1<?php
2/*
3** Zabbix
4** Copyright (C) 2001-2021 Zabbix SIA
5**
6** This program is free software; you can redistribute it and/or modify
7** it under the terms of the GNU General Public License as published by
8** the Free Software Foundation; either version 2 of the License, or
9** (at your option) any later version.
10**
11** This program is distributed in the hope that it will be useful,
12** but WITHOUT ANY WARRANTY; without even the implied warranty of
13** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14** GNU General Public License for more details.
15**
16** You should have received a copy of the GNU General Public License
17** along with this program; if not, write to the Free Software
18** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
19**/
20
21
22/**
23 * A helper class for storing relations between objects, and mapping related objects.
24 */
25class CRelationMap {
26
27	/**
28	 * A hash with IDs of base objects as keys and hashes of related object IDs as values.
29	 *
30	 * @var array
31	 */
32	protected $map = [];
33
34	/**
35	 * A hash of related object IDs.
36	 *
37	 * @var array
38	 */
39	protected $relatedIds = [];
40
41	/**
42	 * Adds a new relation.
43	 *
44	 * @param string $baseObjectId
45	 * @param string $relatedObjectId
46	 */
47	public function addRelation($baseObjectId, $relatedObjectId) {
48		$this->map[$baseObjectId][$relatedObjectId] = $relatedObjectId;
49		$this->relatedIds[$relatedObjectId] = $relatedObjectId;
50	}
51
52	/**
53	 * Returns the IDs of all related objects.
54	 *
55	 * @return array
56	 */
57	public function getRelatedIds() {
58		return array_values($this->relatedIds);
59	}
60
61	/**
62	 * Maps multiple related objects to the base objects and adds them under the $name property. Each base object will
63	 * have an array of related objects.
64	 *
65	 * @param array  $baseObjects		a hash of base objects with IDs as keys
66	 * @param array  $relatedObjects	a hash of related objects with IDs as keys
67	 * @param string $name				the name of the property under which the related objects will be added
68	 * @param int    $limit				maximum number of related objects for each base objects
69	 *
70	 * @return array
71	 */
72	public function mapMany(array $baseObjects, array $relatedObjects, $name, $limit = null) {
73		foreach ($baseObjects as $baseObjectId => &$baseObject) {
74			$baseObject[$name] = [];
75
76			if (isset($this->map[$baseObjectId]) && $this->map[$baseObjectId]) {
77				$matchingRelatedObjects = array_values(array_intersect_key($relatedObjects, $this->map[$baseObjectId]));
78
79				if ($matchingRelatedObjects) {
80					if ($limit) {
81						$matchingRelatedObjects = array_slice($matchingRelatedObjects, 0, $limit);
82					}
83
84					$baseObject[$name] = $matchingRelatedObjects;
85				}
86			}
87		}
88		unset($baseObject);
89
90		return $baseObjects;
91	}
92
93	/**
94	 * Maps multiple related objects to the base objects and adds them under the $name property.
95	 * Each base object will have only one related object.
96	 *
97	 * @param array  $baseObjects		a hash of base objects with IDs as keys
98	 * @param array  $relatedObjects	a hash of related objects with IDs as keys
99	 * @param string $name				the name of the property under which the related object will be added
100	 *
101	 * @return array
102	 */
103	public function mapOne(array $baseObjects, array $relatedObjects, $name) {
104		foreach ($baseObjects as $baseObjectId => &$baseObject) {
105			$matchingRelatedObject = [];
106
107			if (isset($this->map[$baseObjectId])) {
108				$matchingRelatedId = reset($this->map[$baseObjectId]);
109
110				if (isset($relatedObjects[$matchingRelatedId])) {
111					$matchingRelatedObject = $relatedObjects[$matchingRelatedId];
112				}
113			}
114
115			$baseObject[$name] = $matchingRelatedObject;
116		}
117		unset($baseObject);
118
119		return $baseObjects;
120	}
121}
122