/*
 * 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.
 */
package org.apache.ode.bpel.runtime;

import java.util.Calendar;
import java.util.Date;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.ode.bpel.common.FaultException;
import org.apache.ode.bpel.explang.EvaluationContext;
import org.apache.ode.bpel.explang.EvaluationException;
import org.apache.ode.bpel.obj.OWait;
import org.apache.ode.bpel.runtime.channels.Termination;
import org.apache.ode.bpel.runtime.channels.TimerResponse;
import org.apache.ode.jacob.ReceiveProcess;
import org.apache.ode.utils.xsd.Duration;

import static org.apache.ode.jacob.ProcessUtil.compose;


/**
 * JacobRunnable that performs the work of the <code><wait></code> activity.
 */
class WAIT extends ACTIVITY {
    private static final long serialVersionUID = 1L;
    private static final Logger __log = LoggerFactory.getLogger(WAIT.class);

    WAIT(ActivityInfo self, ScopeFrame scopeFrame, LinkFrame linkFrame) {
        super(self, scopeFrame, linkFrame);
    }

    public final void run() {
        Date dueDate = null;
        try{
            dueDate = getDueDate();
        } catch(FaultException e){
            __log.error("Fault while calculating due date: "
                    + e.getQName()
                    + "; Reason: " + e.getMessage());
            _self.parent.completed(createFault(e.getQName(), _self.o), CompensationHandler.emptySet());
            return;
        } catch (EvaluationException ee) {
            String msg = "Unexpected error evaluating wait condition.";
            __log.error(msg, ee);
            _self.parent.completed(createFault(_self.o.getOwner().getConstants().getQnSubLanguageExecutionFault(),  _self.o), CompensationHandler.emptySet());
            return;
        }


        if(dueDate.getTime() > getBpelRuntimeContext().getCurrentEventDateTime().getTime()) {
            final TimerResponse timerChannel = newChannel(TimerResponse.class);
            getBpelRuntimeContext().registerTimer(timerChannel, dueDate);

            object(false, compose(new ReceiveProcess() {
                private static final long serialVersionUID = 3120518305645437327L;
            }.setChannel(timerChannel).setReceiver(new TimerResponse() {
                public void onTimeout() {
                    _self.parent.completed(null, CompensationHandler.emptySet());
                }

                public void onCancel() {
                    _self.parent.completed(null, CompensationHandler.emptySet());
                }
            })).or(new ReceiveProcess() {
                private static final long serialVersionUID = -2791243270691333946L;
            }.setChannel(_self.self).setReceiver(new Termination() {
                public void terminate() {
                    _self.parent.completed(null, CompensationHandler.emptySet());
                    object(new ReceiveProcess() {
                        private static final long serialVersionUID = 677746737897792929L;
                    }.setChannel(timerChannel).setReceiver(new TimerResponse() {
                        public void onTimeout() {
                            //ignore
                        }

                        public void onCancel() {
                            //ingore
                        }
                    }));
                }
            })));
        } else {
            _self.parent.completed(null, CompensationHandler.emptySet());
        }
    }


    protected Date getDueDate() throws FaultException, EvaluationException {

        OWait wait = (OWait)_self.o;

        // Assume the data was well formed (we have a deadline or a duration)
        assert wait.hasFor() || wait.hasUntil();

        EvaluationContext evalCtx = getEvaluationContext();

        Date dueDate = null;
        if (wait.hasFor()) {
            Calendar cal = Calendar.getInstance();
            Duration duration = getBpelRuntimeContext().getExpLangRuntime().evaluateAsDuration(wait.getForExpression(), evalCtx);
            duration.addTo(cal);
            dueDate = cal.getTime();
        } else if (wait.hasUntil()) {
            Calendar cal = getBpelRuntimeContext().getExpLangRuntime().evaluateAsDate(wait.getUntilExpression(), evalCtx);
            dueDate = cal.getTime();
        } else {
            throw new AssertionError("Static checks failed to find bad WaitActivity!");
        }

        // For now if we cannot evaluate a due date, we assume it is due now.
        // TODO: BPEL-ISSUE: verify BPEL spec for proper handling of these errors
        if (dueDate == null)
            dueDate = new Date();

        return dueDate;
    }

}