/*
 * (C) Copyright 1996- ECMWF.
 *
 * This software is licensed under the terms of the Apache Licence Version 2.0
 * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
 * In applying this licence, ECMWF does not waive the privileges and immunities
 * granted to it by virtue of its status as an intergovernmental organisation nor
 * does it submit to any jurisdiction.
 */

/// @author Baudouin Raoult
/// @author Tiago Quintino
/// @author Pedro Maciel
/// @date April 2016


#include "mir/util/Function.h"

#include <iostream>
#include <map>

#include "eckit/exception/Exceptions.h"
#include "eckit/thread/AutoLock.h"
#include "eckit/thread/Once.h"
#include "eckit/thread/Mutex.h"


namespace mir {
namespace util {


namespace {


static eckit::Mutex *local_mutex = nullptr;
static std::map<std::string, Function *> *m = nullptr;

static pthread_once_t once = PTHREAD_ONCE_INIT;

static void init() {
    local_mutex = new eckit::Mutex();
    m = new std::map<std::string, Function *>();
}

}


Function::Function(const std::string& name):
    name_(name) {

    pthread_once(&once, init);

    eckit::AutoLock<eckit::Mutex> lock(local_mutex);

    ASSERT(m->find(name) == m->end());
    (*m)[name] = this;
}


Function::~Function() {
    eckit::AutoLock<eckit::Mutex> lock(local_mutex);
    m->erase(name_);
}



const Function& Function::lookup(const std::string &name) {

    pthread_once(&once, init);

    eckit::AutoLock<eckit::Mutex> lock(local_mutex);
    std::map<std::string, Function *>::const_iterator j = m->find(name);


    if (j == m->end()) {
        eckit::Log::error() << "No Function for [" << name << "]" << std::endl;
        eckit::Log::error() << "Functions are:" << std::endl;
        for (j = m->begin() ; j != m->end() ; ++j)
            eckit::Log::error() << "   " << (*j).first << std::endl;
        throw eckit::SeriousBug(std::string("No Function called ") + name);
    }

    return *(*j).second;
}


} // namespace util
} // namespace mir

