Stripped down Discord Minesweeper

minesweeper.php

<?php

// http://thisismywww.com/blog/2018/09/minesweeper-in-php/
// edited the above for some Discord fun.

// Note: 9x9 is prolly maximum grid
// 10x10 will leave off the last emoji for some reason

class MineSweeper {

  // private $spacer = '🟥';
  private $empty = '🟦';
  private $bomb = '💣';
  private $caps = ['0️⃣','1️⃣','2️⃣','3️⃣','4️⃣','5️⃣','6️⃣','7️⃣','8️⃣','9️⃣','🔟'];

  public $grid_reference = [];
  public $cell_values = [];
  public $mine_cells = [];

  public $num_rows;
  public $num_cols;
  public $num_mines;

  public function __construct(
    $num_rows = 10,
    $num_cols = 10,
    $num_mines = 5
  )
  {
    $this->num_rows = $num_rows;
    $this->num_cols = $num_cols;
    $this->num_mines = $num_mines;

    $this->generate_grid();
    $this->generate_values();
  }

  function generate_grid(){
    for ($x=10;$x<($this->num_rows+10);$x++){
      for ($y=10;$y<($this->num_cols+10);$y++){
        array_push($this->grid_reference,$x.$y);
      }
    }
  }

  function generate_values(){
    // Generate mine_cells and cell_values - need to know mine_cells before cell values
    // Mine Cells are created by using the grid references, minus clicked cell then trimmed
    $this->mine_cells = $this->grid_reference;
    // $key = array_search($this->submitted_block, $this->mine_cells);
    // unset($this->mine_cells[$key]);
    shuffle($this->mine_cells);
    $this->mine_cells = array_values(array_slice($this->mine_cells, 0, $this->num_mines));
    
    // Calculate how many mines are surrounding each cell if cell isn't a bomb
    // If none, don't set value
    
    foreach($this->grid_reference as $cell){
      if (!in_array($cell,$this->mine_cells)){
        $cells_to_check = [];
        $cells_to_check = $this->get_surrounding_cells($cell);
        $number = count(array_intersect($cells_to_check,$this->mine_cells));
        if ($number>0){
        $this->cell_values[$cell]=$number;
        }
      }
    }
    // On first round, make the submitted block visible
    // $this->process_cell($this->submitted_block);  
  }

  function get_surrounding_cells($cell){
    // Sloppy, but generates array of all cells surrounding the submitted cell, making sure
    // the values are only those one in the grid reference array.
    // also removes marked cells so it's not included in a cell which is checked.
    $cells_to_check = [];
    array_push($cells_to_check, substr($cell,0,2)-1 .substr($cell,2,2)-1);
    array_push($cells_to_check, substr($cell,0,2)-1 .substr($cell,2,2));
    array_push($cells_to_check, substr($cell,0,2)-1 .substr($cell,2,2)+1);
    array_push($cells_to_check, substr($cell,0,2) .substr($cell,2,2)-1);
    array_push($cells_to_check, substr($cell,0,2) .substr($cell,2,2)+1);
    array_push($cells_to_check, substr($cell,0,2)+1 .substr($cell,2,2)-1);
    array_push($cells_to_check, substr($cell,0,2)+1 .substr($cell,2,2));
    array_push($cells_to_check, substr($cell,0,2)+1 .substr($cell,2,2)+1);
    return array_intersect($cells_to_check,$this->grid_reference);
  }

  /** @test */
  public function generate_field()
  {
    $lines = "";
    for ($x=10;$x<($this->num_rows+10);$x++){
      $lines .= "";
      for ($y=10;$y<($this->num_cols+10);$y++){
        $block = $x.$y;
        // $lines .= $this->cell_content($block);
        $lines .= '||'.$this->cell_content($block).'||';
      }
      $lines .= "\n";
    }
    return $lines;
  }

  function cell_content($block){
    $line = '';
      
      if (array_key_exists($block,$this->cell_values)){
          $line .= $this->color_number($this->cell_values[$block]);
        }else{
          if (in_array($block,$this->mine_cells)){
            $line .= $this->bomb;
          }else{
            $line .= $this->empty;
        }
      }
    return $line;
  }

  function color_number($number){
    return $this->caps[$number];
  }
  
}


echo '<pre>', (new MineSweeper(9,9,9))->generate_field(), '</pre>';

Stripped down, because I used the following blog post xD:
http://thisismywww.com/blog/2018/09/minesweeper-in-php/