/**
* 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.common.model.pathfinding;
import net.sf.freecol.common.model.Tile;
import net.sf.freecol.common.model.Unit;
/**
* Class for determining the cost of a single move.
*
* <br /><br />
*
* This {@link CostDecider} is used as a default by
* {@link net.sf.freecol.common.model.Map#findPath} and
* {@link net.sf.freecol.common.model.Map#search}
* if no other <code>CostDecider</code> has been specified.
*/
class BaseCostDecider implements CostDecider {
private int movesLeft;
private boolean newTurn;
/**
* Determines the cost of a single move.
*
* @param unit The <code>Unit</code> making the move.
* @param oldTile The <code>Tile</code> we are moving from.
* @param newTile The <code>Tile</code> we are moving to.
* @param movesLeftBefore The moves left before making the move.
* @return The cost of moving the given unit from the
* <code>oldTile</code> to the <code>newTile</code>.
*/
public int getCost(final Unit unit, final Tile oldTile, final Tile newTile,
int movesLeftBefore) {
newTurn = false;
// Not allowed to use an unexplored tile.
if (!newTile.isExplored()) {
return ILLEGAL_MOVE;
}
// Disallow illegal moves.
// Special moves and moving off a carrier consume a whole turn.
boolean consumeMove = false;
switch (unit.getSimpleMoveType(oldTile, newTile)) {
case MOVE_HIGH_SEAS:
break;
case ATTACK_UNIT:
// Ignore hostile units in the base case, treating attacks
// as moves.
case MOVE:
if (!(unit.getLocation() instanceof Unit)) break;
// Fall through if disembarking.
case ATTACK_SETTLEMENT:
case EXPLORE_LOST_CITY_RUMOUR:
case EMBARK:
case ENTER_INDIAN_SETTLEMENT_WITH_FREE_COLONIST:
case ENTER_INDIAN_SETTLEMENT_WITH_SCOUT:
case ENTER_INDIAN_SETTLEMENT_WITH_MISSIONARY:
case ENTER_FOREIGN_COLONY_WITH_SCOUT:
case ENTER_SETTLEMENT_WITH_CARRIER_AND_GOODS:
consumeMove = true;
break;
default:
return ILLEGAL_MOVE;
}
int moveCost = unit.getMoveCost(oldTile, newTile, movesLeftBefore);
if (moveCost <= movesLeftBefore) {
movesLeft = movesLeftBefore - moveCost;
} else { // This move takes an extra turn to complete:
final int thisTurnMovesLeft = movesLeftBefore;
int initialMoves = unit.getInitialMovesLeft();
final int moveCostNextTurn = unit.getMoveCost(oldTile, newTile,
initialMoves);
moveCost = thisTurnMovesLeft + moveCostNextTurn;
movesLeft = initialMoves - moveCostNextTurn;
newTurn = true;
}
if (consumeMove) {
moveCost += movesLeft;
movesLeft = 0;
}
return moveCost;
}
/**
* Gets the number of moves left. This method should be
* called after invoking {@link #getCost}.
*
* @return The number of moves left.
*/
public int getMovesLeft() {
return movesLeft;
}
/**
* Checks if a new turn is needed in order to make the
* move. This method should be called after invoking
* {@link #getCost}.
*
* @return <code>true</code> if the move requires a
* new turn and <code>false</code> otherwise.
*/
public boolean isNewTurn() {
return newTurn;
}
}