/*    Copyright 2012 10gen Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
 *    as published by the Free Software Foundation.
 *
 *    This program 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 Affero General Public License for more details.
 *
 *    You should have received a copy of the GNU Affero General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the GNU Affero General Public License in all respects
 *    for all of the code used other than as permitted herein. If you modify
 *    file(s) with this exception, you may extend this exception to your
 *    version of the file(s), but you are not obligated to do so. If you do not
 *    wish to do so, delete this exception statement from your version. If you
 *    delete this exception statement from all source files in the program,
 *    then also delete it in the license file.
 */

#pragma once

#include <string>
#include <vector>

#include "mongo/base/disallow_copying.h"
#include "mongo/base/initializer_context.h"
#include "mongo/base/initializer_dependency_graph.h"
#include "mongo/base/status.h"

namespace mongo {

/**
 * Class representing an initialization process.
 *
 * Such a process is described by a directed acyclic graph of initialization operations, the
 * InitializerDependencyGraph.  One constructs an initialization process by adding nodes and
 * edges to the graph.  Then, one executes the process, causing each initialization operation to
 * execute in an order that respects the programmer-established prerequistes.
 */
class Initializer {
    MONGO_DISALLOW_COPYING(Initializer);

public:
    Initializer();
    ~Initializer();

    /**
     * Get the initializer dependency graph, presumably for the purpose of adding more nodes.
     */
    InitializerDependencyGraph& getInitializerDependencyGraph() {
        return _graph;
    }

    /**
     * Execute the initializer process, using the given argv and environment data as input.
     *
     * Returns Status::OK on success.  All other returns constitute initialization failures,
     * and the thing being initialized should be considered dead in the water.
     */
    Status execute(const InitializerContext::ArgumentVector& args,
                   const InitializerContext::EnvironmentMap& env) const;

private:
    InitializerDependencyGraph _graph;
};

/**
 * Run the global initializers.
 *
 * It's a programming error for this to fail, but if it does it will return a status other
 * than Status::OK.
 *
 * This means that the few initializers that might want to terminate the program by failing
 * should probably arrange to terminate the process themselves.
 */
Status runGlobalInitializers(const InitializerContext::ArgumentVector& args,
                             const InitializerContext::EnvironmentMap& env);

Status runGlobalInitializers(int argc, const char* const* argv, const char* const* envp);

/**
 * Same as runGlobalInitializers(), except prints a brief message to std::cerr
 * and terminates the process on failure.
 */
void runGlobalInitializersOrDie(int argc, const char* const* argv, const char* const* envp);

}  // namespace mongo