app/Models/ChatLib.php

   1 <?php
   2
   3 namespace App\Models;
   4
   5 class ChatLib {
   6
   7         public function addMessage($msg) {
   8                 $tokens = array_values(array_filter(preg_split('/\b/', $msg->text_content)));
   9                 if (empty($tokens)) return;
  10                 $tokens [] = '';
  11                 foreach ($tokens as $num => $token) {
  12                         if ($num === 0) {
  13                                 $this->addStart($token);
  14                         } else if ($num === 1) {
  15                                 $this->addOne($tokens[0], $token);
  16                         } else if ($num === 2) {
  17                                 $this->addOne($tokens[1], $token);
  18                                 $this->addTwo($tokens[0], $tokens[1], $token);
  19                         } else {
  20                                 $this->addOne($tokens[$num - 1], $token);
  21                                 $this->addTwo($tokens[$num - 2], $tokens[$num - 1], $token);
  22                                 $this->addThree($tokens[$num - 3], $tokens[$num - 2], $tokens[$num - 1], $token);
  23                         }
  24                 }
  25         }
  26
  27         public function compile() {
  28                 $this->start = $this->index($this->start);
  29                 foreach ($this->one as $key => $value) {
  30                         $this->one[$key] = $this->index($this->one[$key]);
  31                 }
  32                 foreach ($this->two as $key => $value) {
  33                         $this->two[$key] = $this->index($this->two[$key]);
  34                 }
  35                 foreach ($this->three as $key => $value) {
  36                         $this->three[$key] = $this->index($this->three[$key]);
  37                 }
  38         }
  39
  40         public function generate($limit = 50) {
  41                 $tokens = [];
  42                 $start = $this->randomStart();
  43                 $tokens[] = $start;
  44                 $generated = $start;
  45                 while (strlen($generated) < $limit) {
  46                         $next = $this->randomNext($tokens);
  47                         if (empty($next)) break;
  48                         $tokens[] = $next;
  49                         $generated .= $next;
  50                 }
  51                 return $generated;
  52         }
  53
  54         private function index($arr) {
  55                 $result = [];
  56                 $sum = 0;
  57                 asort($arr);
  58                 foreach ($arr as $key => $weight) {
  59                         $lower = $sum;
  60                         $sum += $weight;
  61                         $result[] = [$key, $lower, $sum];
  62                 }
  63                 return $result;
  64         }
  65
  66         private function randomStart() {
  67                 return $this->pick($this->start);
  68         }
  69
  70         private function randomNext($tokens) {
  71                 $cnt = count($tokens);
  72                 if ($cnt >= 3) {
  73                         $cmb = $tokens[$cnt - 3].$tokens[$cnt - 2].$tokens[$cnt - 1];
  74                         if (isset($this->three[$cmb])) {
  75                                 return $this->pick($this->three[$cmb]);
  76                         }
  77                 }
  78                 if ($cnt >= 2) {
  79                         $cmb = $tokens[$cnt - 2].$tokens[$cnt - 1];
  80                         if (isset($this->two[$cmb])) {
  81                                 return $this->pick($this->two[$cmb]);
  82                         }
  83                 }
  84                 if ($cnt >= 1) {
  85                         $cmb = $tokens[$cnt - 1];
  86                         if (isset($this->one[$cmb])) {
  87                                 return $this->pick($this->one[$cmb]);
  88                         }
  89                 }
  90                 return '';
  91         }
  92
  93         private function pick($options) {
  94                 $max = end($options)[2];
  95                 $num = random_int(0, $max);
  96                 $min_index = 0;
  97                 $max_index = count($options) - 1;
  98                 while ($min_index < $max_index) {
  99                         $cur_index = intval(($min_index + $max_index) / 2);
 100                         $cur_low = $options[$cur_index][1];
 101                         $cur_high = $options[$cur_index][2];
 102                         if ($cur_low > $num) {
 103                                 $max_index = $cur_index;
 104                         } else if ($cur_high < $num) {
 105                                 $min_index = $cur_index + 1;
 106                         } else {
 107                                 $min_index = $cur_index;
 108                                 break;
 109                         }
 110                 }
 111                 return $options[$min_index][0];
 112         }
 113
 114         private function addStart($token) {
 115                 if (empty($token)) return;
 116                 if (!isset($this->start[$token])) {
 117                         $this->start[$token] = 1;
 118                 } else {
 119                         ++$this->start[$token];
 120                 }
 121         }
 122
 123         private function addOne($one, $token) {
 124                 if (!isset($this->one[$one])) {
 125                         $this->one[$one] = [];
 126                 }
 127                 if (!isset($this->one[$one][$token])) {
 128                         $this->one[$one][$token] = 1;
 129                 } else {
 130                         ++$this->one[$one][$token];
 131                 }
 132         }
 133
 134         private function addTwo($one, $two, $token) {
 135                 $cmb = $one.$two;
 136                 if (!isset($this->two[$cmb])) {
 137                         $this->two[$cmb] = [];
 138                 }
 139                 if (!isset($this->two[$cmb][$token])) {
 140                         $this->two[$cmb][$token] = 1;
 141                 } else {
 142                         ++$this->two[$cmb][$token];
 143                 }
 144         }
 145
 146         private function addThree($one, $two, $three, $token) {
 147                 $cmb = $one.$two.$three;
 148                 if (!isset($this->three[$cmb])) {
 149                         $this->three[$cmb] = [];
 150                 }
 151                 if (!isset($this->three[$cmb][$token])) {
 152                         $this->three[$cmb][$token] = 1;
 153                 } else {
 154                         ++$this->three[$cmb][$token];
 155                 }
 156         }
 157
 158         private $start = [];
 159         private $one = [];
 160         private $two = [];
 161         private $three = [];
 162
 163 }