<?php

namespace App\Services\Rooms;

use App\Enums\RoomStateChange;
use App\Events\RoomStateChanged;
use App\Models\Player;
use App\Models\Room;
use App\Models\User;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\ValidationException;

class RoomParticipationService
{
    public function findByJoinCode(string $joinCode): ?Room
    {
        if ($joinCode === '') {
            return null;
        }

        return Room::query()
            ->where('join_code', $joinCode)
            ->first();
    }

    public function findExistingPlayer(
        Room $room,
        ?User $user,
        mixed $sessionPlayerId,
    ): ?Player {
        if ($user !== null) {
            return $room->players()
                ->where('user_id', $user->id)
                ->first();
        }

        if (! is_numeric($sessionPlayerId)) {
            return null;
        }

        return $room->players()->find((int) $sessionPlayerId);
    }

    /**
     * @param  array{join_code: string, player_name: string}  $data
     * @param  array<string, mixed>  $sessionPlayerIds
     * @return array{Room, Player}
     */
    public function join(array $data, ?User $user, array $sessionPlayerIds): array
    {
        [$room, $player] = DB::transaction(function () use ($data, $user, $sessionPlayerIds): array {
            $room = Room::query()
                ->where('join_code', $data['join_code'])
                ->lockForUpdate()
                ->firstOrFail();

            if ($room->isClosed()) {
                throw ValidationException::withMessages([
                    'join_code' => 'Dieser Raum ist geschlossen.',
                ]);
            }

            $player = $this->findExistingPlayer(
                $room,
                $user,
                $sessionPlayerIds[$room->id] ?? null,
            );

            if ($player === null) {
                $player = $room->players()->create([
                    'user_id' => $user?->id,
                    'name' => $data['player_name'],
                    'is_moderator' => false,
                    'last_seen_at' => now(),
                ]);
            } else {
                $player->update([
                    'last_seen_at' => now(),
                    'inactive_at' => null,
                ]);
            }

            $room->update([
                'last_activity_at' => now(),
                'state_version' => $room->state_version + 1,
            ]);

            return [$room, $player];
        });

        RoomStateChanged::dispatch(
            $room->id,
            $room->state_version,
            RoomStateChange::PlayerJoined,
        );

        return [$room, $player];
    }
}