bic.sarl

/*
 * $Id$
 *
 * SARL is an general-purpose agent programming language.
 * More details on http://www.sarl.io
 *
 * Copyright (C) 2014-2017 the original authors or authors.
 *
 * Licensed 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 io.sarl.core

import java.text.MessageFormat
import java.util.UUID
import java.util.concurrent.TimeUnit
import java.util.Collection
import java.util.logging.Logger

import io.sarl.core.AgentTask
import io.sarl.lang.core.EventSpace
import io.sarl.lang.core.Address
import io.sarl.lang.core.Agent
import io.sarl.lang.core.AgentContext
import io.sarl.lang.core.Behavior
import io.sarl.lang.core.Event
import io.sarl.lang.core.EventListener
import io.sarl.lang.core.Scope
import io.sarl.lang.core.Space
import io.sarl.lang.core.SpaceID
import io.sarl.lang.util.SynchronizedCollection
import io.sarl.lang.util.SynchronizedSet
import io.sarl.lang.util.SynchronizedIterable

/**
 * Provides functions for accessing and managing the external contexts of an agent.
 */	 
capacity ExternalContextAccess {

	/**
	 * Replies all contexts this agent is a member of, including the default context.
	 *
	 * @return the list of the agent contexts.
	 */	 
	@Pure
	def getAllContexts : SynchronizedIterable<AgentContext>

	/**
	 * Replies the AgentContext for the given ID.
	 * The agent must have joined the context before calling this action or use its parentContextID
	 *
	 * @param contextID the ID of the context to get.
	 * @return the agent context instance.
	 * @throws UnknownContextException if the context specified context is not known by the agent.
	 * @see io.sarl.lang.core.Agent#getParentID
	 * @see #join
	 */
	@Pure
	def getContext(contextID : UUID): AgentContext

    /**
	 * Joins a new parent context (a new super holon).
	 * <p>
	 * The agent will be involved in the context with the ID given by <var>contextID</var>.
	 * The parameter <var>expectedDefaultSpaceID</var> is only used to check if
	 * the caller of this function knows the ID of the default space in the context to
	 * be involved in. Note that the context must already exists, and the default space
	 * inside this context must have the sams ID as <var>expectedDefaultSpaceID</var>.
	 * If the given <var>expectedDefaultSpaceID</var> does not match the ID of the
	 * default space in the context <var>contextID</var>, then the access to the context
	 * is forbidden.
	 *
	 * <p>This actions registers the agent in the default Space of the context with the
	 * ID <var>contextID</var>.
	 *
	 * @param contextID the identifier of the context to join.
	 * @param expectedDefaultSpaceID the known identifier of the default space in the agent context with the given identifier.
	 * @fires ContextJoined in its inner Context default space (Behaviors#wake).
	 * @fires MemberJoined in its parent Context default Space 
	 */
	def join(contextID : UUID, expectedDefaultSpaceID : UUID) fires ContextJoined, MemberJoined

	/**
	 * Leaves the parent's context. 
	 *
	 * @param contextID the identifier of the context to leave.
	 * @fires ContextLeft in its inner Context default space (Behaviors#wake).
	 * @fires MemberLeft in its parent Context default Space 
	 */
	def leave(contextID : UUID) fires ContextLeft, MemberLeft

	/** Replies if the given event was emitted in the given space.
	 *
	 * @param event the event to test.
	 * @param space the space in which the event may be.
	 * @return <code>true</code> if the given event was emitted in the
	 *     given space. Otherwise <code>false</code>.
	 * @since 0.2
	 */
	@Pure
	def isInSpace(^event : Event, ^space : Space) : boolean

	/** Replies if the given event was emitted in the space with
	 * the given identifier..
	 *
	 * @param event - the event to test.
	 * @param spaceID - the identifier of the space in which the event may be.
	 * @return <code>true</code> if the given event was emitted in the
	 *     space with the given identifier. Otherwise <code>false</code>.
	 * @since 0.2
	 */
	@Pure
	def isInSpace(^event : Event, spaceID : SpaceID) : boolean

	/** Replies if the given event was emitted in the space with
	 * the given identifier..
	 *
	 * @param event - the event to test.
	 * @param spaceID - the identifier of the space in which the event may be.
	 * @return <code>true</code> if the given event was emitted in the
	 *     space with the given identifier. Otherwise <code>false</code>.
	 * @since 0.2
	 */
	@Pure
	def isInSpace(^event : Event, spaceID : UUID) : boolean

}

/**
 * Provides functions for accessing and managing the internal contexts of an agent.
 */	 
capacity InnerContextAccess {

	/** Replies the inner context.
	 *
	 * @return the instanceof the internal agent context.
	 */
	@Pure
	def getInnerContext : AgentContext
	
	/** Replies if the calling agent has other agents
	 * as members of its inner context.
	 * A member agent is an agent which is not the
	 * calling agent, and is a member of at least
	 * one space of the inner context.
	 *
	 * @return <code>true</code> if the current agent has other agents as member of its internal context; otherwise <code>false</code>
	 */
	@Pure
	def hasMemberAgent : boolean
	
	/** Replies the number of agents that are members
	 * of the inner context of the calling agent.
	 * A member agent is an agent which is not the
	 * calling agent, and is a member of at least
	 * one space of the inner context.
	 *
	 * <p>The replied number includes the current agent. Indeed, the current agent is member of its internal context with the role of super-holon.
	 *
	 * @return the number of members in the internal context of the current agent.
	 */
	@Pure
	def getMemberAgentCount : int

	/**
	 * Replies all the member agents in the inner context.
	 * A member agent is an agent which is not the
	 * calling agent, and is a member of at least
	 * one space of the inner context. 
	 *
	 * @return the identifiers of the members of the internal context of the current agent.
	 */	 
	@Pure
	def getMemberAgents : SynchronizedIterable<UUID>

	/** Replies if the given space is the default space of the inner context.
	 *
	 * @param space the space to test.
	 * @return <code>true</code> if the given space is the default space of
	 *     the inner context. Otherwise <code>false</code>.
	 * @since 0.2
	 */
	@Pure
	def isInnerDefaultSpace(^space : Space) : boolean

	/** Replies if the given identifier is the identifier of the
	 * default space of the inner context.
	 *
	 * @param spaceID - the identifier to test.
	 * @return <code>true</code> if the given identifier is the identifier
	 *     of the default space of the inner context. Otherwise <code>false</code>.
	 * @since 0.2
	 */
	@Pure
	def isInnerDefaultSpace(spaceID : SpaceID) : boolean

	/** Replies if the given identifier is the identifier of the
	 * default space of the inner context.
	 *
	 * @param spaceID - the identifier to test.
	 * @return <code>true</code> if the given identifier is the identifier
	 *     of the default space of the inner context. Otherwise <code>false</code>.
	 * @since 0.2
	 */
	@Pure
	def isInnerDefaultSpace(spaceID : UUID) : boolean

	/** Replies if the given event was emitted in the default space
	 * of the inner context.
	 *
	 * @param event - the event to test.
	 * @return <code>true</code> if the given event was emitted
	 *     in the default space of the inner context. Otherwise <code>false</code>.
	 * @since 0.2
	 */
	@Pure
	def isInInnerDefaultSpace(^event : Event) : boolean

}

/**
 * Agent behaviors management.
 */
capacity Behaviors {

	/** Replies <code>true</code> if at least a behavior is registered.
	 *
	 * <p>A registered behavior is not necessary running. It may wait for events.
	 *
	 * @return <code>true</code> if a behavior is registered; otherwise <code>false</code>.
	 * @since 0.5
	 */
	def hasRegisteredBehavior : boolean

	/** Replies the registered behaviors.
	 *
	 * <p>A registered behavior is not necessary running. It may wait for events.
	 *
	 * @return the unmodifiable collection of the registered behavior.
	 * @since 0.5
	 */
	def getRegisteredBehaviors : SynchronizedIterable<Behavior>

	/**
	 * Register a Behavior for the owner agent.
	 * The new Behavior will react to all declared events received by the agent.
	 *
	 * <p>If the filter is provided, it will be used for determining if the given behavior accepts a specific event.
	 * If the filter function replies {@code true} for a specific event as argument, the event is fired in the
	 * behavior context. If the filter function replies {@code false}, the event is not fired in the behavior context. 
	 *
	 * @param attitude the behavior to add to the agent.
	 * @param filter the filter that enables to indicates if an event is accepted by a behavior.
	 * @return the given behavior.
	 * @since 0.5 for the {@code filter} parameter.
	 */
	def registerBehavior(attitude : Behavior, filter : (Event) => boolean = null) : Behavior
	
	/**
	 * Unregisters a behavior for the owner agent.
	 *
	 * @param attitude the behavior to remove to the agent.
	 * @return the given behavior.
	 */
	def unregisterBehavior(attitude : Behavior) : Behavior
	
	/**
	 * Wake the agent's behaviors reacting to the Event evt.
	 *
	 * <p>Note that the scope parameter could be used only for filtering the agents (the current agent and its sub-agents)
	 * in order to determine the ones that will receive the event.
	 * The behaviors of the current agent (registered with {@link #registerBehavior(Behavior)} will always
	 * receive the event if the current agent is not discarded. Indeed, because the behaviors have no associated address,
	 * they cannot be filtered individually.
	 *
	 * @param event the event to emit to the agent's behaviors and in the internal context.
	 * @param scope the definition of the scope that will be used for selected the receivers of the events.
	 */
	def wake(^event : Event, scope : Scope<Address> = null)
	
	/**
	 * Replies the interface to dispatch an event to agent's Behaviors.
	 *
	 * @return the event listener.
	 */
	@Pure
	def asEventListener : EventListener

}

/**
 * Lifecycle related actions.
 */
capacity Lifecycle {

	/**
	 * Spawns a new Agent inside the default context of this agent.
	 * This action must automatically register the newly created agent
	 * within the default space of the context.
	 *
	 * @param agentType the type of the agent to spawn.
	 * @param params the arguments to pass in the initialization event to the spawned agent.
	 * @return the identifier of the spawned agent.
	 * @fires AgentSpawned in DefaultSpace
	 * @since 0.5
	 */
	def spawn(agentType : Class<? extends Agent>, params : Object*) : UUID fires AgentSpawned

	/**
	 * Spawns a group of agents inside the default context of this agent.
	 * This action must automatically register the newly created agents
	 * within the default space of the context.
	 *
	 * @param nbAgents the number of agents to spawn.
	 * @param agentType the type of the agents to spawn.
	 * @param params the arguments to pass in the initialization event to the spawned agents. All the agents
	 *     will receive the same initialization parameters.
	 * @return the identifiers of the spawned agents.
	 * @fires AgentSpawned in DefaultSpace
	 * @since 0.5
	 */
	def spawn(nbAgents : int, agentType : Class<? extends Agent>, params : Object*) : Iterable<UUID> fires AgentSpawned

	/**
	 * Spawns a new member agent in the parent's context (parentID).
	 *
	 * @param agentClass the type of the agent to spawn.
	 * @param context the context in which the agent must be spawned.
	 * @param params the arguments to pass to the initialization event that will be sent to the spawned agent.
	 * @return the identifier of the spawned agent.
	 * @fires AgentSpawned inside the default context of the parent. The source of the event is this agent.
	 */
	def spawnInContext(agentClass : Class <? extends Agent>, context : AgentContext, params : Object*) : UUID fires AgentSpawned
	
	/**
	 * Spawns a group of agents in the parent's context (parentID).
	 *
	 * @param nbAgents the number of agents to spawn.
	 * @param agentClass the type of the agents to spawn.
	 * @param context the context in which the agents must be spawned.
	 * @param params the arguments to pass to the initialization event that will be sent to the spawned agents. All the agents
	 *     will receive the same initialization parameters.
	 * @return the identifiers of the spawned agents.
	 * @fires AgentSpawned inside the default context of the parent. The source of the event is this agent.
	 * @since 0.5
	 */
	def spawnInContext(nbAgents : int, agentClass : Class <? extends Agent>, context : AgentContext, params : Object*) : Iterable<UUID> fires AgentSpawned

	/**
	 * Spawns a new member agent in the parent's context (parentID).
	 *
	 * @param agentClass the type of the agent to spawn.
	 * @param agentID the identifier of the spawned agent.
	 * @param context the context in which the agent must be spawned.
	 * @param params the arguments to pass to the initialization event that will be sent to the spawned agent.
	 * @return the given identifier.
	 * @fires AgentSpawned inside the default context of the parent. The source of the event is this agent.
	 */
	def spawnInContextWithID(agentClass : Class <? extends Agent>, agentID : UUID, context : AgentContext, params : Object*) : UUID fires AgentSpawned

    /**
	 * Kills this agent. 
	 *
	 * <p>This action must automatically unregister this agent from the default context 
	 * and therefore all its spaces including the DefaultSpace.
	 * If this is a composable agent, it must not have any members before calling this action. 
	 * Otherwise a RuntimeException will be thrown.  
	 *
	 * @fires AgentKilled in DefaultSpace of all Contexts to which this agent belongs
	 * @fires Destroy inside the agent
	 */
	def killMe fires AgentKilled, Destroy
}


/**
 * Schedules actions in time.
 */
capacity Schedules {

	/**
	 * Replies the names of the active tasks.
	 *
	 * @return the names of the active tasks.
	 * @since 0.5
	 */
	def getActiveTasks : SynchronizedSet<String>
	
	/**
	 * Schedule a given task to be executed after the specified delay.
	 *
	 * <p>The given procedure takes one parameter: the agent associated to the task. It is name <code>it</code> by default.
	 *
	 * <p>If this function is invoked from a {@code Behavior} and there is no provided task,
	 * the created task will be associated to the behavior instance. It means that the task will
	 * be automatically cancelled when the behavior instance is unregistered from the the owning agent.
	 *
	 * @param task the task that will run the given closure. If <code>null</code>, a new task is created.
	 * @param delay time in milliseconds to delay the procedure execution.
	 * @param procedure the closure to execute.
	 * @return the generated task.
	 */
	def in(task : AgentTask = null, delay : long, procedure : (Agent) => void) : AgentTask

	/**
	 * Create a named task that can be retrieved and schedule later.
	 * If a task with the specified name already exists, this task is returned.
	 *
	 * <p>If this function is invoked from a {@code Behavior}, the created task will be associated
	 * to the behavior instance. It means that the task will be automatically cancelled when the behavior
	 * instance is unregistered from the the owning agent.
	 *
	 * @param name the name of the task. If {@code null} or empty, a random name will be given to the task.
	 * @return the task instance.
	 */
	def task(name : String) : AgentTask

	/**
	 * Attempts to cancel execution of this task.  This attempt will
	 * fail if the task has already completed, has already been cancelled,
	 * or could not be cancelled for some other reason. If successful,
	 * and this task has not started when <code>cancel</code> is called,
	 * this task should never run.  If the task has already started,
	 * then the <code>mayInterruptIfRunning</code> parameter determines
	 * whether the thread executing this task should be interrupted in
	 * an attempt to stop the task.
	 *
	 * @param task the task to cancel.
	 * @param mayInterruptIfRunning <code>true</code> if the thread executing this
	 *     task should be interrupted; otherwise, in-progress tasks are allowed
	 *     to complete
	 * @return <code>false</code> if the task could not be cancelled,
	 *     typically because it has already completed normally;
	 *     <code>true</code> otherwise
	 */
	def cancel(task : AgentTask, mayInterruptIfRunning : boolean = true) : boolean

	/**
	 * Replies if the given task was canceled.
	 *
	 * @param task the task.
	 * @return <code>true</code> if the task was canceled with {@link #cancel(AgentTask,boolean)}
	 *     or {@link #cancel(AgentTask)}; <code>false</code> otherwise.
	 * @since 0.5
	 */
	def isCanceled(task : AgentTask) : boolean

	/**
	 * Schedule a periodic execution of the given task.
	 *
	 * <p>If the duration of the task is greater to the given period length, then
	 * multiple task's instances will be run in parallel, in opposite to the
	 * {@code atFixedDelay()} function.
	 * For example, consider the following code:
	 * <pre><code>
	 * every(500) [ sleep(2000) ]
	 * </code></pre>
	 * At a given time, 4 instances (A, B, C, D) of the task may be run in parallel:
	 * <pre><code>
	 * t=0   0500   1000   1500   2000   2500   3000   3500   4000   4500
	 *   |    |      |      |      |      |      |      |      |      |
	 *   [-A-----------------------]
	 *        [-B-------------------------]
	 *               [-C-------------------------]
	 *                      [-D-------------------------]
	 *                             [-E-------------------------]
	 *                                    [-F-------------------------]
	 * </code></pre>
	 * For executing a task with a fixed delay between the runs, and not at a fixed rate,
	 * you should use the {@code atFixedDelay()} function.
	 *
	 * <p>The given procedure takes one parameter: the agent associated to the task. It is name <code>it</code> by default.
	 *
	 * <p>If this function is invoked from a {@code Behavior} and there is no provided task,
	 * the created task will be associated to the behavior instance. It means that the task will
	 * be automatically cancelled when the behavior instance is unregistered from the the owning agent.
	 *
	 * @param task the task to associate to the procedure. If <code>null</code> a new task is created.
	 * @param period the number of milliseconds between two launches of the given procedure.
	 * @param procedure the procedure to launch. The parameter of the procedure is the agent.
	 * @return the given task.
	 */
	def every(task : AgentTask = null, period : long, procedure : (Agent) => void ) : AgentTask

	/**
	 * Schedule a single-execution task.
	 *
	 * <p>If the duration of the task is greater to the given delay length, then
	 * no multiple task's instance are run in parallel, in opposite to the
	 * {@code every()} function.
	 * For example, consider the following code:
	 * <pre><code>
	 * atFixedDelay(500) [ sleep(2000) ]
	 * </code></pre>
	 * At a given time, 3 instances (A, B, C) of the task are run in sequence, and
	 * each run is separated by 500 milliseconds:
	 * <pre><code>
	 * t=0   0500   1000   1500   2000   2500   3000   3500   4000   4500   5000
	 *   |    |      |      |      |      |      |      |      |      |      |
	 *   [-A-----------------------]
	 *                                    [-B-------------------------]
	 *                                                                       [-C-------------------------]
	 * </code></pre>
	 * For executing a task with a fixed rate, and not with a fixed delay between the task runs,
	 * you should use the {@code every()} function.
	 *
	 * <p>The given procedure takes one parameter: the agent associated to the task. It is name <code>it</code> by default.
	 *
	 * <p>It is recommended that the SRAL run-time environment, which is providing the implementation
	 * of this function to provide an efficient implementation in the case the argument
	 * {@code delay} is equal to zero. Indeed, if the {@code delay} is equal to zero, the task
	 * should be run in an infinite loop until it is canceled, or the owning agent is killed.
	 *
	 * @param task the task to associate to the procedure. If <code>null</code> a new task is created.
	 * @param delay the delay in milliseconds.
	 * @param procedure the procedure to launch. The parameter of the procedure is the agent.
	 * @return the given task.
	 * @since 0.5
	 */
	def atFixedDelay(task : AgentTask = null, delay : long, procedure : (Agent) => void ) : AgentTask

	/**
	 * Schedule a single-execution task.
	 *
	 * <p>This function is the easy to use version and efficient implementation of the code
	 * {@code in(0) [statements]}.
	 *
	 * <p>The given procedure takes one parameter: the agent associated to the task. It is name <code>it</code> by default.
	 *
	 * @param task the task to associate to the procedure. If <code>null</code> a new task is created.
	 * @param procedure the procedure to launch. The parameter of the procedure is the agent.
	 * @return the given task.
	 * @since 0.5
	 */
	def execute(task : AgentTask = null, procedure : (Agent) => void ) : AgentTask

}


/**
 * Gives access to the DefaultContext of the agent and common actions on its default space.
 * Defines a set of commonly accessed action performed on the Default Space 
 * of the Default Context of the agent.
 */
capacity DefaultContextInteractions {

	/**
	 * Returns the Default context fo the agent.
	 *
	 * @return the default context.
	 */
	@Pure
	def getDefaultContext : AgentContext
	
	/**
	 * Returns the Default Space of the Default Context.
	 * Equivalent to <code>defaultContext.defaultSpace</code>.
	 *
	 * @return the default event space.
	 */
	@Pure
	def getDefaultSpace : EventSpace
	
	/**
	 * Return the Address of the agent in the Default Space of the Default Context.
	 * Equivalent to <code>defaultContext.defaultSpace.getAddress(this.ID)</code>
	 *
	 * @return the address of the agent in the default space.
	 */
	@Pure
	def getDefaultAddress : Address

	/**
	 * Emits a given event with the provided scope in the DefaultSpace of the DefaultContext.
	 * Equivalent to <code>defaultContext.defaultSpace.emit(e,scope)</code>
	 *
	 * @param event the event to emit.
	 * @param scope the definition of the scope that will be used for selected the receivers of the events. If <code>null</code>, all the agents in the space will receive the event.
	 */
	def emit(^event : Event, scope : Scope<Address> = null)

	/**
	 * Inverse signature of send. Useful to send events using the agent's UUID.
	 * Example:
	 * If you need to send an event to a newly created agent you should usually do :
	 * <code>
	 * ...
	 * const mySpawnArgs = ...
	 * const myAgentAddr = MyAgent.spawn(mySpawnArgs)
	 * defaultSpace.emit(new StartWorkingEvent, AddressScope::scope(myAgentAddr)
	 * </code> 
	 *  The equivalent using receive could be written:
	 * <code>
	 * ...
	 * MyAgent.spawn(mySpawnArgs).receive(new StartWorkingEvent)
	 * </code>
	 *
	 * @param receiver the identifier of the expected receiver.
	 * @param event the event to emit.
	 * @deprecated see {@link #willReceive(UUID, Event)}
	 */
	@Deprecated
	@Inline(value = "willReceive($1, $2)")
	def receive(receiver : UUID, ^event : Event)
	
	/**
	 * Inverse signature of send. Useful to send events using the agent's UUID.
	 * Example:
	 *  If you need to send an event to a newly created agent you should usually do :
	 * <code>
	 * ...
	 * const mySpawnArgs = ...
	 * const myAgentAddr = MyAgent.spawn(mySpawnArgs)
	 * defaultSpace.emit(new StartWorkingEvent, AddressScope::scope(myAgentAddr))
	 * </code> 
	 * <p>The equivalent using receive could be written:
	 * <code>
	 * ...
	 * MyAgent.spawn(mySpawnArgs).willReceive(new StartWorkingEvent)
	 * </code>
	 *
	 * @param receiver the identifier of the expected receiver.
	 * @param event the event to emit.
	 * @since 0.4
	 */
	def willReceive(receiver : UUID, ^event : Event)

	/** Replies if the given space is the default space of the default context.
	 *
	 * @param space the space to test.
	 * @return <code>true</code> if the given space is the default space of
	 *     the default context. Otherwise <code>false</code>.
	 * @since 0.2
	 */
	@Pure
	def isDefaultSpace(^space : Space) : boolean
	
	/** Replies if the given identifier is the identifier of the default space of
	 * the default context.
	 *
	 * @param space the space to test.
	 * @return <code>true</code> if the given identifier is the identifier
	 *     of the default space of the default context. Otherwise <code>false</code>.
	 * @since 0.2
	 */
	@Pure
	def isDefaultSpace(^space : SpaceID) : boolean

	/** Replies if the given identifier is the identifier of the default space of
	 * the default context.
	 *
	 * @param space the space to test.
	 * @return <code>true</code> if the given identifier is the identifier
	 *     of the default space of the default context. Otherwise <code>false</code>.
	 * @since 0.2
	 */
	@Pure
	def isDefaultSpace(^space : UUID) : boolean

	/** Replies if the given event was emitted in the default space of
	 * the default context.
	 *
	 * @param event the event to test.
	 * @return <code>true</code> if the given event is emitted in the default
	 *     space of the default context. Otherwise <code>false</code>.
	 * @since 0.2
	 */
	@Pure
	def isInDefaultSpace(^event : Event) : boolean

	/** Replies if the given context is the default context.
	 *
	 * @param context the agent context to test.
	 * @return <code>true</code> if the given context is the default context.
	 *     Otherwise <code>false</code>.
	 * @since 0.2
	 */
	@Pure
	def isDefaultContext(context : AgentContext) : boolean
	
	/** Replies if the given identifier is the identifier of the default context.
	 *
	 * @param contextID the identifier of the context.
	 * @return <code>true</code> if the given identifier is the identifier
	 *     of the default context. Otherwise <code>false</code>.
	 * @since 0.2
	 */
	@Pure
	def isDefaultContext(contextID : UUID) : boolean

	/**
	 * Spawns a new Agent inside the default context of this agent.
	 * This action must automatically register the newly created agent
	 * within the default space of the context.
	 *
	 * @param agentType the type of the agent to spawn.
	 * @param params the arguments to pass in the initialization event to the spawned agent.
	 * @return the identifier of the spawned agent.
	 * @fires AgentSpawned in DefaultSpace
	 * @deprecated See the {@link Lifecycle} capacity.
	 */
	@Deprecated
	def spawn(agentType : Class<? extends Agent>, params : Object*) : UUID fires AgentSpawned

}

/**
 * Gives access to the logging mechanism associated to the agent.
 */
capacity Logging {

	/** Change the name used for logging.
	 *
	 * @param name - the name used for logging.
	 */
	def setLoggingName(name : String)

	/** Print the given message at information logging level.
	 * <p>
	 * <strong>This function is deprecated.</strong> Please use
	 * {@link #info(Object,Object...)} in place of <code>println</code>.
	 *
	 * @param message - the elements to display.
	 * @deprecated Use {@link #info(Object,Object...)}.
	 */
	@Deprecated
	def println(message : Object)
	
	/** Print the given message at error logging level.
	 *
	 * @param message - the elements to display. The format of the message must follow {@link MessageFormat}.
	 * @param exception - the exception that is the cause of the error.
	 * @param parameters - the values to dynamically insert into the message.
	 */
	def error(message : Object, exception : Throwable=null, parameters : Object*)

	/** Print the given message at warning logging level.
	 *
	 * @param message - the elements to display. The format of the message must follow {@link MessageFormat}.
	 * @param exception - the exception that is the cause of the error.
	 * @param parameters - the values to dynamically insert into the message.
	 */
	def warning(message : Object, exception : Throwable=null, parameters : Object*)

	/** Print the given message at information logging level.
	 *
	 * @param message - the elements to display. The format of the message must follow {@link MessageFormat}.
	 * @param parameters - the values to dynamically insert into the message.
	 */
	def info(message : Object, parameters : Object*)

	/** Print the given message at debug logging level.
	 *
	 * @param message - the elements to display. The format of the message must follow {@link MessageFormat}.
	 * @param parameters - the values to dynamically insert into the message.
	 */
	def debug(message : Object, parameters : Object*)

	/** Replies if the logging system is displaying the errors.
	 *
	 * @return <code>true</code> if the errors are logged,
	 *         <code>false</code> if not.
	 */
	@Pure
	def isErrorLogEnabled : boolean

	/** Replies if the logging system is displaying the warnings.
	 *
	 * @return <code>true</code> if the warnings are logged,
	 *         <code>false</code> if not.
	 */
	@Pure
	def isWarningLogEnabled : boolean

	/** Replies if the logging system is displaying the information messages.
	 *
	 * @return <code>true</code> if the information messages are logged,
	 *         <code>false</code> if not.
	 */
	@Pure
	def isInfoLogEnabled : boolean

	/** Replies if the logging system is displaying the debugging messages.
	 *
	 * @return <code>true</code> if the debugging messages are logged,
	 *         <code>false</code> if not.
	 */
	@Pure
	def isDebugLogEnabled : boolean

	/** Replies the logging level.
	 *
	 * @return <code>0</code> for no logging, <code>1</code> for error,
	 *         <code>2</code> for warning, <code>3</code> for info,
	 *         <code>5</code> for debug.
	 */
	@Pure
	def getLogLevel : int

	/** Set the logging level.
	 *
	 * @param level - <code>0</code> for no logging, <code>1</code> for error,
	 *         <code>2</code> for warning, <code>3</code> for info,
	 *         <code>5</code> for debug.
	 */
	def setLogLevel(level : int)

	/** Replies the backend logger.
	 *
	 * @return the backend logger.
	 */
	@Pure
	def getLogger : Logger

}

/**
* Gives access to the time in the agent application.
* Time management is application-dependent. This capacity does not make any assumption
* on neither time evolution nor time refresh rate.
*/
capacity Time {

	/** Replies the current time.
	 *
	 * @param timeUnit if present, specifies the time unit of the value to reply. By default is it seconds. 
	 * @return the current time.
	 */
 	def getTime(timeUnit : TimeUnit = null) : double

	/** Replies the scaling factor between the agent time and the operating system time.
	 * <p>Consider time in the agent application. It may evolves at a different rate than
	 * the operating system time. The value that is replied by this function permits to
	 * determine the proportionally between the agent application time and the operating system time.
	 * A typical equation for representing this relation is: os time = OSTimeFactor * agent time.
	 *
	 * @return the factor between agent time and operating system time.
	 */
	def getOSTimeFactor : double

}