<?php

namespace DeliciousBrains\WPMDB\Common\Alerts\Email;

use DeliciousBrains\WPMDB\Common\Alerts\AbstractAlert;
use DeliciousBrains\WPMDB\Common\Alerts\AlertInterface;
use DeliciousBrains\WPMDB\Common\Exceptions\InvalidAlertTemplate;
use DeliciousBrains\WPMDB\Common\MigrationState\Migrations\RemoteSiteState;
use DeliciousBrains\WPMDB\Common\MigrationState\StateFactory;

class EmailAlert extends AbstractAlert {
	/**
	 * Gets the contents for the provided template.
	 *
	 * @param string $template_name
	 *
	 * @return string
	 * @throws InvalidAlertTemplate
	 */

	private function get_template( $template_name ) {
		$templates_path = __DIR__ . '/templates/' . $template_name . '.html';
		if ( is_file( $templates_path ) ) {
			return file_get_contents( $templates_path );
		}

		throw new InvalidAlertTemplate( sprintf( "Template %s doesn't exist.", $templates_path ) );
	}

	/**
	 * Replaces placeholders in the templates' contents with their respective values.
	 *
	 * @param string $template_name
	 * @param string $migration_id
	 *
	 * @return string
	 */
	private function get_formatted_template( $template_name, $migration_id ) {
		$content = $this->get_template( $template_name );

		$content = str_replace( '{MIGRATION_ID}', $migration_id, $content );
		$content = str_replace( '{DESTINATION_SITE_URL}', $this->get_destination_site_url( $migration_id ), $content );
		$content = str_replace( '{URL_OF_THE_MIGRATE_TAB}', $this->get_source_migrate_url( $migration_id ), $content );
		$content = str_replace(
			'{DESTINATION_LOGIN_URL}',
			$this->get_destination_login_url( $migration_id ),
			$content
		);
		$content = str_replace( '{INSTALL_NAME}', $this->get_destination_install_name( $migration_id ), $content );
		$content = str_replace( '{SOURCE_SITE_URL}', $this->get_source_site_url( $migration_id ), $content );

		return $content;
	}

	/**
	 * Uses wp_mail to send and email to the user.
	 *
	 * @param string $migration_id
	 * @param string $subject
	 * @param string $content
	 *
	 * @return void
	 */
	private function send_email( $migration_id, $subject, $content ) {
		$site_migration_state = StateFactory::create( 'site_migration' )->load_state( $migration_id );
		$user_email           = $site_migration_state->get( 'notificationEmail' );
		$user_email           = sanitize_email( $user_email );
		$headers              = array( 'Content-Type: text/html; charset=UTF-8' );

		if ( ! empty( $user_email ) ) {
			add_filter( 'wp_mail_from_name', array( $this, 'set_from_name' ) );
			wp_mail( $user_email, $subject, $content, $headers );
			remove_filter( 'wp_mail_from_name', array( $this, 'set_from_name' ) );
		}
	}

	/**
	 * Get destination site url
	 *
	 * @param string $migration_id
	 *
	 * @return string
	 */
	private function get_destination_site_url( $migration_id ) {
		$remote_site_state = StateFactory::create( 'remote_site' )->load_state( $migration_id );

		return $remote_site_state->get( 'url' );
	}

	/**
	 * Get source site url
	 *
	 * @param string $migration_id
	 *
	 * @return string
	 */
	private function get_source_site_url( $migration_id ) {
		$local_site_state = StateFactory::create( 'local_site' )->load_state( $migration_id );

		return $local_site_state->get( 'this_url' );
	}

	/**
	 * Get local site WP Migrate/WPESM url
	 *
	 * @param string $migration_id
	 *
	 * @return mixed
	 */
	private function get_source_migrate_url( $migration_id ) {
		$site_state = StateFactory::create( 'local_site' )->load_state( $migration_id );

		return $site_state->get( 'site_details' )['migrate_url'];
	}

	/**
	 * Get destination site login url
	 *
	 * @param string $migration_id
	 *
	 * @return mixed
	 */
	private function get_destination_login_url( $migration_id ) {
		$remote_site_state = StateFactory::create( 'remote_site' )->load_state( $migration_id );

		return $remote_site_state->get( 'site_details' )['login_url'];
	}

	/**
	 * @param string $migration_id
	 *
	 * @handles wpmdb_migration_started
	 * @return  void
	 */
	public function started( $migration_id ) {
		$content = $this->get_formatted_template( 'started', $migration_id );
		$subject = __( '🚀 Site migration started', 'wp-migrate-db' );

		$this->send_email( $migration_id, $subject, $content );
	}

	/**
	 * @param string $migration_id
	 *
	 * @handles wpmdb_migration_completed
	 * @return  void
	 */
	public function completed( $migration_id ) {
		$content = $this->get_formatted_template( 'completed', $migration_id );
		$subject = __( '✅ Site migration completed', 'wp-migrate-db' );

		$this->send_email( $migration_id, $subject, $content );
	}

	/**
	 * @param string $migration_id
	 *
	 * @handles wpmdb_migration_failed
	 * @return  void
	 */
	public function failed( $migration_id ) {
		$content = $this->get_formatted_template( 'failed', $migration_id );
		$subject = __( '🚨 Site migration failed', 'wp-migrate-db' );

		$this->send_email( $migration_id, $subject, $content );
	}

	/**
	 * @param string $migration_id
	 *
	 * @handles wpmdb_migration_canceled
	 * @return  void
	 */
	public function canceled( $migration_id ) {
		//Implement canceled email
	}

	/**
	 * Returns the sender name.
	 *
	 * @param string $from_name
	 *
	 * @handles wp_mail_from_name
	 * @return string
	 */
	public function set_from_name( $from_name ) {
		return __( 'WP Engine Site Migration', 'wp-migrate-db' );
	}

	/**
	 * Returns the PWP Install name on WPE sites or an empty string on other platforms.
	 *
	 * @param string $migration_id
	 *
	 * @return string
	 */
	public function get_destination_install_name( $migration_id ) {
		$remote_site_state = StateFactory::create( 'remote_site' )->load_state( $migration_id );
		$string_format     = '&wpesm_install=%s';
		if (
			is_a( $remote_site_state, RemoteSiteState::class ) &&
			is_array( $remote_site_state->get( 'site_details' ) ) &&
			! empty( $remote_site_state->get( 'site_details' )['pwp_name'] )
		) {
			return sprintf( $string_format, $remote_site_state->get( 'site_details' )['pwp_name'] );
		}

		return '';
	}
}