<?php

namespace App\Support\Badges;

use InvalidArgumentException;

final class BadgeSpec
{
    /**
     * @var array<int, string>
     */
    private const ALLOWED_COLORS = [
        'gray',
        'info',
        'success',
        'warning',
        'danger',
        'primary',
    ];

    public function __construct(
        public readonly string $label,
        public readonly string $color,
        public readonly ?string $icon = null,
        public readonly ?string $iconColor = null,
        public readonly ?OperatorSemanticAxis $semanticAxis = null,
        public readonly ?OperatorStateClassification $classification = null,
        public readonly ?OperatorNextActionPolicy $nextActionPolicy = null,
        public readonly ?string $diagnosticLabel = null,
        /**
         * @var list<string>
         */
        public readonly array $legacyAliases = [],
        public readonly ?string $notes = null,
    ) {
        if (trim($this->label) === '') {
            throw new InvalidArgumentException('BadgeSpec label must be a non-empty string.');
        }

        if (! in_array($this->color, self::ALLOWED_COLORS, true)) {
            throw new InvalidArgumentException('BadgeSpec color must be one of: '.implode(', ', self::ALLOWED_COLORS));
        }

        if ($this->icon !== null && trim($this->icon) === '') {
            throw new InvalidArgumentException('BadgeSpec icon must be null or a non-empty string.');
        }

        if ($this->iconColor !== null && ! in_array($this->iconColor, self::ALLOWED_COLORS, true)) {
            throw new InvalidArgumentException('BadgeSpec iconColor must be null or one of: '.implode(', ', self::ALLOWED_COLORS));
        }

        $hasTaxonomyMetadata = $this->semanticAxis !== null
            || $this->classification !== null
            || $this->nextActionPolicy !== null
            || $this->diagnosticLabel !== null
            || $this->legacyAliases !== []
            || $this->notes !== null;

        if ($hasTaxonomyMetadata && ($this->semanticAxis === null || $this->classification === null || $this->nextActionPolicy === null)) {
            throw new InvalidArgumentException('BadgeSpec taxonomy metadata requires semanticAxis, classification, and nextActionPolicy together.');
        }

        if ($this->diagnosticLabel !== null && trim($this->diagnosticLabel) === '') {
            throw new InvalidArgumentException('BadgeSpec diagnosticLabel must be null or a non-empty string.');
        }

        foreach ($this->legacyAliases as $legacyAlias) {
            if (! is_string($legacyAlias) || trim($legacyAlias) === '') {
                throw new InvalidArgumentException('BadgeSpec legacyAliases must contain only non-empty strings.');
            }
        }

        if ($this->notes !== null && trim($this->notes) === '') {
            throw new InvalidArgumentException('BadgeSpec notes must be null or a non-empty string.');
        }

        if ($this->classification === OperatorStateClassification::Diagnostic && in_array($this->color, ['warning', 'danger'], true)) {
            throw new InvalidArgumentException('Diagnostic badge specs cannot use warning or danger colors.');
        }

        if ($this->classification === OperatorStateClassification::Primary
            && in_array($this->color, ['warning', 'danger'], true)
            && $this->nextActionPolicy === OperatorNextActionPolicy::None) {
            throw new InvalidArgumentException('Primary warning or danger badge specs must declare an operator next-action policy.');
        }
    }

    /**
     * @return array<int, string>
     */
    public static function allowedColors(): array
    {
        return self::ALLOWED_COLORS;
    }

    public static function unknown(): self
    {
        return new self(
            label: 'Unknown',
            color: 'gray',
            icon: 'heroicon-m-question-mark-circle',
            iconColor: 'gray',
        );
    }
}