<?php
/*
	FusionPBX
	Version: MPL 1.1

	The contents of this file are subject to the Mozilla Public License Version
	1.1 (the "License"); you may not use this file except in compliance with
	the License. You may obtain a copy of the License at
	http://www.mozilla.org/MPL/

	Software distributed under the License is distributed on an "AS IS" basis,
	WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
	for the specific language governing rights and limitations under the
	License.

	The Original Code is FusionPBX

	The Initial Developer of the Original Code is
	Mark J Crane <markjcrane@fusionpbx.com>
	Portions created by the Initial Developer are Copyright (C) 2008-2024
	the Initial Developer. All Rights Reserved.

	Contributor(s):
	Mark J Crane <markjcrane@fusionpbx.com>
*/

//includes files
	require_once dirname(__DIR__, 2) . "/resources/require.php";
	require_once "resources/check_auth.php";

//check permissions
	if (!permission_exists('voicemail_greeting_play') || (!permission_exists('voicemail_greeting_download') && !extension_assigned($_REQUEST["id"]))) {
		echo "access denied";
		return;
	}

//get voicemail id
	$voicemail_id = trim($_GET['id']);

//used (above) to search the array to determine if an extension is assigned to the user
	/**
	 * Checks if a specific extension has been assigned to the current user.
	 *
	 * @param string $number The extension number or alias to check for assignment.
	 *
	 * @return boolean True if the extension is assigned, false otherwise.
	 */
	function extension_assigned($number) {
		foreach ($_SESSION['user']['extension'] as $row) {
			if ((is_numeric($row['number_alias']) && $row['number_alias'] == $number) || $row['user'] == $number) {
				return true;
			}
		}
		return false;
	}

//define name recording directory
	if (!empty($settings->get('switch', 'storage'))) {
		$recording_dir = $settings->get('switch', 'storage').'/voicemail/default/'.$_SESSION['domains'][$domain_uuid]['domain_name'].'/'.$voicemail_id;
	}

//download the name recording
	if (permission_exists('voicemail_greeting_play') || permission_exists('voicemail_greeting_download')) {

		if (file_exists($recording_dir.'/recorded_name.wav')) {

			$fd = fopen($recording_dir.'/recorded_name.wav', "rb");
			header("Content-Type: audio/x-wav");
			header("Content-Disposition: attachment; filename='recorded_name.wav'");
			header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1
			header("Expires: Sat, 26 Jul 1997 05:00:00 GMT"); // Date in the past
			ob_clean();

			//content-range
			if (isset($_SERVER['HTTP_RANGE'])) {
				range_download($recording_dir.'/recorded_name.wav');
			}

			fpassthru($fd);
		}

	}

//define the download function (helps safari play audio sources)
	/**
	 * Downloads a file in range mode.
	 *
	 * This function sends the file to the client in chunks, allowing for partial downloads
	 * and resuming from where the download was left off.
	 *
	 * @param string $file The path to the file being downloaded.
	 */
	function range_download($file) {
		$fp = @fopen($file, 'rb');

		$size   = filesize($file); // File size
		$length = $size;           // Content length
		$start  = 0;               // Start byte
		$end    = $size - 1;       // End byte
		// Now that we've gotten so far without errors we send the accept range header
		/* At the moment we only support single ranges.
		* Multiple ranges requires some more work to ensure it works correctly
		* and comply with the spesifications: http://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html#sec19.2
		*
		* Multirange support annouces itself with:
		* header('Accept-Ranges: bytes');
		*
		* Multirange content must be sent with multipart/byteranges mediatype,
		* (mediatype = mimetype)
		* as well as a boundry header to indicate the various chunks of data.
		*/
		header("Accept-Ranges: 0-$length");
		// header('Accept-Ranges: bytes');
		// multipart/byteranges
		// http://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html#sec19.2
		if (isset($_SERVER['HTTP_RANGE'])) {

			$c_start = $start;
			$c_end   = $end;
			// Extract the range string
			[, $range] = explode('=', $_SERVER['HTTP_RANGE'], 2);
			// Make sure the client hasn't sent us a multibyte range
			if (strpos($range, ',') !== false) {
				// (?) Shoud this be issued here, or should the first
				// range be used? Or should the header be ignored and
				// we output the whole content?
				header('HTTP/1.1 416 Requested Range Not Satisfiable');
				header("Content-Range: bytes $start-$end/$size");
				// (?) Echo some info to the client?
				exit;
			}
			// If the range starts with an '-' we start from the beginning
			// If not, we forward the file pointer
			// And make sure to get the end byte if spesified
			if (!empty($range0) && $range0 == '-') {
				// The n-number of the last bytes is requested
				$c_start = $size - substr($range, 1);
			}
			else {
				$range  = explode('-', $range);
				$c_start = $range[0];
				$c_end   = (isset($range[1]) && is_numeric($range[1])) ? $range[1] : $size;
			}
			/* Check the range and make sure it's treated according to the specs.
			* http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
			*/
			// End bytes can not be larger than $end.
			$c_end = ($c_end > $end) ? $end : $c_end;
			// Validate the requested range and return an error if it's not correct.
			if ($c_start > $c_end || $c_start > $size - 1 || $c_end >= $size) {

				header('HTTP/1.1 416 Requested Range Not Satisfiable');
				header("Content-Range: bytes $start-$end/$size");
				// (?) Echo some info to the client?
				exit;
			}
			$start  = $c_start;
			$end    = $c_end;
			$length = $end - $start + 1; // Calculate new content length
			fseek($fp, $start);
			header('HTTP/1.1 206 Partial Content');
		}
		// Notify the client the byte range we'll be outputting
		header("Content-Range: bytes $start-$end/$size");
		header("Content-Length: $length");

		// Start buffered download
		$buffer = 1024 * 8;
		while(!feof($fp) && ($p = ftell($fp)) <= $end) {
			if ($p + $buffer > $end) {
				// In case we're only outputtin a chunk, make sure we don't
				// read past the length
				$buffer = $end - $p + 1;
			}
			set_time_limit(0); // Reset time limit for big files
			echo fread($fp, $buffer);
			flush(); // Free up memory. Otherwise large files will trigger PHP's memory limit.
		}

		fclose($fp);
	}

?>