#include<stdio.h>
#include<sql.h>
#include<sqlext.h>
#include<exception>
#include<iostream>

#define NAME_LEN 50
#define ID_LEN 20

void show_error() {
    printf("SQL fetch Error");
}
/**
 * @brief error handling for SQL* functions
 */
void check_error(SQLRETURN ret_val, std::string act_str)
{
    switch (ret_val)
    {
        case SQL_SUCCESS:
        case SQL_SUCCESS_WITH_INFO:
            break;
        case SQL_NO_DATA:
            std::cerr << "end of data\n";
            break;
        default:
            throw std::runtime_error(act_str);
    }
}

int main() {
    SQLHENV henv;
    SQLHDBC hdbc;
    SQLHSTMT hstmt = 0;
    SQLRETURN retcode;
    SQLCHAR outstr[1024];
    SQLSMALLINT outstrlen;

    SQLCHAR szName[NAME_LEN], szID[ID_LEN];
    SQLLEN cbName = 0, cbID = 0;

    try {
        //Allocate environment handle
        retcode = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv);
        check_error(retcode, "Allocate Environment Handle");
        //Set the ODBC version environment attribute
        retcode = SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION, (SQLPOINTER*)SQL_OV_ODBC3, 0);
        check_error(retcode, "Set ODBC version enviroment attribute");
        //Allocate connection handle
        retcode = SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);
        check_error(retcode, "Allocate connection Handle");
        //Set login timeout to 5 seconds
        SQLSetConnectAttr(hdbc, SQL_LOGIN_TIMEOUT, (SQLPOINTER)5, 0);
        check_error(retcode, "set login timeout attribute");

        /**
         * Connect to data source
         */
        retcode = SQLDriverConnect(hdbc, NULL, (SQLCHAR*)"DSN=csipmssql;uid=sa;pwd=csurams#1", SQL_NTS, outstr, sizeof(outstr), &outstrlen, SQL_DRIVER_COMPLETE);
        check_error(retcode, "connect to the data source");

        //Allocate statement handle
        retcode = SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmt);
        check_error(retcode, "allocate a statement handle");

        /**
         * statement to be executed.
         */
        retcode = SQLExecDirect (hstmt, (SQLCHAR *) "select count(*) from ssurgo.legend", SQL_NTS);
        check_error(retcode, "execute the statement");

        /**
         * Bind a column to a variable
         */
        retcode = SQLBindCol(hstmt, 1, SQL_C_CHAR, szName, NAME_LEN, &cbName);
        check_error(retcode, "bind 1 column to the statement");
        retcode = SQLBindCol(hstmt, 2, SQL_C_CHAR, szID, ID_LEN, &cbID);
        check_error(retcode, "bind 2 column to the statement");

        /**
         * fetch sql hstmt untill there is no data and print
         */
        for (int i=0 ; ; i++)
        {
            retcode = SQLFetch(hstmt);
            if(retcode == SQL_NO_DATA)break;
            else printf( "%d: %s %s %s\n", i + 1, szID, szName);
        }

        SQLCancel(hstmt);
        SQLFreeHandle(SQL_HANDLE_STMT, hstmt);

        SQLDisconnect(hdbc);
        SQLFreeHandle(SQL_HANDLE_DBC, hdbc);
        SQLFreeHandle(SQL_HANDLE_ENV, henv);
    }
    catch(std::exception &e)
    {
        std::cerr << e.what() << std::endl;
        return 1;
    }
    return 0;
}