<?php

namespace NoccyLabs\PulseAudio;

use ArrayAccess;
use IteratorAggregate;
use Countable;

class PropertyList implements ArrayAccess, IteratorAggregate, Countable
{

    protected $properties = [];

    protected $readOnly = false;

    public function __construct(array $properties=[], $readOnly=false)
    {
        $this->properties = $properties;
        $this->readOnly = $readOnly;
    }

    public function getIterator()
    {
        return new ArrayIterator($this->properties);
    }

    public function offsetGet($key)
    {
        if (!array_key_exist($key, $this->properties)) {
            throw new InvalidArgumentException("No such property: {$key}");
        }
        return $this->properties[$key];
    }

    public function offsetSet($key, $value)
    {
        if ($this->readOnly) {
            return;
        }
        $this->properties[$key] = $value;
    }

    public function offsetUnset($key)
    {
        if ($this->readOnly) {
            return;
        }
        unset($this->properties[$key]);
    }

    public function offsetExists($key)
    {
        return array_key_exists($key, $this->properties);
    }

    public function count()
    {
        return count($this->properties);
    }
}