/* -------------------------------------------------------------------------- */
/* Copyright 2002-2012, OpenNebula Project Leads (OpenNebula.org)             */
/*                                                                            */
/* Licensed 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.                                             */
/* -------------------------------------------------------------------------- */

#ifndef HISTORY_H_
#define HISTORY_H_

#include "ObjectSQL.h"

using namespace std;

/**
 *  The History class, it represents an execution record of a Virtual Machine.
 */

class History:public ObjectSQL, public ObjectXML
{
public:
    enum MigrationReason
    {
        NONE,       /** < Normal termination in host */
        ERROR,      /** < The VM was migrated because of an error */
        STOP_RESUME,/** < The VM was migrated because of a stop/resume request*/
        USER,       /** < The VM was migrated because of an explicit request */
        CANCEL      /** < The VM was migrated because of an explicit cancel */
    };

    History(int oid, int _seq = -1);

    History(
        int oid,
        int seq,
        int hid,
        const string& hostname,
        const string& vm_dir,
        const string& vmm,
        const string& vnm,
        const string& tm);

    ~History(){};

    /**
     *  Function to write the History Record in an output stream
     */
    friend ostream& operator<<(ostream& os, const History& history);

    /**
     * Function to print the History object into a string in
     * XML format
     *  @param xml the resulting XML string
     *  @return a reference to the generated string
     */
    string& to_xml(string& xml) const;

private:
    friend class VirtualMachine;
    friend class VirtualMachinePool;

    // ----------------------------------------
    // DataBase implementation variables
    // ----------------------------------------

    static const char * table;

    static const char * db_names;

    static const char * db_bootstrap;

    void non_persistent_data();

    // ----------------------------------------
    // History fields
    // ----------------------------------------
    int     oid;
    int     seq;

    string  hostname;
    string  vm_dir;

    int     hid;

    string  vmm_mad_name;
    string  vnm_mad_name;
    string  tm_mad_name;

    time_t  stime;
    time_t  etime;

    time_t  prolog_stime;
    time_t  prolog_etime;

    time_t  running_stime;
    time_t  running_etime;

    time_t  epilog_stime;
    time_t  epilog_etime;

    MigrationReason reason;

    //Non-persistent history fields
    string  vm_lhome;
    string  transfer_file;
    string  deployment_file;
    string  context_file;

    string  vm_rhome;
    string  checkpoint_file;
    string  rdeployment_file;

    /**
     *  Writes the history record in the DB
     *    @param db pointer to the database.
     *    @return 0 on success.
     */
    int insert(SqlDB * db, string& error_str)
    {
        error_str.clear();

        return insert_replace(db, false);
    }

    /**
     *  Reads the history record from the DB
     *    @param db pointer to the database.
     *    @return 0 on success.
     */
    int select(SqlDB * db);

    /**
     *  Updates the history record
     *    @param db pointer to the database.
     *    @return 0 on success.
     */
     int update(SqlDB * db)
     {
        return insert_replace(db, true);
     }

    /**
     *  Removes the all history records from the DB
     *    @param db pointer to the database.
     *    @return 0 on success.
     */
    int drop(SqlDB * db);

    /**
     *  Execute an INSERT or REPLACE Sql query.
     *    @param db The SQL DB
     *    @param replace Execute an INSERT or a REPLACE
     *    @return 0 on success
     */
    int insert_replace(SqlDB *db, bool replace);

    /**
     *  Callback function to unmarshall a history object (History::select)
     *    @param num the number of columns read from the DB
     *    @para names the column names
     *    @para vaues the column values
     *    @return 0 on success
     */
    int select_cb(void *nil, int num, char **values, char **names);

    /**
     *  Rebuilds the object from an xml node
     *    @param node The xml node pointer
     *
     *    @return 0 on success, -1 otherwise
     */
    int from_xml_node(const xmlNodePtr node)
    {
        ObjectXML::update_from_node(node);

        return rebuild_attributes();
    }

    /**
     *  Rebuilds the object from an xml formatted string
     *    @param xml_str The xml-formatted string
     *
     *    @return 0 on success, -1 otherwise
     */
    int from_xml(const string &xml_str)
    {
        ObjectXML::update_from_str(xml_str);

        return rebuild_attributes();
    }

    /**
     *  Rebuilds the internal attributes using xpath
     */
    int rebuild_attributes();
};

#endif /*HISTORY_H_*/