<?php

namespace App\Classes\File;

use Carbon\Carbon;
use Illuminate\Support\Arr;
use Illuminate\Support\Facades\Log;
use Symfony\Component\HttpFoundation\File\Exception\FileException;

use App\Classes\Protocol;
use App\Exceptions\FileGrewException;
use App\Jobs\{PacketProcess,TicProcess};
use App\Models\Address;

/**
 * Object representing the files we are receiving
 *
 * @property-read resource $fd
 * @property-read int total_recv
 * @property-read int total_recv_bytes
 */
class Receive extends Base
{
	private const LOGKEY = 'IR-';

	private const compression = [
		'BZ2',
		'GZ',
	];

	private Address $ao;

	/** @var ?string The compression used by the incoming file */
	private ?string $comp;
	/** @var string|null The compressed data received */
	private ?string $comp_data;
	private $queue = FALSE;

	public function __construct()
	{
		// Initialise our variables
		if (get_class($this) === self::class) {
			$this->list = collect();
			$this->f = NULL;
		}
	}

	public function __get($key)
	{
		switch ($key) {
			case 'completed':
				return $this->list
					->filter(function($item) { return $item->complete === TRUE; });

			case 'fd':
				return is_resource($this->f);

			case 'recvmtime':
			case 'recvsize':
			case 'mtime':
			case 'nameas':
			case 'size':
			case 'name_size_time':
			case 'pref_name':
				return $this->receiving->{$key};

			case 'pos':
				return $this->pos;

			case 'receiving':
				return $this->list->get($this->index);

			case 'ready':
				return (! is_null($this->index));

			case 'togo_count':
				return $this->list
					->filter(function($item) { return $item->complete === FALSE; })
					->count();

			case 'total_recv':
				return $this->completed->count();

			case 'total_recv_bytes':
				return $this->completed->sum(function($item) { return $item->recvsize; });

			default:
				throw new \Exception('Unknown key: '.$key);
		}
	}

	/**
	 * Close the file descriptor for our incoming file
	 *
	 * @throws \Exception
	 */
	public function close(): void
	{
		if (! $this->receiving)
			throw new \Exception('No file to close');

		if ($this->f) {
			$rcvd_time = Carbon::now();

			if ($this->pos !== $this->receiving->recvsize)
				Log::warning(sprintf('%s:- Closing [%s], but missing [%d] bytes',self::LOGKEY,$this->receiving->nameas,$this->receiving->recvsize-$this->pos));
			else
				$this->receiving->complete = TRUE;

			$end = time()-$this->start;
			Log::debug(sprintf('%s:- Closing [%s], received in [%d]',self::LOGKEY,$this->receiving->nameas,$end));

			if ($this->comp)
				Log::info(sprintf('%s:= Compressed file using [%s] was [%d] bytes (%d). Compression rate [%3.2f%%]',self::LOGKEY,$this->comp,$x=strlen($this->comp_data),$this->receiving->recvsize,$x/$this->receiving->recvsize*100));

			fclose($this->f);
			// Set our mtime
			Log::debug(sprintf('%s:= Setting file [%s] to time [%s]',self::LOGKEY,$this->receiving->full_name,$this->receiving->recvmtime));
			touch($this->receiving->full_name,$this->receiving->recvmtime);
			$this->f = NULL;

			// If we received a packet, we'll dispatch a job to process it, if we got it all
			if ($this->receiving->complete)
				switch ($this->receiving->whatType()) {
					case self::IS_ARC:
					case self::IS_PKT:
						try {
							// If packet is greater than a size, lets queue it
							if ($this->queue || ($this->receiving->size > config('fido.queue_size',0))) {
								Log::info(sprintf('%s:- Packet [%s] will be sent to the queue for processing because its [%d] size, or queue forced',self::LOGKEY,$this->receiving->full_name,$this->receiving->size));
								PacketProcess::dispatch($this->receiving->rel_name,$this->ao->system,FALSE,$rcvd_time);
							} else
								PacketProcess::dispatchSync($this->receiving->rel_name,$this->ao->system,TRUE,$rcvd_time);

						} catch (\Exception $e) {
							Log::error(sprintf('%s:! Got error dispatching packet [%s] (%d:%s-%s).',self::LOGKEY,$this->receiving->rel_name,$e->getLine(),$e->getFile(),$e->getMessage()));
						}

						break;

					case self::IS_TIC:
						Log::info(sprintf('%s:- Processing TIC file [%s]',self::LOGKEY,$this->receiving->nameas));

						// Queue the tic to be processed later, in case the referenced file hasnt been received yet
						TicProcess::dispatch($this->receiving->pref_name)->delay(60);

						break;

					default:
						Log::debug(sprintf('%s:- Leaving file [%s] in the inbound dir',self::LOGKEY,$this->receiving->nameas));
				}
		}

		$this->index = NULL;
	}

	/**
	 * Add a new file to receive
	 *
	 * @param array $file The name of the receiving file
	 * @param Address $ao Sender sending a file to us
	 * @param bool $queue Force sending received items to the queue
	 * @throws \Exception
	 */
	public function new(array $file,Address $ao,$queue=FALSE): void
	{
		Log::debug(sprintf('%s:+ Receiving new file [%s]',self::LOGKEY,join('|',$file)));

		if ($this->index)
			throw new \Exception('Can only have 1 file receiving at a time');

		$this->ao = $ao;
		$this->queue = $queue;

		$this->list->push(new Item($ao,Arr::get($file,'name'),(int)Arr::get($file,'mtime'),(int)Arr::get($file,'size')));
		$this->index = $this->list->count()-1;
	}

	/**
	 * Open the file descriptor to receive a file
	 *
	 * @param bool $check
	 * @param string|null $comp If the incoming file will be compressed
	 * @return int
	 * @throws \Exception
	 * @todo $comp should be parsed, in case it contains other items
	 */
	public function open(bool $check=FALSE,string $comp=NULL): int
	{
		// @todo implement return 4 - SUSPEND(?) file
		if (is_null($this->index))
			throw new \Exception('No files currently receiving');

		$this->comp_data = '';
		$this->comp = $comp;

		/*
		if ($this->receiving->size <= self::MAX_COMPSIZE) {
			$this->comp = $comp;

		} else {
			Log::alert(sprintf('%s:- Compression [%s] disabled for file [%s], its size is too big [%d]',self::LOGKEY,$comp,$this->receiving->name,$this->receiving->size));
		}
		*/

		if ($this->comp && (! in_array($this->comp,self::compression)))
			throw new \Exception('Unsupported compression:'.$this->comp);
		elseif ($this->comp)
			Log::debug(sprintf('%s:- Receiving file with [%s] compression',self::LOGKEY,$this->comp));

		$this->pos = 0;
		$this->start = time();

		if ($this->receiving->exists && $this->receiving->match_mtime && $this->receiving->match_size) {
			Log::alert(sprintf('%s:- File already exists - skipping [%s]', self::LOGKEY,$this->receiving->nameas));
			return Protocol::FOP_GOT;

		} elseif ($this->receiving->exists && $this->receiving->size > 0) {
			Log::alert(sprintf('%s:- File exists with different details - skipping [%s] (size: %d, mtime: %d)',self::LOGKEY,$this->receiving->nameas,$this->receiving->size,$this->receiving->mtime));
			return Protocol::FOP_SKIP;

		} else {
			// @todo I dont think we are enabling resumable sessions - need to check
			Log::debug(sprintf('%s:- Opening [%s]',self::LOGKEY,$this->receiving->nameas));
		}

		// If we are only checking, we'll return (NR mode)
		if ($check)
			return Protocol::FOP_OK;

		$this->f = fopen($this->receiving->full_name,'wb');

		if (! $this->f) {
			Log::error(sprintf('%s:! Unable to open file [%s] for writing',self::LOGKEY,$this->receiving->nameas));
			return Protocol::FOP_ERROR;
		}

		Log::info(sprintf('%s:= File [%s] opened for writing',self::LOGKEY,$this->receiving->nameas));
		return Protocol::FOP_OK;
	}

	/**
	 * Write data to the file we are receiving
	 *
	 * @param string $buf
	 * @return bool
	 * @throws \Exception
	 */
	public function write(string $buf): bool
	{
		if (! $this->fd)
			throw new \Exception('No file open for write');

		$data = '';

		// If we are using compression mode, then we need to buffer the right until we have everything
		if ($this->comp) {
			$this->comp_data .= $buf;

			// See if we can uncompress the data yet
			switch ($this->comp) {
				case 'BZ2':
					if (($data=bzdecompress($this->comp_data,TRUE)) === FALSE)
						throw new FileException('BZ2 decompression failed?');
					elseif (is_numeric($data))
						throw new FileException(sprintf('BZ2 decompression failed with (:%d)?',$data));

					break;

				case 'GZ':
					if (($data=gzdeflate($this->comp_data)) === FALSE)
						throw new FileException('BZ2 decompression failed?');

					break;
			}

			// Compressed file grew
			if (! strlen($data)) {
				if (strlen($this->comp_data) > $this->receiving->size) {
					fclose($this->f);
					$this->f = NULL;

					throw new FileGrewException(sprintf('Error compressed file grew, rejecting [%d] -> [%d]', strlen($this->comp_data), $this->receiving->size));
				}

				return TRUE;
			}

		} else {
			$data = $buf;
		}

		if (($x=$this->pos+strlen($data)) > $this->receiving->recvsize)
			throw new \Exception(sprintf('Too many bytes received [%d] (%d)?',$x,$this->receiving->recvsize));

		$rc = fwrite($this->f,$data);

		if ($rc === FALSE)
			throw new FileException('Error while writing to file');

		$this->pos += $rc;
		Log::debug(sprintf('%s:- Write [%d] bytes, file pos now [%d] of [%d] (%d)',self::LOGKEY,$rc,$this->pos,$this->receiving->recvsize,strlen($buf)));

		if (strlen($this->comp_data) > $this->receiving->recvsize)
			Log::alert(sprintf('%s:- Compression grew the file during transfer (%d->%d)',self::LOGKEY,$this->receiving->recvsize,strlen($this->comp_data)));

		return TRUE;
	}
}