/*************************************************************************
*									 *
*	 YAP Prolog 							 *
*									 *
*	Yap Prolog was developed at NCCUP - Universidade do Porto	 *
*									 *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997	 *
*									 *
**************************************************************************
*									 *
* File:		myddas_top_level.c					 *
* Last rev:	27/01/06						 *
* mods:									 *
* comments:	Top Level of the MYDDAS Interface                        *
*									 *
*************************************************************************/

#if defined MYDDAS_TOP_LEVEL && defined MYDDAS_MYSQL

#include "Yap.h"
#include "Yatom.h"
#include "myddas_util.h"
#include "myddas_structs.h"
#include "myddas_statistics.h"
#include <mysql/mysql.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <readline/readline.h>
#include <readline/history.h>
#include <sys/times.h>


STATIC_PROTO(Int c_db_tl_top_level_mysql,(void));
STATIC_PROTO(Int c_db_tl_readline,(void));

STATIC_PROTO(Int com_quit,(char *,char*));
STATIC_PROTO(Int myddas_top_level_command,(char *,char *));
STATIC_PROTO(void myddas_top_level_print_time,(MYDDAS_STATS_TIME));


void Yap_InitMYDDAS_TopLevelPreds(void)
{
  /* c_db_readline: +Prompt x -Line */
  Yap_InitCPred("c_db_tl_readline", 2, c_db_tl_readline,  SafePredFlag|SyncPredFlag|HiddenPredFlag);
  
  Yap_InitCPred("c_db_tl_top_level_mysql", 2, c_db_tl_top_level_mysql,  SafePredFlag|SyncPredFlag|HiddenPredFlag);
}


typedef struct {
  const char *name;		/* User printable name of the function. */
  char cmd_char;		/* msql command character */
  Int (*func)(char *str,char *); /* Function to call to do the job. */
  //bool takes_params;		/* Max parameters for command */
  const char *doc;		/* Documentation for this function.  */
} COMMANDS;


static COMMANDS commands[] = {
  //  { "?",      '?', com_help,   1, "Synonym for `help'." },
  //  { "use",   'u', com_use,  "Use another database. Takes database name as argument."},
  { "exit",   'q', com_quit,  "Exit MYDDAS Top Level. Same as quit."},
  { "quit",   'q', com_quit,  "Quit MYDDAS Top Level." },
  // End of the vector
  { (char *)NULL,       0, 0, ""}
};

static Int
c_db_tl_readline(void) {
  Term arg_prompt = Deref(ARG1);
  Term arg_line = Deref(ARG2);

  char *prompt = AtomName(AtomOfTerm(arg_prompt));
  char *line;
 
  while (strlen(line = readline(prompt)) == 0) {
    free(line);         
  }
  add_history(line);
  
  Term line_read = MkAtomTerm(Yap_LookupAtom(line));
  free(line);
  
  if (!Yap_unify(arg_line,line_read))
    return FALSE;
  return TRUE;
  
}

static Int
c_db_tl_top_level_mysql(void) {
  Term arg_conn = Deref(ARG1);
  Term arg_res_set_mode = Deref(ARG2);
  
  MYSQL *con = (MYSQL *) IntegerOfTerm(arg_conn);
  char *res_set_mode = AtomName(AtomOfTerm(arg_res_set_mode));
  char *line;
  Int quit;
  
  Yap_REGS.MYDDAS_GLOBAL_POINTER->myddas_top_level_connection = myddas_util_search_connection(con);

  printf ("\n");
  for (;;) {
    /* Ignore empty lines */
    while (strlen(line = readline("mysql> ")) == 0) {
      free(line);         
    }
    add_history(line);
    quit = myddas_top_level_command(line,res_set_mode);
    free(line);           
    if (quit == -1)
      return TRUE;
  }
  
}

static Int    
myddas_top_level_command(char *line,char *res_set_mode){
  
  Int i;
  MYSQL *conn;
  MYSQL_RES *res_set;

  if ( (line[0] == '#' ||
	(line[0] == '-' && line[1] == '-') ||
	line[0] == 0))
    return 0;					// Skip comment lines


  for (i=0;commands[i].name!=NULL;i++)
    if (!strcmp(commands[i].name,line))
      {
	Int quit = (*(commands[i].func))(NULL,NULL);
	return quit;
      }

  Int length=strlen(line);

  conn = (MYSQL *) (Yap_REGS.MYDDAS_GLOBAL_POINTER->myddas_top_level_connection->connection);

  MYDDAS_STATS_TIME start = myddas_stats_walltime();
  if (mysql_real_query(conn, line, length) != 0){
    printf ("ERROR %d (%s): %s\n",mysql_errno(conn),mysql_sqlstate(conn),mysql_error(conn));
  }
  else{
    
    
    if (strcmp(res_set_mode,"store_result")==0) //True
      res_set = mysql_store_result(conn);
    else
      res_set = mysql_use_result(conn);
    
    MYDDAS_STATS_TIME end = myddas_stats_walltime();
    MYDDAS_STATS_TIME diff;
    
    MYDDAS_STATS_INITIALIZE_TIME_STRUCT(diff,time_copy);
    myddas_stats_subtract_time(diff,end,start);
    diff = myddas_stats_time_copy_to_final(diff);
  
    myddas_util_table_write(res_set);
    printf ("%lld rows in set ",mysql_num_rows(res_set));
    myddas_top_level_print_time(diff);
    printf ("\n");
    mysql_free_result(res_set);
  }
  return 0;
}

Int com_quit(char *nill,char *null){
  Yap_REGS.MYDDAS_GLOBAL_POINTER->myddas_top_level_connection = NULL;
  printf ("Bye\n");
  return -1;
}

static void
myddas_top_level_print_time(MYDDAS_STATS_TIME time){

  //TODO test for big queries, and see the output of mysql
  printf("(");
  
  printf("%d",time->u.time_final.seconds);
  //MiliSeconds 2 decimal points
  printf(".%d",time->u.time_final.miliseconds/10); 
  printf (" sec)");
}

#endif