<?php
/**
 * Immutable capability set.
 *
 * @package Kayvandra\MarginBeacon
 */

declare(strict_types=1);

namespace Kayvandra\MarginBeacon\Application\Entitlement;

/**
 * Resolved entitlement capabilities for the current site.
 */
final class CapabilitySet {

	/**
	 * Tier: free|pro|expired|unavailable|corrupted.
	 *
	 * @var string
	 */
	private $tier;

	/**
	 * Capability flags.
	 *
	 * @var array<string,bool>
	 */
	private $caps;

	/**
	 * @param string             $tier Tier.
	 * @param array<string,bool> $caps Caps.
	 */
	public function __construct( $tier, array $caps ) {
		$this->tier = $tier;
		$this->caps = $caps;
	}

	/**
	 * @return string
	 */
	public function tier() {
		return $this->tier;
	}

	/**
	 * @param string $capability Capability key.
	 * @return bool
	 */
	public function can( $capability ) {
		return ! empty( $this->caps[ $capability ] );
	}

	/**
	 * Free baseline capability set.
	 *
	 * @return CapabilitySet
	 */
	public static function free() {
		return new self(
			'free',
			array(
				'cogs_wizard'                       => true,
				'selected_coupon_preflight'         => true,
				'transaction_risk_promoted'         => true,
				'recent_orders_preview'             => true,
				'health_cli'                        => true,
				'basic_health_ui'                   => true,
				'acknowledge_loss_leader'           => true,
				'full_scan'                         => false,
				'scheduled_scan'                    => false,
				'category_thresholds'               => false,
				'category_assumed_cost'             => false,
				'baseline_order_monitor'            => false,
				'line_level_evidence'               => false,
				'price_history'                     => false,
				'advanced_filters'                  => false,
				'export'                            => false,
				'advanced_diagnostics'              => false,
				'representative_fixed_cart_baskets' => false,
				'advanced_cli'                      => false,
				'pairwise_stacking'                 => false,
				'publish_gate'                      => false,
			)
		);
	}

	/**
	 * Pro companion capability set (V1.0 surface + V1.1 pairwise).
	 *
	 * @return CapabilitySet
	 */
	public static function pro() {
		return self::free()->with_enabled(
			array(
				'full_scan'                         => true,
				'scheduled_scan'                    => true,
				'category_thresholds'               => true,
				'category_assumed_cost'             => true,
				'baseline_order_monitor'            => true,
				'line_level_evidence'               => true,
				'price_history'                     => true,
				'advanced_filters'                  => true,
				'export'                            => true,
				'advanced_diagnostics'              => true,
				'representative_fixed_cart_baskets' => true,
				'advanced_cli'                      => true,
				'pairwise_stacking'                 => true,
				'publish_gate'                      => false,
			),
			'pro'
		);
	}

	/**
	 * Pro expired: Free execution remains; Pro controls disabled; data retained read-only (FR-012 / §8.6).
	 *
	 * @return CapabilitySet
	 */
	public static function expired() {
		return new self( 'expired', self::free()->all() );
	}

	/**
	 * Entitlement temporarily unavailable (network/channel): last-known Free-safe surface.
	 *
	 * @return CapabilitySet
	 */
	public static function unavailable() {
		return new self( 'unavailable', self::free()->all() );
	}

	/**
	 * Corrupted entitlement payload: degrade to Free caps without fatal.
	 *
	 * @return CapabilitySet
	 */
	public static function corrupted() {
		return new self( 'corrupted', self::free()->all() );
	}

	/**
	 * Whether this tier may run Pro execution controls (scans, exports, etc.).
	 *
	 * @return bool
	 */
	public function allows_pro_execution() {
		return in_array( $this->tier, array( 'pro', 'direct' ), true );
	}

	/**
	 * Return a copy with capability overrides and optional new tier.
	 *
	 * @param array<string,bool> $enabled Caps to merge.
	 * @param string|null        $tier    Optional tier override.
	 * @return CapabilitySet
	 */
	public function with_enabled( array $enabled, $tier = null ) {
		return new self(
			null !== $tier ? (string) $tier : $this->tier,
			array_merge( $this->caps, $enabled )
		);
	}

	/**
	 * @return array<string,bool>
	 */
	public function all() {
		return $this->caps;
	}
}