<?php
/**
 * THttpResponse class
 *
 * @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;

use Prado\Exceptions\TInvalidDataValueException;
use Prado\Exceptions\TInvalidOperationException;
use Prado\Prado;
use Prado\TPropertyValue;

/**
 * THttpResponse class
 *
 * THttpResponse implements the mechanism for sending output to client users.
 *
 * To output a string to client, use {@link write()}. By default, the output is
 * buffered until {@link flush()} is called or the application ends. The output in
 * the buffer can also be cleaned by {@link clear()}. To disable output buffering,
 * set BufferOutput property to false.
 *
 * To send cookies to client, use {@link getCookies()}.
 * To redirect client browser to a new URL, use {@link redirect()}.
 * To send a file to client, use {@link writeFile()}.
 *
 * By default, THttpResponse is registered with {@link TApplication} as the
 * response module. It can be accessed via {@link TApplication::getResponse()}.
 *
 * THttpResponse may be configured in application configuration file as follows
 *
 * <module id="response" class="Prado\Web\THttpResponse" CacheExpire="20" CacheControl="nocache" BufferOutput="true" />
 *
 * where {@link getCacheExpire CacheExpire}, {@link getCacheControl CacheControl}
 * and {@link getBufferOutput BufferOutput} are optional properties of THttpResponse.
 *
 * THttpResponse sends charset header if either {@link setCharset() Charset}
 * or {@link TGlobalization::setCharset() TGlobalization.Charset} is set.
 *
 * Since 3.1.2, HTTP status code can be set with the {@link setStatusCode StatusCode} property.
 *
 * Note: Some HTTP Status codes can require additional header or body information. So, if you use {@link setStatusCode StatusCode}
 * in your application, be sure to add theses informations.
 * E.g : to make an http authentication :
 * <code>
 *  public function clickAuth ($sender, $param)
 *  {
 *     $response=$this->getResponse();
 *     $response->setStatusCode(401);
 *     $response->appendHeader('WWW-Authenticate: Basic realm="Test"');
 *  }
 * </code>
 *
 * This event handler will sent the 401 status code (Unauthorized) to the browser, with the WWW-Authenticate header field. This
 * will force the browser to ask for a username and a password.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 3.0
 */
class THttpResponse extends \Prado\TModule implements \Prado\IO\ITextWriter
{
	public const DEFAULT_CONTENTTYPE = 'text/html';
	public const DEFAULT_CHARSET = 'UTF-8';

	/**
	 * @var array<int, string> The differents defined status code by RFC 2616 {@link http://www.faqs.org/rfcs/rfc2616}
	 */
	private static $HTTP_STATUS_CODES = [
		100 => 'Continue', 101 => 'Switching Protocols',
		200 => 'OK', 201 => 'Created', 202 => 'Accepted', 203 => 'Non-Authoritative Information', 204 => 'No Content', 205 => 'Reset Content', 206 => 'Partial Content',
		300 => 'Multiple Choices', 301 => 'Moved Permanently', 302 => 'Found', 303 => 'See Other', 304 => 'Not Modified', 305 => 'Use Proxy', 307 => 'Temporary Redirect',
		400 => 'Bad Request', 401 => 'Unauthorized', 402 => 'Payment Required', 403 => 'Forbidden', 404 => 'Not Found', 405 => 'Method Not Allowed', 406 => 'Not Acceptable', 407 => 'Proxy Authentication Required', 408 => 'Request Time-out', 409 => 'Conflict', 410 => 'Gone', 411 => 'Length Required', 412 => 'Precondition Failed', 413 => 'Request Entity Too Large', 414 => 'Request-URI Too Large', 415 => 'Unsupported Media Type', 416 => 'Requested range not satisfiable', 417 => 'Expectation Failed',
		500 => 'Internal Server Error', 501 => 'Not Implemented', 502 => 'Bad Gateway', 503 => 'Service Unavailable', 504 => 'Gateway Time-out', 505 => 'HTTP Version not supported'
	];

	/**
	 * @var bool whether to buffer output
	 */
	private $_bufferOutput = true;
	/**
	 * @var bool if the application is initialized
	 */
	private $_initialized = false;
	/**
	 * @var THttpCookieCollection list of cookies to return
	 */
	private $_cookies;
	/**
	 * @var int response status code
	 */
	private $_status = 200;
	/**
	 * @var string reason correspond to status code
	 */
	private $_reason = 'OK';
	/**
	 * @var string HTML writer type
	 */
	private $_htmlWriterType = '\Prado\Web\UI\THtmlWriter';
	/**
	 * @var string content type
	 */
	private $_contentType;
	/**
	 * @var bool|string character set, e.g. UTF-8 or false if no character set should be send to client
	 */
	private $_charset = '';
	/**
	 * @var THttpResponseAdapter adapter.
	 */
	private $_adapter;
	/**
	 * @var bool whether http response header has been sent
	 */
	private $_httpHeaderSent;
	/**
	 * @var bool whether content-type header has been sent
	 */
	private $_contentTypeHeaderSent;

	/**
	 * Destructor.
	 * Flushes any existing content in buffer.
	 */
	public function __destruct()
	{
		//if($this->_bufferOutput)
		//	@ob_end_flush();
		parent::__destruct();
	}

	/**
	 * @param THttpResponseAdapter $adapter response adapter
	 */
	public function setAdapter(THttpResponseAdapter $adapter)
	{
		$this->_adapter = $adapter;
	}

	/**
	 * @return THttpResponseAdapter response adapter, null if not exist.
	 */
	public function getAdapter()
	{
		return $this->_adapter;
	}

	/**
	 * @return bool true if adapter exists, false otherwise.
	 */
	public function getHasAdapter()
	{
		return $this->_adapter !== null;
	}

	/**
	 * Initializes the module.
	 * This method is required by IModule and is invoked by application.
	 * It starts output buffer if it is enabled.
	 * @param \Prado\Xml\TXmlElement $config module configuration
	 */
	public function init($config)
	{
		if ($this->_bufferOutput) {
			ob_start();
		}
		$this->_initialized = true;
		$this->getApplication()->setResponse($this);
		parent::init($config);
	}

	/**
	 * @return int time-to-live for cached session pages in minutes, this has no effect for nocache limiter. Defaults to 180.
	 */
	public function getCacheExpire()
	{
		return session_cache_expire();
	}

	/**
	 * @param int $value time-to-live for cached session pages in minutes, this has no effect for nocache limiter.
	 */
	public function setCacheExpire($value)
	{
		session_cache_expire(TPropertyValue::ensureInteger($value));
	}

	/**
	 * @return string cache control method to use for session pages
	 */
	public function getCacheControl()
	{
		return session_cache_limiter();
	}

	/**
	 * @param string $value cache control method to use for session pages. Valid values
	 *               include none/nocache/private/private_no_expire/public
	 */
	public function setCacheControl($value)
	{
		session_cache_limiter(TPropertyValue::ensureEnum($value, ['none', 'nocache', 'private', 'private_no_expire', 'public']));
	}

	/**
	 * @param string $type content type, default is text/html
	 */
	public function setContentType($type)
	{
		if ($this->_contentTypeHeaderSent) {
			throw new \Exception('Unable to alter content-type as it has been already sent');
		}
		$this->_contentType = $type;
	}

	/**
	 * @return string current content type
	 */
	public function getContentType()
	{
		return $this->_contentType;
	}

	/**
	 * @return bool|string output charset.
	 */
	public function getCharset()
	{
		return $this->_charset;
	}

	/**
	 * @param bool|string $charset output charset.
	 */
	public function setCharset($charset)
	{
		$this->_charset = (strToLower($charset) === 'false') ? false : (string) $charset;
	}

	/**
	 * @return bool whether to enable output buffer
	 */
	public function getBufferOutput()
	{
		return $this->_bufferOutput;
	}

	/**
	 * @param bool $value whether to enable output buffer
	 * @throws TInvalidOperationException if session is started already
	 */
	public function setBufferOutput($value)
	{
		if ($this->_initialized) {
			throw new TInvalidOperationException('httpresponse_bufferoutput_unchangeable');
		} else {
			$this->_bufferOutput = TPropertyValue::ensureBoolean($value);
		}
	}

	/**
	 * @return int HTTP status code, defaults to 200
	 */
	public function getStatusCode()
	{
		return $this->_status;
	}

	/**
	 * Set the HTTP status code for the response.
	 * The code and its reason will be sent to client using the currently requested http protocol version (see {@link THttpRequest::getHttpProtocolVersion})
	 * Keep in mind that HTTP/1.0 clients might not understand all status codes from HTTP/1.1
	 *
	 * @param int $status HTTP status code
	 * @param null|string $reason HTTP status reason, defaults to standard HTTP reasons
	 */
	public function setStatusCode($status, $reason = null)
	{
		if ($this->_httpHeaderSent) {
			throw new \Exception('Unable to alter response as HTTP header already sent');
		}
		$status = TPropertyValue::ensureInteger($status);
		if (isset(self::$HTTP_STATUS_CODES[$status])) {
			$this->_reason = self::$HTTP_STATUS_CODES[$status];
		} else {
			if ($reason === null || $reason === '') {
				throw new TInvalidDataValueException("response_status_reason_missing");
			}
			$reason = TPropertyValue::ensureString($reason);
			if (strpos($reason, "\r") != false || strpos($reason, "\n") != false) {
				throw new TInvalidDataValueException("response_status_reason_barchars");
			}
			$this->_reason = $reason;
		}
		$this->_status = $status;
	}

	/**
	 * @return string HTTP status reason
	 */
	public function getStatusReason()
	{
		return $this->_reason;
	}

	/**
	 * @return THttpCookieCollection list of output cookies
	 */
	public function getCookies()
	{
		if ($this->_cookies === null) {
			$this->_cookies = new THttpCookieCollection($this);
		}
		return $this->_cookies;
	}

	/**
	 * Outputs a string.
	 * It may not be sent back to user immediately if output buffer is enabled.
	 * @param string $str string to be output
	 */
	public function write($str)
	{
		// when starting output make sure we send the headers first
		if (!$this->_bufferOutput && !$this->_httpHeaderSent) {
			$this->ensureHeadersSent();
		}
		echo $str;
	}

	/**
	 * Sends a file back to user.
	 * Make sure not to output anything else after calling this method.
	 * @param string $fileName file name
	 * @param null|string $content content to be set. If null, the content will be read from the server file pointed to by $fileName.
	 * @param null|string $mimeType mime type of the content.
	 * @param null|array $headers list of headers to be sent. Each array element represents a header string (e.g. 'Content-Type: text/plain').
	 * @param null|bool $forceDownload force download of file, even if browser able to display inline. Defaults to 'true'.
	 * @param null|string $clientFileName force a specific file name on client side. Defaults to 'null' means auto-detect.
	 * @param null|int $fileSize size of file or content in bytes if already known. Defaults to 'null' means auto-detect.
	 * @throws TInvalidDataValueException if the file cannot be found
	 */
	public function writeFile($fileName, $content = null, $mimeType = null, $headers = null, $forceDownload = true, $clientFileName = null, $fileSize = null)
	{
		static $defaultMimeTypes = [
			'css' => 'text/css',
			'gif' => 'image/gif',
			'png' => 'image/png',
			'jpg' => 'image/jpeg',
			'jpeg' => 'image/jpeg',
			'htm' => 'text/html',
			'html' => 'text/html',
			'js' => 'javascript/js',
			'pdf' => 'application/pdf',
			'xls' => 'application/vnd.ms-excel',
		];

		if ($mimeType === null) {
			$mimeType = 'text/plain';
			if (function_exists('mime_content_type')) {
				$mimeType = mime_content_type($fileName);
			} elseif (($ext = strrchr($fileName, '.')) !== false) {
				$ext = substr($ext, 1);
				if (isset($defaultMimeTypes[$ext])) {
					$mimeType = $defaultMimeTypes[$ext];
				}
			}
		}

		if ($clientFileName === null) {
			$clientFileName = basename($fileName);
		} else {
			$clientFileName = basename($clientFileName);
		}

		if ($fileSize === null || $fileSize < 0) {
			$fileSize = ($content === null ? filesize($fileName) : strlen($content));
		}

		$this->sendHttpHeader();
		if (is_array($headers)) {
			foreach ($headers as $h) {
				header($h);
			}
		} else {
			header('Pragma: public');
			header('Expires: 0');
			header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
			header("Content-Type: $mimeType");
			$this->_contentTypeHeaderSent = true;
		}

		header('Content-Length: ' . $fileSize);
		header("Content-Disposition: " . ($forceDownload ? 'attachment' : 'inline') . "; filename=\"$clientFileName\"");
		header('Content-Transfer-Encoding: binary');
		if ($content === null) {
			readfile($fileName);
		} else {
			echo $content;
		}
	}

	/**
	 * Redirects the browser to the specified URL.
	 * The current application will be terminated after this method is invoked.
	 * @param string $url URL to be redirected to. If the URL is a relative one, the base URL of
	 * the current request will be inserted at the beginning.
	 */
	public function redirect($url)
	{
		if ($this->getHasAdapter()) {
			$this->_adapter->httpRedirect($url);
		} else {
			$this->httpRedirect($url);
		}
	}

	/**
	 * Redirect the browser to another URL and exists the current application.
	 * This method is used internally. Please use {@link redirect} instead.
	 *
	 * @since 3.1.5
	 * You can set the set {@link setStatusCode StatusCode} to a value between 300 and 399 before
	 * calling this function to change the type of redirection.
	 * If not specified, StatusCode will be 302 (Found) by default
	 *
	 * @param string $url URL to be redirected to. If the URL is a relative one, the base URL of
	 * the current request will be inserted at the beginning.
	 */
	public function httpRedirect($url)
	{
		$this->ensureHeadersSent();

		// Under IIS, explicitly send an HTTP response including the status code
		// this is handled automatically by PHP on Apache and others
		$isIIS = (stripos($this->getRequest()->getServerSoftware(), "microsoft-iis") !== false);
		if ($url[0] === '/') {
			$url = $this->getRequest()->getBaseUrl() . $url;
		}
		if ($this->_status >= 300 && $this->_status < 400) {
			// The status code has been modified to a valid redirection status, send it
			if ($isIIS) {
				header('HTTP/1.1 ' . $this->_status . ' ' . self::$HTTP_STATUS_CODES[
					array_key_exists($this->_status, self::$HTTP_STATUS_CODES)
						? $this->_status
						: 302
					]);
			}
			header('Location: ' . str_replace('&amp;', '&', $url), true, $this->_status);
		} else {
			if ($isIIS) {
				header('HTTP/1.1 302 ' . self::$HTTP_STATUS_CODES[302]);
			}
			header('Location: ' . str_replace('&amp;', '&', $url));
		}

		if (!$this->getApplication()->getRequestCompleted()) {
			$this->getApplication()->onEndRequest();
		}

		exit();
	}

	/**
	 * Reloads the current page.
	 * The effect of this method call is the same as user pressing the
	 * refresh button on his browser (without post data).
	 **/
	public function reload()
	{
		$this->redirect($this->getRequest()->getRequestUri());
	}

	/**
	 * Flush the response contents and headers.
	 * @param bool $continueBuffering
	 */
	public function flush($continueBuffering = true)
	{
		if ($this->getHasAdapter()) {
			$this->_adapter->flushContent($continueBuffering);
		} else {
			$this->flushContent($continueBuffering);
		}
	}

	/**
	 * Ensures that HTTP response and content-type headers are sent
	 */
	public function ensureHeadersSent()
	{
		$this->ensureHttpHeaderSent();
		$this->ensureContentTypeHeaderSent();
	}

	/**
	 * Outputs the buffered content, sends content-type and charset header.
	 * This method is used internally. Please use {@link flush} instead.
	 * @param bool $continueBuffering whether to continue buffering after flush if buffering was active
	 */
	public function flushContent($continueBuffering = true)
	{
		Prado::trace("Flushing output", 'Prado\Web\THttpResponse');
		$this->ensureHeadersSent();
		if ($this->_bufferOutput) {
			// avoid forced send of http headers (ob_flush() does that) if there's no output yet
			if (ob_get_length() > 0) {
				if (!$continueBuffering) {
					$this->_bufferOutput = false;
					ob_end_flush();
				} else {
					ob_flush();
				}
				flush();
			}
		} else {
			flush();
		}
	}

	/**
	 * Ensures that the HTTP header with the status code and status reason are sent
	 */
	protected function ensureHttpHeaderSent()
	{
		if (!$this->_httpHeaderSent) {
			$this->sendHttpHeader();
		}
	}

	/**
	 * Send the HTTP header with the status code (defaults to 200) and status reason (defaults to OK)
	 */
	protected function sendHttpHeader()
	{
		$protocol = $this->getRequest()->getHttpProtocolVersion();
		if ($this->getRequest()->getHttpProtocolVersion() === null) {
			$protocol = 'HTTP/1.1';
		}

		header($protocol . ' ' . $this->_status . ' ' . $this->_reason, true, TPropertyValue::ensureInteger($this->_status));

		$this->_httpHeaderSent = true;
	}

	/**
	 * Ensures that the HTTP header with the status code and status reason are sent
	 */
	protected function ensureContentTypeHeaderSent()
	{
		if (!$this->_contentTypeHeaderSent) {
			$this->sendContentTypeHeader();
		}
	}

	/**
	 * Sends content type header with optional charset.
	 */
	protected function sendContentTypeHeader()
	{
		$contentType = $this->_contentType === null ? self::DEFAULT_CONTENTTYPE : $this->_contentType;
		$charset = $this->getCharset();
		if ($charset === false) {
			$this->appendHeader('Content-Type: ' . $contentType);
			return;
		}

		if ($charset === '' && ($globalization = $this->getApplication()->getGlobalization(false)) !== null) {
			$charset = $globalization->getCharset();
		}

		if ($charset === '') {
			$charset = self::DEFAULT_CHARSET;
		}
		$this->appendHeader('Content-Type: ' . $contentType . ';charset=' . $charset);

		$this->_contentTypeHeaderSent = true;
	}

	/**
	 * Returns the content in the output buffer.
	 * The buffer will NOT be cleared after calling this method.
	 * Use {@link clear()} is you want to clear the buffer.
	 * @return string output that is in the buffer.
	 */
	public function getContents()
	{
		Prado::trace("Retrieving output", 'Prado\Web\THttpResponse');
		return $this->_bufferOutput ? ob_get_contents() : '';
	}

	/**
	 * Clears any existing buffered content.
	 */
	public function clear()
	{
		if ($this->_bufferOutput && ob_get_length() > 0) {
			ob_clean();
		}
		Prado::trace("Clearing output", 'Prado\Web\THttpResponse');
	}

	/**
	 * @param null|int $case Either {@link CASE_UPPER} or {@link CASE_LOWER} or as is null (default)
	 * @return array
	 */
	public function getHeaders($case = null)
	{
		$result = [];
		$headers = headers_list();
		foreach ($headers as $header) {
			$tmp = explode(':', $header);
			$key = trim(array_shift($tmp));
			$value = trim(implode(':', $tmp));
			if (isset($result[$key])) {
				$result[$key] .= ', ' . $value;
			} else {
				$result[$key] = $value;
			}
		}

		if ($case !== null) {
			return array_change_key_case($result, $case);
		}

		return $result;
	}

	/**
	 * Sends a header.
	 * @param string $value header
	 * @param bool $replace whether the header should replace a previous similar header, or add a second header of the same type
	 */
	public function appendHeader($value, $replace = true)
	{
		Prado::trace("Sending header '$value'", 'Prado\Web\THttpResponse');
		header($value, $replace);
	}

	/**
	 * Writes a log message into error log.
	 * This method is simple wrapper of PHP function error_log.
	 * @param string $message The error message that should be logged
	 * @param int $messageType where the error should go
	 * @param string $destination The destination. Its meaning depends on the message parameter as described above
	 * @param string $extraHeaders The extra headers. It's used when the message parameter is set to 1. This message type uses the same internal function as mail() does.
	 * @see http://us2.php.net/manual/en/function.error-log.php
	 */
	public function appendLog($message, $messageType = 0, $destination = '', $extraHeaders = '')
	{
		error_log($message, $messageType, $destination, $extraHeaders);
	}

	/**
	 * Sends a cookie.
	 * Do not call this method directly. Operate with the result of {@link getCookies} instead.
	 * @param THttpCookie $cookie cook to be sent
	 */
	public function addCookie($cookie)
	{
		$request = $this->getRequest();
		if ($request->getEnableCookieValidation()) {
			$value = $this->getApplication()->getSecurityManager()->hashData($cookie->getValue());
		} else {
			$value = $cookie->getValue();
		}

		if (PHP_VERSION_ID >= 70300) {
			setcookie(
				$cookie->getName(),
				$value,
				$cookie->getPhpOptions()
			);
		} else {
			setcookie(
				$cookie->getName(),
				$value,
				$cookie->getExpire(),
				$cookie->getPath(),
				$cookie->getDomain(),
				$cookie->getSecure(),
				$cookie->getHttpOnly()
			);
		}
	}

	/**
	 * Deletes a cookie.
	 * Do not call this method directly. Operate with the result of {@link getCookies} instead.
	 * @param THttpCookie $cookie cook to be deleted
	 */
	public function removeCookie($cookie)
	{
		if (PHP_VERSION_ID >= 70300) {
			$options = $cookie->getPhpOptions();
			$options['expires'] = 0;
			setcookie(
				$cookie->getName(),
				null,
				$options
			);
		} else {
			setcookie(
				$cookie->getName(),
				null,
				0,
				$cookie->getPath(),
				$cookie->getDomain(),
				$cookie->getSecure(),
				$cookie->getHttpOnly()
			);
		}
	}

	/**
	 * @return string the type of HTML writer to be used, defaults to THtmlWriter
	 */
	public function getHtmlWriterType()
	{
		return $this->_htmlWriterType;
	}

	/**
	 * @param string $value the type of HTML writer to be used, may be the class name or the namespace
	 */
	public function setHtmlWriterType($value)
	{
		$this->_htmlWriterType = $value;
	}

	/**
	 * Creates a new instance of HTML writer.
	 * If the type of the HTML writer is not supplied, {@link getHtmlWriterType HtmlWriterType} will be assumed.
	 * @param string $type type of the HTML writer to be created. If null, {@link getHtmlWriterType HtmlWriterType} will be assumed.
	 */
	public function createHtmlWriter($type = null)
	{
		if ($type === null) {
			$type = $this->getHtmlWriterType();
		}
		if ($this->getHasAdapter()) {
			return $this->_adapter->createNewHtmlWriter($type, $this);
		} else {
			return $this->createNewHtmlWriter($type, $this);
		}
	}

	/**
	 * Create a new html writer instance.
	 * This method is used internally. Please use {@link createHtmlWriter} instead.
	 * @param string $type type of HTML writer to be created.
	 * @param \Prado\IO\ITextWriter $writer text writer holding the contents.
	 */
	public function createNewHtmlWriter($type, $writer)
	{
		return Prado::createComponent($type, $writer);
	}
}