/*****************************************************************************
*
* MODULE:       SQL statement parser library 
*   	    	
* AUTHOR(S):    lex.l and yac.y were originaly taken from unixODBC and
*               probably written by Peter Harvey <pharvey@codebydesigns.com>,
*               original modifications & added code by 
*                     Radim Blazek <radim.blazek gmail.com>
*               Glynn Clements <glynn gclements.plus.com>,
*               Markus Neteler <neteler itc.it>,
*               Martin Landa <landa.martin gmail.com>,
*               Moritz Lennert <mlennert club.worldonline.be>,
*               Hamish Bowman <hamish_nospam yahoo.com>,
*               Daniel Calvelo Aros <dca.gis gmail.com>,
*               Paul Kelly <paul-grass stjohnspoint.co.uk>,
*               Alex Shevlakov <sixote yahoo.com>
*
* PURPOSE:      Parse input string containing SQL statement to 
*               SQLPSTMT structure.
*               SQL parser may be used by simple database drivers. 
*
* COPYRIGHT:    (C) 2000-2007 by the GRASS Development Team
*
*               This program is free software under the GNU General Public
*   	    	License (>=v2). Read the file COPYING that comes with GRASS
*   	    	for details.
*
*****************************************************************************/

#define SQLP_MAIN 

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <assert.h>
#include <grass/sqlp.h>

/* save string to value */
int sqpSaveStr(SQLPVALUE *val, char *c )
{
    int len = 0;

    len = strlen ( c ) + 1;
    val->s = (char *) realloc (val->s, len);

    strcpy ( val->s, c );

    return (1);
}

void
sqpInitValue ( SQLPVALUE *val)
{
    val->type = SQLP_NULL;
    val->s = NULL;
    val->i = 0;
    val->d = 0.0;
}

void
sqpCopyValue ( SQLPVALUE *from, SQLPVALUE *to)
{
    to->type = from->type;
    
    if ( to->s )
	free ( to->s );
	
    if ( from->s ) 
        to->s = strdup ( from->s );
    
    to->i = from->i;
    to->d = from->d;
}
    
int sqpInitParser(SQLPSTMT *st)
{
    sqlpStmt = st;
    sqlpStmt->cur = sqlpStmt->stmt;

    sqlpStmt->errmsg[0] = '\0';
    sqlpStmt->table[0] = '\0';
    sqlpStmt->nCol = 0;
    sqlpStmt->nVal = 0;
    sqlpStmt->upperNodeptr = NULL;
    sqlpStmt->orderCol = NULL;

    return (1);
}

void sqpCommand( int command )
{
    sqlpStmt->command = command;          
    return;
}

void sqpTable( char *tbl )
{
    strncpy (sqlpStmt->table,  tbl, SQLP_MAX_TABLE );
    return;
}

void sqpColumn( char *col )
{
    int i;

    i = sqlpStmt->nCol;
    sqpAllocCol(sqlpStmt, i + 1 );
    sqpSaveStr ( &(sqlpStmt->Col[i]), col );

    sqlpStmt->nCol++;
    return;
}

void sqpColumnDef( char *col, int type, int width, int decimals )
{
    int i;
    
    i = sqlpStmt->nCol;
    sqpAllocCol(sqlpStmt, i + 1 );
    sqpSaveStr ( &(sqlpStmt->Col[i]), col );
    sqlpStmt->ColType[i] = type;
    sqlpStmt->ColWidth[i] = width;
    sqlpStmt->ColDecim[i] = decimals;

    sqlpStmt->nCol++;
    return;
}

void sqpValue( char *strval, int intval, double dblval, int type )
{
    int i;
    
    i = sqlpStmt->nVal;

    /* allocate space for cols because if in INSERT cols were not
     * specified array for ColNum would not be allocated */
    sqpAllocCol(sqlpStmt, i + 1 );

    sqpAllocVal(sqlpStmt, i + 1 );
    sqlpStmt->Val[i].s = NULL;
    sqlpStmt->Val[i].i = 0;    /* not necessay I think */
    sqlpStmt->Val[i].d = 0.0;  /* not necessay I think */
    
    sqlpStmt->Val[i].type = type;
    switch ( type  )
      {
        case (SQLP_S):
            sqpSaveStr ( &(sqlpStmt->Val[i]), strval );
            break;	
        case (SQLP_I):
            sqlpStmt->Val[i].i = intval;
            break;	
        case (SQLP_D):
            sqlpStmt->Val[i].d = dblval;
            break;	
	/* SQLP_NULL, nothing to do */
      }

    sqlpStmt->nVal++;
    return;
}

void sqpAssignment( char *col, char *strval, int intval, double dblval, SQLPNODE *expval, int type )
{
    int i;
    
    i = sqlpStmt->nCol;

    sqpAllocCol(sqlpStmt, i + 1 );
    sqpSaveStr ( &(sqlpStmt->Col[i]), col );

    sqpAllocVal(sqlpStmt, i + 1 );
    sqlpStmt->Val[i].s = NULL;
    sqlpStmt->Val[i].i = 0;    /* not necessay I think */
    sqlpStmt->Val[i].d = 0.0;  /* not necessay I think */

    sqlpStmt->Val[i].type = type;
    switch ( type  )
      {
      case (SQLP_S):
	  sqpSaveStr ( &(sqlpStmt->Val[i]), strval );
	  break;	
      case (SQLP_I):
	  sqlpStmt->Val[i].i = intval;
	  break;	
      case (SQLP_D):
	  sqlpStmt->Val[i].d = dblval;
	  break;
      case (SQLP_EXPR):
	sqlpStmt->Val[i].expr = expval;
	/* Don't do anything right now; come back to this when executing */
	break;
	/* SQLP_NULL, nothing to do */
      }

    sqlpStmt->nCol++;
    sqlpStmt->nVal++;
    return;
}

void sqpOrderColumn( char *col, int dir )
{
    sqlpStmt->orderCol = (char *) realloc (sqlpStmt->orderCol, strlen(col)+1);
    strcpy ( sqlpStmt->orderCol, col );
    sqlpStmt->orderDir = dir;
    return;
}

/* Create and init new node */
SQLPNODE *sqpNewNode ( void ) 
{
    SQLPNODE *np;

    np = (SQLPNODE *) calloc ( 1, sizeof (SQLPNODE) );
    return np;
}

SQLPNODE *
sqpNewExpressionNode (int oper, SQLPNODE *left, SQLPNODE *right)
{
    SQLPNODE *np;

    np = sqpNewNode ();

    np->node_type = SQLP_NODE_EXPRESSION;
    np->oper = oper;
    np->left = left;
    np->right = right;

    return np;
}

SQLPNODE *
sqpNewColumnNode ( char *name )
{
    SQLPNODE *np;

    np = sqpNewNode ();

    np->node_type = SQLP_NODE_COLUMN;
    np->column_name = strdup ( name );

    return np;
}

SQLPNODE *
sqpNewValueNode (char *strval, int intval, double dblval, int type)
{
    SQLPNODE *np;

    np = sqpNewNode ();

    np->node_type = SQLP_NODE_VALUE;

    np->value.type = type;
    if ( strval )
        np->value.s = strdup ( strval );
    np->value.i = intval;
    np->value.d = dblval;

    return np;
}

void 
sqpFreeNode ( SQLPNODE *np ) 
{
    if ( !np ) return;

    if ( np->left )
	sqpFreeNode ( np->left );

    if ( np->right )
	sqpFreeNode ( np->right );

    if ( np->column_name )
	free ( np->column_name );

    if ( np->value.s )
	free ( np->value.s );

    free ( np );
}

int
sqpOperatorCode( char *oper)
{
    char *tmp, *ptr;

    /* Convert to lower case */
    tmp = strdup ( oper );
    ptr = tmp;
    while ( *ptr ) {
	*ptr = tolower ( *ptr );
	ptr++;
    }

    if ( strcmp ( oper, "=") == 0 )
	return SQLP_EQ;
    else if ( strcmp ( oper, "<") == 0 )
	return SQLP_LT;
    else if ( strcmp ( oper, "<=") == 0 )
	return SQLP_LE;
    else if ( strcmp ( oper, ">") == 0 )
	return SQLP_GT;
    else if ( strcmp ( oper, ">=") == 0 )
	return SQLP_GE;
    else if ( strcmp ( oper, "<>") == 0 )
	return SQLP_NE;
    else if ( strcmp ( oper, "~") == 0 )
	return SQLP_MTCH;
    else if ( strcmp ( oper, "+") == 0 )
	return SQLP_ADD;
    else if ( strcmp ( oper, "-") == 0 )
	return SQLP_SUBTR;
    else if ( strcmp ( oper, "*") == 0 )
	return SQLP_MLTP;
    else if ( strcmp ( oper, "/") == 0 )
	return SQLP_DIV;
    else if ( strcmp ( oper, "and") == 0 )
	return SQLP_AND;
    else if ( strcmp ( oper, "or") == 0 )
	return SQLP_OR;
    else if ( strcmp ( oper, "not") == 0 )
	return SQLP_NOT;

    free ( tmp );
    
    return 0;
}

char *
sqpOperatorName( int oper )
{
    switch ( oper ) { 
	case SQLP_EQ:
	    return "=";
	    break;
	case SQLP_LT:
	    return "<";
	    break;
	case SQLP_LE:
	    return "<=";
	    break;
	case SQLP_GT:
	    return ">";
	    break;
	case SQLP_GE:
	    return ">=";
	    break;
	case SQLP_NE:
	    return "<>";
	    break;
	case SQLP_MTCH:
	    return "~";
	    break;
	case SQLP_ADD:
	    return "+";
	    break;
	case SQLP_SUBTR:
	    return "-";
	    break;
	case SQLP_MLTP:
	    return "*";
	    break;
	case SQLP_DIV:
	    return "/";
	    break;
	case SQLP_AND:
	    return "AND";
	    break;
	case SQLP_OR:
	    return "OR";
	    break;
	case SQLP_NOT:
	    return "NOT";
	    break;
    }
    return "?";
}