/**
* Copyright (C) 2002-2012 The FreeCol Team
*
* This file is part of FreeCol.
*
* FreeCol 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, either version 2 of the License, or
* (at your option) any later version.
*
* FreeCol 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 FreeCol. If not, see <http://www.gnu.org/licenses/>.
*/
package net.sf.freecol.server.ai.mission;
import java.util.logging.Logger;
import net.sf.freecol.common.model.Colony;
import net.sf.freecol.common.model.FreeColGameObject;
import net.sf.freecol.common.model.Location;
import net.sf.freecol.common.model.Map.Direction;
import net.sf.freecol.common.model.Ownable;
import net.sf.freecol.common.model.PathNode;
import net.sf.freecol.common.model.Player;
import net.sf.freecol.common.model.Player.Stance;
import net.sf.freecol.common.model.Settlement;
import net.sf.freecol.common.model.Tension;
import net.sf.freecol.common.model.Tile;
import net.sf.freecol.common.model.Unit;
import net.sf.freecol.common.model.pathfinding.CostDeciders;
import net.sf.freecol.common.model.pathfinding.GoalDecider;
import net.sf.freecol.common.networking.Connection;
import net.sf.freecol.server.ai.AIMain;
import net.sf.freecol.server.ai.AIMessage;
import net.sf.freecol.server.ai.AIUnit;
import org.freecolandroid.xml.stream.XMLStreamException;
import org.freecolandroid.xml.stream.XMLStreamReader;
import org.freecolandroid.xml.stream.XMLStreamWriter;
import org.w3c.dom.Element;
/**
* Mission for attacking a specific target, be it a Unit or a Settlement.
*/
public class UnitSeekAndDestroyMission extends Mission {
private static final Logger logger = Logger.getLogger(UnitSeekAndDestroyMission.class.getName());
/**
* The object we are trying to destroy. This can be a
* either <code>Settlement</code> or a <code>Unit</code>.
*/
private Location target;
/**
* Creates a mission for the given <code>AIUnit</code>.
*
* @param aiMain The main AI-object.
* @param aiUnit The <code>AIUnit</code> this mission
* is created for.
* @param target The object we are trying to destroy. This can be either a
* <code>Settlement</code> or a <code>Unit</code>.
*/
public UnitSeekAndDestroyMission(AIMain aiMain, AIUnit aiUnit, Location target) {
super(aiMain, aiUnit);
this.target = target;
if (!(target instanceof Ownable)) {
logger.warning("!(target instanceof Ownable)");
throw new IllegalArgumentException("!(target instanceof Ownable)");
}
if (!(target instanceof Unit || target instanceof Settlement)) {
logger.warning("!(target instanceof Unit || target instanceof Settlement)");
throw new IllegalArgumentException("!(target instanceof Unit || target instanceof Settlement)");
}
}
/**
* Loads a mission from the given element.
*
* @param aiMain The main AI-object.
* @param element An <code>Element</code> containing an
* XML-representation of this object.
*/
public UnitSeekAndDestroyMission(AIMain aiMain, Element element) {
super(aiMain);
readFromXMLElement(element);
}
/**
* Creates a new <code>UnitSeekAndDestroyMission</code> and reads the given element.
*
* @param aiMain The main AI-object.
* @param in The input stream containing the XML.
* @throws XMLStreamException if a problem was encountered
* during parsing.
* @see net.sf.freecol.server.ai.AIObject#readFromXML
*/
public UnitSeekAndDestroyMission(AIMain aiMain, XMLStreamReader in) throws XMLStreamException {
super(aiMain);
readFromXML(in);
}
/**
* Performs the mission. This is done by searching for hostile units
* that are located within one tile and attacking them. If no such units
* are found, then wander in a random direction.
*
* @param connection The <code>Connection</code> to the server.
*/
@Override
public void doMission(Connection connection) {
Unit unit = getUnit();
if (!isValid()) {
return;
}
PathNode pathToTarget = null;
if (unit.isOnCarrier()) {
if (unit.getTile() != null) {
pathToTarget = getDisembarkPath(unit, unit.getTile(), target.getTile(), (Unit) unit.getLocation());
if (pathToTarget.getTransportDropNode() != pathToTarget) {
pathToTarget = null;
}
}
} else {
if (unit.getTile() != null) {
pathToTarget = getUnit().findPath(target.getTile());
}
}
if (pathToTarget != null) {
Direction direction = moveTowards(pathToTarget);
if (direction != null && unit.getMoveType(direction).isAttack()) {
Tile newTile = unit.getTile().getNeighbourOrNull(direction);
Unit defender = newTile.getDefendingUnit(unit);
if (defender == null) {
logger.warning("MoveType is ATTACK, but no defender is present!");
} else if (unit.getTile().getSettlement() != null
&& unit.getTile().getSettlement().getUnitCount() < 2) {
// Do not risk attacking out of a settlement that
// might collapse.
} else {
Player enemy = defender.getOwner();
if (unit.getOwner().atWarWith(enemy)
|| enemy.owns((Ownable) target)) {
AIMessage.askAttack(getAIUnit(), direction);
}
}
}
}
}
private PathNode getDisembarkPath(Unit unit, Tile start, final Tile end, Unit carrier) {
GoalDecider gd = new GoalDecider() {
private PathNode goal = null;
public PathNode getGoal() {
return goal;
}
public boolean hasSubGoals() {
return false;
}
public boolean check(Unit u, PathNode pathNode) {
goal = pathNode;
if (pathNode.getTile().getSettlement() == null) {
for (Direction direction : Direction.values()) {
Tile attackTile = pathNode.getTile().getNeighbourOrNull(direction);
if (attackTile == null) continue;
if (end == attackTile
&& attackTile.getSettlement() != null
&& pathNode.getTile().isLand()) {
int cost = pathNode.getCost();
int movesLeft = pathNode.getMovesLeft();
int turns = pathNode.getTurns();
goal = new PathNode(attackTile, cost, cost, direction, movesLeft, turns);
goal.previous = pathNode;
return true;
}
}
}
return pathNode.getTile() == end;
}
};
return unit.search(start, gd,
CostDeciders.avoidSettlementsAndBlockingUnits(),
Integer.MAX_VALUE, carrier);
}
/**
* Check to see if this is a valid hostility with a valid target.
*
* @return True if this mission is valid.
*/
public boolean isValid() {
Player owner = getUnit().getOwner();
Player targetPlayer;
return super.isValid()
&& target != null && !((FreeColGameObject)target).isDisposed()
&& target.getTile() != null
&& getUnit().isOffensiveUnit()
&& !(target instanceof Unit
&& target.getTile().getSettlement() != null)
&& (targetPlayer = ((Ownable)target).getOwner()) != null
&& targetPlayer != owner
&& (owner.getStance(targetPlayer) == Stance.WAR
|| (owner.isIndian()
&& owner.getTension(targetPlayer).getLevel()
.compareTo(Tension.Level.CONTENT) >= 0));
}
/**
* Returns the destination for this <code>Transportable</code>.
* This can either be the target {@link Tile} of the transport
* or the target for the entire <code>Transportable</code>'s
* mission. The target for the transport is determined by
* {@link TransportMission} in the latter case.
*
* @return The destination for this <code>Transportable</code>.
*/
@Override
public Tile getTransportDestination() {
if (target == null) {
return null;
}
Tile dropTarget = target.getTile();
if (getUnit().getTile() == null) {
return dropTarget;
} else if (getUnit().isOnCarrier()) {
PathNode p = getDisembarkPath(getUnit(),
getUnit().getTile(),
target.getTile(),
(Unit) getUnit().getLocation());
if (p != null) {
dropTarget = p.getTransportDropNode().getTile();
}
}
if (getUnit().isOnCarrier()) {
return dropTarget;
} else if (getUnit().getLocation().getTile() == target) {
return null;
} else if (getUnit().findPath(target.getTile()) == null) {
return dropTarget;
} else {
return null;
}
}
/**
* Returns the priority of getting the unit to the
* transport destination.
*
* @return The priority.
*/
@Override
public int getTransportPriority() {
if (getTransportDestination() != null) {
return NORMAL_TRANSPORT_PRIORITY;
} else {
return 0;
}
}
/**
* Returns the object we are trying to destroy.
*
* @return The object which should be destroyed.
* This can be either a <code>Settlement</code>
* or a <code>Unit</code>.
*/
public Location getTarget() {
return target;
}
/**
* Sets the object we are trying to destroy.
*
* @param target The object which should be destroyed.
* This can be either a <code>Settlement</code>
* or a <code>Unit</code>.
*/
public void setTarget(Location target) {
this.target = target;
}
/**
* Gets debugging information about this mission.
* This string is a short representation of this
* object's state.
*
* @return The <code>String</code>.
*/
@Override
public String getDebuggingInfo() {
if (target == null) {
return "No target";
} else {
final String name;
if (target instanceof Unit) {
name = ((Unit) target).toString();
} else if (target instanceof Colony) {
name = ((Colony) target).getName();
} else {
name = "";
}
return target.getTile().getPosition() + " " + name;
}
}
/**
* Writes all of the <code>AIObject</code>s and other AI-related
* information to an XML-stream.
*
* @param out The target stream.
* @throws XMLStreamException if there are any problems writing to the
* stream.
*/
protected void toXMLImpl(XMLStreamWriter out) throws XMLStreamException {
toXML(out, getXMLElementTagName());
}
@Override
protected void writeAttributes(XMLStreamWriter out) throws XMLStreamException {
super.writeAttributes(out);
if (getTarget() != null) {
out.writeAttribute("target", getTarget().getId());
}
}
@Override
protected void readAttributes(XMLStreamReader in)
throws XMLStreamException {
super.readAttributes(in);
setTarget((Location) getGame()
.getFreeColGameObject(in.getAttributeValue(null, "target")));
}
/**
* Returns the tag name of the root element representing this object.
*
* @return "unitSeekAndDestroyMission".
*/
public static String getXMLElementTagName() {
return "unitSeekAndDestroyMission";
}
}