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<?php |
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namespace Michaelc\Voting\STV; |
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use Michaelc\Voting\STV\{Election, Ballot, Candidate}; |
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class VoteHandler |
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{ |
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/** |
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* Election object |
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* |
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* @var \Michaelc\Voting\STV\Election; |
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*/ |
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protected $election; |
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/** |
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* Array of all ballots in election |
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* |
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* @var \MichaelC\Voting\STV\Ballot[] |
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*/ |
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protected $ballots; |
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/** |
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* Quota of votes needed for a candidate to be elected |
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* |
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* @var int |
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*/ |
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protected $quota; |
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/** |
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* Constructor |
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* |
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* @param Election $election |
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*/ |
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public function __construct(Election $election) |
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{ |
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$this->election = $election; |
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$this->ballots = $this->election->getBallots(); |
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$this->quota = $this->getQuota(); |
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} |
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public function step($step) |
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{ |
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foreach ($this->ballots as $i => $ballot) |
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{ |
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$this->allocateVotes($ballot); |
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} |
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$candidates = $election->getActiveCandidates(); |
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foreach ($candidates as $i => $candidate) |
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{ |
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if ($candidate->getVotes() >= $this->quota) |
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{ |
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$this->electCandidate($candidate); |
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} |
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} |
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} |
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protected function allocateVotes(&$ballot): Ballot |
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{ |
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$weight = $ballot->getWeight(); |
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$candidate = $ballot->getNextPreference(); |
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$this->election->getCandidate($candidate->getId())->addVotes($weight); |
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$ballot->setLastUsedLevel(($step - 1)); |
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return $ballot; |
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} |
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protected function transferVotes(float $votes, Candidate $candidate) |
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{ |
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return; |
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} |
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/** |
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* Elect a candidate after they've passed the threshold |
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* |
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* @param \Michaelc\Voting\STV\Candidate $candidate |
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* @return null |
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*/ |
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protected function electCandidate(Candidate $candidate) |
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{ |
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if ($candidate->getVotes() < $this->quota) |
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{ |
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throw new Exception("We shouldn't be electing someone who hasn't met the quota"); |
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} |
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$candidate->setState(Candidate::ELECTED); |
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$surplus = $candidate->getVotes() - $quota; |
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$this->transferVotes($surplus, $candidate); |
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return; |
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} |
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/** |
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* Get the quota to win |
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* |
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* @return int |
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*/ |
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public function getQuota(): int |
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{ |
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return floor( |
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($this->election->getNumBallots() / |
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($this->election->getWinnersCount() + 1) |
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) |
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+ 1); |
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} |
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} |
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Let’s assume that you have a directory layout like this:
. |-- OtherDir | |-- Bar.php | `-- Foo.php `-- SomeDir `-- Foo.phpand let’s assume the following content of
Bar.php:If both files
OtherDir/Foo.phpandSomeDir/Foo.phpare loaded in the same runtime, you will see a PHP error such as the following:PHP Fatal error: Cannot use SomeDir\Foo as Foo because the name is already in use in OtherDir/Foo.phpHowever, as
OtherDir/Foo.phpdoes not necessarily have to be loaded and the error is only triggered if it is loaded beforeOtherDir/Bar.php, this problem might go unnoticed for a while. In order to prevent this error from surfacing, you must import the namespace with a different alias: