2022-09-29 00:33:29 +02:00

143 lines
3.4 KiB
PHP

<?php
namespace germanairlinesva\file\recording;
class Recording
{
private const ident = "VGAR";
private const header_unpack = "a4ident/Cversion";
private const segment_unpack = "Vtime/Saltitude/Sgroundspeed/elatitude/elongitude";
private string $file_path = "";
private array $segments = [];
public function __construct(string $path)
{
$this->file_path = $path;
$this->read();
}
/**
* Generates a json representation
*
* @return array Json representation with path as geoJSON and profile as array
*/
public function to_json(): array
{
$path = [
"type" => "FeatureCollection",
"features" => [
0 => [
"type" => "Feature",
"properties" => [
"stroke" => "#ff0000",
"stroke-width" => 2,
"stroke-opacity" => 1
],
"geometry" => [
"type" => "LineString",
"coordinates" => []
]
]
]
];
$path["features"][0]["geometry"]["coordinates"] = array_map(function ($segment) {
return array($segment["longitude"], $segment["latitude"]);
}, $this->segments);
$profile = array_map(function ($segment) {
return array("altitude" => $segment["altitude"], "groundspeed" => $segment["groundspeed"]);
}, $this->segments);
return ["path" => $path, "profile" => $profile];
}
/**
* Generates a json string representation
*
* @return string Json string representation with path as geoJSON and profile as array
*/
public function to_json_string(): string
{
return json_encode($this->to_json());
}
/**
* Reads recording
*/
private function read()
{
if (!file_exists($this->file_path)) {
throw new \InvalidArgumentException("File not found");
}
$file = fopen($this->file_path, "rb");
if ($file) {
flock($file, LOCK_SH);
$version = $this->read_header($file);
if ($version == 1) {
while ($this->read_segment_1($file) != false);
}
flock($file, LOCK_UN);
fclose($file);
} else {
throw new \Exception("fopen Error");
}
}
/**
* Reads one segment entry
*
* @param resource $file File handle
*
* @return true If not EOF
* @return false If EOF
*
* @throws InvalidArgumentException If file is not a resource
*/
private function read_segment_1($file): bool
{
if (false === is_resource($file)) {
throw new \InvalidArgumentException(sprintf('Argument must be a valid resource type. %s given.', gettype($file)));
}
$data = fread($file, 24);
if ($data) {
array_push($this->segments, unpack(Recording::segment_unpack, $data));
return true;
}
return false;
}
/**
* Reads the file header
*
* @param resource $file File handle
*
* @return string File version
*
* @throws InvalidArgumentException If file is not a resource
* @throws UnexpectedValueException If ident mismatches
*/
private function read_header($file): string
{
if (false === is_resource($file)) {
throw new \InvalidArgumentException(sprintf('Argument must be a valid resource type. %s given.', gettype($file)));
}
$header = unpack(Recording::header_unpack, fread($file, 5));
if ($header["ident"] !== Recording::ident) {
throw
new \UnexpectedValueException(sprintf("Ident mismatch. Got %s, expected %s", $header["ident"], Recording::ident));
}
return $header["version"];
}
}