<?php
/**
 * Resolves the MarginBeacon Pro upgrade state for UI CTA rendering.
 *
 * State is derived from the official WordPress plugin API (installed vs
 * active) and the project EntitlementService (execution entitlement) — never
 * only from a constant, file presence, or class existence.
 *
 * @package Kayvandra\MarginBeacon
 */

declare(strict_types=1);

namespace Kayvandra\MarginBeacon\Support;

use Kayvandra\MarginBeacon\Application\Entitlement\EntitlementService;

/**
 * Enumerates the CTA-relevant channel states and exposes the resolved one.
 */
final class UpgradeStateResolver {

	const STATE_FREE_ONLY               = 'free_only';
	const STATE_PRO_INSTALLED_INACTIVE  = 'pro_installed_inactive';
	const STATE_PRO_ACTIVE_NOT_ENTITLED = 'pro_active_not_entitled';
	const STATE_PRO_ACTIVE              = 'pro_active';
	const STATE_DIRECT                  = 'direct';

	/**
	 * @var callable():bool Returns whether the Pro companion is network/site active.
	 */
	private $is_pro_active;

	/**
	 * @var callable():bool Returns whether the Pro companion is installed (any state).
	 */
	private $is_pro_installed;

	/**
	 * @var callable():bool Returns whether the resolved entitlement allows Pro execution.
	 */
	private $allows_pro_execution;

	/**
	 * @var callable():bool Returns whether the single-package Direct channel is active.
	 */
	private $is_direct;

	/**
	 * @param callable|null $is_pro_active       Active detector (defaults to WP plugin API).
	 * @param callable|null $is_pro_installed    Installed detector (defaults to WP plugin API).
	 * @param callable|null $allows_pro_execution Entitlement detector (defaults to EntitlementService).
	 * @param callable|null $is_direct             Direct channel detector.
	 */
	public function __construct( ?callable $is_pro_active = null, ?callable $is_pro_installed = null, ?callable $allows_pro_execution = null, ?callable $is_direct = null ) {
		$this->is_pro_active        = $is_pro_active ?? array( __CLASS__, 'default_is_pro_active' );
		$this->is_pro_installed     = $is_pro_installed ?? array( __CLASS__, 'default_is_pro_installed' );
		$this->allows_pro_execution = $allows_pro_execution ?? static function () {
			return ( new EntitlementService() )->resolve()->allows_pro_execution();
		};
		$this->is_direct            = $is_direct ?? array( DistributionChannel::class, 'is_direct' );
	}

	/**
	 * Resolved state.
	 *
	 * @return string One of the STATE_* constants.
	 */
	public function resolve() {
		if ( call_user_func( $this->is_direct ) ) {
			return self::STATE_DIRECT;
		}

		$active = (bool) call_user_func( $this->is_pro_active );

		if ( $active ) {
			return call_user_func( $this->allows_pro_execution )
				? self::STATE_PRO_ACTIVE
				: self::STATE_PRO_ACTIVE_NOT_ENTITLED;
		}

		return call_user_func( $this->is_pro_installed )
			? self::STATE_PRO_INSTALLED_INACTIVE
			: self::STATE_FREE_ONLY;
	}

	/**
	 * Whether the current state warrants a primary purchase/upgrade CTA.
	 *
	 * @return bool
	 */
	public function shows_upgrade_cta() {
		return self::STATE_FREE_ONLY === $this->resolve();
	}

	/**
	 * Whether Pro is installed but inactive (activation prompt, not purchase).
	 *
	 * @return bool
	 */
	public function is_pro_installed_inactive() {
		return self::STATE_PRO_INSTALLED_INACTIVE === $this->resolve();
	}

	/**
	 * Whether Pro is active but not entitled (license setup prompt, not purchase).
	 *
	 * @return bool
	 */
	public function is_pro_active_not_entitled() {
		return self::STATE_PRO_ACTIVE_NOT_ENTITLED === $this->resolve();
	}

	/**
	 * Whether Pro is active and fully entitled (hide all CTA/price).
	 *
	 * @return bool
	 */
	public function is_pro_active_entitled() {
		return self::STATE_PRO_ACTIVE === $this->resolve();
	}

	/**
	 * Whether the single-package Direct edition is active.
	 *
	 * @return bool
	 */
	public function is_direct() {
		return self::STATE_DIRECT === $this->resolve();
	}

	/**
	 * Human-readable label for a state (for tests / logs).
	 *
	 * @param string $state State constant.
	 * @return string
	 */
	public static function label( $state ) {
		switch ( $state ) {
			case self::STATE_DIRECT:
				return 'Direct Edition';
			case self::STATE_PRO_INSTALLED_INACTIVE:
				return 'Pro installed (inactive)';
			case self::STATE_PRO_ACTIVE_NOT_ENTITLED:
				return 'Pro active (not entitled)';
			case self::STATE_PRO_ACTIVE:
				return 'Pro active';
			case self::STATE_FREE_ONLY:
			default:
				return 'Free-only';
		}
	}

	/**
	 * Default active detector using the WordPress plugin API.
	 *
	 * @return bool
	 */
	private static function default_is_pro_active() {
		if ( ! function_exists( 'is_plugin_active' ) ) {
			require_once ABSPATH . 'wp-admin/includes/plugin.php';
		}
		if ( ! function_exists( 'is_plugin_active' ) ) {
			return false;
		}
		return is_plugin_active( Constants::PRO_PLUGIN_BASENAME );
	}

	/**
	 * Default installed detector using the WordPress plugin API.
	 *
	 * @return bool
	 */
	private static function default_is_pro_installed() {
		if ( ! function_exists( 'get_plugins' ) ) {
			require_once ABSPATH . 'wp-admin/includes/plugin.php';
		}
		if ( ! function_exists( 'get_plugins' ) ) {
			return false;
		}
		$plugins = get_plugins();
		return isset( $plugins[ Constants::PRO_PLUGIN_BASENAME ] );
	}
}