ActiveCallController.php

<?php

namespace App\Http\Controllers;

use App\Cdr;
use Carbon\Carbon;
use Illuminate\Http\Request;
const HOURS=8;
const MAX_PHONECALL = 2;

class ActiveCallController extends Controller
{
    public function index(Request $request)
    {
        if ($request->has('date')) {
            $startDate = Carbon::parse($request->date);
        } else {
            $startDate = Carbon::now();
        }

        $date1 = Carbon::parse($startDate)->subHours(HOURS);
        $date2 = Carbon::parse($startDate)->subHours(HOURS+MAX_PHONECALL);
        $date3 = Carbon::parse($startDate);

        $startActiveCalls = Cdr::where('answer_stamp', '>', $date2)
            ->where('answer_stamp', '<', $date1)
            ->where('end_stamp', '>', $date1)->count();

        $cdrs = Cdr::where('answer_stamp', '<', $date3)
            ->where('answer_stamp', '>', $date1)->get();

        $answered = $cdrs->map(function($cdr) {
            return (object)[
                'id' => $cdr->xml_cdr_uuid,
                'action' => 'answer',
                'timestamp' => $cdr->answer_stamp];
        });

        $ended = $cdrs->map(function($cdr) {
            return (object)[
                'id' => $cdr->xml_cdr_uuid,
                'action' => 'end',
                'timestamp' => $cdr->end_stamp];
        });

        $events = $ended
            ->merge($answered)
            ->sortBy('timestamp')
            ->values();

        $minutes = collect();

        for ($i = (HOURS*60); $i >= 0; $i--) {
            $minutes->push(Carbon::parse($date3)->subMinutes($i)->format('YmdHi'));
        }

        $maxActiveCalls = collect();

        $currentActiveCalls = $startActiveCalls;
        $maxActiveThisMinute = $currentActiveCalls;

        foreach ($minutes as $minute) {
            $eventsForThisMinute = $events->filter(function ($event) use ($minute){
                return Carbon::parse($event->timestamp)->format('YmdHi') === $minute;
            });

            foreach ($eventsForThisMinute as $event) {
                if ($event->action === 'answer') {
                    $currentActiveCalls++;
                    if ($maxActiveThisMinute < $currentActiveCalls)
                        $maxActiveThisMinute = $currentActiveCalls;
                } else if ($event->action === 'end') {
                    $currentActiveCalls--;
                }
            }

            $maxActiveCalls->push(
                (object)[
                    'time' => $minute,
                    'max' => $maxActiveThisMinute
                ]);
            $maxActiveThisMinute = $currentActiveCalls;
        }

        return $maxActiveCalls;
    }
}