<?php
/**
 * TUrlManager class file
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link https://github.com/pradosoft/prado
 * @license https://github.com/pradosoft/prado/blob/master/LICENSE
 */

namespace Prado\Web;

/**
 * TUrlManager class
 *
 * TUrlManager is the base class for managing URLs that can be
 * recognized by PRADO applications. It provides the default implementation
 * for parsing and constructing URLs.
 *
 * Derived classes may override {@link constructUrl} and {@link parseUrl}
 * to provide customized URL schemes.
 *
 * By default, {@link THttpRequest} uses TUrlManager as its URL manager.
 * If you want to use your customized URL manager, load your manager class
 * as an application module and set {@link THttpRequest::setUrlManager THttpRequest.UrlManager}
 * with the ID of your URL manager module.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 3.0.6
 */
class TUrlManager extends \Prado\TModule
{
	/**
	 * Constructs a URL that can be recognized by PRADO.
	 *
	 * This method provides the actual implementation used by {@link THttpRequest::constructUrl}.
	 * Override this method if you want to provide your own way of URL formatting.
	 * If you do so, you may also need to override {@link parseUrl} so that the URL can be properly parsed.
	 *
	 * The URL is constructed as the following format:
	 * /entryscript.php?serviceID=serviceParameter&get1=value1&...
	 * If {@link THttpRequest::setUrlFormat THttpRequest.UrlFormat} is 'Path',
	 * the following format is used instead:
	 * /entryscript.php/serviceID/serviceParameter/get1,value1/get2,value2...
	 * If {@link THttpRequest::setUrlFormat THttpRequest.UrlFormat} is 'HiddenPath',
	 * then entryscript.php will be hidden and the following format is used instead:
	 * /serviceID/serviceParameter/get1,value1/get2,value2...
	 * In order to use the 'HiddenPath' format you need proper url rewrite configuration;
	 * here's an example for Apache's .htaccess:
	 * <cdde>
	 * Options +FollowSymLinks
	 * RewriteEngine On
	 * RewriteCond %{REQUEST_FILENAME} !-d
	 * RewriteCond %{REQUEST_FILENAME} !-f
	 * RewriteRule ^(.*)$ index.php/$1 [L]
	 * </code>
	 * @param string $serviceID service ID
	 * @param string $serviceParam service parameter
	 * @param array $getItems GET parameters, null if not provided
	 * @param bool $encodeAmpersand whether to encode the ampersand in URL
	 * @param bool $encodeGetItems whether to encode the GET parameters (their names and values)
	 * @return string URL
	 * @see parseUrl
	 */
	public function constructUrl($serviceID, $serviceParam, $getItems, $encodeAmpersand, $encodeGetItems)
	{
		$url = $serviceID . '=' . urlencode($serviceParam);
		$amp = $encodeAmpersand ? '&amp;' : '&';
		$request = $this->getRequest();
		if (is_array($getItems) || $getItems instanceof \Traversable) {
			if ($encodeGetItems) {
				foreach ($getItems as $name => $value) {
					if (is_array($value)) {
						$name = urlencode($name . '[]');
						foreach ($value as $v) {
							$url .= $amp . $name . '=' . urlencode($v);
						}
					} else {
						$url .= $amp . urlencode($name) . '=' . urlencode($value);
					}
				}
			} else {
				foreach ($getItems as $name => $value) {
					if (is_array($value)) {
						foreach ($value as $v) {
							$url .= $amp . $name . '[]=' . $v;
						}
					} else {
						$url .= $amp . $name . '=' . $value;
					}
				}
			}
		}

		switch ($request->getUrlFormat()) {
			case THttpRequestUrlFormat::Path:
				return $request->getApplicationUrl() . '/' . strtr($url, [$amp => '/', '?' => '/', '=' => $request->getUrlParamSeparator()]);
			case THttpRequestUrlFormat::HiddenPath:
				return rtrim(dirname($request->getApplicationUrl()), '/') . '/' . strtr($url, [$amp => '/', '?' => '/', '=' => $request->getUrlParamSeparator()]);
			default:
				return $request->getApplicationUrl() . '?' . $url;
		}
	}

	/**
	 * Parses the request URL and returns an array of input parameters.
	 * This method is automatically invoked by {@link THttpRequest} when
	 * handling a user request.
	 *
	 * In general, this method should parse the path info part of the requesting URL
	 * and generate an array of name-value pairs according to some scheme.
	 * The current implementation deals with both 'Get' and 'Path' URL formats.
	 *
	 * You may override this method to support customized URL format.
	 * @return array list of input parameters, indexed by parameter names
	 * @see constructUrl
	 */
	public function parseUrl()
	{
		$request = $this->getRequest();
		$pathInfo = trim($request->getPathInfo(), '/');
		if (($request->getUrlFormat() === THttpRequestUrlFormat::Path ||
			$request->getUrlFormat() === THttpRequestUrlFormat::HiddenPath) &&
			$pathInfo !== '') {
			$separator = $request->getUrlParamSeparator();
			$paths = explode('/', $pathInfo);
			$getVariables = [];
			foreach ($paths as $path) {
				if (($path = trim($path)) !== '') {
					if (($pos = strpos($path, $separator)) !== false) {
						$name = substr($path, 0, $pos);
						$value = substr($path, $pos + 1);
						if (($pos = strpos($name, '[]')) !== false) {
							$getVariables[substr($name, 0, $pos)][] = $value;
						} else {
							$getVariables[$name] = $value;
						}
					} else {
						$getVariables[$path] = '';
					}
				}
			}
			return $getVariables;
		} else {
			return [];
		}
	}
}