/**
 * @file Transaction.cpp
 * @ingroup SQLiteCpp
 * @brief A Transaction is way to group multiple SQL statements into an atomic secured operation.
 *
 * Copyright (c) 2012-2025 Sebastien Rombauts (sebastien.rombauts@gmail.com)
 *
 * Distributed under the MIT License (MIT) (See accompanying file LICENSE.txt
 * or copy at http://opensource.org/licenses/MIT)
 */
#include <SQLiteCpp/Transaction.h>

#include <SQLiteCpp/Database.h>
#include <SQLiteCpp/Assertion.h>

#include <sqlite3.h>

namespace SQLite
{

// Begins the SQLite transaction
Transaction::Transaction(Database& aDatabase, TransactionBehavior behavior) :
 mDatabase(aDatabase)
{
 const char *stmt;
 switch (behavior) {
 case TransactionBehavior::DEFERRED:
 stmt = "BEGIN DEFERRED";
 break;
 case TransactionBehavior::IMMEDIATE:
 stmt = "BEGIN IMMEDIATE";
 break;
 case TransactionBehavior::EXCLUSIVE:
 stmt = "BEGIN EXCLUSIVE";
 break;
 default:
 throw SQLite::Exception("invalid/unknown transaction behavior", SQLITE_ERROR);
 }
 mDatabase.exec(stmt);
}

// Begins the SQLite transaction
Transaction::Transaction(Database &aDatabase) :
 mDatabase(aDatabase)
{
 mDatabase.exec("BEGIN TRANSACTION");
}

// Safely rollback the transaction if it has not been committed.
Transaction::~Transaction()
{
 if (false == mbCommited)
 {
 try
 {
 mDatabase.exec("ROLLBACK TRANSACTION");
 }
 catch (SQLite::Exception&)
 {
 // Never throw an exception in a destructor: error if already rollbacked, but no harm is caused by this.
 }
 }
}

// Commit the transaction.
void Transaction::commit()
{
 if (false == mbCommited)
 {
 mDatabase.exec("COMMIT TRANSACTION");
 mbCommited = true;
 }
 else
 {
 throw SQLite::Exception("Transaction already committed.");
 }
}

// Rollback the transaction
void Transaction::rollback()
{
 if (false == mbCommited)
 {
 mDatabase.exec("ROLLBACK TRANSACTION");
 }
 else
 {
 throw SQLite::Exception("Transaction already committed.");
 }
}

} // namespace SQLite