<?php

namespace AIbender\ArticleVault\Payments;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

use AIbender\ArticleVault\Access\AccessManager;
use AIbender\ArticleVault\Access\SecureToken;
use AIbender\ArticleVault\Core\Constants;
use AIbender\ArticleVault\Databases\PurchaseRepository;

class StripeCheckout {

	private StripeManager $stripe_manager;

	private StripeSession $stripe_session;

	private PurchaseRepository $purchase_repository;

	private AccessManager $access_manager;

	private SecureToken $secure_token;

	public function __construct(
		StripeManager $stripe_manager,
		StripeSession $stripe_session,
		PurchaseRepository $purchase_repository,
		AccessManager $access_manager,
		SecureToken $secure_token
	) {

		$this->stripe_manager      = $stripe_manager;
		$this->stripe_session      = $stripe_session;
		$this->purchase_repository = $purchase_repository;
		$this->access_manager      = $access_manager;
		$this->secure_token        = $secure_token;

	}

	public function register(): void {

		add_action(
			'admin_post_' . Constants::STRIPE_CHECKOUT_ACTION,
			array( $this, 'handle_checkout_request' )
		);

		add_action(
			'admin_post_nopriv_' . Constants::STRIPE_CHECKOUT_ACTION,
			array( $this, 'handle_checkout_request' )
		);

		add_action(
			'template_redirect',
			array( $this, 'maybe_handle_payment_return' )
		);

		add_filter(
    	'allowed_redirect_hosts',
    	array( $this, 'allow_stripe_redirect_host' )
		);

	}

	public function handle_checkout_request(): void {

		$article_id = isset( $_POST['articlevault_article_id'] )
			? absint( $_POST['articlevault_article_id'] )
			: 0;

		$nonce = isset( $_POST['articlevault_checkout_nonce'] )
			? sanitize_text_field( wp_unslash( $_POST['articlevault_checkout_nonce'] ) )
			: '';

		if (
			! $article_id
			|| ! wp_verify_nonce(
				$nonce,
				'articlevault_checkout_' . $article_id
			)
		) {
			wp_die(
				esc_html__( 'Security check failed.', 'aibender-articlevault-pro' )
			);
		}

		if ( 'publish' !== get_post_status( $article_id ) ) {
			wp_die(
				esc_html__( 'Invalid article.', 'aibender-articlevault-pro' )
			);
		}

		if ( ! $this->stripe_manager->is_configured() ) {
			wp_die(
				esc_html__( 'Stripe is not configured.', 'aibender-articlevault-pro' )
			);
		}

		$email = isset( $_POST['articlevault_email'] )
			? sanitize_email( wp_unslash( $_POST['articlevault_email'] ) )
			: '';

		$session = $this->stripe_session->create_checkout_session(
			$article_id,
			$email
		);

		if ( is_wp_error( $session ) ) {
			wp_die(
				esc_html( $session->get_error_message() )
			);
		}

		if ( empty( $session['id'] ) || empty( $session['url'] ) ) {
			wp_die(
				esc_html__(
					'Unable to create Stripe Checkout session.',
					'aibender-articlevault-pro'
				)
			);
		}

		$this->purchase_repository->create_pending_purchase(
			sanitize_text_field( $session['id'] ),
			$article_id,
			$email,
			$this->stripe_manager->get_price_cents(),
			$this->stripe_manager->get_currency()
		);

		$this->redirect_to_stripe(
			$session['url']
		);

	}

	public function maybe_handle_payment_return(): void {

		$payment_status = isset( $_GET['articlevault_payment'] )
			? sanitize_key( wp_unslash( $_GET['articlevault_payment'] ) )
			: '';

		if ( 'cancelled' === $payment_status ) {
			$this->render_cancel_page();
		}

		if ( 'success' !== $payment_status ) {
			return;
		}

		$this->handle_success_return();

	}

	private function handle_success_return(): void {

		$session_id = isset( $_GET['session_id'] )
			? sanitize_text_field( wp_unslash( $_GET['session_id'] ) )
			: '';

		if ( '' === $session_id ) {
			$this->render_error_page(
				__( 'The Stripe session ID is missing.', 'aibender-articlevault-pro' )
			);
		}

		$session = $this->stripe_session->retrieve_checkout_session(
			$session_id
		);

		if ( is_wp_error( $session ) ) {
			$this->render_error_page(
				__( 'We could not verify this payment.', 'aibender-articlevault-pro' )
			);
		}

		if (
			empty( $session['payment_status'] )
			|| 'paid' !== $session['payment_status']
		) {
			$this->render_error_page(
				__( 'This payment has not been completed.', 'aibender-articlevault-pro' )
			);
		}

		$purchase = $this->purchase_repository->find_by_session_id(
			$session_id
		);

		if ( ! $purchase ) {
			$this->render_error_page(
				__( 'The matching purchase could not be found.', 'aibender-articlevault-pro' )
			);
		}

		$article_id = ! empty( $session['metadata']['article_id'] )
			? absint( $session['metadata']['article_id'] )
			: absint( $session['client_reference_id'] ?? 0 );

		$amount   = absint( $session['amount_total'] ?? 0 );
		$currency = strtolower(
			sanitize_text_field( $session['currency'] ?? '' )
		);

		if (
			! $article_id
			|| (int) $purchase['article_id'] !== $article_id
			|| (int) $purchase['amount'] !== $amount
			|| strtolower( (string) $purchase['currency'] ) !== $currency
		) {
			$this->render_error_page(
				__( 'The payment details did not match this purchase.', 'aibender-articlevault-pro' )
			);
		}

		if ( 'publish' !== get_post_status( $article_id ) ) {
			$this->render_error_page(
				__( 'The purchased article is no longer available.', 'aibender-articlevault-pro' )
			);
		}

		$email = '';

		if ( ! empty( $session['customer_details']['email'] ) ) {
			$email = sanitize_email( $session['customer_details']['email'] );
		} elseif ( ! empty( $session['customer_email'] ) ) {
			$email = sanitize_email( $session['customer_email'] );
		}

		$raw_token  = $this->secure_token->generate();
		$token_hash = $this->secure_token->hash( $raw_token );

		if ( 'paid' !== (string) $purchase['status'] ) {
			$this->purchase_repository->mark_paid(
				$session_id,
				sanitize_text_field( $session['payment_intent'] ?? '' ),
				$article_id,
				$email,
				$amount,
				$currency,
				$token_hash
			);
		}

		if (
			! $this->purchase_repository->claim_access_token(
				$session_id,
				$token_hash
			)
		) {
			if ( $this->access_manager->user_has_access( $article_id ) ) {
				$this->render_success_page(
					get_permalink( $article_id )
				);
			}

			$this->render_error_page(
				__( 'This payment return has already been used. Please open the article in the browser where the purchase was completed.', 'aibender-articlevault-pro' )
			);
		}

		$this->access_manager->grant_access(
			$article_id,
			$raw_token
		);

		$this->render_success_page(
			get_permalink( $article_id )
		);

	}

	private function render_success_page( string $redirect_url ): void {

		$this->render_status_page(
			__( 'Payment successful', 'aibender-articlevault-pro' ),
			__( 'Thank you for your purchase. Your article is now unlocked.', 'aibender-articlevault-pro' ),
			$redirect_url,
			__( 'Continue to article', 'aibender-articlevault-pro' ),
			true
		);

	}

	private function render_cancel_page(): void {

		$article_id = get_queried_object_id();
		$return_url = $article_id ? get_permalink( $article_id ) : home_url( '/' );

		$this->render_status_page(
			__( 'Payment cancelled', 'aibender-articlevault-pro' ),
			__( 'No payment was taken. You can return to the article and try again.', 'aibender-articlevault-pro' ),
			$return_url,
			__( 'Return to article', 'aibender-articlevault-pro' ),
			false
		);

	}

	private function render_error_page( string $message ): void {

		$article_id = get_queried_object_id();
		$return_url = $article_id ? get_permalink( $article_id ) : home_url( '/' );

		$this->render_status_page(
			__( 'Payment verification failed', 'aibender-articlevault-pro' ),
			$message,
			$return_url,
			__( 'Return to article', 'aibender-articlevault-pro' ),
			false
		);

	}

	private function render_status_page(
		string $title,
		string $message,
		string $button_url,
		string $button_text,
		bool $auto_redirect
	): void {

		nocache_headers();
		status_header( 200 );

		$safe_button_url = esc_url( $button_url );

		?>
		<!doctype html>
		<html <?php language_attributes(); ?>>
		<head>
			<meta charset="<?php bloginfo( 'charset' ); ?>">
			<meta name="viewport" content="width=device-width, initial-scale=1">
			<title><?php echo esc_html( $title ); ?></title>

			<?php if ( $auto_redirect ) : ?>
				<meta http-equiv="refresh" content="2;url=<?php echo esc_attr( $safe_button_url ); ?>">
			<?php endif; ?>

			<?php
			wp_enqueue_style(
				'articlevault-payment-status',
				plugins_url( '../../assets/css/payment-status.css', __FILE__ ),
				array(),
				'0.6.3'
			);

			wp_print_styles( 'articlevault-payment-status' );
			?>
		</head>
		<body>
			<main class="articlevault-payment-status">
				<h1><?php echo esc_html( $title ); ?></h1>
				<p><?php echo esc_html( $message ); ?></p>

				<a href="<?php echo esc_url( $safe_button_url ); ?>">
					<?php echo esc_html( $button_text ); ?>
				</a>
			</main>
		</body>
		</html>
		<?php

		exit;

	}

	public function allow_stripe_redirect_host( array $hosts ): array {

    $hosts[] = 'checkout.stripe.com';

    return array_unique( $hosts );

}

	private function redirect_to_stripe( string $checkout_url ): void {

		$checkout_url = esc_url_raw( $checkout_url );
		$url_parts    = wp_parse_url( $checkout_url );

		$scheme = $url_parts['scheme'] ?? '';
		$host   = $url_parts['host'] ?? '';

		if (
			'https' !== $scheme
			|| 'checkout.stripe.com' !== strtolower( $host )
		) {
			wp_die(
				esc_html__(
					'Invalid Stripe Checkout URL.',
					'aibender-articlevault-pro'
				)
			);
		}

		wp_safe_redirect( $checkout_url );

		exit;

	}

}