/* OpenCOBOL SQLite/3 interface
 *  Author:    Brian Tiffin
 *  Date:      16-Sep-2008
 *  Rights:    Copyright (c) 2008 OpenCOBOL project
 *  Requires:  libsqlite3, sqlite3-dev
 *  Tectonics: cobc -c ocsqlite.c
 *             cobc -x -lsqlite3 sqlcaller.cob ocsqlite.o
 */

#include <stdio.h>
#include <string.h>
#include <sqlite3.h>

/* Need to stash the COBOL callback procedure address and name/value lengths */
/* This routine sends an unused pointer, field count, field index, name, value */ 
static int (*ocsql_callback)(void*, int*, int*, char*, char*);
static int ocsql_namelen;
static int ocsql_datalen;

/* wrap the COBOL callback */
static int cobolback(void *NotUsed, int argc, char **argv, char **azColName) {
    int i, recnum, ret;
    char name[ocsql_namelen];
    char value[ocsql_datalen];

    /* we are changing the nature of the callback for OpenCOBOL */
    for (i = 0; i < argc; i++) {
        memset(name, ' ', ocsql_namelen);
        memset(value, ' ', ocsql_datalen);
        strncpy(name, azColName[i], ocsql_namelen);
        /* The strncpy keeps the null if there is room,
         *   and COBOL can use this? or should it be spaced?
         */
        //if (name[ocsql_namelen-1] == '\0') {
        //    name[ocsql_namelen-1] = ' ';
        //}
        strncpy(value, argv[i], ocsql_datalen);
        //if (value[ocsql_datalen-1] == '\0') {
        //    value[ocsql_datalen-1] = ' ';
        //}
        ret = ocsql_callback(NotUsed, &argc, &i, name, value); 
    }
    return ret;
}

/* Open a database */
int sqlopen(sqlite3 **db, char *dbname, char *errstr, int errlen) {
    int rc;

    rc = sqlite3_open(dbname, db);
    if (rc) {
        memset(errstr, ' ', errlen);
        strncpy(errstr, sqlite3_errmsg(*db), errlen);
        if (errlen > 0 && errstr[errlen-1] == '\0') {
            errstr[errlen-1] = ' ';
        }
        sqlite3_close(*db);
    }
    return rc;
}

// int sqlexec(sqlite3 *db, int (*ocback)(void*, int, char**, char**), char *query, int qlen, char *errstr, int errlen) {
/* the wrapped sqlite exec function */
int sqlexec(sqlite3 *db, int (*ocback)(void*, int*, int*, char*, char*),
  char *query, int qlen, char *errstr, int errlen, int namelen, int datalen) {
    int rc;
    char *errmsg = 0;

    /* Stash away the COBOL callback and field data and field name lengths */
    ocsql_namelen = namelen;
    ocsql_datalen = datalen;
    ocsql_callback = ocback;

    /* Evaluate the sql query, wrapping the callback */
    rc = sqlite3_exec(db, query, cobolback, 0, &errmsg);
    if (rc != SQLITE_OK) {
        if (errmsg != NULL) {
            memset(errstr, ' ', errlen);
            strncpy(errstr, errmsg, errlen);
            if (errlen > 0 && errstr[errlen-1] == '\0') {
                errstr[errlen-1] = ' ';
            }
            sqlite3_free(errmsg);
        }
    }
    return rc;
}

/* Close a db connection */
int sqlclose(sqlite3 *db) {
    int rc;

    rc = sqlite3_close(db);
    return rc;
}