Global Report

 1<?php ...
 2 
 3namespace Thunk\Verbs\Examples\Subscriptions\States;
 4 
 5use Illuminate\Support\Carbon;
 6use Thunk\Verbs\Examples\Subscriptions\Events\SubscriptionCancelled;
 7use Thunk\Verbs\Examples\Subscriptions\Events\SubscriptionStarted;
 8use Thunk\Verbs\State; 
 9 
10class GlobalReportState extends State
11{
12    public int $total_subscriptions = 0;
13 
14    public int $subscribes_since_last_report = 0;
15 
16    public int $unsubscribes_since_last_report = 0;
17 
18    public Carbon $last_reported_at;
19 
20    public function summary(): string
21    {
22        $churn = $this->subscribes_since_last_report > 0
23            ? ($this->unsubscribes_since_last_report / $this->subscribes_since_last_report) * 100
24            : 0;
25 
26        return implode('; ', [
27            "{$this->subscribes_since_last_report} subscribe(s)",
28            "{$this->unsubscribes_since_last_report} unsubscribe(s)",
29            "{$churn}% churn",
30        ]);
31    }
32 
33    public function applySubscriptionStarted(SubscriptionStarted $e)
34    {
35        $this->total_subscriptions++;
36        $this->subscribes_since_last_report++;
37    }
38 
39    public function applySubscriptionCancelled(SubscriptionCancelled $e)
40    {
41        $this->total_subscriptions--;
42        $this->unsubscribes_since_last_report++;
43    }
44}