<?php

class mtgMetaFunc extends mtgMetaUnit implements mtgType
{
  private string $name;
  private $args = array();
  private $ret_type;

  function __construct($name)
  {
    $this->name = $name;
  }

  function validate(mtgMetaInfo $meta)
  {}

  function __toString()
  {
    $str = "func ";

    $str .= $this->name.'(';
    foreach($this->getArgs() as $arg)
      $str .= $arg->getType() . ',';
    $str = rtrim($str, ',');
    $str .= ')';
    if($ret_type = $this->getReturnType())
      $str .= ':'.$ret_type;
    return $str;
  }

  function setReturnType(mtgTypeRef $type)
  {
    $this->ret_type = $type;
  }

  function getReturnType() : ?mtgType
  {
    return $this->ret_type ? $this->ret_type->resolve() : null;
  }

  function getName() : string
  {
    return $this->name;
  }

  function getArgs()
  {
    return $this->args;
  }

  function setArgs(array $args)
  {
    foreach($args as $arg)
      $this->addArg($arg);
  }

  function addArg(mtgMetaField $arg)
  {
    if($this->hasArg($arg->getName()))
      throw new Exception("Func '{$this->name}' already has arg '{$arg->getName()}'");

    $this->args[$arg->getName()] = $arg;
  }

  function hasArg($name)
  {
    return isset($this->args[$name]);
  }

  function getArg($name)
  {
    if(!isset($this->args[$name]))
      throw new Exception("No such arg '$name'");
    return $this->args[$name];
  }
}