VoteHandler::eliminateCandidates() - Code Metrics - Inspection of "Break out lowest candidate code" - michaelcullum/voting-system - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( fa8b74...6961b9 )

by Michael

created 2016-08-16 01:32 UTC

VoteHandler::eliminateCandidates() A

↳ Parent: VoteHandler

Complexity

Conditions	2
Paths	2

Size

Total Lines	12
Code Lines	6

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	0
CRAP Score	6

Importance

Changes

Metric	Value
dl	0
loc	12
ccs	0
cts	6
cp	0
rs	9.4285
c	0
b	0
f	0
cc	2
eloc	6
nc	2
nop	1
crap	6

<?php

namespace Michaelc\Voting\STV;

class VoteHandler
{
    /**
     * Election object
     *
     * @var \Michaelc\Voting\STV\Election;
     */
    protected $election;

    /**
     * Array of all ballots in election
     *
     * @var \MichaelC\Voting\STV\Ballot[]
     */
    protected $ballots;

    /**
     * Quota of votes needed for a candidate to be elected
     *
     * @var int
     */
    protected $quota;

    /**
     * Number of candidates elected so far
     *
     * @var int
     */
    protected $electedCandidates;

    /**
     * Invalid ballots
     *
     * @var \MichaelC\Voting\STV\Ballot[]
     */
    protected $rejectedBallots;

    /**
     * Constructor
     *
     * @param Election $election
     */
    public function __construct(Election $election)
    {
        $this->election = $election;
        $this->ballots = $this->election->getBallots();
        $this->quota = $this->getQuota();
        $this->rejectedBallots = [];
    }

    /**
     * Run the election
     *
     * @return \MichaelC\Voting\STV\Candidate[]	Winning candidates
     */
    public function run()
    {
        $this->rejectInvalidBallots();

        $this->firstStep();

        $candidates = $this->election->getActiveCandidates();

        while ($this->electedCandidates < $this->election->getWinnersCount())
        {
            if (!$this->checkCandidates($candidates))
            {
                $this->eliminateCandidates($candidates);
            }
        }

        return $this->election->getElectedCandidates();
    }

    /**
     * Perform the initial vote allocation
     *
     * @return
     */
    protected function firstStep()
    {
        foreach ($this->ballots as $i => $ballot)
        {
            $this->allocateVotes($ballot);
        }

        return;
    }

    /**
     * Check if any candidates have reached the quota and can be elected
     *
     * @param  array  $candidates 	Array of active candidates to check
     * @return bool 				Whether any candidates were changed to elected
     */
    protected function checkCandidates(array &$candidates): bool
    {
        foreach ($candidates as $i => $candidate)
        {
            if ($candidate->getVotes() >= $this->quota)
            {
                $this->electCandidate($candidate);
                $elected = true;
            }
        }

        return ($elected ?? false);
function myFunction($a) {
    switch ($a) {
        case 'foo':
            $x = 1;
            break;

        case 'bar':
            $x = 2;
            break;
    }

    // $x is potentially undefined here.
    echo $x;
}
    }

    /**
     * Allocate the next votes from a Ballot
     *
     * @param Ballot $ballot 		The ballot to allocate the votes from
     * @param float  $multiplier 	Number to multiply the weight by (surplus)
     * @param float  $divisor 		The divisor of the weight (Total number of
     *                          	candidate votes)
     * @return Ballot 	The same ballot passed in modified
     */
    protected function allocateVotes(Ballot &$ballot, float $multiplier = 1.0, float $divisor = 1.0): Ballot
    {
        $weight = $ballot->setWeight(($ballot->getWeight() * $multiplier) / $divisor);
        $candidate = $ballot->getNextChoice();

        if ($candidate !== null)
        {
            $this->election->getCandidate($candidate)->addVotes($weight);
            $ballot->incrementLevelUsed();
        }

        return $ballot;
    }

    /**
     * Transfer the votes from one candidate to other candidates
     *
     * @param  float     $surplus   The number of surplus votes to transfer
     * @param  Candidate $candidate The candidate being elected to transfer
     *                              the votes from
     * @return
     */
    protected function transferSurplusVotes(float $surplus, Candidate $candidate)
    {
    	$totalVotes = $candidate->getVotes();
    	$candidateId = $candidate->getId();

    	foreach ($this->ballots as $i => $ballot)
    	{
        	if ($ballot->getLastChoice() == $candidateId)
        	{
		        $this->allocateVotes($ballot, $surplus, $totalVotes);
        	}
    	}

        return;
    }

    /**
     * Transfer the votes from one eliminated candidate to other candidates
     *
     * @param  Candidate $candidate  Candidate being eliminated to transfer
     *                               the votes from
     * @return
     */
    protected function transferEliminatedVotes(Candidate $candidate)
    {
    	$candidateId = $candidate->getId();

    	foreach ($this->ballots as $i => $ballot)
        {
        	if ($ballot->getLastChoice() == $candidateId)
        	{
		        $this->allocateVotes($ballot);
        	}
        }

        return;
    }

    /**
     * Elect a candidate after they've passed the threshold
     *
     * @param  \Michaelc\Voting\STV\Candidate $candidate
     * @return null
     */
    protected function electCandidate(Candidate $candidate)
    {
        if ($candidate->getVotes() < $this->quota)
        {
            throw new Exception("We shouldn't be electing someone who hasn't met the quota");
        }

        $candidate->setState(Candidate::ELECTED);
        $this->electedCandidates++;

        if ($this->electedCandidates < $this->election->getWinnersCount())
        {
            $surplus = $candidate->getVotes() - $this->quota;
            $this->transferSurplusVotes($surplus, $candidate);
        }

        return;
    }

    /**
     * Eliminate the candidate(s) with the lowest number of votes
     * and reallocated their votes
     *
     * @param  \Michaelc\Voting\STV\Candidate[] $candidates
     *                              Array of active candidates
     * @return int 					Number of candidates eliminated
     */
    protected function eliminateCandidates(array &$candidates): int
    {
        $minimumCandidates = $this->getLowestCandidates($candidates);

        foreach ($minimumCandidates as $minimumCandidate)
        {
            $this->transferEliminatedVotes($minimumCandidate);
            $minimumCandidate->setState(Candidate::DEFEATED);
        }

        return count($minimumCandidates);
    }

    /**
     * Get candidates with the lowest number of votes
     *
     * @param  \Michaelc\Voting\STV\Candidate[] $candidates
     *                             Array of active candidates
     * @return \Michaelc\Voting\STV\Candidate[]
     *                             Candidates with lowest score
     */
    protected function getLowestCandidates(array $candidates): array
    {
        $minimum = 0;
        $minimumCandidates = [];

        foreach ($candidates as $i => $candidate)
        {
            if ($candidate->getVotes() > $minimum)
            {
                $minimum = $candidate->getVotes();
                unset($minimumCandidates);
                $minimumCandidates[] = $candidate;
            }
            elseif ($candidate->getVotes() == $minimum)
            {
                $minimumCandidates[] = $candidate;
            }
        }

        return $minimumCandidates;
    }

    /**
     * Reject any invalid ballots
     *
     * @return int    Number of rejected ballots
     */
    protected function rejectInvalidBallots(): int
    {
        foreach ($this->ballots as $i => $ballot)
        {
            if (!$this->checkBallotValidity($ballot))
            {
                $this->rejectedBallots[] = clone $ballot;
                unset($this->ballots[$i]);
            }
        }

        return count($this->rejectedBallots);
    }

    /**
     * Check if ballot is valid
     *
     * @param  Ballot &$Ballot  Ballot to test
     * @return bool             True if valid, false if invalid
     */
    private function checkBallotValidity(Ballot &$Ballot): bool

    {
        if (count($ballot->getRanking()) > $this->election->getCandidateCount())

        {
            return false;
        }
        else
        {
            $candidateIds = $this->election->getCandidateIds();

            foreach ($ballot->getRanking() as $i => $candidate)

            {
                if (!in_array($candidate, $candidateIds))
                {
                    return false;
                }
            }
        }

        return true;
    }

    /**
     * Get the quota to win
     *
     * @return int
     */
    public function getQuota(): int
    {
        return floor(
            ($this->election->getNumBallots() /
                ($this->election->getWinnersCount() + 1)
            )
            + 1);
    }
}


1		<?php
2
3		namespace Michaelc\Voting\STV;
4
5		class VoteHandler
6		{
7		/**
8		* Election object
9		*
10		* @var \Michaelc\Voting\STV\Election;
11		*/
12		protected $election;
13
14		/**
15		* Array of all ballots in election
16		*
17		* @var \MichaelC\Voting\STV\Ballot[]
18		*/
19		protected $ballots;
20
21		/**
22		* Quota of votes needed for a candidate to be elected
23		*
24		* @var int
25		*/
26		protected $quota;
27
28		/**
29		* Number of candidates elected so far
30		*
31		* @var int
32		*/
33		protected $electedCandidates;
34
35		/**
36		* Invalid ballots
37		*
38		* @var \MichaelC\Voting\STV\Ballot[]
39		*/
40		protected $rejectedBallots;
41
42		/**
43		* Constructor
44		*
45		* @param Election $election
46		*/
47	1	public function __construct(Election $election)
48		{
49	1	$this->election = $election;
50	1	$this->ballots = $this->election->getBallots();
51	1	$this->quota = $this->getQuota();
52	1	$this->rejectedBallots = [];
53	1	}
54
55		/**
56		* Run the election
57		*
58		* @return \MichaelC\Voting\STV\Candidate[] Winning candidates
59		*/
60		public function run()
61		{
62		$this->rejectInvalidBallots();
63
64		$this->firstStep();
65
66		$candidates = $this->election->getActiveCandidates();
67
68		while ($this->electedCandidates < $this->election->getWinnersCount())
69		{
70		if (!$this->checkCandidates($candidates))
71		{
72		$this->eliminateCandidates($candidates);
73		}
74		}
75
76		return $this->election->getElectedCandidates();
77		}
78
79		/**
80		* Perform the initial vote allocation
81		*
82		* @return
83		*/
84		protected function firstStep()
85		{
86		foreach ($this->ballots as $i => $ballot)
87		{
88		$this->allocateVotes($ballot);
89		}
90
91		return;
92		}
93
94		/**
95		* Check if any candidates have reached the quota and can be elected
96		*
97		* @param array $candidates Array of active candidates to check
98		* @return bool Whether any candidates were changed to elected
99		*/
100		protected function checkCandidates(array &$candidates): bool
101		{
102		foreach ($candidates as $i => $candidate)
103		{
104		if ($candidate->getVotes() >= $this->quota)
105		{
106		$this->electCandidate($candidate);
107		$elected = true;
108		}
109		}
110
111		return ($elected ?? false);
		0 ignored issues – show Bug introduced 2016-08-16 00:32 UTC by Report Bug Copy Issue Report The variable `$elected` does not seem to be defined for all execution paths leading up to this point. If you define a variable conditionally, it can happen that it is not defined for all execution paths. Let’s take a look at an example: function myFunction($a) { switch ($a) { case 'foo': $x = 1; break; case 'bar': $x = 2; break; } // $x is potentially undefined here. echo $x; } In the above example, the variable `$x` is defined if you pass “foo” or “bar” as argument for `$a`. However, since the `switch` statement has no default case statement, if you pass any other value, the variable `$x` would be undefined. Available Fixes Check for existence of the variable explicitly: function myFunction($a) { switch ($a) { case 'foo': $x = 1; break; case 'bar': $x = 2; break; } if (isset($x)) { // Make sure it's always set. echo $x; } } Define a default value for the variable: function myFunction($a) { $x = ''; // Set a default which gets overridden for certain paths. switch ($a) { case 'foo': $x = 1; break; case 'bar': $x = 2; break; } echo $x; } Add a value for the missing path: function myFunction($a) { switch ($a) { case 'foo': $x = 1; break; case 'bar': $x = 2; break; // We add support for the missing case. default: $x = ''; break; } echo $x; } Loading history...
112		}
113
114		/**
115		* Allocate the next votes from a Ballot
116		*
117		* @param Ballot $ballot The ballot to allocate the votes from
118		* @param float $multiplier Number to multiply the weight by (surplus)
119		* @param float $divisor The divisor of the weight (Total number of
120		* candidate votes)
121		* @return Ballot The same ballot passed in modified
122		*/
123		protected function allocateVotes(Ballot &$ballot, float $multiplier = 1.0, float $divisor = 1.0): Ballot
124		{
125		$weight = $ballot->setWeight(($ballot->getWeight() * $multiplier) / $divisor);
126		$candidate = $ballot->getNextChoice();
127
128		if ($candidate !== null)
129		{
130		$this->election->getCandidate($candidate)->addVotes($weight);
131		$ballot->incrementLevelUsed();
132		}
133
134		return $ballot;
135		}
136
137		/**
138		* Transfer the votes from one candidate to other candidates
139		*
140		* @param float $surplus The number of surplus votes to transfer
141		* @param Candidate $candidate The candidate being elected to transfer
142		* the votes from
143		* @return
144		*/
145		protected function transferSurplusVotes(float $surplus, Candidate $candidate)
146		{
147		$totalVotes = $candidate->getVotes();
148		$candidateId = $candidate->getId();
149
150		foreach ($this->ballots as $i => $ballot)
151		{
152		if ($ballot->getLastChoice() == $candidateId)
153		{
154		$this->allocateVotes($ballot, $surplus, $totalVotes);
155		}
156		}
157
158		return;
159		}
160
161		/**
162		* Transfer the votes from one eliminated candidate to other candidates
163		*
164		* @param Candidate $candidate Candidate being eliminated to transfer
165		* the votes from
166		* @return
167		*/
168		protected function transferEliminatedVotes(Candidate $candidate)
169		{
170		$candidateId = $candidate->getId();
171
172		foreach ($this->ballots as $i => $ballot)
173		{
174		if ($ballot->getLastChoice() == $candidateId)
175		{
176		$this->allocateVotes($ballot);
177		}
178		}
179
180		return;
181		}
182
183		/**
184		* Elect a candidate after they've passed the threshold
185		*
186		* @param \Michaelc\Voting\STV\Candidate $candidate
187		* @return null
188		*/
189		protected function electCandidate(Candidate $candidate)
190		{
191		if ($candidate->getVotes() < $this->quota)
192		{
193		throw new Exception("We shouldn't be electing someone who hasn't met the quota");
194		}
195
196		$candidate->setState(Candidate::ELECTED);
197		$this->electedCandidates++;
198
199		if ($this->electedCandidates < $this->election->getWinnersCount())
200		{
201		$surplus = $candidate->getVotes() - $this->quota;
202		$this->transferSurplusVotes($surplus, $candidate);
203		}
204
205		return;
206		}
207
208		/**
209		* Eliminate the candidate(s) with the lowest number of votes
210		* and reallocated their votes
211		*
212		* @param \Michaelc\Voting\STV\Candidate[] $candidates
213		* Array of active candidates
214		* @return int Number of candidates eliminated
215		*/
216		protected function eliminateCandidates(array &$candidates): int
217		{
218		$minimumCandidates = $this->getLowestCandidates($candidates);
219
220		foreach ($minimumCandidates as $minimumCandidate)
221		{
222		$this->transferEliminatedVotes($minimumCandidate);
223		$minimumCandidate->setState(Candidate::DEFEATED);
224		}
225
226		return count($minimumCandidates);
227		}
228
229		/**
230		* Get candidates with the lowest number of votes
231		*
232		* @param \Michaelc\Voting\STV\Candidate[] $candidates
233		* Array of active candidates
234		* @return \Michaelc\Voting\STV\Candidate[]
235		* Candidates with lowest score
236		*/
237		protected function getLowestCandidates(array $candidates): array
238		{
239		$minimum = 0;
240		$minimumCandidates = [];
241
242		foreach ($candidates as $i => $candidate)
243		{
244		if ($candidate->getVotes() > $minimum)
245		{
246		$minimum = $candidate->getVotes();
247		unset($minimumCandidates);
248		$minimumCandidates[] = $candidate;
249		}
250		elseif ($candidate->getVotes() == $minimum)
251		{
252		$minimumCandidates[] = $candidate;
253		}
254		}
255
256		return $minimumCandidates;
257		}
258
259		/**
260		* Reject any invalid ballots
261		*
262		* @return int Number of rejected ballots
263		*/
264		protected function rejectInvalidBallots(): int
265		{
266		foreach ($this->ballots as $i => $ballot)
267		{
268		if (!$this->checkBallotValidity($ballot))
269		{
270		$this->rejectedBallots[] = clone $ballot;
271		unset($this->ballots[$i]);
272		}
273		}
274
275		return count($this->rejectedBallots);
276		}
277
278		/**
279		* Check if ballot is valid
280		*
281		* @param Ballot &$Ballot Ballot to test
282		* @return bool True if valid, false if invalid
283		*/
284		private function checkBallotValidity(Ballot &$Ballot): bool
		0 ignored issues – show Unused Code introduced 2016-08-16 01:30 UTC by Report Bug Copy Issue Report The parameter `$Ballot` is not used and could be removed. This check looks from parameters that have been defined for a function or method, but which are not used in the method body. Loading history...
285		{
286		if (count($ballot->getRanking()) > $this->election->getCandidateCount())
		0 ignored issues – show Bug introduced 2016-08-16 01:30 UTC by Report Bug Copy Issue Report The variable `$ballot` does not exist. Did you mean `$Ballot`? This check looks for variables that are accessed but have not been defined. It raises an issue if it finds another variable that has a similar name. The variable may have been renamed without also renaming all references. Loading history...
287		{
288		return false;
289		}
290		else
291		{
292		$candidateIds = $this->election->getCandidateIds();
293
294		foreach ($ballot->getRanking() as $i => $candidate)
		0 ignored issues – show Bug introduced 2016-08-16 01:30 UTC by Report Bug Copy Issue Report The variable `$ballot` does not exist. Did you mean `$Ballot`? This check looks for variables that are accessed but have not been defined. It raises an issue if it finds another variable that has a similar name. The variable may have been renamed without also renaming all references. Loading history...
295		{
296		if (!in_array($candidate, $candidateIds))
297		{
298		return false;
299		}
300		}
301		}
302
303		return true;
304		}
305
306		/**
307		* Get the quota to win
308		*
309		* @return int
310		*/
311	1	public function getQuota(): int
312		{
313	1	return floor(
314	1	($this->election->getNumBallots() /
315	1	($this->election->getWinnersCount() + 1)
316		)
317	1	+ 1);
318		}
319		}
320

michaelcullum / voting-system

Push — master ( fa8b74...6961b9 )

VoteHandler::eliminateCandidates() A

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Duplication

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