<?php

declare(strict_types=1);

namespace Intervention\Image\Colors\Hsl\Decoders;

use Intervention\Image\Colors\Hsl\Color;
use Intervention\Image\Drivers\AbstractDecoder;
use Intervention\Image\Exceptions\InvalidArgumentException;
use Intervention\Image\Interfaces\ColorInterface;
use Intervention\Image\Interfaces\DecoderInterface;

class StringColorDecoder extends AbstractDecoder implements DecoderInterface
{
    /**
     * Regex pattern of HSL color syntax
     */
    private const string PATTERN =
    '/^hsla? ?\( ?' .
        '(?P<h>[0-9\.]+)(?:deg)?((, ?)| )' .
        '(?P<s>[0-9\.]+%?)((, ?)| )' .
        '(?P<l>[0-9\.]+%?)' .
        '(?:(?:(?: ?\/ ?)|(?:[, ]) ?)' .
        '(?<a>(?:0\.[0-9]+)|1\.0|\.[0-9]+|[0-9]{1,3}%|1|0))?' .
        ' ?\)$/i';

    /**
     * {@inheritdoc}
     *
     * @see DecoderInterface::supports()
     */
    public function supports(mixed $input): bool
    {
        if (!is_string($input)) {
            return false;
        }

        if (!str_starts_with(strtolower($input), 'hsl')) {
            return false;
        }

        return true;
    }

    /**
     * Decode hsl color strings.
     *
     * @throws InvalidArgumentException
     */
    public function decode(mixed $input): ColorInterface
    {
        if (preg_match(self::PATTERN, $input, $matches) != 1) {
            throw new InvalidArgumentException('Invalid hsl() color syntax "' . $input . '"');
        }

        $values = array_map(fn(string $value): int => match (strpos($value, '%')) {
            false => intval(trim($value)),
            default => intval(trim(str_replace('%', '', $value))),
        }, [$matches['h'], $matches['s'], $matches['l']]);

        // alpha value
        if (array_key_exists('a', $matches)) {
            $values[] = match (strpos($matches['a'], '%')) {
                false => floatval(trim($matches['a'])),
                default => floatval(trim(str_replace('%', '', $matches['a']))) / 100,
            };
        }

        return new Color(...$values);
    }
}
