private function considerNextMove(GameState $newState) : DecisionWithScore
{
$nextPlayerIsFriendly = $newState->getNextPlayer()->isFriendsWith($this->objectivePlayer);
$comparator = $nextPlayerIsFriendly ? DecisionWithScore::getBestComparator() : DecisionWithScore::getWorstComparator();
$nextDecisionPoint = new static($this->objectivePlayer, $newState, $this->depthLeft - 1, $comparator);
return $nextDecisionPoint->decide();
}
/**
* Evaluate possible decisions and take the best one
*/
public function decide(GameState $state) : Decision
{
if (!$state->getNextPlayer()->equals($this->objectivePlayer)) {
throw new BadMethodCallException('It is not this players turn');
}
$topLevelNode = new DecisionPoint($this->objectivePlayer, $state, $this->maxDepth, DecisionWithScore::getBestComparator());
$decisionWithScore = $topLevelNode->decide();
if ($decisionWithScore->decision === null) {
throw new RuntimeException('There are no possible moves');
}
return $decisionWithScore->decision;
}