<?php

namespace App\Services;

use App\Models\Task;
use App\Notifications\TaskDueNotification;

class TaskReminderService
{
    public function sendDueNotifications(): int
    {
        $sent = 0;
        $now = now();

        Task::active()
            ->whereNotNull('assigned_to')
            ->where(function ($query) use ($now): void {
                $query->where(fn ($reminders) => $reminders->whereNotNull('reminder_at')->where('reminder_at', '<=', $now))
                    ->orWhere(fn ($overdue) => $overdue->whereNotNull('due_at')->where('due_at', '<', $now));
            })
            ->orderBy('id')
            ->chunkById(100, function ($tasks) use (&$sent, $now): void {
                foreach ($tasks as $task) {
                    if ($task->reminder_at?->lte($now)) {
                        TaskDueNotification::send($task, 'reminder');
                        $sent++;
                    }
                    if ($task->due_at?->lt($now)) {
                        TaskDueNotification::send($task, 'overdue');
                        $sent++;
                    }
                }
            });

        return $sent;
    }
}