<?php

namespace NoccyLabs\Mercureact\Broker;

use SplObjectStorage;

class Message
{
    /** @var array<int,string> The topic, if more than one the first is canonical, but all receive delivery */
    public readonly array $topic;
    /** @var string|null The SSE event type */
    public readonly ?string $type;
    /** @var string|null Message data */
    public readonly ?string $data;
    /** @var bool|null Private update*/
    public readonly ?bool $private;
    /** @var string|null Message ID */
    public readonly ?string $id;
    /** @var int SSE retry interval */
    public readonly ?int $retry;

    private readonly int $created;

    public function __construct(
        array $topic,
        ?string $data=null,
        ?string $type=null,
        ?bool $private=null,
        ?string $id=null,
        ?int $retry=null
    )
    {
        $this->topic = $topic;
        $this->type = $type;
        $this->data = $data;
        $this->private = $private;
        $this->id = $id;
        $this->retry = $retry;
        $this->created = time();
    }

    public function getAge(): int
    {
        return time() - $this->created;
    }

    public function toString(): string
    {
        $msg = [];
        if ($this->type) $msg[] = "event: ".$this->type;
        if ($this->retry) $msg[] = "retry: ".$this->retry;
        if ($this->id) $msg[] = "id: ".$this->id;
        if ($this->data) $msg[] = "data: ".$this->data;
        return join("\n", $msg)."\n\n";
    }

    public static function fromData(array $data): Message
    {
        return new Message(
            topic: (array)$data['topic'],
            type: $data['type']??null,
            data: $data['data']??null,
            private: match ($data['private']??null) { "on" => true, true => true, null => null, default => false },
            id: $data['id']??null,
            retry: $data['retry']??null,
        );
    }
}