/**
 * Relational pipes
 * Copyright © 2020 František Kučera (Frantovo.cz, GlobalCode.info)
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 3 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include <cstring>
#include <codecvt>
#include <locale>
#include <iostream>

#include <sql.h>
#include <sqlext.h>

#include "SqlException.h"
#include "OdbcCommon.h"

namespace relpipe {
namespace tr {
namespace sql {

SqlException::SqlException(std::wstring message) : message(message) {
}

SqlException::SqlException(std::wstring message, SQLRETURN resultCode, SQLSMALLINT handleType, SQLHANDLE handle, bool freeHandle) : message(message), resultCode(resultCode) {
	std::wstring_convert < std::codecvt_utf8<wchar_t>> convertor; // TODO: support also other encodings
	SQLCHAR buffer[SQL_MAX_MESSAGE_LENGTH + 1];
	SQLCHAR sqlstate[SQL_SQLSTATE_SIZE + 1];
	memset(buffer, 0, sizeof (buffer));
	memset(sqlstate, 0, sizeof (sqlstate));
	SQLINTEGER sqlcode;
	SQLSMALLINT length;
	for (SQLSMALLINT i = 1; SQLGetDiagRec(handleType, handle, i, sqlstate, &sqlcode, buffer, SQL_MAX_MESSAGE_LENGTH + 1, &length) == SQL_SUCCESS; i++) {
		for (size_t i = 0; i < sizeof (buffer); i++) if (buffer[i] > 126 || buffer[i] == '\r') buffer[i] = '?'; // keep only ASCII characters and avoid CR which breaks the output
		diagnostics.push_back({convertor.from_bytes((char*) sqlstate), sqlcode, convertor.from_bytes((char*) buffer)});
		// FIXME: decoding fails is error message contains unicode characters – exception is thrown:
		// terminate called after throwing an instance of 'std::range_error'
		//   what():  wstring_convert::from_bytes
		// Exception can be avoided by:
		//   std::wstring_convert < std::codecvt_utf8<wchar_t>> convertor("", L"XXX Unable to decode error message from SQLGetDiagRec()");
		// but actual error message is then lost.
		// So as a workaround we keep only ASCII characters.
		// It seems that we sometimes get valid ISO-8859-2 or ISO-8859-1 encoded messages even if our platform encoding is UTF-8.

	}
	if (freeHandle) OdbcCommon::freeHandle(handleType, handle);
}

std::vector<SqlException::SqlDiagnosticsRecord> SqlException::getDiagnostics() const {
	return diagnostics;
}

std::wstring SqlException::getMessage() const {
	if (resultCode) return message + L" SQLRETURN=" + std::to_wstring(resultCode);
	else return message;
}

SQLRETURN SqlException::getResultCode() const {
	return resultCode;
}



}
}
}