<?php

namespace CBChangeMailSender\Admin;

// Exit if accessed directly.
use CBChangeMailSender\Helpers\CB_Change_Mail_Sender_Install_Skin;
use CBChangeMailSender\Helpers\PluginSilentUpgrader;

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

/**
 * Class SMTP.
 *
 * Handles the SMTP tab.
 */
class SMTP {

	/**
	 * SMTP tab slug.
	 *
	 * @since 1.3.0
	 *
	 * @var string
	 */
	const TAB_SLUG = 'smtp';

	/**
	 * Nonce action for SMTP page.
	 *
	 * @since 1.3.0
	 *
	 * @var string
	 */
	const NONCE_ACTION = 'cb-change-mail-sender-admin-smtp';

	/**
	 * Configuration.
	 *
	 * @since 1.3.0
	 *
	 * @var string[]
	 */
	private $config = [
		'lite_plugin'       => 'wp-mail-smtp/wp_mail_smtp.php',
		'lite_wporg_url'    => 'https://wordpress.org/plugins/wp-mail-smtp/',
		'lite_download_url' => 'https://downloads.wordpress.org/plugin/wp-mail-smtp.zip',
		'pro_plugin'        => 'wp-mail-smtp-pro/wp_mail_smtp.php',
		'smtp_settings_url' => 'admin.php?page=wp-mail-smtp',
		'smtp_wizard_url'   => 'admin.php?page=wp-mail-smtp-setup-wizard',
	];

	/**
	 * Constructor.
	 *
	 * @since 1.3.0
	 */
	public function __construct() {

		$this->hooks();
	}

	/**
	 * Hook the STMP page.
	 *
	 * @since 1.3.0
	 *
	 * @return void
	 */
	private function hooks() {

		add_action( 'wp_ajax_cb_change_mail_sender_install_smtp', [ $this, 'ajax_install_wp_mail_smtp_plugin' ] );
		add_action( 'wp_ajax_cb_change_mail_sender_activate_smtp', [ $this, 'ajax_activate_wp_mail_smtp_plugin' ] );
		add_action( 'wp_ajax_cb_change_mail_sender_smtp_page_check_plugin_status', [ $this, 'ajax_check_plugin_status' ] );

		add_action( 'current_screen', [ $this, 'current_screen' ] );
	}

	/**
	 * AJAX operation to install and activate WP Mail SMTP plugin.
	 *
	 * @since 1.3.0
	 *
	 * @return void
	 */
	public function ajax_install_wp_mail_smtp_plugin() {

		check_ajax_referer( self::NONCE_ACTION, 'nonce' );

		$generic_error = __( 'There was an error while performing your request.', 'cb-mail' );

		if ( ! $this->can_install_plugin() ) {
			wp_send_json_error( esc_html( $generic_error ) );
		}

		$error = esc_html__( 'Could not install the plugin. Please download and install it manually.', 'cb-mail' );
		$url   = esc_url_raw( add_query_arg(
			'tab',
			self::TAB_SLUG,
			cb_change_mail_sender()->get_admin()->get_url()
		) );

		ob_start();

		$creds = request_filesystem_credentials(
			$url,
			'',
			false,
			false,
			null
		);

		// Hide the filesystem credentials form.
		ob_end_clean();

		if ( $creds === false || ! WP_Filesystem( $creds ) ) {
			wp_send_json_error( $error );
		}

		/*
		* We do not need any extra credentials if we have gotten this far, so let's install the plugin.
		*/
		require_once cb_change_mail_sender()->get_plugin_path() . DIRECTORY_SEPARATOR . 'src/Helpers/class-install-skin.php';

		// Do not allow WordPress to search/download translations, as this will break JS output.
		remove_action( 'upgrader_process_complete', [ 'Language_Pack_Upgrader', 'async_upgrade' ], 20 );

		// Create the plugin upgrader with our custom skin.
		$installer = new PluginSilentUpgrader( new CB_Change_Mail_Sender_Install_Skin() );

		// Error check.
		if ( ! method_exists( $installer, 'install' ) ) {
			wp_send_json_error( $error );
		}

		$installer->install( $this->config['lite_download_url'] );

		// Flush the cache and return the newly installed plugin basename.
		wp_cache_flush();

		if ( empty( $installer->plugin_info() ) ) {
			wp_send_json_error( $error );
		}

		add_option( 'wp_mail_smtp_source', 'cb-change-mail-sender' );

		$result = [
			'msg'          => $generic_error,
			'is_activated' => false,
			'basename'     => $installer->plugin_info(),
		];

		if ( ! current_user_can( 'activate_plugins' ) ) {

			$result['msg'] = esc_html__( 'Plugin installed.', 'cb-mail' );

			wp_send_json_success( $result );
		}

		// Activate the plugin silently.
		$activated = activate_plugin( $installer->plugin_info() );

		if ( ! is_wp_error( $activated ) ) {

			update_option( 'wp_mail_smtp_activation_prevent_redirect', true );

			$result['is_activated'] = true;
			$result['msg']          = esc_html__( 'Plugin installed & activated.', 'cb-mail' );

			wp_send_json_success( $result );
		}

		// Fallback error just in case.
		wp_send_json_error( $result );
	}

	/**
	 * AJAX operation to activate WP Mail SMTP plugin.
	 *
	 * @since 1.3.0
	 *
	 * @return void
	 */
	public function ajax_activate_wp_mail_smtp_plugin() {

		check_ajax_referer( self::NONCE_ACTION, 'nonce' );

		if ( ! current_user_can( 'activate_plugins' ) ) {
			wp_send_json_error( esc_html__( 'Plugin activation is disabled for you on this site.', 'cb-mail' ) );
		}

		if ( empty( $_POST['plugin'] ) ) {
			wp_send_json_error( esc_html__( 'There was an error while performing your request.', 'cb-mail' ) );
		}

		$activate = activate_plugins( sanitize_text_field( wp_unslash( $_POST['plugin'] ) ) );

		if ( ! is_wp_error( $activate ) ) {
			update_option( 'wp_mail_smtp_activation_prevent_redirect', true );
			add_option( 'wp_mail_smtp_source', 'cb-change-mail-sender' );
			wp_send_json_success( esc_html__( 'Plugin activated.', 'cb-mail' ) );
		}

		wp_send_json_error( esc_html__( 'Could not activate the plugin. Please activate it on the Plugins page.', 'cb-mail' ) );
	}

	/**
	 * AJAX operation to check plugin setup status.
	 *
	 * Used to properly init step 'Setup' section after completing step 'Install'.
	 *
	 * @since 1.3.0
	 */
	public function ajax_check_plugin_status() {

		if ( ! check_ajax_referer( self::NONCE_ACTION, 'nonce', false ) ||
			! current_user_can( 'activate_plugins' )
		) {

			wp_send_json_error(
				[
					'error' => esc_html__( 'You do not have permission.', 'cb-mail' ),
				]
			);
		}

		if ( ! $this->is_smtp_activated() ) {

			wp_send_json_error(
				[
					'error' => esc_html__( 'Plugin unavailable.', 'cb-mail' ),
				]
			);
		}

		$result = [
			'setup_status' => (int) $this->is_smtp_configured(),
		];

		// Prevent redirect to the WP Mail SMTP Setup Wizard on the fresh installs.
		// We need this workaround since WP Mail SMTP doesn't check whether the mailer is already configured when redirecting to the Setup Wizard on the first run.
		if ( $result['setup_status'] > 0 ) {
			update_option( 'wp_mail_smtp_activation_prevent_redirect', true );
		}

		wp_send_json_success( $result );
	}

	/**
	 * Settings page-specific hooks.
	 *
	 * @since 1.3.0
	 *
	 * @return void
	 */
	public function current_screen() {

		$current_screen = get_current_screen();

		if ( $current_screen->id !== cb_change_mail_sender()->get_admin()->get_page_hook_suffix() ) {
			return;
		}

		if ( cb_change_mail_sender()->get_admin()->get_active_tab() !== self::TAB_SLUG ) {
			return;
		}

		add_action( 'admin_enqueue_scripts', [ $this, 'enqueue_scripts' ] );
		add_action( 'cb_change_mail_sender_admin_core_render_admin_page_tab', [ $this, 'render_content' ] );
		add_filter( 'admin_title', [ $this, 'page_title' ] );
	}

	/**
	 * Enqueue the plugin admin scripts.
	 *
	 * @since 1.3.0
	 *
	 * @return void
	 */
	public function enqueue_scripts() {

		// Enqueue Lity.
		wp_enqueue_script(
			'cb-change-mail-sender-admin-lity',
			cb_change_mail_sender()->get_assets_url() . "/lib/lity/lity.min.js",
			[],
			'2.4.1',
			true
		);

		wp_enqueue_style(
			'cb-change-mail-sender-admin-lity',
			cb_change_mail_sender()->get_assets_url() . "/lib/lity/lity.min.css",
			[],
			'2.4.1'
		);

		$min = '';

		if ( ! defined( 'SCRIPT_DEBUG' ) || ! SCRIPT_DEBUG ) {
			$min = '.min';
		}

		wp_enqueue_style(
			'cb-change-mail-sender-admin-smtp',
			cb_change_mail_sender()->get_assets_url() . "/css/admin-smtp{$min}.css",
			[],
			CB_CHANGE_MAIL_SENDER_VERSION
		);

		wp_enqueue_script(
			'cb-change-mail-sender-admin-smtp',
			cb_change_mail_sender()->get_assets_url() . "/js/admin-smtp{$min}.js",
			[ 'jquery' ],
			CB_CHANGE_MAIL_SENDER_VERSION,
			true
		);

		$error_could_not_install = sprintf(
			wp_kses( /* translators: %s - Lite plugin download URL. */
				__( 'Could not install the plugin automatically. Please <a href="%s">download</a> it and install it manually.', 'cb-mail' ),
				[
					'a' => [
						'href' => true,
						],
					]
			),
			esc_url( $this->config['lite_download_url'] )
		);

		$error_could_not_activate = sprintf(
			wp_kses( /* translators: %s - Lite plugin download URL. */
				__( 'Could not activate the plugin. Please activate it on the <a href="%s">Plugins page</a>.', 'cb-mail' ),
				[
					'a' => [
						'href' => true,
					],
				]
			),
			esc_url( admin_url( 'plugins.php' ) )
		);

		wp_localize_script(
			'cb-change-mail-sender-admin-smtp',
			'cb_change_mail_sender_admin_smtp',
			[
				'ajaxurl'                  => admin_url( 'admin-ajax.php' ),
				'nonce'                    => wp_create_nonce( self::NONCE_ACTION ),
				'activating'               => esc_html__( 'Activating...', 'cb-mail' ),
				'installing'               => esc_html__( 'Installing...', 'cb-mail' ),
				'activated'                => esc_html__( 'WP Mail SMTP Installed & Activated', 'cb-mail' ),
				'download_now'             => esc_html__( 'Download Now', 'cb-mail' ),
				'plugins_page'             => esc_html__( 'Go to Plugins page', 'cb-mail' ),
				'error_could_not_install'  => $error_could_not_install,
				'error_could_not_activate' => $error_could_not_activate,
				'manual_install_url'       => $this->config['lite_download_url'],
				'manual_activate_url'      => admin_url( 'plugins.php' ),
				'smtp_wizard_url'          => esc_url( $this->config['smtp_wizard_url'] ),
				'smtp_wizard'              => esc_html__( 'Open Setup Wizard', 'cb-mail' ),
				'smtp_settings'            => esc_html__( 'Go to SMTP settings', 'cb-mail' ),
				'smtp_settings_url'        => esc_url( $this->config['smtp_settings_url'] ),
			]
		);
	}

	/**
	 * Render the tab content.
	 *
	 * @since 1.3.0
	 *
	 * @return void
	 */
	public function render_content() {

		echo '<div id="cb-change-mail-sender-admin-wrap" class="wrap">';
			// Admin notices display after the first heading tag.
			echo '<h1 class="cb-change-mail-sender-hide">' . esc_html__( 'Change Mail Sender', 'cb-mail' ) . '</h1>';
			echo '<div id="cb-change-mail-sender-admin-smtp">';
				$this->output_section_heading();
				$this->output_section_screenshot();
				$this->output_section_step_install();
				$this->output_section_step_setup();
			echo '</div>';
		echo '</div>';
	}

	/**
	 * Generate and output heading section HTML.
	 *
	 * @since 1.3.0
	 */
	private function output_section_heading() {

		// Heading section.
		printf(
			'<section class="top">
				<img class="img-top" src="%1$s" srcset="%2$s 2x" alt="%3$s"/>
				<h2>%4$s</h2>
				<p>%5$s</p>
			</section>',
			esc_url( cb_change_mail_sender()->get_assets_url() . '/images/smtp/wpmailsmtp-logo.png' ),
			esc_url( cb_change_mail_sender()->get_assets_url() . '/images/smtp/wpmailsmtp-logo@2x.png' ),
			esc_attr__( 'WP Mail SMTP', 'cb-mail' ),
			esc_html__( 'Making Email Deliverability Easy for WordPress', 'cb-mail' ),
			esc_html__( 'WP Mail SMTP fixes deliverability problems with your WordPress emails and form notifications. It\'s built by the same folks behind WPForms.', 'cb-mail' )
		);
	}

	/**
	 * Generate and output screenshot section HTML.
	 *
	 * @since 1.3.0
	 */
	private function output_section_screenshot() {

		// Screenshot section.
		printf(
			'<section class="screenshot">
				<div class="cont">
					<img src="%1$s" alt="%2$s"/>
					<a href="%3$s" class="hover" data-lity></a>
				</div>
				<ul>
					<li>%4$s</li>
					<li>%5$s</li>
					<li>%6$s</li>
					<li>%7$s</li>
				</ul>
			</section>',
			esc_url( cb_change_mail_sender()->get_assets_url() . '/images/smtp/screenshot-tnail.png?ver=' . CB_CHANGE_MAIL_SENDER_VERSION ),
			esc_attr__( 'WP Mail SMTP screenshot', 'cb-mail' ),
			esc_url( cb_change_mail_sender()->get_assets_url() . '/images/smtp/screenshot-full.png?ver=' . CB_CHANGE_MAIL_SENDER_VERSION ),
			esc_html__( 'Improves email deliverability in WordPress.', 'cb-mail' ),
			esc_html__( 'Used by 3+ million websites.', 'cb-mail' ),
			esc_html__( 'Free mailers: SendLayer, SMTP.com, Sendinblue, Gmail, Mailgun, Postmark, SendGrid, SparkPost.', 'cb-mail' ),
			esc_html__( 'Pro mailers: Amazon SES, Microsoft 365 / Outlook.com, Zoho Mail.', 'cb-mail' )
		);
	}

	/**
	 * Generate and output step 'Install' section HTML.
	 *
	 * @since 1.3.0
	 */
	private function output_section_step_install() {

		$step = $this->get_data_step_install();

		if ( empty( $step ) ) {
			return;
		}

		$button_format       = '<button class="button %3$s" data-plugin="%1$s" data-action="%4$s">%2$s</button>';
		$button_allowed_html = [
			'button' => [
				'class'       => true,
				'data-plugin' => true,
				'data-action' => true,
				],
			];

		if (
			! $this->output_data['plugin_installed'] &&
			! $this->output_data['pro_plugin_installed'] &&
			! $this->can_install_plugin()
		) {
			$button_format       = '<a class="link" href="%1$s" target="_blank" rel="nofollow noopener">%2$s <span aria-hidden="true" class="dashicons dashicons-external"></span></a>';
			$button_allowed_html = [
				'a'    => [
					'class'  => true,
					'href'   => true,
					'target' => true,
					'rel'    => true,
				],
				'span' => [
					'class'       => true,
					'aria-hidden' => true,
				],
			];
		}

		$button = sprintf( $button_format, esc_attr( $step['plugin'] ), esc_html( $step['button_text'] ), esc_attr( $step['button_class'] ), esc_attr( $step['button_action'] ) );

		printf(
			'<section class="step step-install">
				<aside class="num">
					<img src="%1$s" alt="%2$s" />
					<i class="loader hidden"></i>
				</aside>
				<div>
					<h2>%3$s</h2>
					<p>%4$s</p>
					%5$s
				</div>
			</section>',
			esc_url( cb_change_mail_sender()->get_assets_url() . '/images/smtp/' . $step['icon'] ),
			esc_attr__( 'Step 1', 'cb-mail' ),
			esc_html( $step['heading'] ),
			esc_html( $step['description'] ),
			wp_kses( $button, $button_allowed_html )
		);
	}

	/**
	 * Step 'Install' data.
	 *
	 * @since 1.3.0
	 *
	 * @return array Step data.
	 */
	private function get_data_step_install() {

		$step = [];
		$step['heading']     = esc_html__( 'Install and Activate WP Mail SMTP', 'cb-mail' );
		$step['description'] = esc_html__( 'Install WP Mail SMTP from the WordPress.org plugin repository.', 'cb-mail' );

		$this->output_data['all_plugins']          = get_plugins();
		$this->output_data['plugin_installed']     = array_key_exists( $this->config['lite_plugin'], $this->output_data['all_plugins'] );
		$this->output_data['pro_plugin_installed'] = array_key_exists( $this->config['pro_plugin'], $this->output_data['all_plugins'] );
		$this->output_data['plugin_activated']     = false;
		$this->output_data['plugin_setup']         = false;

		if ( ! $this->output_data['plugin_installed'] && ! $this->output_data['pro_plugin_installed'] ) {
			$step['icon']          = 'step-1.svg';
			$step['button_text']   = esc_html__( 'Install WP Mail SMTP', 'cb-mail' );
			$step['button_class']  = 'button-primary';
			$step['button_action'] = 'install';
			$step['plugin']        = '';

			if ( ! $this->can_install_plugin() ) {
				$step['heading']     = esc_html__( 'WP Mail SMTP', 'cb-mail' );
				$step['description'] = '';
				$step['button_text'] = esc_html__( 'WP Mail SMTP on WordPress.org', 'cb-mail' );
				$step['plugin']      = $this->config['lite_wporg_url'];
			}

			return $step;
		}

		$this->output_data['plugin_activated'] = $this->is_smtp_activated();
		$this->output_data['plugin_setup']     = $this->is_smtp_configured();
		$step['icon']                          = $this->output_data['plugin_activated'] ? 'step-complete.svg' : 'step-1.svg';
		$step['button_text']                   = $this->output_data['plugin_activated'] ? esc_html__( 'WP Mail SMTP Installed & Activated', 'cb-mail' ) : esc_html__( 'Activate WP Mail SMTP', 'cb-mail' );
		$step['button_class']                  = $this->output_data['plugin_activated'] ? 'grey disabled' : 'button-primary';
		$step['button_action']                 = $this->output_data['plugin_activated'] ? '' : 'activate';
		$step['plugin']                        = $this->output_data['pro_plugin_installed'] ? $this->config['pro_plugin'] : $this->config['lite_plugin'];

		return $step;
	}

	/**
	 * Determine if plugin installation is allowed.
	 *
	 * @since 1.3.0
	 *
	 * @return bool
	 */
	private function can_install_plugin() {

		if ( ! current_user_can( 'install_plugins' ) || ! wp_is_file_mod_allowed( 'cb_change_mail_sender_can_install_plugin' ) ) {
			return false;
		}

		return true;
	}

	/**
	 * Whether WP Mail SMTP plugin active or not.
	 *
	 * @since 1.3.0
	 *
	 * @return bool True if SMTP plugin is active.
	 */
	private function is_smtp_activated() {

		return function_exists( 'wp_mail_smtp' ) && ( is_plugin_active( $this->config['lite_plugin'] ) || is_plugin_active( $this->config['pro_plugin'] ) );
	}

	/**
	 * Whether WP Mail SMTP plugin configured or not.
	 *
	 * @since 1.3.0
	 *
	 * @return bool True if some mailer is selected and configured properly.
	 */
	private function is_smtp_configured() {

		if ( ! $this->is_smtp_activated() ) {
			return false;
		}

		$phpmailer = $this->get_phpmailer();
		$mailer    = \WPMailSMTP\Options::init()->get( 'mail', 'mailer' );

		return ! empty( $mailer ) &&
			$mailer !== 'mail' &&
			wp_mail_smtp()->get_providers()->get_mailer( $mailer, $phpmailer )->is_mailer_complete();
	}

	/**
	 * Get $phpmailer instance.
	 *
	 * @since 1.3.0
	 *
	 * @return \PHPMailer|\PHPMailer\PHPMailer\PHPMailer Instance of PHPMailer.
	 */
	private function get_phpmailer() {

		if ( version_compare( get_bloginfo( 'version' ), '5.5-alpha', '<' ) ) {
			$phpmailer = $this->get_phpmailer_v5();
		} else {
			$phpmailer = $this->get_phpmailer_v6();
		}

		return $phpmailer;
	}

	/**
	 * Get $phpmailer v5 instance.
	 *
	 * @since 1.3.0
	 *
	 * @return \PHPMailer Instance of PHPMailer.
	 */
	private function get_phpmailer_v5() {

		global $phpmailer;

		if ( ! ( $phpmailer instanceof \PHPMailer ) ) {
			require_once ABSPATH . WPINC . '/class-phpmailer.php';
			require_once ABSPATH . WPINC . '/class-smtp.php';
			$phpmailer = new \PHPMailer( true ); // phpcs:ignore WordPress.WP.GlobalVariablesOverride.Prohibited
		}

		return $phpmailer;
	}

	/**
	 * Get $phpmailer v6 instance.
	 *
	 * @since 1.3.0
	 *
	 * @return \PHPMailer\PHPMailer\PHPMailer Instance of PHPMailer.
	 */
	private function get_phpmailer_v6() {

		global $phpmailer;

		if ( ! ( $phpmailer instanceof \PHPMailer\PHPMailer\PHPMailer ) ) {
			require_once ABSPATH . WPINC . '/PHPMailer/PHPMailer.php';
			require_once ABSPATH . WPINC . '/PHPMailer/SMTP.php';
			require_once ABSPATH . WPINC . '/PHPMailer/Exception.php';
			$phpmailer = new \PHPMailer\PHPMailer\PHPMailer( true ); // phpcs:ignore WordPress.WP.GlobalVariablesOverride.Prohibited
		}

		return $phpmailer;
	}

	/**
	 * Generate and output step 'Setup' section HTML.
	 *
	 * @since 1.3.0
	 */
	private function output_section_step_setup() {

		$step = $this->get_data_step_setup();

		if ( empty( $step ) ) {
			return;
		}

		printf(
			'<section class="step step-setup %1$s">
				<aside class="num">
					<img src="%2$s" alt="%3$s" />
					<i class="loader hidden"></i>
				</aside>
				<div>
					<h2>%4$s</h2>
					<p>%5$s</p>
					<button class="button %6$s" data-url="%7$s">%8$s</button>
				</div>
			</section>',
			esc_attr( $step['section_class'] ),
			esc_url( cb_change_mail_sender()->get_assets_url() . '/images/smtp/' . $step['icon'] ),
			esc_attr__( 'Step 2', 'cb-mail' ),
			esc_html__( 'Set Up WP Mail SMTP', 'cb-mail' ),
			esc_html__( 'Select and configure your mailer.', 'cb-mail' ),
			esc_attr( $step['button_class'] ),
			esc_url( admin_url( $this->config['smtp_wizard_url'] ) ),
			esc_html( $step['button_text'] )
		);
	}

	/**
	 * Step 'Setup' data.
	 *
	 * @since 1.3.0
	 *
	 * @return array Step data.
	 */
	private function get_data_step_setup() {

		$step = [
			'icon' => 'step-2.svg',
		];

		if ( $this->output_data['plugin_activated'] ) {
			$step['section_class'] = '';
			$step['button_class']  = 'button-primary';
			$step['button_text']   = esc_html__( 'Open Setup Wizard', 'cb-mail' );
		} else {
			$step['section_class'] = 'grey';
			$step['button_class']  = 'grey disabled';
			$step['button_text']   = esc_html__( 'Start Setup', 'cb-mail' );
		}

		if ( $this->output_data['plugin_setup'] ) {
			$step['icon']        = 'step-complete.svg';
			$step['button_text'] = esc_html__( 'Go to SMTP settings', 'cb-mail' );
		}

		return $step;
	}

	/**
	 * Filter the `<title>` in SMTP page.
	 *
	 * @since 1.3.0
	 *
	 * @return string
	 */
	public function page_title() {

		return esc_html__( 'Change Mail Sender SMTP &lsaquo; Change Mail Sender &#8212; WordPress', 'cb-mail' );
	}
}