| 1 |  |  | <?php | 
            
                                                                                                            
                            
            
                                    
            
            
                | 2 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 3 |  |  | declare(strict_types=1); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 4 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 5 |  |  | namespace Smoren\ProbabilitySelector; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 6 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 7 |  |  | /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 8 |  |  |  * Probability-based selection manager. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 9 |  |  |  * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 10 |  |  |  * @template T | 
            
                                                                                                            
                            
            
                                    
            
            
                | 11 |  |  |  * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 12 |  |  |  * @implements \IteratorAggregate<int, T> | 
            
                                                                                                            
                            
            
                                    
            
            
                | 13 |  |  |  */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 14 |  |  | class ProbabilitySelector implements \IteratorAggregate | 
            
                                                                                                            
                            
            
                                    
            
            
                | 15 |  |  | { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 16 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 17 |  |  |      * @var array<T> data storage | 
            
                                                                                                            
                            
            
                                    
            
            
                | 18 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 19 |  |  |     protected array $data = []; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 20 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 21 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 22 |  |  |      * @var array<array{float, int}> | 
                            
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                | 23 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 24 |  |  |     protected array $probabilities = []; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 25 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 26 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 27 |  |  |      * @var float sum of all the weights of data | 
            
                                                                                                            
                            
            
                                    
            
            
                | 28 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 29 |  |  |     protected float $weightSum = 0; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 30 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 31 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 32 |  |  |      * @var int usage counters sum of data | 
            
                                                                                                            
                            
            
                                    
            
            
                | 33 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 34 |  |  |     protected int $totalUsageCounter = 0; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 35 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 36 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 37 |  |  |      * ProbabilitySelector constructor. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 38 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 39 |  |  |      * @param array<array{T, float}|array{T, float, int}> $data | 
                            
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                | 40 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 41 | 47 |  |     public function __construct(array $data = []) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 42 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 43 | 47 |  |         foreach ($data as $item) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 44 | 46 |  |             if (\count($item) === 2) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 45 | 41 |  |                 $item[] = 0; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 46 |  |  |             } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 47 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 48 |  |  |             /** @var array{T, float, int} $item */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 49 | 46 |  |             [$datum, $weight, $usageCounter] = $item; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 50 | 46 |  |             $this->addItem($datum, $weight, $usageCounter); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 51 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 52 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 53 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 54 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 55 |  |  |      * Adds datum to the select list. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 56 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 57 |  |  |      * @param T $datum datum to add | 
            
                                                                                                            
                            
            
                                    
            
            
                | 58 |  |  |      * @param float $weight weight of datum | 
            
                                                                                                            
                            
            
                                    
            
            
                | 59 |  |  |      * @param int $usageCounter initial usage counter value for datum | 
            
                                                                                                            
                            
            
                                    
            
            
                | 60 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 61 |  |  |      * @return $this | 
            
                                                                                                            
                            
            
                                    
            
            
                | 62 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 63 | 46 |  |     public function addItem($datum, float $weight, int $usageCounter): self | 
            
                                                                                                            
                            
            
                                    
            
            
                | 64 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 65 | 46 |  |         if ($weight <= 0) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 66 | 4 |  |             throw new \InvalidArgumentException('Weight cannot be negative'); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 67 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 68 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 69 | 43 |  |         $this->data[] = $datum; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 70 | 43 |  |         $this->probabilities[] = [$weight, $usageCounter]; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 71 | 43 |  |         $this->weightSum += $weight; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 72 | 43 |  |         $this->totalUsageCounter += $usageCounter; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 73 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 74 | 43 |  |         return $this; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 75 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 76 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 77 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 78 |  |  |      * Chooses and returns datum from select list, marks it used. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 79 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 80 |  |  |      * @return T chosen datum | 
            
                                                                                                            
                            
            
                                    
            
            
                | 81 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 82 |  |  |      * @throws \LengthException when selectable list is empty | 
            
                                                                                                            
                            
            
                                    
            
            
                | 83 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 84 | 43 |  |     public function decide() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 85 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 86 | 43 |  |         $maxScore = -INF; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 87 | 43 |  |         $maxScoreWeight = -INF; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 88 | 43 |  |         $maxScoreId = null; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 89 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 90 | 43 |  |         if (\count($this->probabilities) === 0) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 91 | 1 |  |             throw new \LengthException('Candidate not found in empty list'); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 92 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 93 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 94 | 42 |  |         foreach ($this->probabilities as $id => [$weight, $usageCounter]) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 95 | 42 |  |             $score = $weight / ($usageCounter + 1); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 96 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 97 | 42 |  |             if ($this->areFloatsEqual($score, $maxScore) && $weight > $maxScoreWeight || $score > $maxScore) { | 
                            
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                | 98 | 42 |  |                 $maxScore = $score; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 99 | 42 |  |                 $maxScoreWeight = $weight; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 100 | 42 |  |                 $maxScoreId = $id; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 101 |  |  |             } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 102 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 103 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 104 |  |  |         /** @var int $maxScoreId */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 105 | 42 |  |         $this->incrementUsageCounter($maxScoreId); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 106 | 42 |  |         return $this->data[$maxScoreId]; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 107 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 108 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 109 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 110 |  |  |      * Returns iterator to get decisions sequence. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 111 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 112 |  |  |      * @param int|null $limit | 
            
                                                                                                            
                            
            
                                    
            
            
                | 113 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 114 |  |  |      * @return \Generator | 
            
                                                                                                            
                            
            
                                    
            
            
                | 115 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 116 | 32 |  |     public function getIterator(?int $limit = null): \Generator | 
            
                                                                                                            
                            
            
                                    
            
            
                | 117 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 118 | 32 |  |         for ($i = 0; $limit === null || $i < $limit; ++$i) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 119 | 32 |  |             yield $this->totalUsageCounter => $this->decide(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 120 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 121 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 122 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 123 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 124 |  |  |      * Exports data with probabilities and usage counters. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 125 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 126 |  |  |      * @return array<array{T, float, int}> | 
                            
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                | 127 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 128 | 2 |  |     public function export(): array | 
            
                                                                                                            
                            
            
                                    
            
            
                | 129 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 130 | 2 |  |         return array_map(fn ($datum, $config) => [$datum, ...$config], $this->data, $this->probabilities); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 131 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 132 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 133 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 134 |  |  |      * Increments usage counter of datum by its ID. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 135 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 136 |  |  |      * @param int $id datum ID | 
            
                                                                                                            
                            
            
                                    
            
            
                | 137 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 138 |  |  |      * @return int current value of usage counter | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 139 |  |  |      */ | 
            
                                                                        
                            
            
                                    
            
            
                | 140 | 42 |  |     protected function incrementUsageCounter(int $id): int | 
            
                                                                        
                            
            
                                    
            
            
                | 141 |  |  |     { | 
            
                                                                        
                            
            
                                    
            
            
                | 142 | 42 |  |         $this->totalUsageCounter++; | 
            
                                                                        
                            
            
                                    
            
            
                | 143 | 42 |  |         return ++$this->probabilities[$id][1]; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 144 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 145 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 146 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 147 |  |  |      * Returns true if parameters are equal. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 148 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 149 |  |  |      * @param float $lhs | 
            
                                                                                                            
                            
            
                                    
            
            
                | 150 |  |  |      * @param float $rhs | 
            
                                                                                                            
                            
            
                                    
            
            
                | 151 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 152 |  |  |      * @return bool | 
            
                                                                                                            
                            
            
                                    
            
            
                | 153 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 154 | 42 |  |     protected function areFloatsEqual(float $lhs, float $rhs): bool | 
            
                                                                                                            
                            
            
                                    
            
            
                | 155 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 156 | 42 |  |         return \abs($lhs - $rhs) < PHP_FLOAT_EPSILON; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 157 |  |  |     } | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 158 |  |  | } | 
            
                                                        
            
                                    
            
            
                | 159 |  |  |  |