<?php
/**
 * CodeCanyon purchase code (CodeCanyon build only): activation without an account, or linking to a connected account.
 *
 * @package Keepwatch
 */

namespace Keepwatch\Cloud;

use Keepwatch\Vendor\WPXLab\Client\Client;

defined( 'ABSPATH' ) || exit;

/**
 * Sends the purchase code to WPXLab in a signed request; WPXLab checks it with Envato. activate() connects the site
 * with the purchase code and an e-mail address (no WPXLab account needed, ADR-0011); redeem() links the code to the
 * account an already connected site belongs to. The Envato token never ships with the plugin (CLAUDE.md rule 13). Nothing is sent
 * unless the site is connected, i.e. the administrator already accepted the consent screen (rule 7).
 * The code itself is not stored on the site: only the last four characters and what WPXLab returned (rule 3).
 * Local features never depend on it (rule 11).
 */
final class PurchaseCode {

	public const OPTION = 'keepwatch_envato';

	/**
	 * WPXLab client.
	 *
	 * @var Client
	 */
	private $client;

	/**
	 * Constructor.
	 *
	 * @param Client $client WPXLab client.
	 */
	public function __construct( Client $client ) {
		$this->client = $client;
	}

	/**
	 * Last linked purchase, if any.
	 *
	 * @return array{item: string, license_type: string, code_last4: string, supported_until: string, redeemed_at: int, account_created: bool}|null
	 */
	public static function state(): ?array {
		$stored = get_option( self::OPTION );
		if ( ! is_array( $stored ) || empty( $stored['code_last4'] ) ) {
			return null;
		}

		return array(
			'item'            => isset( $stored['item'] ) ? (string) $stored['item'] : '',
			'license_type'    => isset( $stored['license_type'] ) ? (string) $stored['license_type'] : '',
			'code_last4'      => (string) $stored['code_last4'],
			'supported_until' => isset( $stored['supported_until'] ) ? (string) $stored['supported_until'] : '',
			'redeemed_at'     => isset( $stored['redeemed_at'] ) ? (int) $stored['redeemed_at'] : 0,
			'account_created' => ! empty( $stored['account_created'] ),
		);
	}

	/**
	 * Activate this site with a purchase code and the buyer's e-mail (no WPXLab account needed).
	 * WPXLab verifies the code with Envato, opens an account for the e-mail if there is none, and connects this site.
	 * Nothing is sent before the administrator accepts what is shared (CLAUDE.md rule 7).
	 *
	 * @param string $code    Purchase code.
	 * @param string $email   Buyer e-mail.
	 * @param bool   $consent Whether the consent box was ticked.
	 * @return array{ok: bool, error: string, message: string, account_created: bool}
	 */
	public function activate( string $code, string $email, bool $consent ): array {
		if ( ! $consent ) {
			return self::failure( 'consent_required', __( 'Please accept what Keepwatch will send before connecting.', 'keepwatch' ) ) + array( 'account_created' => false );
		}

		$code  = strtolower( trim( $code ) );
		$email = strtolower( trim( $email ) );
		if ( 1 !== preg_match( '/^[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$/', $code ) ) {
			return self::failure( 'purchase_code_format', self::message_for( 'purchase_code_format' ) ) + array( 'account_created' => false );
		}
		if ( ! is_email( $email ) ) {
			return self::failure( 'purchase_code_email', self::message_for( 'purchase_code_email' ) ) + array( 'account_created' => false );
		}

		global $wp_version;

		// The Hub calls back /wp-json/keepwatch/v1/verify while this request runs; only then do we sign challenges.
		set_transient( Connection::PENDING, time(), Connection::PENDING_SECONDS );

		$response = $this->client->api()->request(
			'POST',
			'/keepwatch/envato/activate',
			array(
				'purchase_code'  => $code,
				'email'          => $email,
				'install_uuid'   => $this->client->install_uuid(),
				'home_url'       => home_url( '/' ),
				'plugin_version' => KEEPWATCH_VERSION,
				'wp_version'     => (string) $wp_version,
				'php_version'    => PHP_VERSION,
			)
		);

		delete_transient( Connection::PENDING );

		if ( 201 !== $response['status'] ) {
			$error = isset( $response['body']['error'] ) ? (string) $response['body']['error'] : 'unexpected';
			return self::failure( $error, self::message_for( $error ) ) + array( 'account_created' => false );
		}

		$body = $response['body'];
		Connection::remember( $body );
		$purchase = isset( $body['purchase'] ) && is_array( $body['purchase'] ) ? $body['purchase'] : array();
		$created  = ! empty( $body['account_created'] );
		self::store( $purchase, $code, $created );

		return array(
			'ok'              => true,
			'error'           => '',
			'message'         => '',
			'account_created' => $created,
		);
	}

	/**
	 * Link a purchase code to the connected WPXLab account.
	 *
	 * @param string $code Purchase code (xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx).
	 * @return array{ok: bool, error: string, message: string}
	 */
	public function redeem( string $code ): array {
		if ( ! Connection::is_connected() ) {
			return self::failure( 'site_not_connected', self::message_for( 'site_not_connected' ) );
		}

		$code = strtolower( trim( $code ) );
		if ( 1 !== preg_match( '/^[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$/', $code ) ) {
			return self::failure( 'purchase_code_format', self::message_for( 'purchase_code_format' ) );
		}

		$response = $this->client->api()->request(
			'POST',
			'/envato/redeem',
			array(
				'product'       => 'keepwatch',
				'purchase_code' => $code,
			)
		);

		if ( 200 !== $response['status'] && 201 !== $response['status'] ) {
			$error = isset( $response['body']['error'] ) ? (string) $response['body']['error'] : 'unexpected';
			return self::failure( $error, self::message_for( $error ) );
		}

		self::store( $response['body'], $code, false );

		return array(
			'ok'      => true,
			'error'   => '',
			'message' => '',
		);
	}

	/**
	 * Store only a summary of the purchase; the code itself never stays on the site (rule 3).
	 *
	 * @param array<string, mixed> $body            Purchase summary from the Hub.
	 * @param string               $code            Purchase code (only the last four characters are kept).
	 * @param bool                 $account_created Whether WPXLab opened a new account for the buyer.
	 */
	private static function store( array $body, string $code, bool $account_created ): void {
		update_option(
			self::OPTION,
			array(
				'item'            => isset( $body['item'] ) ? sanitize_text_field( (string) $body['item'] ) : '',
				'license_type'    => isset( $body['license_type'] ) ? sanitize_text_field( (string) $body['license_type'] ) : '',
				'code_last4'      => substr( $code, -4 ),
				'supported_until' => isset( $body['supported_until'] ) ? sanitize_text_field( (string) $body['supported_until'] ) : '',
				'redeemed_at'     => time(),
				'account_created' => $account_created,
			),
			false
		);
	}

	/**
	 * Forget the stored purchase summary (e.g. after disconnecting).
	 */
	public static function forget(): void {
		delete_option( self::OPTION );
	}

	/**
	 * Human readable message for an API error code.
	 *
	 * @param string $error Error code.
	 */
	public static function message_for( string $error ): string {
		switch ( $error ) {
			case 'site_not_connected':
				return __( 'Connect this site to your WPXLab account first, then add the purchase code.', 'keepwatch' );
			case 'purchase_code_format':
				return __( 'The purchase code must look like xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.', 'keepwatch' );
			case 'purchase_code_invalid':
				return __( 'This purchase code was not found on Envato. Please check it.', 'keepwatch' );
			case 'purchase_code_email':
				return __( 'Please enter a valid e-mail address.', 'keepwatch' );
			case 'purchase_code_account_exists':
				return __( 'A WPXLab account with this e-mail already exists. Sign in at wpxlab.com, create a connection code under Keepwatch and connect with it below; then add the purchase code.', 'keepwatch' );
			case 'purchase_code_taken':
				return __( 'This purchase code is already linked to another WPXLab account. If it is yours, contact support.', 'keepwatch' );
			case 'purchase_code_unknown_item':
				return __( 'This purchase code is for a different item. Please contact support.', 'keepwatch' );
			case 'purchase_code_unavailable':
				return __( 'Envato is not responding right now. Please try again shortly.', 'keepwatch' );
			case 'network':
			case 'site_limit_reached':
			case 'site_already_connected':
			case 'site_unreachable':
			case 'site_verification_failed':
			case 'site_url_invalid':
				return Connection::message_for( $error );
			default:
				return __( 'The purchase code could not be added. Please try again.', 'keepwatch' );
		}
	}

	/**
	 * Failure result.
	 *
	 * @param string $error   Code.
	 * @param string $message Message.
	 * @return array{ok: bool, error: string, message: string}
	 */
	private static function failure( string $error, string $message ): array {
		return array(
			'ok'      => false,
			'error'   => $error,
			'message' => $message,
		);
	}
}