/*

  Copyright 2009 Nathan Phillip Brink, Ethan Zonca, Matthew Orlando

  This file is a part of DistRen.

  DistRen is free software: you can redistribute it and/or modify

  it under the terms of the GNU Affero General Public License as published by

  the Free Software Foundation, either version 3 of the License, or

  (at your option) any later version.

  DistRen 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 DistRen.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "mysql.h"

#include <mysql/mysql.h>

#include "common/asprintf.h"

#include "common/protocol.h"

#include <stdio.h>

#include <string.h>

#include <unistd.h>

#include <stdlib.h>

#include <sys/stat.h>

#include <fcntl.h>

/**

   local types

 */

#define SEVENTY_FIVE 75

#define FORTY_TWO 42

/**

   performs mysql query.

   errors will be logged to the user by this function.

   @return pointer to query handle on success, NULL on failure or if expected_columns=0 (no result set expected)

 */

distrend_mysql_result_t mysqlQuery(distrend_mysql_conn_t conn, char *query, MYSQL_FIELD_OFFSET expected_columns);

/**

   frees mysql query result. Accepts a NULL pointer and ignores it to

   help deal with one-shot calls to mysqlQuery so that you don't have to

   check if it returned NULL or not.

   @return 0 on success

 */

int mysqlResultFree(distrend_mysql_result_t result);

/**

   reads an integer mysql field value

   @return 0 on success

*/

int distrend_mysql_getint(MYSQL_ROW row, MYSQL_FIELD_OFFSET column, int32_t *theint)

{

  if(!row[column])

    return 1;

  *theint = atol(row[column]);

  return 0;

}

struct distrend_mysql_conn

{

  MYSQL *mysqlconn;

  short pointlesscheck;

};

struct distrend_mysql_result

{

  MYSQL_RES *mysqlresult;

  short pointlesscheck;

};

/**

    funcs

 */

int mysqlConnect(distrend_mysql_conn_t *conn)

{

  MYSQL *mysqlconn;

  char *server = "zserver1";

  char *user = "distren";

  char *password = "HwLxuBqTvJ6J7FWj";

  char *database = "distren";

  mysqlconn = mysql_init(NULL);

  if(!mysql_real_connect(mysqlconn, server, user, password, database, 0, NULL, CLIENT_MULTI_STATEMENTS))

    {

      fprintf(stderr, "%s\n", mysql_error(mysqlconn));

      return 1;

    }

  mysql_options(mysqlconn, MYSQL_OPT_RECONNECT,"true"); // After mysql_real_connect due to bug fixed in MySQL 5.1.6 and later

  *conn = malloc(sizeof(struct distrend_mysql_conn));

  if(!*conn)

    {

      mysql_close(mysqlconn);

      mysql_server_end();

      return 2;

    }

  (*conn)->mysqlconn = mysqlconn;

  (*conn)->pointlesscheck = SEVENTY_FIVE;

  return 0;

}

int mysqlDisconnect(distrend_mysql_conn_t conn)

{

  /**

     check if this handle is valid

   */

  if(conn->pointlesscheck != SEVENTY_FIVE)

    fprintf(stderr, "warning, I was passed a bad struct distrend_mysql_conn...\n");

  /**

     invalidate handle :-D

   */

  conn->pointlesscheck ++;

  mysql_close(conn->mysqlconn);

  mysql_server_end();

  free(conn);

  return 0;

}

distrend_mysql_result_t mysqlQuery(distrend_mysql_conn_t conn, char *query, MYSQL_FIELD_OFFSET expected_columns)

{

  MYSQL_RES *result;

  distrend_mysql_result_t distrenresult;

  MYSQL_FIELD_OFFSET num_columns;

  /**

     pointless sanity check

  */

  if(conn->pointlesscheck != SEVENTY_FIVE)

    fprintf(stderr, "warning, I was passed a bad struct distrend_mysql_conn...\n");

  /** make sure that connection is still alive

   */

  if(mysql_ping(conn->mysqlconn))

    fprintf(stderr, "MySQL connection broken, and reconnect is disabled!\n");

  fprintf(stderr,"Querying... ");

  if (mysql_query(conn->mysqlconn, query))

     fprintf(stderr, "%s\n", mysql_error(conn->mysqlconn));

  fprintf(stderr,"Queried!\n");

  fprintf(stderr,"Getting results... ");

  result = mysql_use_result(conn->mysqlconn);

  num_columns = mysql_num_fields(result);

  if(num_columns != expected_columns)

    {

      fprintf(stderr, "Expected %d columns, got %d for ``%s''\n", expected_columns, num_columns, query);

      mysql_free_result(result);

      return NULL;

    }

  fprintf(stderr,"Done!\n");

  distrenresult = malloc(sizeof(struct distrend_mysql_result));

  if(!distrenresult)

    {

      mysql_free_result(result);

      return NULL;

    }

  distrenresult->mysqlresult = result;

  distrenresult->pointlesscheck = FORTY_TWO;

  return distrenresult;

}

int mysqlResultFree(distrend_mysql_result_t result)

{

  size_t counter;

  if(!result)

    return 0;

  if(result->pointlesscheck != FORTY_TWO)

    fprintf(stderr, "%s:%d: I didn't get the type of handle I wanted\n", __FILE__, __LINE__);

  /**

     Must flush the resultset buffer.

   */

  for(counter = 0;

      mysql_fetch_row(result->mysqlresult);

      counter ++)

    ;

  if(counter)

    fprintf(stderr, "Calling function did not flush all of the rows it should've\n");

  mysql_free_result(result->mysqlresult);

  free(result);

  return 0;

}

/*

   Individual query functions:

 */

void finish_frame(distrend_mysql_conn_t conn, int32_t slavekey, int32_t jobkey, int32_t framenum)

{

  char *query;

  _distren_asprintf(&query, "CALL `distren`.`Frame_Complete`(%d,%d,%d);", slavekey, jobkey, framenum);

  mysqlQuery(conn, query, 0);

  free(query);

}

void start_frame(distrend_mysql_conn_t conn, int32_t slavekey, int32_t jobkey, int32_t framenum)

{

  char *query;

  _distren_asprintf(&query, "CALL `distren`.`Frame_Start`(%d,%d,%d);", slavekey, jobkey, framenum);

  mysqlQuery(conn, query, 0);

  free(query);

}

int change_job_priority(distrend_mysql_conn_t conn, int32_t jobkey, int32_t newpriority)

{

  char *query;

  _distren_asprintf(&query, "UPDATE `distren`.`Job` SET `Priority`=%d WHERE `Job_Key`=%d",

		    newpriority, jobkey);

  mysqlQuery(conn, query, 0);

  return 0;

}

int find_jobframe(distrend_mysql_conn_t conn, int32_t slavekey, jobnum_t *jobkey, int32_t *framenum)

{

  distrend_mysql_result_t result;

  char *query;

  MYSQL_ROW row;

  int rtn;

  _distren_asprintf(&query, "CALL `distren`.`Frame_Get`(%d);", slavekey);

  result = mysqlQuery(conn, query, 2);

  free(query);

  if(!result)

    return 1;

  row = mysql_fetch_row(result->mysqlresult);

  if(!row)

    {

      mysqlResultFree(result);

      return 1;

    }

  rtn = distrend_mysql_getint(row, 0, (int32_t *)jobkey);

  rtn += distrend_mysql_getint(row, 1, framenum);

  mysqlResultFree(result);

  return rtn;

}