xref: /plugin/dw2pdf/vendor/mpdf/mpdf/src/Conversion/DecToRoman.php (revision f0f0e1f39daa7ca1a09f0394ff18d1d176fadbc4) 
1<?php
2
3namespace Mpdf\Conversion;
4
5/**
6 * @link https://github.com/JeroenDeDauw/RomanNumbers
7 * @license GNU GPL v2+
8 */
9class DecToRoman
10{
11
12	private $symbolMap;
13
14	public function __construct(array $symbolMap = [])
15	{
16		if ($symbolMap !== []) {
17			$this->symbolMap = $symbolMap;
18		} else {
19			$this->symbolMap = [['I', 'V'], ['X', 'L'], ['C', 'D'], ['M']];
20		}
21	}
22
23	public function convert($number)
24	{
25		$this->ensureNumberIsAnInteger($number);
26		$this->ensureNumberIsWithinBounds($number);
27
28		return $this->constructRomanString($number);
29	}
30
31	private function ensureNumberIsAnInteger($number)
32	{
33		if (!is_int($number)) {
34			throw new \InvalidArgumentException('Can only translate integers to roman');
35		}
36	}
37
38	private function ensureNumberIsWithinBounds($number)
39	{
40		if ($number < 1) {
41			throw new \OutOfRangeException('Numbers under one cannot be translated to roman');
42		}
43
44		if ($number > $this->getUpperBound()) {
45			throw new \OutOfBoundsException('The provided number is to big to be fully translated to roman');
46		}
47	}
48
49	public function getUpperBound()
50	{
51		$symbolGroupCount = count($this->symbolMap);
52		$valueOfOne = pow(10, $symbolGroupCount - 1);
53
54		$hasFiveSymbol = array_key_exists(1, $this->symbolMap[$symbolGroupCount - 1]);
55
56		return $valueOfOne * ($hasFiveSymbol ? 9 : 4) - 1;
57	}
58
59	private function constructRomanString($number)
60	{
61		$romanNumber = '';
62
63		for ($i = 0; $i < count($this->symbolMap); $i++) {
64			$divisor = pow(10, $i + 1);
65			$remainder = $number % $divisor;
66			$digit = $remainder / pow(10, $i);
67
68			$number -= $remainder;
69			$romanNumber = $this->formatDigit($digit, $i) . $romanNumber;
70
71			if ($number === 0) {
72				break;
73			}
74		}
75
76		return $romanNumber;
77	}
78
79	private function formatDigit($digit, $orderOfMagnitude)
80	{
81		if ($digit === 0) {
82			return '';
83		}
84
85		if ($digit === 4 || $digit === 9) {
86			return $this->formatFourOrNine($digit, $orderOfMagnitude);
87		}
88
89		$romanNumber = '';
90
91		if ($digit >= 5) {
92			$digit -= 5;
93			$romanNumber .= $this->getFiveSymbol($orderOfMagnitude);
94		}
95
96		$romanNumber .= $this->formatOneToThree($orderOfMagnitude, $digit);
97
98		return $romanNumber;
99	}
100
101	private function formatFourOrNine($digit, $orderOfMagnitude)
102	{
103		$firstSymbol = $this->getOneSymbol($orderOfMagnitude);
104		$secondSymbol = $digit === 4
105			? $this->getFiveSymbol($orderOfMagnitude)
106			: $this->getTenSymbol($orderOfMagnitude);
107
108		return $firstSymbol . $secondSymbol;
109	}
110
111	private function formatOneToThree($orderOfMagnitude, $digit)
112	{
113		return str_repeat($this->getOneSymbol($orderOfMagnitude), $digit);
114	}
115
116	private function getOneSymbol($orderOfMagnitude)
117	{
118		return $this->symbolMap[$orderOfMagnitude][0];
119	}
120
121	private function getFiveSymbol($orderOfMagnitude)
122	{
123		return $this->symbolMap[$orderOfMagnitude][1];
124	}
125
126	private function getTenSymbol($orderOfMagnitude)
127	{
128		return $this->symbolMap[$orderOfMagnitude + 1][0];
129	}
130
131}
132