<?php
/**
 * Orange Management
 *
 * PHP Version 7.0
 *
 * @category   TBD
 * @package    TBD
 * @author     OMS Development Team <dev@oms.com>
 * @author     Dennis Eichhorn <d.eichhorn@oms.com>
 * @copyright  2013 Dennis Eichhorn
 * @license    OMS License 1.0
 * @version    1.0.0
 * @link       http://orange-management.com
 */
namespace phpOMS\Utils;

/**
 * Multimap utils.
 *
 * @category   Framework
 * @package    Utils
 * @author     OMS Development Team <dev@oms.com>
 * @author     Dennis Eichhorn <d.eichhorn@oms.com>
 * @license    OMS License 1.0
 * @link       http://orange-management.com
 * @since      1.0.0
 */
class MultiMap implements \Countable
{

    /**
     * Stored values.
     *
     * @var array
     * @since 1.0.0
     */
    private $values = [];

    /**
     * Associated keys for values.
     *
     * @var array
     * @since 1.0.0
     */
    private $keys = [];

    /**
     * Constructor.
     *
     * @since  1.0.0
     * @author Dennis Eichhorn <d.eichhorn@oms.com>
     */
    public function __construct()
    {
    }

    /**
     * Add data.
     *
     * @param array $keys      Keys for value
     * @param mixed $value     Value to store
     * @param \bool $overwrite Add value if key exists
     *
     * @return bool
     *
     * @since  1.0.0
     * @author Dennis Eichhorn
     */
    public function add(array $keys, $value, \bool $overwrite = true) : \bool
    {
        $id       = count($this->values);
        $inserted = false;

        foreach ($keys as $key) {
            if ($overwrite || !isset($this->keys[$key])) {
                $id               = $this->keys[$key] ?? $id;
                $this->keys[$key] = $id;

                $inserted = true;
            }
        }

        if ($inserted) {
            $this->values[$id] = $value;
        }

        // todo: is this really required???? - i don't think so!
        $this->garbageCollect();

        return $inserted;
    }

    /**
     * Garbage collect unreferenced values/keys
     *
     * @since  1.0.0
     * @author Dennis Eichhorn
     */
    private function garbageCollect()
    {
        foreach ($this->keys as $key => $keyValue) {
            if (!isset($this->values[$keyValue])) {
                unset($this->keys[$key]);
            }
        }

        foreach ($this->values as $valueKey => $value) {
            if (!in_array($valueKey, $this->keys)) {
                unset($this->values[$valueKey]);
            }
        }
    }

    /**
     * Get data.
     *
     * @param mixed $key Key used to identify value
     *
     * @return mixed
     *
     * @since  1.0.0
     * @author Dennis Eichhorn
     */
    public function get($key)
    {
        return isset($this->keys[$key]) ? $this->values[$this->keys[$key]] ?? null : null;
    }

    /**
     * Set existing key with data.
     *
     * @param mixed $key   Key used to identify value
     * @param mixed $value Value to store
     *
     * @return \bool
     *
     * @since  1.0.0
     * @author Dennis Eichhorn
     */
    public function set($key, $value) : \bool
    {
        if (isset($this->keys[$key])) {
            $this->values[$this->keys[$key]] = $value;

            return true;
        }

        return false;
    }

    /**
     * Remove value and all sibling keys based on key.
     *
     * @param mixed $key Key used to identify value
     *
     * @return \bool
     *
     * @since  1.0.0
     * @author Dennis Eichhorn
     */
    public function remove($key) : \bool
    {
        if (isset($this->keys[$key])) {
            $id = $this->keys[$key];

            unset($this->values[$id]);

            $this->garbageCollect();

            return true;
        }

        return false;
    }

    /**
     * Remap key to a different value.
     *
     * Both keys need to exist in the multimap.
     *
     * @param mixed $old Old key
     * @param mixed $new New key
     *
     * @return \bool
     *
     * @since  1.0.0
     * @author Dennis Eichhorn
     */
    public function remap($old, $new) : \bool
    {
        if (isset($this->keys[$old]) && isset($this->keys[$new])) {
            $this->keys[$old] = $this->keys[$new];

            $this->garbageCollect();

            return true;
        }

        return false;
    }

    /**
     * Remove key.
     *
     * This only removes the value if no other key exists for this value.
     *
     * @param mixed $key Key used to identify value
     *
     * @return \bool
     *
     * @since  1.0.0
     * @author Dennis Eichhorn
     */
    public function removeKey($key) : \bool
    {
        if (isset($this->keys[$key])) {
            unset($this->keys[$key]);

            $this->garbageCollect();

            return true;
        }

        return false;
    }

    /**
     * Get all sibling keys.
     *
     * @param mixed $key Key to find siblings for
     *
     * @return array
     *
     * @since  1.0.0
     * @author Dennis Eichhorn
     */
    public function getSiblings($key) : array
    {
        $siblings = [];

        if (isset($this->keys[$key])) {
            $id = $this->keys[$key];

            foreach ($this->keys as $found => $value) {
                if ($value === $id && $found !== $key) {
                    $siblings[] = $found;
                }
            }
        }

        return $siblings;
    }

    /**
     * Get all keys.
     *
     * @return array
     *
     * @since  1.0.0
     * @author Dennis Eichhorn
     */
    public function keys() : array
    {
        return $this->keys;
    }

    /**
     * Get all values.
     *
     * @return array
     *
     * @since  1.0.0
     * @author Dennis Eichhorn
     */
    public function values() : array
    {
        return $this->values;
    }

    /**
     * Count values.
     *
     * @return \int
     *
     * @since  1.0.0
     * @author Dennis Eichhorn
     */
    public function count() : \int
    {
        return count($this->values);
    }
}