/*
 * Copyright (c) 2015 Wind River Systems, Inc.
*
* SPDX-License-Identifier: Apache-2.0
*
 */

/**
 * @file
 * Wind River CGTS Platform PostgreSQL Database Access module for maintenance.
 *
 * pqdmClass member primitive implementation.
 *
 * query
 *
 *
 */

#include "pgdbClass.h"

#define MAX_SQL_RESPONSE_MAX (4096)
#define SENSOR_SAMPLE_TABLE  "sample"

/* DB connection status */
#define DB_DISCONNECTED       0
#define DB_CONNECTED          1

pgdbClass::pgdbClass()
{
	pg.uri = NULL;
	pg.conn = NULL;
	pg.connected = false ;
}

pgdbClass::~pgdbClass()
{
	if (pg.conn)
    {
		PQfinish(pg.conn);
	}
    pg.connected = false ;
}

int pgdbClass::connect(const char *uri)
{
	const char *val = NULL;

	/* make a connection to the specified database */
	this->pg.conn = PQconnectdb(uri);

	/* verify the connection */
	if ((this->pg.conn == NULL) || (PQstatus(this->pg.conn) != CONNECTION_OK))
    {
		elog ("failed to connected to DB: (%s)\n", uri);
		PQfinish(this->pg.conn);
		return FAIL;
	}

	this->pg.connected = true ;
	this->pg.uri = uri;

	val = get_parameter_status("standard_conforming_strings");
	ilog ("server standard_conforming_strings parameter: %s\n", val ? val : "unavailable");

    this->pg.equote = (val && (0 == strcmp("off", val)));
	ilog ("server requires E'' quotes: %s\n", this->pg.equote ? "YES" : "NO");

	this->pg.server_version = PQserverVersion(this->pg.conn);
	this->pg.protocol = PQprotocolVersion(this->pg.conn);
	this->pg.encoding = get_parameter_status("client_encoding");

	return PASS ;
}

int pgdbClass::monitor( void )
{
	if (PQstatus(this->pg.conn) != CONNECTION_OK)
    {
		elog ("failed connection audit to '%s' (%s)\n", this->pg.uri, PQerrorMessage(this->pg.conn));
		disconnect();

        /* TODO: make this an FSM, otherwise this will bang away */
		// return connect(this->pg.uri);
        return (FAIL);
	 }
	return PASS ;
}

void pgdbClass::disconnect()
{
	if (this->pg.conn != NULL)
    {
		PQfinish(this->pg.conn);
	}
	if (this->pg.connected == true )
    {
		this->pg.connected = false ;
	}
}

const char * pgdbClass::get_parameter_status(const char *param)
{
	return PQparameterStatus(this->pg.conn, param);
}

int pgdbClass::cmd(const char *db_cmd)
{
	PGresult *res;
	int rc = PASS;

	if (monitor() != PASS )
    {
		elog ("Failed to reconnect: %s", PQerrorMessage(this->pg.conn));
		return FAIL ;
	}
	res = PQexec(this->pg.conn, db_cmd);
	if (PQresultStatus(res) != PGRES_COMMAND_OK)
    {
		elog ("Request Status: %s\n", PQresStatus(PQresultStatus(res)));
		elog ("execute Status: %s (%s)\n", db_cmd, PQresultErrorMessage(res));
		rc = FAIL;
	}
	if (rc == PASS )
    {
		int row = atoi(PQcmdTuples(res));
		ilog ("SQL command returned successful: %d rows affected.\n", row); /* dlog */
		if (row < 1)
        {
            rc = FAIL;
        }
	}
	PQclear(res);
	return rc;
}


int pgdbUtil_get_version ( void )
{
    int ver = PQlibVersion();
    ilog ("libpq version: %d\n", ver);
    return ver ;
}

int pgdbClass::query (const char * db_cmd , mtc_query_type & result)
{
	PGresult *res;
	int nfields, ntuples, i, j;

	if (monitor() != PASS)
    {
		elog ("Failed to reconnect: %s\n", PQerrorMessage(this->pg.conn));
		return (FAIL) ;
	}

	res = PQexec( pg.conn, db_cmd);
	if (PQresultStatus(res) != PGRES_TUPLES_OK)
    {
		elog("request status: %s\n", PQresStatus(PQresultStatus(res)));
		elog("execute status: %s (%s)\n", db_cmd, PQresultErrorMessage(res));
		PQclear(res);
		return(FAIL);
	}

	nfields = PQnfields(res);
	ntuples = PQntuples(res);
	ilog ("Cmd: (%s) OK, entries found: (%d)\n", db_cmd, ntuples); /* dlog */

	for (i = 0; i < ntuples; ++i)
    {
		mtc_key_value_type key_value ;

		for (j =0; j < nfields; ++j)
        {
			char * key = PQfname(res, j);
			char * value = PQgetvalue(res, i, j);
			key_value[key] = value;
		}
		result.push_back ( key_value );
	}
	PQclear(res);
	return(PASS);
}