<?php
// Own namespace
namespace Org\Mxchange\CoreFramework\Iterator\Registry;

// Import framework stuff
use Org\Mxchange\CoreFramework\Generic\FrameworkInterface;
use Org\Mxchange\CoreFramework\Generic\NullPointerException;
use Org\Mxchange\CoreFramework\Iterator\BaseIterator;
use Org\Mxchange\CoreFramework\Registry\Register;
use Org\Mxchange\CoreFramework\Registry\Registerable;
use Org\Mxchange\CoreFramework\Registry\Sub\SubRegistry;

// Import SPL stuff
use \BadMethodCallException;
use \LogicException;

/**
 * A registry iterator
 *
 * @author		Roland Haeder <webmaster@ship-simu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2020 Core Developer Team
 * @license		GNU GPL 3.0 or any newer version
 * @link		http://www.ship-simu.org
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
class RegistryIterator extends BaseIterator implements IteratableRegistry {
	/**
	 * All found registry keys
	 */
	private $registryKeys = [];

	/**
	 * An array containing keys ob sub-registries which keys should only be
	 * included in the iterator.
	 */
	private $onlyRegistries = [];

	/**
	 * Current array key
	 */
	private $key = NULL;

	/**
	 * Protected constructor
	 *
	 * @return	void
	 */
	protected function __construct () {
		// Call parent constructor
		parent::__construct(__CLASS__);

		// Init registry keys array
		$this->registryKeys = [
			// Generic registry
			'generic' => [],
			// Instance registry
			'instance' => [],
		];
	}

	/**
	 * Creates an instance of this class
	 *
	 * @param	$registryInstance	An instance of a Register class
	 * @return	$iteratorInstance	An instance of a Iterator class
	 */
	public final static function createRegistryIterator (Register $registryInstance) {
		// Get new instance
		$iteratorInstance = new RegistryIterator();

		// Set registry here
		$iteratorInstance->setRegistryInstance($registryInstance);

		// Return the prepared instance
		return $iteratorInstance;
	}

	/**
	 * Setter for only-registries array
	 *
	 * @param	$onlyRegistries		Array with keys only being iterated over
	 * @return	void
	 */
	private function setOnlyRegistries (array $onlyRegistries) {
		$this->onlyRegistries = $onlyRegistries;
	}

	/**
	 * Initializes this iterator by scanning over the registry for all keys.
	 *
	 * @param	$onlyRegistries		Only iterate on these sub-registry keys, default is all
	 * @return	void
	 * @throws	LogicException	If a registry entry does not implement Registerable
	 * @throws	NullPointerException	If criteriaKey or criteriaMethod is not set but a call-back instance is set
	 */
	public function initIterator (array $onlyRegistries = []) {
		// Set it in this registry
		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR: onlyRegistries()=%d - CALLED!', count($onlyRegistries)));
		$this->setOnlyRegistries($onlyRegistries);

		// Get generic registry entries from it
		$entries = $this->getRegistryInstance()->getGenericRegistry();

		// Anything in there?
		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[generic]: entries()=%d', count($entries)));
		if (count($entries) > 0) {
			// Debugging:
			/* DEBUG-DIE: */ die(sprintf('[%s:%d]: UNFINISHED: entries=%s', __METHOD__, __LINE__, print_r($entries, TRUE)));
		} // END - if

		// Get instance registry entries from it
		$entries = $this->getRegistryInstance()->getInstanceRegistry();

		// Anything in there?
		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[instance]: entries()=%d', count($entries)));
		if (count($entries) > 0) {
			// Then run over all
			foreach ($entries as $key => $entry) {
				// Is an unwanted registry found?
				/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[instance]: key=%s,entry[]=%s', $key, gettype($entry)));
				if (substr($key, -8, 8) == 'registry') {
					// Skip this!
					/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[instance]: key=%s is a registry key, skipping ...', $key));
					continue;
				}

				// Is it an instance of a sub-registry?
				if (count($onlyRegistries) > 0 && !in_array($key, $onlyRegistries, TRUE)) {
					// Not in requested registries
					/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[instance]: key=%s is not wanted, skipping ...', $key));
					continue;
				} elseif ($entry instanceof SubRegistry) {
					// Get iterator from this instance
					$subRegistryInstances = $entry->getInstanceRegistry();

					// Add all sub-registry keys to this registry keys array
					/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[instance]: subRegistryInstances()=%d', count($subRegistryInstances)));
					//* DEBUG-DIE: */ die(sprintf('[%s:%d]: key=%s,subRegistryInstances=%s', __METHOD__, __LINE__, $key, print_r($subRegistryInstances, TRUE)));
					foreach (array_keys($subRegistryInstances) as $subKey) {
						// Add it
						/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[instance]: Adding key=%s,subKey=%s ...', $key, $subKey));
						array_push($this->registryKeys['instance'], $subKey);

						// Is the current key set?
						if (is_null($this->key)) {
							// Init key
							/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[instance]: Setting subKey=%s as first key ...', $subKey));
							$this->key = $subKey;
						}
					}

					// Skip below code
					continue;
				} elseif (!($entry instanceof Registerable)) {
					// Not registerable?!
					throw new LogicException(sprintf('entry[]=%s does not implement Registerable.', gettype($entry)));
				}

				// Is the current key set?
				if (is_null($this->key)) {
					// Init key
					/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[instance]: Setting key=%s as first key ...', $key));
					$this->key = $key;
				}

				// Add key to array
				/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[instance]: key=%s - Adding ...', $key));
				//* DEBUG-DIE: */ die(sprintf('[%s:%d]: key=%s,entry=%s', __METHOD__, __LINE__, $key, print_r($entry, TRUE)));
				array_push($this->registryKeys['instance'], $key);
			} // END - foreach
		} // END - if

		// Trace message
		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('REGISTRY-ITERATOR: EXIT!');
	}

	/**
	 * Getter for all registry keys (array)
	 *
	 * @return	$registryKeys	Registry keys
	 */
	public final function getRegistryKeys () {
		// Return it
		return $this->registryKeys;
	}

	/**
	 * Getter for current value from group or generic
	 *
	 * @return	$current	Current value in iteration
	 * @throws	NullPointerException	If current key points to a non-existing entry in searched registries
	 */
	public function current () {
		// Default is null
		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[%s]: CALLED!', $this->key()));
		//* DEBUG-DIE: */ die(sprintf('[%s:%d]: this->key(%d)[%s]=%s,this->valid=%d,this->registryKeys=%s', __METHOD__, __LINE__, strlen($this->key()), gettype($this->key()), $this->key(), intval($this->valid()), print_r($this->registryKeys, TRUE)));
		$current = NULL;
		$entries = [];

		// Get all registries
		$allRegistries = $this->getRegistryInstance()->getInstanceRegistry();

		// Loop through all sub-sets
		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[%s]: allRegistries()=%d', $this->key(), count($allRegistries)));
		foreach ($allRegistries as $registryKey => $registryInstance) {
			// Is this key wanted?
			/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[%s]: registryKey=%s', $this->key(), $registryKey));
			if (count($this->onlyRegistries) == 0 || in_array($registryKey, $this->onlyRegistries)) {
				// Yes, then loop through them only
				$instances = $registryInstance->getInstanceRegistry();

				// The key should be there
				/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[%s]: Handling registryKey=%s ...', $this->key(), $registryKey));
				//* DEBUG-DIE: */ die(sprintf('[%s:%d]: instances=%s', __METHOD__, __LINE__, print_r($instances, TRUE)));
				if (!isset($instances[$this->key()])) {
					// Skip below code
					/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[%s]: registryKey=%s has no this->key=%s, skipping ...', $this->key(), $registryKey));
					continue;
				}

				// Set as current element and leave loop
				$current = $instances[$this->key()];
				/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[%s]: registryKey=%s,current=%s found. - BREAK!', $this->key(), $registryKey, $current->__toString()));
				break;
			}
		}

		// Is current still NULL?
		if (is_null($current)) {
			// This cannot happen and indicates a logic error
			throw new NullPointerException($this, self::EXCEPTION_IS_NULL_POINTER);
		}

		// Return it
		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[%s]: current[%s]=%s - EXIT!', $this->key(), gettype($current), $current));
		return $current;
	}

	/**
	 * Getter for key from group or generic
	 *
	 * @return	$key	Current key in iteration
	 */
	public function key () {
		// Return it
		return $this->key;
	}

	/**
	 * Advances to the next entry
	 *
	 * @return	void
	 * @throws	BadMethodCallException	If $this->valid() returns FALSE
	 */
	public function next () {
		// Is valid() still TRUE?
		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[%s]: CALLED!', $this->key()));
		/* DEBUG-DIE: */ die(sprintf('[%s:%d]: this->key(%d)[%s]=%s,this->valid=%d,this->registryKeys=%s', __METHOD__, __LINE__, strlen($this->key()), gettype($this->key()), $this->key(), intval($this->valid()), print_r($this->registryKeys, TRUE)));
		if (!$this->valid()) {
			// Bad method call!
			throw new BadMethodCallException(sprintf('this->key[%s]=%s is no longer valid, but method was called.', gettype($this->key()), $this->key()));
		}
	}

	/**
	 * Rewinds to the beginning of the iteration
	 *
	 * @return	void
	 * @throws	BadMethodCallException	If $this->key is already the first element
	 */
	public function rewind () {
		// Is current key first key?
		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[%s]: CALLED!', $this->key()));
		/* DEBUG-DIE: */ die(sprintf('[%s:%d]: this->key(%d)[%s]=%s,this->valid=%d,this->registryKeys=%s', __METHOD__, __LINE__, strlen($this->key()), gettype($this->key()), $this->key(), intval($this->valid()), print_r($this->registryKeys, TRUE)));
		if (array_search($this->key(), $this->getRegistryKeys()) === 0) {
			// rewind() cannot rewind first entry!
			throw new BadMethodCallException(sprintf('this->key=%s is already first element, but method was called.', $this->key()));
		}
	}

	/**
	 * Checks wether the current entry is valid (not at the end of the list)
	 *
	 * @return	$valid	Whether the current key is still valid
	 */
	public function valid () {
		// Is the element there?
		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[%s]: CALLED!', $this->key()));
		//* DEBUG-DIE: */ die(sprintf('[%s:%d]: this->key(%d)[%s]=%s,this->registryKeys=%s', __METHOD__, __LINE__, strlen($this->key()), gettype($this->key()), $this->key(), print_r($this->registryKeys, TRUE)));
		$valid = (in_array($this->key(), $this->registryKeys['instance']) || in_array($this->key(), $this->registryKeys['generic']));

		// Return flag
		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('REGISTRY-ITERATOR[%s]: valid=%d - EXIT!', $this->key(), intval($valid)));
		return $valid;
	}

}