<?php

declare(strict_types=1);

/**
 * @copyright Copyright (c) 2022, Varun Patil <radialapps@gmail.com>
 *
 * @author Varun Patil <radialapps@gmail.com>
 *
 * @license AGPL-3.0-or-later
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

namespace OCA\Memories\Command;

use OCP\Encryption\IManager;
use OCP\Files\File;
use OCP\Files\Folder;
use OCP\Files\IRootFolder;
use OCP\Files\StorageNotAvailableException;
use OCP\IConfig;
use OCP\IDBConnection;
use OCP\IPreview;
use OCP\IUser;
use OCP\IUserManager;
use OCA\Files_External\Service\GlobalStoragesService;
use OCA\Memories\Db\TimelineWrite;
use Psr\Container\ContainerExceptionInterface;
use Psr\Container\ContainerInterface;
use Symfony\Component\Console\Command\Command;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Input\InputOption;
use Symfony\Component\Console\Output\OutputInterface;

class Index extends Command {

    /** @var ?GlobalStoragesService */
    protected $globalService;

    /** @var int[][] */
    protected array $sizes;

    protected IUserManager $userManager;
    protected IRootFolder $rootFolder;
    protected IPreview $previewGenerator;
    protected IConfig $config;
    protected OutputInterface $output;
    protected IManager $encryptionManager;
    protected IDBConnection $connection;
    protected TimelineWrite $timelineWrite;

    // Stats
    private int $nProcessed = 0;
    private int $nSkipped = 0;
    private int $nInvalid = 0;

    public function __construct(IRootFolder $rootFolder,
                                IUserManager $userManager,
                                IPreview $previewGenerator,
                                IConfig $config,
                                IManager $encryptionManager,
                                IDBConnection $connection,
                                ContainerInterface $container) {
        parent::__construct();

        $this->userManager = $userManager;
        $this->rootFolder = $rootFolder;
        $this->previewGenerator = $previewGenerator;
        $this->config = $config;
        $this->encryptionManager = $encryptionManager;
        $this->connection = $connection;
        $this->timelineWrite = new TimelineWrite($this->connection);

        try {
            $this->globalService = $container->get(GlobalStoragesService::class);
        } catch (ContainerExceptionInterface $e) {
            $this->globalService = null;
        }
    }

    /** Make sure exiftool is available */
    private function testExif() {
        $testfile = dirname(__FILE__). '/../../exiftest.jpg';
        $stream = fopen($testfile, 'rb');
        if (!$stream) {
            error_log("Couldn't open Exif test file $testfile");
            return false;
        }

        $exif = null;
        try {
            $exif = \OCA\Memories\Exif::getExifFromStream($stream);
        } catch (\Exception $e) {
            error_log("Couldn't read Exif data from test file: " . $e->getMessage());
            return false;
        } finally {
            fclose($stream);
        }

        if (!$exif) {
            error_log("Got blank Exif data from test file");
            return false;
        }

        if ($exif["DateTimeOriginal"] !== "2004:08:31 19:52:58") {
            error_log("Got unexpected Exif data from test file");
            return false;
        }
        return true;
    }

    protected function configure(): void {
        $this
            ->setName('memories:index')
            ->setDescription('Generate photo entries')
            ->addOption(
                'refresh',
                'f',
                InputOption::VALUE_NONE,
                'Refresh existing entries'
            )
            ->addOption(
                'clear',
                null,
                InputOption::VALUE_NONE,
                'Clear existing index before creating a new one (SLOW)'
            );
    }

    protected function execute(InputInterface $input, OutputInterface $output): int {
        // Get options and arguments
        $refresh = $input->getOption('refresh') ? true : false;
        $clear = $input->getOption('clear') ? true : false;

        // Clear index if asked for this
        if ($clear && $input->isInteractive()) {
            $output->write("Are you sure you want to clear the existing index? (y/N): ");
            $answer = trim(fgets(STDIN));
            if ($answer !== 'y') {
                $output->writeln("Aborting");
                return 1;
            }
        }
        if ($clear) {
            $this->timelineWrite->clear();
            $output->writeln("Cleared existing index");
        }

        // Run with the static process
        try {
            \OCA\Memories\Exif::ensureStaticExiftoolProc();
            return $this->executeWithOpts($output, $refresh);
        } catch (\Exception $e) {
            error_log("FATAL: " . $e->getMessage());
            return 1;
        } finally {
            \OCA\Memories\Exif::closeStaticExiftoolProc();
        }
    }

    protected function executeWithOpts(OutputInterface $output, bool &$refresh): int {
        // Refuse to run without exiftool
        if (!$this->testExif()) {
            error_log('FATAL: exiftool could not be found or test failed');
            error_log('Please install exiftool (at least v12) and make sure it is in the PATH');
            return 1;
        }

        // Time measurement
        $startTime = microtime(true);

        if ($this->encryptionManager->isEnabled()) {
            error_log('FATAL: Encryption is enabled. Aborted.');
            return 1;
        }
        $this->output = $output;

        $this->userManager->callForSeenUsers(function (IUser &$user) use (&$refresh) {
            $this->generateUserEntries($user, $refresh);
        });

        // Show some stats
        $endTime = microtime(true);
        $execTime = intval(($endTime - $startTime)*1000)/1000 ;
        $nTotal = $this->nInvalid + $this->nSkipped + $this->nProcessed;
        $this->output->writeln("==========================================");
        $this->output->writeln("Checked $nTotal files in $execTime sec");
        $this->output->writeln($this->nInvalid . " not valid media items");
        $this->output->writeln($this->nSkipped . " skipped because unmodified");
        $this->output->writeln($this->nProcessed . " (re-)processed");
        $this->output->writeln("==========================================");

        return 0;
    }

    private function generateUserEntries(IUser &$user, bool &$refresh): void {
        \OC_Util::tearDownFS();
        \OC_Util::setupFS($user->getUID());

        $uid = $user->getUID();
        $userFolder = $this->rootFolder->getUserFolder($uid);
        $this->parseFolder($userFolder, $refresh, $uid);
    }

    private function parseFolder(Folder &$folder, bool &$refresh, string $uid): void {
        try {
            $folderPath = $folder->getPath();

            // Respect the '.nomedia' file. If present don't traverse the folder
            if ($folder->nodeExists('.nomedia')) {
		        $this->output->writeln('Skipping folder ' . $folderPath);
                return;
            }

            $this->output->writeln('Scanning folder ' . $folderPath);

            $nodes = $folder->getDirectoryListing();

            foreach ($nodes as &$node) {
                if ($node instanceof Folder) {
                    $this->parseFolder($node, $refresh, $uid);
                } elseif ($node instanceof File) {
                    $this->parseFile($node, $refresh, $uid);
                }
            }
        } catch (StorageNotAvailableException $e) {
            $this->output->writeln(sprintf('<error>Storage for folder folder %s is not available: %s</error>',
                $folder->getPath(),
                $e->getHint()
            ));
        }
    }

    private function parseFile(File &$file, bool &$refresh, string $uid): void {
        $res = $this->timelineWrite->processFile($file, $refresh, $uid);
        if ($res === 2) {
            $this->nProcessed++;
        } else if ($res === 1) {
            $this->nSkipped++;
        } else {
            $this->nInvalid++;
        }
    }
}