<?php

/**
* Hoa
*
*
* @license
*
* New BSD License
*
* Copyright © 2007-2017, Hoa community. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the Hoa nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS AND CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

namespace Hoa\Protocol\Node;

use Hoa\Consistency;
use Hoa\Protocol;

/**
* Class \Hoa\Protocol\Node\Node.
*
* Abstract class for all `hoa://`'s nodes.
*
* @copyright Copyright © 2007-2017 Hoa community
* @license New BSD License
*/
class Node implements \ArrayAccess, \IteratorAggregate
{
/**
* Node's name.
*
* @var string
*/
protected $_name = null;

/**
* Path for the `reach` method.
*
* @var string
*/
protected $_reach = null;

/**
* Children of the node.
*
* @var array
*/
private $_children = [];



/**
* Construct a protocol's node.
* If it is not a data object (i.e. if it does not extend this class to
* overload the `$_name` attribute), we can set the `$_name` attribute
* dynamically. This is useful to create a node on-the-fly.
*
* @param string $name Node's name.
* @param string $reach Path for the `reach` method.
* @param array $children Node's children.
*/
public function __construct($name = null, $reach = null, array $children = [])
{
if (null !== $name) {
$this->_name = $name;
}

if (null !== $reach) {
$this->_reach = $reach;
}

foreach ($children as $child) {
$this[] = $child;
}

return;
}

/**
* Add a node.
*
* @param string $name Node's name. If null, will be
* set to name of `$node`.
* @param \Hoa\Protocol\Protocol $node Node to add.
* @return \Hoa\Protocol\Protocol
* @throws \Hoa\Protocol\Exception
*/
public function offsetSet($name, $node)
{
if (!($node instanceof self)) {
throw new Protocol\Exception(
'Protocol node must extend %s.',
0,
__CLASS__
);
}

if (empty($name)) {
$name = $node->getName();
}

if (empty($name)) {
throw new Protocol\Exception(
'Cannot add a node to the `hoa://` protocol without a name.',
1
);
}

$this->_children[$name] = $node;

return;
}

/**
* Get a specific node.
*
* @param string $name Node's name.
* @return \Hoa\Protocol\Protocol
* @throws \Hoa\Protocol\Exception
*/
public function offsetGet($name)
{
if (!isset($this[$name])) {
throw new Protocol\Exception(
'Node %s does not exist.',
2,
$name
);
}

return $this->_children[$name];
}

/**
* Check if a node exists.
*
* @param string $name Node's name.
* @return bool
*/
public function offsetExists($name)
{
return true === array_key_exists($name, $this->_children);
}

/**
* Remove a node.
*
* @param string $name Node's name to remove.
* @return void
*/
public function offsetUnset($name)
{
unset($this->_children[$name]);

return;
}

/**
* Resolve a path, i.e. iterate the nodes tree and reach the queue of
* the path.
*
* @param string $path Path to resolve.
* @param array &$accumulator Combination of all possibles paths.
* @param string $id ID.
* @return mixed
*/
protected function _resolve($path, &$accumulator, $id = null)
{
if (substr($path, 0, 6) == 'hoa://') {
$path = substr($path, 6);
}

if (empty($path)) {
return null;
}

if (null === $accumulator) {
$accumulator = [];
$posId = strpos($path, '#');

if (false !== $posId) {
$id = substr($path, $posId + 1);
$path = substr($path, 0, $posId);
} else {
$id = null;
}
}

$path = trim($path, '/');
$pos = strpos($path, '/');

if (false !== $pos) {
$next = substr($path, 0, $pos);
} else {
$next = $path;
}

if (isset($this[$next])) {
if (false === $pos) {
if (null === $id) {
$this->_resolveChoice($this[$next]->reach(), $accumulator);

return true;
}

$accumulator = null;

return $this[$next]->reachId($id);
}

$tnext = $this[$next];
$this->_resolveChoice($tnext->reach(), $accumulator);

return $tnext->_resolve(substr($path, $pos + 1), $accumulator, $id);
}

$this->_resolveChoice($this->reach($path), $accumulator);

return true;
}

/**
* Resolve choices, i.e. a reach value has a “;”.
*
* @param string $reach Reach value.
* @param array &$accumulator Combination of all possibles paths.
* @return void
*/
protected function _resolveChoice($reach, array &$accumulator)
{
if (empty($accumulator)) {
$accumulator = explode(RS, $reach);

return;
}

if (false === strpos($reach, RS)) {
if (false !== $pos = strrpos($reach, "\r")) {
$reach = substr($reach, $pos + 1);

foreach ($accumulator as &$entry) {
$entry = null;
}
}

foreach ($accumulator as &$entry) {
$entry .= $reach;
}

return;
}

$choices = explode(RS, $reach);
$ref = $accumulator;
$accumulator = [];

foreach ($choices as $choice) {
if (false !== $pos = strrpos($choice, "\r")) {
$choice = substr($choice, $pos + 1);

foreach ($ref as $entry) {
$accumulator[] = $choice;
}
} else {
foreach ($ref as $entry) {
$accumulator[] = $entry . $choice;
}
}
}

unset($ref);

return;
}

/**
* Queue of the node.
* Generic one. Must be overrided in children classes.
*
* @param string $queue Queue of the node (generally a filename,
* with probably a query).
* @return mixed
*/
public function reach($queue = null)
{
return empty($queue) ? $this->_reach : $queue;
}

/**
* ID of the component.
* Generic one. Should be overrided in children classes.
*
* @param string $id ID of the component.
* @return mixed
* @throws \Hoa\Protocol\Exception
*/
public function reachId($id)
{
throw new Protocol\Exception(
'The node %s has no ID support (tried to reach #%s).',
4,
[$this->getName(), $id]
);
}

/**
* Set a new reach value.
*
* @param string $reach Reach value.
* @return string
*/
public function setReach($reach)
{
$old = $this->_reach;
$this->_reach = $reach;

return $old;
}

/**
* Get node's name.
*
* @return string
*/
public function getName()
{
return $this->_name;
}

/**
* Get reach's root.
*
* @return string
*/
protected function getReach()
{
return $this->_reach;
}

/**
* Get an iterator.
*
* @return \ArrayIterator
*/
public function getIterator()
{
return new \ArrayIterator($this->_children);
}

/**
* Get root the protocol.
*
* @return \Hoa\Protocol\Protocol
*/
public static function getRoot()
{
return Protocol::getInstance();
}

/**
* Print a tree of component.
*
* @return string
*/
public function __toString()
{
static $i = 0;

$out = str_repeat(' ', $i) . $this->getName() . "\n";

foreach ($this as $node) {
++$i;
$out .= $node;
--$i;
}

return $out;
}
}

/**
* Flex entity.
*/
Consistency::flexEntity('Hoa\Protocol\Node\Node');