/*
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 *
 */
#include "qpid/broker/DtxWorkRecord.h"
#include "qpid/framing/reply_exceptions.h"
#include <boost/format.hpp>
#include <boost/mem_fn.hpp>
using boost::mem_fn;
using qpid::sys::Mutex;

using namespace qpid::broker;
using namespace qpid::framing;

DtxWorkRecord::DtxWorkRecord(const std::string& _xid, TransactionalStore* const _store) :
    xid(_xid), store(_store), completed(false), rolledback(false), prepared(false), expired(false) {}

DtxWorkRecord::~DtxWorkRecord()
{
    if (timeout.get()) {
        timeout->cancel();
    }
}

bool DtxWorkRecord::prepare()
{
    Mutex::ScopedLock locker(lock);
    if (check()) {
        txn = store->begin(xid);
        if (prepare(txn.get())) {
            store->prepare(*txn);
            prepared = true;
        } else {
            abort();
            //TODO: this should probably be flagged as internal error
        }
    } else {
        //some part of the work has been marked rollback only
        abort();
    }
    return prepared;
}

bool DtxWorkRecord::prepare(TransactionContext* _txn)
{
    bool succeeded(true);
    for (Work::iterator i = work.begin(); succeeded && i != work.end(); i++) {
        succeeded = (*i)->prepare(_txn);
    }
    return succeeded;
}

bool DtxWorkRecord::commit(bool onePhase)
{
    Mutex::ScopedLock locker(lock);
    if (check()) {
        if (prepared) {
            //already prepared i.e. 2pc
            if (onePhase) {
                throw IllegalStateException(QPID_MSG("Branch with xid " << xid << " has been prepared, one-phase option not valid!"));
            }

            store->commit(*txn);
            txn.reset();

            std::for_each(work.begin(), work.end(), mem_fn(&TxBuffer::commit));
            return true;
        } else {
            //1pc commit optimisation, don't need a 2pc transaction context:
            if (!onePhase) {
                throw IllegalStateException(QPID_MSG("Branch with xid " << xid << " has not been prepared, one-phase option required!"));
            }
            std::auto_ptr<TransactionContext> localtxn = store->begin();
            if (prepare(localtxn.get())) {
                store->commit(*localtxn);
                std::for_each(work.begin(), work.end(), mem_fn(&TxBuffer::commit));
                return true;
            } else {
                store->abort(*localtxn);
                abort();
                //TODO: this should probably be flagged as internal error
                return false;
            }
        }
    } else {
        //some part of the work has been marked rollback only
        abort();
        return false;
    }
}

void DtxWorkRecord::rollback()
{
    Mutex::ScopedLock locker(lock);
    check();
    abort();
}

void DtxWorkRecord::add(DtxBuffer::shared_ptr ops)
{
    Mutex::ScopedLock locker(lock);
    if (expired) {
        throw DtxTimeoutException(QPID_MSG("Branch with xid " << xid << " has timed out."));
    }
    if (completed) {
        throw CommandInvalidException(QPID_MSG("Branch with xid " << xid << " has been completed!"));
    }
    work.push_back(ops);
}

bool DtxWorkRecord::check()
{
    if (expired) {
        throw DtxTimeoutException();
    }
    if (!completed) {
        //iterate through all DtxBuffers and ensure they are all ended
        for (Work::iterator i = work.begin(); i != work.end(); i++) {
            if (!(*i)->isEnded()) {
                throw IllegalStateException(QPID_MSG("Branch with xid " << xid << " not completed!"));
            } else if ((*i)->isRollbackOnly()) {
                rolledback = true;
            }
        }
        completed = true;
    }
    return !rolledback;
}

void DtxWorkRecord::abort()
{
    if (txn.get()) {
        store->abort(*txn);
        txn.reset();
    }
    std::for_each(work.begin(), work.end(), mem_fn(&TxBuffer::rollback));
}

void DtxWorkRecord::recover(std::auto_ptr<TPCTransactionContext> _txn, DtxBuffer::shared_ptr ops)
{
    add(ops);
    txn = _txn;
    ops->markEnded();
    completed = true;
    prepared = true;
}

void DtxWorkRecord::timedout()
{
    Mutex::ScopedLock locker(lock);
    expired = true;
    rolledback = true;
    if (!completed) {
        for (Work::iterator i = work.begin(); i != work.end(); i++) {
            if (!(*i)->isEnded()) {
                (*i)->timedout();
            }
        }
    }
    abort();
}

size_t DtxWorkRecord::indexOf(const DtxBuffer::shared_ptr& buf) {
    Work::iterator i = std::find(work.begin(), work.end(), buf);
    if (i == work.end()) throw NotFoundException(
        QPID_MSG("Can't find DTX buffer for xid: " << buf->getXid()));
    return i - work.begin();
}

DtxBuffer::shared_ptr DtxWorkRecord::operator[](size_t i) const {
    if (i > work.size())
        throw NotFoundException(
            QPID_MSG("Can't find DTX buffer " << i << " for xid: " << xid));
    return work[i];
}
