1<?php
  2/**
  3 * Case-insensitive dictionary, suitable for HTTP headers
  4 *
  5 * @package Requests
  6 */
  7
  8namespace WpOrg\Requests\Response;
  9
 10use WpOrg\Requests\Exception;
 11use WpOrg\Requests\Exception\InvalidArgument;
 12use WpOrg\Requests\Utility\CaseInsensitiveDictionary;
 13use WpOrg\Requests\Utility\FilteredIterator;
 14
 15/**
 16 * Case-insensitive dictionary, suitable for HTTP headers
 17 *
 18 * @package Requests
 19 */
 20class Headers extends CaseInsensitiveDictionary {
 21	/**
 22	 * Get the given header
 23	 *
 24	 * Unlike {@see \WpOrg\Requests\Response\Headers::getValues()}, this returns a string. If there are
 25	 * multiple values, it concatenates them with a comma as per RFC2616.
 26	 *
 27	 * Avoid using this where commas may be used unquoted in values, such as
 28	 * Set-Cookie headers.
 29	 *
 30	 * @param string $offset Name of the header to retrieve.
 31	 * @return string|null Header value
 32	 */
 33	public function offsetGet($offset) {
 34		if (is_string($offset)) {
 35			$offset = strtolower($offset);
 36		}
 37
 38		if (!isset($this->data[$offset])) {
 39			return null;
 40		}
 41
 42		return $this->flatten($this->data[$offset]);
 43	}
 44
 45	/**
 46	 * Set the given item
 47	 *
 48	 * @param string $offset Item name
 49	 * @param string $value Item value
 50	 *
 51	 * @throws \WpOrg\Requests\Exception On attempting to use dictionary as list (`invalidset`)
 52	 */
 53	public function offsetSet($offset, $value) {
 54		if ($offset === null) {
 55			throw new Exception('Object is a dictionary, not a list', 'invalidset');
 56		}
 57
 58		if (is_string($offset)) {
 59			$offset = strtolower($offset);
 60		}
 61
 62		if (!isset($this->data[$offset])) {
 63			$this->data[$offset] = [];
 64		}
 65
 66		$this->data[$offset][] = $value;
 67	}
 68
 69	/**
 70	 * Get all values for a given header
 71	 *
 72	 * @param string $offset Name of the header to retrieve.
 73	 * @return array|null Header values
 74	 *
 75	 * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed argument is not valid as an array key.
 76	 */
 77	public function getValues($offset) {
 78		if (!is_string($offset) && !is_int($offset)) {
 79			throw InvalidArgument::create(1, '$offset', 'string|int', gettype($offset));
 80		}
 81
 82		if (is_string($offset)) {
 83			$offset = strtolower($offset);
 84		}
 85
 86		if (!isset($this->data[$offset])) {
 87			return null;
 88		}
 89
 90		return $this->data[$offset];
 91	}
 92
 93	/**
 94	 * Flattens a value into a string
 95	 *
 96	 * Converts an array into a string by imploding values with a comma, as per
 97	 * RFC2616's rules for folding headers.
 98	 *
 99	 * @param string|array $value Value to flatten
100	 * @return string Flattened value
101	 *
102	 * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed argument is not a string or an array.
103	 */
104	public function flatten($value) {
105		if (is_string($value)) {
106			return $value;
107		}
108
109		if (is_array($value)) {
110			return implode(',', $value);
111		}
112
113		throw InvalidArgument::create(1, '$value', 'string|array', gettype($value));
114	}
115
116	/**
117	 * Get an iterator for the data
118	 *
119	 * Converts the internally stored values to a comma-separated string if there is more
120	 * than one value for a key.
121	 *
122	 * @return \ArrayIterator
123	 */
124	public function getIterator() {
125		return new FilteredIterator($this->data, [$this, 'flatten']);
126	}
127}
128