<?php
/**
 * Part of the Joomla Framework Data Package
 *
 * @copyright  Copyright (C) 2005 - 2021 Open Source Matters, Inc. All rights reserved.
 * @license    GNU General Public License version 2 or later; see LICENSE
 */

namespace Joomla\Data;

use Joomla\Registry\Registry;

/**
 * DataObject is a class that is used to store data but allowing you to access the data by mimicking the way PHP handles class properties.
 *
 * @since  1.0
 */
class DataObject implements DumpableInterface, \IteratorAggregate, \JsonSerializable, \Countable
{
	/**
	 * The data object properties.
	 *
	 * @var    array
	 * @since  1.0
	 */
	private $properties = [];

	/**
	 * The class constructor.
	 *
	 * @param   mixed  $properties  Either an associative array or another object by which to set the initial properties of the new object.
	 *
	 * @since   1.0
	 * @throws  \InvalidArgumentException
	 */
	public function __construct($properties = [])
	{
		// Check the properties input.
		if (!empty($properties))
		{
			// Bind the properties.
			$this->bind($properties);
		}
	}

	/**
	 * The magic get method is used to get a data property.
	 *
	 * This method is a public proxy for the protected getProperty method.
	 *
	 * Note: Magic __get does not allow recursive calls. This can be tricky because the error generated by recursing into
	 * __get is "Undefined property:  {CLASS}::{PROPERTY}" which is misleading. This is relevant for this class because
	 * requesting a non-visible property can trigger a call to a sub-function. If that references the property directly in
	 * the object, it will cause a recursion into __get.
	 *
	 * @param   string  $property  The name of the data property.
	 *
	 * @return  mixed  The value of the data property, or null if the data property does not exist.
	 *
	 * @see     DataObject::getProperty()
	 * @since   1.0
	 */
	public function __get($property)
	{
		return $this->getProperty($property);
	}

	/**
	 * The magic isset method is used to check the state of an object property.
	 *
	 * @param   string  $property  The name of the data property.
	 *
	 * @return  boolean
	 *
	 * @since   1.0
	 */
	public function __isset($property)
	{
		return isset($this->properties[$property]);
	}

	/**
	 * The magic set method is used to set a data property.
	 *
	 * This is a public proxy for the protected setProperty method.
	 *
	 * @param   string  $property  The name of the data property.
	 * @param   mixed   $value     The value to give the data property.
	 *
	 * @return  void
	 *
	 * @see     DataObject::setProperty()
	 * @since   1.0
	 */
	public function __set($property, $value)
	{
		$this->setProperty($property, $value);
	}

	/**
	 * The magic unset method is used to unset a data property.
	 *
	 * @param   string  $property  The name of the data property.
	 *
	 * @return  void
	 *
	 * @since   1.0
	 */
	public function __unset($property)
	{
		unset($this->properties[$property]);
	}

	/**
	 * Binds an array or object to this object.
	 *
	 * @param   mixed    $properties   An associative array of properties or an object.
	 * @param   boolean  $updateNulls  True to bind null values, false to ignore null values.
	 *
	 * @return  $this
	 *
	 * @since   1.0
	 * @throws  \InvalidArgumentException
	 */
	public function bind($properties, $updateNulls = true)
	{
		// Check the properties data type.
		if (!\is_array($properties) && !\is_object($properties))
		{
			throw new \InvalidArgumentException(
				sprintf('The $properties argument must be an array or object, a %s was given.', \gettype($properties))
			);
		}

		// Check if the object is traversable.
		if ($properties instanceof \Traversable)
		{
			// Convert iterator to array.
			$properties = iterator_to_array($properties);
		}
		elseif (\is_object($properties))
		{
			// Convert properties to an array.
			$properties = (array) $properties;
		}

		// Bind the properties.
		foreach ($properties as $property => $value)
		{
			// Check if the value is null and should be bound.
			if ($value === null && !$updateNulls)
			{
				continue;
			}

			// Set the property.
			$this->setProperty($property, $value);
		}

		return $this;
	}

	/**
	 * Dumps the data properties into an object, recursively if appropriate.
	 *
	 * @param   integer            $depth   The maximum depth of recursion (default = 3).
	 *                                      For example, a depth of 0 will return a stdClass with all the properties in native
	 *                                      form. A depth of 1 will recurse into the first level of properties only.
	 * @param   \SplObjectStorage  $dumped  An array of already serialized objects that is used to avoid infinite loops.
	 *
	 * @return  \stdClass
	 *
	 * @since   1.0
	 */
	public function dump($depth = 3, \SplObjectStorage $dumped = null)
	{
		// Check if we should initialise the recursion tracker.
		if ($dumped === null)
		{
			$dumped = new \SplObjectStorage;
		}

		// Add this object to the dumped stack.
		$dumped->attach($this);

		// Setup a container.
		$dump = new \stdClass;

		// Dump all object properties.
		foreach (array_keys($this->properties) as $property)
		{
			// Get the property.
			$dump->$property = $this->dumpProperty($property, $depth, $dumped);
		}

		return $dump;
	}

	/**
	 * Gets this object represented as an ArrayIterator.
	 *
	 * This allows the data properties to be access via a foreach statement.
	 *
	 * @return  \ArrayIterator
	 *
	 * @see     IteratorAggregate::getIterator()
	 * @since   1.0
	 */
	public function getIterator()
	{
		return new \ArrayIterator($this->dump(0));
	}

	/**
	 * Gets the data properties in a form that can be serialised to JSON format.
	 *
	 * @return  string
	 *
	 * @since   1.0
	 */
	public function jsonSerialize()
	{
		return $this->dump();
	}

	/**
	 * Dumps a data property.
	 *
	 * If recursion is set, this method will dump any object implementing DumpableInterface (like DataObject and DataSet); it will
	 * convert a DateTimeInterface object to a string; and it will convert a Joomla\Registry\Registry to an object.
	 *
	 * @param   string             $property  The name of the data property.
	 * @param   integer            $depth     The current depth of recursion (a value of 0 will ignore recursion).
	 * @param   \SplObjectStorage  $dumped    An array of already serialized objects that is used to avoid infinite loops.
	 *
	 * @return  mixed  The value of the dumped property.
	 *
	 * @since   1.0
	 */
	protected function dumpProperty($property, $depth, \SplObjectStorage $dumped)
	{
		$value = $this->getProperty($property);

		if ($depth > 0)
		{
			// Check if the object is also a dumpable object.
			if ($value instanceof DumpableInterface)
			{
				// Do not dump the property if it has already been dumped.
				if (!$dumped->contains($value))
				{
					$value = $value->dump($depth - 1, $dumped);
				}
			}

			// Check if the object is a date.
			if ($value instanceof \DateTimeInterface)
			{
				$value = $value->format('Y-m-d H:i:s');
			}
			elseif ($value instanceof Registry)
			{
				$value = $value->toObject();
			}
		}

		return $value;
	}

	/**
	 * Gets a data property.
	 *
	 * @param   string  $property  The name of the data property.
	 *
	 * @return  mixed  The value of the data property.
	 *
	 * @see     DataObject::__get()
	 * @since   1.0
	 */
	protected function getProperty($property)
	{
		return $this->properties[$property] ?? null;
	}

	/**
	 * Sets a data property.
	 *
	 * If the name of the property starts with a null byte, this method will return null.
	 *
	 * @param   string  $property  The name of the data property.
	 * @param   mixed   $value     The value to give the data property.
	 *
	 * @return  mixed  The value of the data property.
	 *
	 * @see     DataObject::__set()
	 * @since   1.0
	 */
	protected function setProperty($property, $value)
	{
		/*
		 * Check if the property starts with a null byte. If so, discard it because a later attempt to try to access it
		 * can cause a fatal error. See http://www.php.net/manual/en/language.types.array.php#language.types.array.casting
		 */
		if (strpos($property, "\0") === 0)
		{
			return;
		}

		// Set the value.
		$this->properties[$property] = $value;

		return $value;
	}

	/**
	 * Count the number of data properties.
	 *
	 * @return  integer  The number of data properties.
	 *
	 * @since   1.0
	 */
	public function count()
	{
		return \count($this->properties);
	}
}
