<?php declare(strict_types=1);
/**
 * This file is part of the SplendidBear Websites' projects.
 *
 * Copyright (c) 2019 @ www.splendidbear.org
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace App\Util;

use App\Entity\Grid;
use App\Entity\GridRow;
use App\Entity\PlayedGame;
use App\Interfaces\RpcManagerInterface;
use DateTime;
use Doctrine\ORM\EntityManagerInterface;
use Exception;
use JsonException;
use Psr\Log\LoggerInterface;
use RuntimeException;

/**
 * Class RpcManager
 *
 * @package  App\Util
 * @author   Lang <https://www.splendidbear.org>
 * @category Class
 * @license  https://www.gnu.org/licenses/lgpl-3.0.en.html GNU Lesser General Public License
 * @link     www.splendidbear.org
 * @since    2026. 04. 09.
 */
class RpcManager implements RpcManagerInterface
{
    private const ROWS  = 16;
    private const COLS  = 16;
    private const MINES = 51;

    public function __construct(
        private readonly EntityManagerInterface $entityManager,
        private readonly LoggerInterface        $logger,
    ) {
    }

    public function getConnectInformation($params): string
    {
        $gameAssoc = is_array($params) ? $params[0] : $params;

        $playedGame = $this->entityManager
            ->getRepository(PlayedGame::class)
            ->findOneByGameAssoc($gameAssoc);

        if (null === $playedGame) {
            try {
                return base64_encode(json_encode([
                    'users'         => null,
                    'revealedCells' => null,
                ], JSON_THROW_ON_ERROR));
            } catch (JsonException $e) {
                throw new RuntimeException($e->getMessage());
            }
        }

        $users         = $this->getUserCollection($playedGame);
        $revealedCells = $this->aggregateRevealedCells($playedGame);

        try {
            return base64_encode(json_encode([
                'users'         => $users,
                'revealedCells' => $revealedCells,
            ], JSON_THROW_ON_ERROR));
        } catch (JsonException $e) {
            throw new RuntimeException($e->getMessage());
        }
    }

    public function saveGrid(string $gameAssoc): bool
    {
        $existingGame = $this->entityManager
            ->getRepository(PlayedGame::class)
            ->findOneByGameAssoc($gameAssoc);

        if (null !== $existingGame) {
            return true;
        }

        $grid2d     = $this->generateGrid();
        $playedGame = new PlayedGame();
        $grid       = new Grid();

        try {
            foreach ($grid2d as $row) {
                $gridRow = new GridRow();
                $gridRow->setGridCol($row);
                $gridRow->setGrid($grid);
                $this->entityManager->persist($gridRow);
            }

            $grid->setPlayedGame($playedGame);
            $this->entityManager->persist($grid);

            $playedGame->setGameAssoc($gameAssoc);
            $playedGame->setGrid($grid);
            $playedGame->setCreated(new DateTime());
            $playedGame->setUpdated(new DateTime());
            $this->entityManager->persist($playedGame);

            $this->entityManager->flush();
        } catch (Exception $e) {
            $this->logger->error($e->getMessage());
        }

        return true;
    }

    /**
     * Generate a random 16×16 grid with 51 mines and adjacent-mine numbers.
     */
    private function generateGrid(): array
    {
        // Build flat set: 51 mines ('m') + remaining water ('w')
        $set = array_merge(
            array_fill(0, self::MINES, 'm'),
            array_fill(0, self::ROWS * self::COLS - self::MINES, 'w'),
        );

        // Fisher-Yates shuffle
        for ($i = count($set) - 1; $i > 0; $i--) {
            $j       = random_int(0, $i);
            [$set[$i], $set[$j]] = [$set[$j], $set[$i]];
        }

        // Reshape to 2-D
        $grid = [];
        for ($r = 0; $r < self::ROWS; $r++) {
            $grid[$r] = array_slice($set, $r * self::COLS, self::COLS);
        }

        // Replace 'w' with adjacent-mine count
        $dirs = [[-1, -1], [-1, 0], [-1, 1], [0, -1], [0, 1], [1, -1], [1, 0], [1, 1]];
        for ($r = 0; $r < self::ROWS; $r++) {
            for ($c = 0; $c < self::COLS; $c++) {
                if ('w' !== $grid[$r][$c]) {
                    continue;
                }
                $count = 0;
                foreach ($dirs as [$dr, $dc]) {
                    if (isset($grid[$r + $dr][$c + $dc]) && 'm' === $grid[$r + $dr][$c + $dc]) {
                        $count++;
                    }
                }
                $grid[$r][$c] = $count;
            }
        }

        return $grid;
    }

    /**
     * Collect all cells revealed so far, enriched with the player colour from each Step.
     */
    private function aggregateRevealedCells(PlayedGame $playedGame): array
    {
        $all = [];

        foreach ($playedGame->getSteps() as $step) {
            if (null === $step->getRevealedCells()) {
                continue;
            }
            $player = $step->getPlayer();
            foreach ($step->getRevealedCells() as $cell) {
                $all[] = array_merge($cell, ['player' => $player]);
            }
        }

        return $all;
    }

    private function getUserCollection(PlayedGame $playedGame): array
    {
        return [
            'red'      => null !== $playedGame->getRed()     ? $playedGame->getRed()->getUsername()     : '',
            'blue'     => null !== $playedGame->getBlue()    ? $playedGame->getBlue()->getUsername()    : '',
            'redAnon'  => null !== $playedGame->getRedAnon() ? $playedGame->getRedAnon()->getUserName() : '',
            'blueAnon' => null !== $playedGame->getBlueAnon()? $playedGame->getBlueAnon()->getUserName(): '',
        ];
    }
}