<?php

/**
 * This file is part of the Nette Framework (https://nette.org)
 * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
 */

declare(strict_types=1);

namespace Nette\Http;

use Nette;
use Nette\Utils\DateTime;


/**
 * HttpResponse class.
 *
 * @property-read array $headers
 */
final class Response implements IResponse
{
	use Nette\SmartObject;

	/** @var string The domain in which the cookie will be available */
	public $cookieDomain = '';

	/** @var string The path in which the cookie will be available */
	public $cookiePath = '/';

	/** @var bool Whether the cookie is available only through HTTPS */
	public $cookieSecure = false;

	/** @var bool Whether the cookie is hidden from client-side */
	public $cookieHttpOnly = true;

	/** @var bool Whether warn on possible problem with data in output buffer */
	public $warnOnBuffer = true;

	/** @var bool  Send invisible garbage for IE 6? */
	private static $fixIE = true;

	/** @var int HTTP response code */
	private $code = self::S200_OK;


	public function __construct()
	{
		if (is_int($code = http_response_code())) {
			$this->code = $code;
		}
	}


	/**
	 * Sets HTTP response code.
	 * @return static
	 * @throws Nette\InvalidArgumentException  if code is invalid
	 * @throws Nette\InvalidStateException  if HTTP headers have been sent
	 */
	public function setCode(int $code, string $reason = null)
	{
		if ($code < 100 || $code > 599) {
			throw new Nette\InvalidArgumentException("Bad HTTP response '$code'.");
		}
		self::checkHeaders();
		$this->code = $code;
		$protocol = $_SERVER['SERVER_PROTOCOL'] ?? 'HTTP/1.1';
		$reason = $reason ?? self::REASON_PHRASES[$code] ?? 'Unknown status';
		header("$protocol $code $reason");
		return $this;
	}


	/**
	 * Returns HTTP response code.
	 */
	public function getCode(): int
	{
		return $this->code;
	}


	/**
	 * Sends a HTTP header and replaces a previous one.
	 * @return static
	 * @throws Nette\InvalidStateException  if HTTP headers have been sent
	 */
	public function setHeader(string $name, ?string $value)
	{
		self::checkHeaders();
		if ($value === null) {
			header_remove($name);
		} elseif (strcasecmp($name, 'Content-Length') === 0 && ini_get('zlib.output_compression')) {
			// ignore, PHP bug #44164
		} else {
			header($name . ': ' . $value, true, $this->code);
		}
		return $this;
	}


	/**
	 * Adds HTTP header.
	 * @return static
	 * @throws Nette\InvalidStateException  if HTTP headers have been sent
	 */
	public function addHeader(string $name, string $value)
	{
		self::checkHeaders();
		header($name . ': ' . $value, false, $this->code);
		return $this;
	}


	/**
	 * @return static
	 * @throws Nette\InvalidStateException  if HTTP headers have been sent
	 */
	public function deleteHeader(string $name)
	{
		self::checkHeaders();
		header_remove($name);
		return $this;
	}


	/**
	 * Sends a Content-type HTTP header.
	 * @return static
	 * @throws Nette\InvalidStateException  if HTTP headers have been sent
	 */
	public function setContentType(string $type, string $charset = null)
	{
		$this->setHeader('Content-Type', $type . ($charset ? '; charset=' . $charset : ''));
		return $this;
	}


	/**
	 * Redirects to a new URL. Note: call exit() after it.
	 * @throws Nette\InvalidStateException  if HTTP headers have been sent
	 */
	public function redirect(string $url, int $code = self::S302_FOUND): void
	{
		$this->setCode($code);
		$this->setHeader('Location', $url);
		if (preg_match('#^https?:|^\s*+[a-z0-9+.-]*+[^:]#i', $url)) {
			$escapedUrl = htmlspecialchars($url, ENT_IGNORE | ENT_QUOTES, 'UTF-8');
			echo "<h1>Redirect</h1>\n\n<p><a href=\"$escapedUrl\">Please click here to continue</a>.</p>";
		}
	}


	/**
	 * Sets the time (like '20 minutes') before a page cached on a browser expires, null means "must-revalidate".
	 * @return static
	 * @throws Nette\InvalidStateException  if HTTP headers have been sent
	 */
	public function setExpiration(?string $time)
	{
		$this->setHeader('Pragma', null);
		if (!$time) { // no cache
			$this->setHeader('Cache-Control', 's-maxage=0, max-age=0, must-revalidate');
			$this->setHeader('Expires', 'Mon, 23 Jan 1978 10:00:00 GMT');
			return $this;
		}

		$time = DateTime::from($time);
		$this->setHeader('Cache-Control', 'max-age=' . ($time->format('U') - time()));
		$this->setHeader('Expires', Helpers::formatDate($time));
		return $this;
	}


	/**
	 * Checks if headers have been sent.
	 */
	public function isSent(): bool
	{
		return headers_sent();
	}


	/**
	 * Returns value of an HTTP header.
	 */
	public function getHeader(string $header): ?string
	{
		if (func_num_args() > 1) {
			trigger_error(__METHOD__ . '() parameter $default is deprecated, use operator ??', E_USER_DEPRECATED);
		}
		$header .= ':';
		$len = strlen($header);
		foreach (headers_list() as $item) {
			if (strncasecmp($item, $header, $len) === 0) {
				return ltrim(substr($item, $len));
			}
		}
		return null;
	}


	/**
	 * Returns a associative array of headers to sent.
	 */
	public function getHeaders(): array
	{
		$headers = [];
		foreach (headers_list() as $header) {
			$a = strpos($header, ':');
			$headers[substr($header, 0, $a)] = (string) substr($header, $a + 2);
		}
		return $headers;
	}


	public function __destruct()
	{
		if (
			self::$fixIE
			&& strpos($_SERVER['HTTP_USER_AGENT'] ?? '', 'MSIE ') !== false
			&& in_array($this->code, [400, 403, 404, 405, 406, 408, 409, 410, 500, 501, 505], true)
			&& preg_match('#^text/html(?:;|$)#', (string) $this->getHeader('Content-Type'))
		) {
			echo Nette\Utils\Random::generate(2000, " \t\r\n"); // sends invisible garbage for IE
			self::$fixIE = false;
		}
	}


	/**
	 * Sends a cookie.
	 * @param  string|int|\DateTimeInterface $time  expiration time, value 0 means "until the browser is closed"
	 * @return static
	 * @throws Nette\InvalidStateException  if HTTP headers have been sent
	 */
	public function setCookie(string $name, string $value, $time, string $path = null, string $domain = null, bool $secure = null, bool $httpOnly = null, string $sameSite = null)
	{
		self::checkHeaders();
		$options = [
			'expires' => $time ? (int) DateTime::from($time)->format('U') : 0,
			'path' => $path === null ? $this->cookiePath : $path,
			'domain' => $domain === null ? $this->cookieDomain : $domain,
			'secure' => $secure === null ? $this->cookieSecure : $secure,
			'httponly' => $httpOnly === null ? $this->cookieHttpOnly : $httpOnly,
			'samesite' => $sameSite,
		];
		if (PHP_VERSION_ID >= 70300) {
			setcookie($name, $value, $options);
		} else {
			setcookie(
				$name,
				$value,
				$options['expires'],
				$options['path'] . ($sameSite ? "; SameSite=$sameSite" : ''),
				$options['domain'],
				$options['secure'],
				$options['httponly']
			);
		}
		return $this;
	}


	/**
	 * Deletes a cookie.
	 * @throws Nette\InvalidStateException  if HTTP headers have been sent
	 */
	public function deleteCookie(string $name, string $path = null, string $domain = null, bool $secure = null): void
	{
		$this->setCookie($name, '', 0, $path, $domain, $secure);
	}


	private function checkHeaders(): void
	{
		if (PHP_SAPI === 'cli') {
		} elseif (headers_sent($file, $line)) {
			throw new Nette\InvalidStateException('Cannot send header after HTTP headers have been sent' . ($file ? " (output started at $file:$line)." : '.'));

		} elseif (
			$this->warnOnBuffer &&
			ob_get_length() &&
			!array_filter(ob_get_status(true), function (array $i): bool { return !$i['chunk_size']; })
		) {
			trigger_error('Possible problem: you are sending a HTTP header while already having some data in output buffer. Try Tracy\OutputDebugger or start session earlier.');
		}
	}
}
