Mime/HeaderBag.php
<?php

namespace Alex\MailCatcher\Mime;

/**
 * Ported from Symfony\Component\HttpFoundation\HeaderBag
 */
class HeaderBag implements \IteratorAggregate, \Countable
{
    protected $headers;

    /**
     * Constructor.
     *
     * @param array $headers An array of HTTP headers
     */
    public function __construct(array $headers = array())
    {
        $this->headers = array();
        foreach ($headers as $key => $values) {
            $this->set($key, $values);
        }
    }

    /**
     * Returns the headers.
     *
     * @return array An array of headers
     */
    public function all()
    {
        return $this->headers;
    }

    /**
     * Returns the parameter keys.
     *
     * @return array An array of parameter keys
     */
    public function keys()
    {
        return array_keys($this->headers);
    }

    /**
     * Replaces the current HTTP headers by a new set.
     *
     * @param array $headers An array of HTTP headers
     */
    public function replace(array $headers = array())
    {
        $this->headers = array();
        $this->add($headers);
    }

    /**
     * Adds new headers the current HTTP headers set.
     *
     * @param array $headers An array of HTTP headers
     */
    public function add(array $headers)
    {
        foreach ($headers as $key => $values) {
            $this->set($key, $values);
        }
    }

    /**
     * Returns a header value by name.
     *
     * @param string  $key     The header name
     * @param mixed   $default The default value
     * @param Boolean $first   Whether to return the first value or all header values
     *
     * @return string|array The first header value if $first is true, an array of values otherwise
     */
    public function get($key, $default = null, $first = true)
    {
        $key = strtr(strtolower($key), '_', '-');

        if (!array_key_exists($key, $this->headers)) {
            if (null === $default) {
                return $first ? null : array();
            }

            return $first ? $default : array($default);
        }

        if ($first) {
            return count($this->headers[$key]) ? $this->headers[$key][0] : $default;
        }

        return $this->headers[$key];
    }

    /**
     * Sets a header by name.
     *
     * @param string       $key     The key
     * @param string|array $values  The value or an array of values
     * @param Boolean      $replace Whether to replace the actual value or not (true by default)
     */
    public function set($key, $values, $replace = true)
    {
        $key = strtr(strtolower($key), '_', '-');

        $values = array_values((array) $values);

        if (true === $replace || !isset($this->headers[$key])) {
            $this->headers[$key] = $values;
        } else {
            $this->headers[$key] = array_merge($this->headers[$key], $values);
        }

        if ('cache-control' === $key) {
            $this->cacheControl = $this->parseCacheControl($values[0]);
        }
    }

    /**
     * Returns true if the HTTP header is defined.
     *
     * @param string $key The HTTP header
     *
     * @return Boolean true if the parameter exists, false otherwise
     */
    public function has($key)
    {
        return array_key_exists(strtr(strtolower($key), '_', '-'), $this->headers);
    }

    /**
     * Returns true if the given HTTP header contains the given value.
     *
     * @param string $key   The HTTP header name
     * @param string $value The HTTP value
     *
     * @return Boolean true if the value is contained in the header, false otherwise
     */
    public function contains($key, $value)
    {
        return in_array($value, $this->get($key, null, false));
    }

    /**
     * Removes a header.
     *
     * @param string $key The HTTP header name
     */
    public function remove($key)
    {
        $key = strtr(strtolower($key), '_', '-');

        unset($this->headers[$key]);

        if ('cache-control' === $key) {
            $this->cacheControl = array();
        }
    }

    /**
     * Returns the HTTP header value converted to a date.
     *
     * @param string    $key     The parameter key
     * @param \DateTime $default The default value
     *
     * @return null|\DateTime The parsed DateTime or the default value if the header does not exist
     *
     * @throws \RuntimeException When the HTTP header is not parseable
     */
    public function getDate($key, \DateTime $default = null)
    {
        if (null === $value = $this->get($key)) {
            return $default;
        }

        if (false === $date = \DateTime::createFromFormat(DATE_RFC2822, $value)) {
            throw new \RuntimeException(sprintf('The %s HTTP header is not parseable (%s).', $key, $value));
        }

        return $date;
    }

    /**
     * Returns an iterator for headers.
     *
     * @return \ArrayIterator An \ArrayIterator instance
     */
    #[\ReturnTypeWillChange]
    public function getIterator()
    {
        return new \ArrayIterator($this->headers);
    }

    /**
     * Returns the number of headers.
     *
     * @return int The number of headers
     */
    #[\ReturnTypeWillChange]
    public function count()
    {
        return count($this->headers);
    }
}
