<?php
namespace ProVM\Common\Helper;

class Tree {
  protected $merger;
  public function __construct($separator) {
    $this->merger = new Merger($separator);
  }
  protected $tree;
  public function add($value, $parent = null, $alias = null): Tree {
    if ($parent === null) {
      if ($alias === null) {
        $this->tree []= $value;
        return $this;
      }
      $this->tree[$alias] = $value;
      return $this;
    }
    if (!isset($this->tree[$parent])) {
      return $this;
    }
    if ($alias === null) {
      $this->tree []= $this->merger->start()
        ->add($this->tree[$parent])
        ->add($value)
        ->merge();
      return $this;
    }
    $this->tree[$alias] = $this->merger->start()
      ->add($this->tree[$parent])
      ->add($value)
      ->merge();
    return $this;
  }
  public function check_keys($tree) {
    $bool = true;
    foreach ($tree as $def) {
      if (!isset($def[2])) {
        continue;
      }
      $key = $def[2];
      $bool &= array_key_exists($key, $this->tree);
    }
    return $bool;
  }
  public function addTree($tree) {
    while (!$this->check_keys($tree)) {
      foreach ($tree as $def) {
        $this->add($def[0], $def[1] ?? null, $def[2] ?? null);
      }
    }
  }
  public function build($tree) {
    $this->tree = [];
    $this->addTree($tree);
    return (object) $this->tree;
  }
}