function testMimeTypeMatch()
 {
     $this->assertEquals('text/html', mimeTypeMatch('text/html', array('application/xhtml+xml' => 1.0, 'text/html' => 0.7, 'text/plain' => 0.3)));
     $this->assertEquals('text/*', mimeTypeMatch('text/html', array('image/*' => 1.0, 'text/*' => 0.5)));
     $this->assertEquals('*/*', mimeTypeMatch('text/html', array('*/*' => 1.0)));
     $this->assertNull(mimeTypeMatch('text/html', array('image/png' => 1.0, 'image/svg+xml' => 0.5)));
 }

/**
 * Returns the 'best' match between a client's requested internet media types
 * and the server's list of available types. Each list should be an associative
 * array of type to preference (preference is a float between 0.0 and 1.0).
 * Wildcards in the types are acceptable.
 *
 * @param array $cprefs Client's acceptable type list
 * @param array $sprefs Server's offered types
 * @return string
 *
 * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
 * XXX: generalize to negotiate other stuff
 */
function wfNegotiateType($cprefs, $sprefs)
{
    $combine = array();
    foreach (array_keys($sprefs) as $type) {
        $parts = explode('/', $type);
        if ($parts[1] != '*') {
            $ckey = mimeTypeMatch($type, $cprefs);
            if ($ckey) {
                $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
            }
        }
    }
    foreach (array_keys($cprefs) as $type) {
        $parts = explode('/', $type);
        if ($parts[1] != '*' && !array_key_exists($type, $sprefs)) {
            $skey = mimeTypeMatch($type, $sprefs);
            if ($skey) {
                $combine[$type] = $sprefs[$skey] * $cprefs[$type];
            }
        }
    }
    $bestq = 0;
    $besttype = null;
    foreach (array_keys($combine) as $type) {
        if ($combine[$type] > $bestq) {
            $besttype = $type;
            $bestq = $combine[$type];
        }
    }
    return $besttype;
}