it) {

        if (name == it->first && (*f = it->second->get_d4_function())) {

            return true;

        }

    }

    return false;

}

/** @brief Returns an iterator pointing to the first key pair in the ServerFunctionList. */

ServerFunctionsList::SFLIter ServerFunctionsList::begin()

{

    return d_func_list.begin();

}

/** @brief Returns an iterator pointing to the last key pair in the ServerFunctionList. */

ServerFunctionsList::SFLIter ServerFunctionsList::end()

{

    return d_func_list.end();

}

/**

 *

 *

 * @brief Returns the ServerFunction pointed to by the passed iterator.

 *

 */

ServerFunction *ServerFunctionsList::getFunction(SFLIter it)

{

    return (*it).second;

}

void ServerFunctionsList::getFunctionNames(vector<string> *names){

	SFLIter fit;

    for(fit = d_func_list.begin(); fit != d_func_list.end(); fit++) {

        ServerFunction *func = fit->second;

        names->push_back(func->getName());

    }

}

} // namespace libdap