<?php

declare(strict_types=1);

namespace Shimmie2;

class ImageInfoSetEvent extends Event
{
    public Image $image;
    public int $slot;
    /** @var array<string, string> */
    public array $params;

    /**
     * currently all post metadata is string => string - in the future
     * we might want to have a more complex type system, but for now
     * we just filter out non-string keys (eg, `only_strings($_POST)`)
     *
     * @param array<string, string> $params
     */
    public function __construct(Image $image, int $slot, array $params)
    {
        parent::__construct();
        $this->image = $image;
        $this->slot = $slot;
        $this->params = $params;
    }

    /**
     * Get a slot-specific value, or a common value, or null. This allows
     * a user to POST an update to multiple images at once, setting eg
     * "source" to be a common default source and "source12" to be a
     * specific source for image 12.
     *
     * Specifically we check for "empty" rather than "isset" because
     * the upload form might have a "source" field that is empty, and
     * we want to allow non-empty values to override empty ones.
     */
    public function get_param(string $name): ?string
    {
        if(!empty($this->params["$name{$this->slot}"])) {
            return $this->params["$name{$this->slot}"];
        }
        if(!empty($this->params[$name])) {
            return $this->params[$name];
        }
        return null;
    }
}