group-by-many.php

<?php
  
  
  $data = [
    ["calendar_id" => 1, "doctor_id" => 1, "date" => "2013-01-01"],
    ["calendar_id" => 1, "doctor_id" => 2, "date" => "2013-01-03"],
    ["calendar_id" => 1, "doctor_id" => 1, "date" => "2013-01-03"],
    
    ["calendar_id" => 2, "doctor_id" => 4, "date" => "2013-01-01"],
    ["calendar_id" => 2, "doctor_id" => 4, "date" => "2013-01-01"],
    ["calendar_id" => 2, "doctor_id" => 5, "date" => "2013-01-01"],
    
    ["calendar_id" => 3, "doctor_id" => 1, "date" => "2013-01-01"],
    ["calendar_id" => 3, "doctor_id" => 1, "date" => "2013-01-02"],
  ];
  
  class ArrayGrouper 
  {
    public function groupByMany(array $items, array $definitions)
    {
      $property = array_shift($definitions);
      $items = $this->group($items, $property);
      if (0 !== sizeof($definitions))
      {
        foreach ($items as &$item)
        {
          $item = $this->groupByMany($item, $definitions); 
        }
      }
      return $items;
    }
    
    private function group(array $items, $property)
    {
      $results = [];
      foreach ($items as $item)
      {
        $key = (new PropertyAccess($property))->resolve($item);
        // $key = $item[$property];
        $results[$key][] = $item;
      }
      return $results;
    }
  }
  
  $grouper = new ArrayGrouper;
  print_r($grouper->groupByMany($data, ['calendar_id', 'doctor_id', 'date']));
?>

group-creator.php

<?php
  class VisitGroup extends ArrayObject {
    protected $type; 
    public function getType() {
      return $type;
    }
    public function setType($type) {
      $this->type = $type;
    }
    public function isType($type) {
      return $type === $this->type;
    }
    
    public function getRange() {
      if ($this->count() === 0) {
        return [];
      }
      if ($this->count() === 1) {
        return [$this->offsetGet(0)['start']];
      }
      return [$this->offsetGet(0)['start'], $this->offsetGet($this->count()-1)['start']];
    }
  }
  
  class GroupCreator {
    public function createGroupList(array $visits) {
      $groups = [];
      $current = null;
      foreach ($visits as $visit) {
        if (null === $current) {
          $current = new VisitGroup;
          $current->setType($visit['type']);
        }
        if (false === $current->isType($visit['type'])) {
          $groups[] = $current;
          $current = new VisitGroup;
          $current->setType($visit['type']);
        }
        $current->append($visit);
      }
      if (null !== $current) {
        $groups[] = $current;  
      }
      return $groups;
    }
  }
  
  $visits = [
     ["type" => "open", "start" => "8:00"],
     ["type" => "closed", "start" => "9:00"],
     ["type" => "closed", "start" => "10:00"],
     ["type" => "open", "start" => "11:00"],
     ["type" => "open", "start" => "12:00"],
     ["type" => "closed", "start" => "13:00"],
  ];
  
  $creator = new GroupCreator;
  $groupList = $creator->createGroupList($visits);
  foreach ($groupList as $group) {
    if ($group->isType('open')) echo "Open group: " , $group->count(), "\n";
    else echo "Closed group: ", implode(" - ", $group->getRange()), "\n";
  }
  
?>