<?php

namespace wellrested;

/**
 * A Request instance contains information relating to the current HTTP request
 * a client sent to the server.
 *
 * Since the main use for this class is to provide info about the one specific
 * request, the class exposes the static getRequest() method for obtaining a
 * singleton Request instance.
 *
 * @property string body       Entity body of the request
 * @property array headers     Associative array of HTTP headers
 * @property string method     HTTP method or verb for the request
 * @property string path       Path component of the URI for the request
 * @property string pathParts  Fragments of the path, delimited by slashes
 * @property array query       Associative array of query parameters
 *
 * @package WellRESTed
 */
class Request {

    /**
     * Entity body of the request
     *
     * @var string
     */
    protected $body;

    /**
     * Associative array of HTTP headers
     *
     * @var array
     */
    protected $headers;

    /**
     * HTTP method or verb for the request
     *
     * @var string
     */
    protected $method;

    /**
     * Path component of the URI for the request
     *
     * @var string
     */
    protected $path;

    /**
     * Array of fragments of the path, delimited by slashes
     *
     * @var array
     */
    protected $pathParts;

    /**
     * Associative array of query parameters
     *
     * @var array
     */
    protected $query;

    /**
     * The full URI of the request
     *
     * @var string
     */
    protected $uri;

    /**
     * Singleton instance derived from reading info from Apache.
     *
     * @var Request
     * @static
     */
    static protected $theRequest;


    // -------------------------------------------------------------------------
    // !Accessors

    /**
     * @param string $name
     * @return array|string
     * @throws \Exception
     */
    public function __get($name) {

        switch ($name) {
            case 'body':
                return $this->getBody();
            case 'headers':
                return $this->getHeaders();
            case 'method':
                return $this->getMethod();
            case 'path':
                return $this->getPath();
            case 'pathParts':
                return $this->getPathParts();
            case 'query':
                return $this->getQuery();
            case 'uri':
                return $this->getUri();
            default:
                throw new \Exception('Property ' . $name . ' does not exist.');
        }

    } // __get()

    /**
     * @param string $name
     * @param mixed $value
     * @throws \Exception
     */
    public function __set($name, $value) {

        switch ($name) {
            case 'path':
                $this->setPath($value);
                return;
            case 'query':
                $this->setQuery($value);
                return;
            case 'uri':
                $this->setUri($value);
                return;
            default:
                throw new \Exception('Property ' . $name . 'does not exist.');
        }

    }

    public function getBody() {
        return $this->body;
    }

    public function getHeaders() {
        return $this->headers;
    }

    public function getMethod() {
        return $this->method;
    }

    public function getPath() {
        return $this->path;
    }

    public function getPathParts() {
        return $this->pathParts;
    }

    public function getQuery() {
        return $this->query;
    }

    public function getUri() {
        return $this->uri;
    }

    /**
     * Set the method for the request.
     *
     * @param string $method
     * @throws \InvalidArgumentException
     */
    public function setMethod($method) {

        if (!is_string($method)) {
            throw new \InvalidArgumentException('method must be a string.');
        }

        $this->method = $method;
    }

    /**
     * Set the path and pathParts members.
     *
     * @param string $path
     */
    public function setPath($path) {

        $this->path = $path;
        $this->pathParts = explode('/', substr($path, 1));

    }

    /**
     * @param string|array $query
     * @throws \InvalidArgumentException
     */
    public function setQuery($query) {

        if (is_string($query)) {
            $qs = $query;
            parse_str($qs, $query);
        }

        if (is_array($query)) {
            $this->query = $query;
        } else {
            throw new \InvalidArgumentException('Unable to parse query string.');
        }

    }

    /**
     * Set the URI for the Request. This method also sets the path, pathParts,
     * and query.
     *
     * @param string $uri
     */
    public function setUri($uri) {

        /*
         * TODO, eventually do all of these:
        http
        host
        port
        user
        pass
        path
        query - after the question mark ?
        fragment - after the hashmark #
        */

        $this->uri = $uri;
        $parsed = parse_url($uri);

        $path = isset($parsed['path']) ? $parsed['path'] : '';
        $this->setPath($path);

        $query = isset($parsed['query']) ? $parsed['query'] : '';
        $this->setQuery($query);

    }


    // -------------------------------------------------------------------------

    /**
     * Set instance members based on the HTTP request sent to the server.
     */
    public function readHttpRequest() {

        $this->body = file_get_contents("php://input");
        $this->headers = apache_request_headers();
        $this->method = $_SERVER['REQUEST_METHOD'];
        $this->setUri($_SERVER['REQUEST_URI']);

    } // readHttpRequest()

    /**
     * Return a reference to the singleton instance of the Request derived
     * from the server's information about the request sent to the script.
     *
     * @return Request
     * @static
     */
    static public function getRequest() {

        if (!isset(self::$theRequest)) {

            $klass = __CLASS__;
            $request = new $klass();
            $request->readHttpRequest();

            self::$theRequest = $request;

        }

        return self::$theRequest;

    } // getRequest()

} // Request

?>