<?php

namespace WPMailSMTP\Pro\Emails\Logs;

use WPMailSMTP\WP;

/**
 * Class Email represents single email log entry.
 *
 * @since 1.5.0
 */
class Email {

	/**
	 * This email is not successfully sent.
	 *
	 * @since 1.5.0
	 */
	const STATUS_UNSENT = 0;

	/**
	 * This email is successfully sent.
	 *
	 * @since 1.5.0
	 */
	const STATUS_SENT = 1;

	/**
	 * This email is waiting the API "is sent" verification check.
	 *
	 * @since 2.5.0
	 */
	const STATUS_WAITING = 2;

	/**
	 * This email was delivered (confirmed via API).
	 *
	 * @since 2.5.0
	 */
	const STATUS_DELIVERED = 3;

	/**
	 * @since 1.5.0
	 *
	 * @var int
	 */
	protected $id = 0;

	/**
	 * Message ID (mainly external ID from email provider).
	 *
	 * @since 3.3.0
	 *
	 * @var string
	 */
	protected $message_id = '';

	/**
	 * @since 1.5.0
	 *
	 * @var string
	 */
	protected $subject = '';

	/**
	 * @since 1.5.0
	 *
	 * @var string JSON string of email header TO/CC/BCC/FROM values.
	 */
	protected $people = '';

	/**
	 * @since 1.5.0
	 *
	 * @var string JSON strong of email header.
	 */
	protected $headers = '';

	/**
	 * Error recorded when email was sent.
	 *
	 * @since 2.5.0
	 *
	 * @var string
	 */
	protected $error_text = '';

	/**
	 * @since 1.5.0
	 *
	 * @var string
	 */
	protected $content_plain = '';

	/**
	 * @since 1.5.0
	 *
	 * @var string
	 */
	protected $content_html = '';

	/**
	 * @since 1.5.0
	 *
	 * @var int Check statuses constants to refer to the meaning of the status value.
	 */
	protected $status = 0;

	/**
	 * @since 1.5.0
	 *
	 * @var \DateTime
	 */
	protected $date_sent;

	/**
	 * @since 1.5.0
	 *
	 * @var string
	 */
	protected $mailer = 'smtp';

	/**
	 * @since 1.5.0
	 *
	 * @var 0 Whether this email had attachments or not. 0 is none, number is any.
	 */
	protected $attachments = 0;

	/**
	 * Name of the plugin/theme (or WP core) that initiated/called the `wp_mail` function.
	 *
	 * @since 3.0.0
	 *
	 * @var string
	 */
	protected $initiator_name = '';

	/**
	 * File path and line number of the plugin/theme (or WP core) that initiated/called the `wp_mail` function.
	 *
	 * @since 3.0.0
	 *
	 * @var string
	 */
	protected $initiator_file = '';

	/**
	 * Retrieve a particular email when constructing the object.
	 *
	 * @since 1.5.0
	 *
	 * @param int|object $id_or_row
	 */
	public function __construct( $id_or_row = null ) {

		$this->populate_email( $id_or_row );
	}

	/**
	 * Get and prepare the email data.
	 *
	 * @since 1.5.0
	 *
	 * @param int|object $id_or_row
	 */
	private function populate_email( $id_or_row ) {

		$email = null;

		if ( is_numeric( $id_or_row ) && $id_or_row > 0 ) {
			// Get by ID.
			$collection = new EmailsCollection( [ 'id' => (int) $id_or_row ] );
			$emails     = $collection->get();

			if ( $emails->valid() ) {
				$email = $emails->current();
			}
		} elseif (
			is_object( $id_or_row ) &&
			isset(
				$id_or_row->id,
				$id_or_row->subject,
				$id_or_row->people,
				$id_or_row->headers,
				$id_or_row->content_plain,
				$id_or_row->content_html,
				$id_or_row->status,
				$id_or_row->date_sent,
				$id_or_row->mailer,
				$id_or_row->attachments
			)
		) {
			$email = $id_or_row;
		}

		if ( $email !== null ) {
			foreach ( get_object_vars( $email ) as $key => $value ) {
				$this->{$key} = $value;
			}
		}
	}

	/**
	 * Get email by message ID.
	 *
	 * @since 3.3.0
	 *
	 * @param string $message_id Message ID.
	 *
	 * @return Email|null
	 */
	public static function get_by_message_id( $message_id ) {

		// Get by message ID.
		$collection = new EmailsCollection( [ 'message_id' => $message_id ] );
		$emails     = $collection->get();

		return $emails->current();
	}

	/**
	 * Email ID as per our DB table.
	 *
	 * @since 1.5.0
	 *
	 * @return int
	 */
	public function get_id() {

		return (int) $this->id;
	}

	/**
	 * Message ID (mainly external ID from email provider).
	 *
	 * @since 3.3.0
	 *
	 * @return string
	 */
	public function get_message_id() {

		return $this->message_id;
	}

	/**
	 * Email subject.
	 *
	 * @since 1.5.0
	 *
	 * @return string
	 */
	public function get_subject() {

		return $this->subject;
	}

	/**
	 * All the people that participated in this email: sent to, from or copied.
	 *
	 * @since 1.5.0
	 *
	 * @param string $type Who exactly to retrieve. Supported values: to, from, cc, bcc. If empty - get everyone.
	 *
	 * @return array|string List of people. Empty array if type is incorrect or everyone are requested.
	 *                      String for some specific type.
	 */
	public function get_people( $type = '' ) {

		$people = WP::is_json( $this->people ) ? json_decode( $this->people ) : array();
		$type   = sanitize_key( $type );

		// Get all.
		if ( empty( $type ) ) {
			$data = $people;
		} elseif ( isset( $people->{$type} ) ) {
			$data = $people->{$type};
		} else {
			$data = array();
		}

		return $data;
	}

	/**
	 * Email from name.
	 *
	 * @since 2.8.0
	 *
	 * @return string
	 */
	public function get_from_name() {

		$from_header = $this->get_header( 'From' );

		if ( ! empty( $from_header ) ) {

			preg_match( '/\s*(.*[^\s])\s*<\s*(.*[^\s])\s*>/', $from_header, $output );

			if ( ! empty( $output[1] ) ) {
				return trim( $output[1] );
			}
		}

		return '';
	}

	/**
	 * All the headers, JSON string.
	 *
	 * @since 1.5.0
	 *
	 * @return string
	 */
	public function get_headers() {

		return WP::is_json( $this->headers ) ? $this->headers : '[]';
	}


	/**
	 * Get a specific header by its name if it exists.
	 *
	 * @since 2.5.0
	 *
	 * @param string $name The name of the header to get.
	 *
	 * @return string
	 */
	public function get_header( $name ) {

		if ( empty( $name ) ) {
			return '';
		}

		$headers = json_decode( $this->get_headers(), true );

		foreach ( $headers as $header ) {
			preg_match( '/^' . $name . ': (.*)/', $header, $output );
			if ( ! empty( $output[1] ) ) {
				return $output[1];
			}
		}

		return '';
	}

	/**
	 * Error recorded when email was attempted to be sent.
	 *
	 * @since 2.5.0
	 *
	 * @return string
	 */
	public function get_error_text() {

		return $this->error_text;
	}

	/**
	 * Get the content of the email.
	 *
	 * @since 1.5.0
	 *
	 * @return string Return HTML content by default. Fallback to plain.
	 */
	public function get_content() {

		$html = $this->get_content_html();

		if ( empty( $html ) ) {
			return $this->get_content_plain();
		}

		return $html;
	}

	/**
	 * Get the plain content of the email.
	 *
	 * @since 1.5.0
	 *
	 * @return string
	 */
	public function get_content_plain() {

		return $this->content_plain;
	}

	/**
	 * Get the HTML content of the email.
	 *
	 * @since 1.5.0
	 *
	 * @return string
	 */
	public function get_content_html() {

		return $this->content_html;
	}

	/**
	 * 1 means sent, 0 means not sent.
	 *
	 * @since 1.5.0
	 *
	 * @return int
	 */
	public function get_status() {

		return (int) $this->status;
	}

	/**
	 * Get human readable status name.
	 *
	 * @since 2.8.0
	 *
	 * @return string
	 */
	public function get_status_name() {

		$statuses = [
			self::STATUS_UNSENT    => __( 'Not Sent', 'wp-mail-smtp-pro' ),
			self::STATUS_SENT      => __( 'Sent', 'wp-mail-smtp-pro' ),
			self::STATUS_WAITING   => __( 'Waiting for confirmation', 'wp-mail-smtp-pro' ),
			self::STATUS_DELIVERED => __( 'Delivered', 'wp-mail-smtp-pro' ),
		];

		return isset( $statuses[ $this->status ] ) ? $statuses[ $this->status ] : '';
	}

	/**
	 * Get the date/time when this email was sent.
	 *
	 * @since 1.5.0
	 * @since 2.6.0 Added UTC timezone.
	 *
	 * @return \DateTime
	 * @throws \Exception Emits exception on incorrect date.
	 */
	public function get_date_sent() {

		$timezone = new \DateTimeZone( 'UTC' );
		$date     = false;

		if ( ! empty( $this->date_sent ) ) {
			$date = \DateTime::createFromFormat( WP::datetime_mysql_format(), $this->date_sent, $timezone );
		}

		if ( $date === false ) {
			$date = new \DateTime( 'now', $timezone );
		}

		return $date;
	}

	/**
	 * @return string
	 */
	public function get_mailer() {

		return $this->mailer;
	}

	/**
	 * Whether email had attachments on not.
	 *
	 * @since 1.5.0
	 *
	 * @return int 0 when no attachments, number if any.
	 */
	public function get_attachments() {

		return (int) $this->attachments;
	}

	/**
	 * Get name of the plugin/theme (or WP core) that initiated/called the `wp_mail` function.
	 *
	 * @since 3.0.0
	 *
	 * @return string
	 */
	public function get_initiator_name() {

		return $this->initiator_name;
	}

	/**
	 * Get file path and line number of the plugin/theme (or WP core) that initiated/called the `wp_mail` function.
	 *
	 * @since 3.0.0
	 *
	 * @return string
	 */
	public function get_initiator_file() {

		return $this->initiator_file;
	}

	/**
	 * Get email content type.
	 *
	 * @since 2.9.0
	 *
	 * @return string
	 */
	public function get_content_type() {

		// Check if HTML content is available.
		if ( ! empty( $this->get_content_html() ) ) {
			return 'text/html';
		}

		// Check the content-type header.
		$content_type_header = $this->get_header( 'Content-Type' );
		$content_type_data   = explode( ';', $content_type_header );

		if ( ! empty( $content_type_data[0] ) ) {
			return strtolower( trim( $content_type_data[0] ) );
		}

		return 'text/plain';
	}

	/**
	 * Get email charset.
	 *
	 * @since 2.9.0
	 *
	 * @return string
	 */
	public function get_charset() {

		$charset = get_bloginfo( 'charset' );

		$content_type_header = $this->get_header( 'Content-Type' );

		list( , $charset_content ) = explode( ';', $content_type_header );
		if ( false !== stripos( $charset_content, 'charset=' ) ) {
			$charset = trim( str_replace( array( 'charset=', '"' ), '', $charset_content ) );
		}

		return $charset;
	}

	/**
	 * Is content type HTML based.
	 *
	 * @since 2.9.0
	 *
	 * @return bool
	 */
	public function is_content_type_html_based() {

		$html_content_types = [
			'text/html',
			'multipart/alternative',
			'multipart/mixed',
		];

		return in_array( $this->get_content_type(), $html_content_types, true );
	}

	/**
	 * Set message ID (mainly external ID from email provider).
	 *
	 * @since 3.3.0
	 *
	 * @param string $message_id Message ID.
	 *
	 * @return Email
	 */
	public function set_message_id( $message_id ) {

		$this->message_id = $message_id;

		return $this;
	}

	/**
	 * Set the email subject.
	 *
	 * @since 1.5.0
	 * @since 2.2.0 Limit the length of the subject to 191 chars because the `subject` DB column is `varchar(191)`.
	 *
	 * @param string $subject
	 *
	 * @return Email
	 */
	public function set_subject( $subject ) {

		$this->subject = substr( wp_kses( $subject, [] ), 0, 191 );

		return $this;
	}

	/**
	 * Set the email people. Contains to/cc/bcc/from.
	 * We require array here.
	 *
	 * @since 1.5.0
	 *
	 * @param array $people
	 *
	 * @return Email
	 */
	public function set_people( $people ) {

		if ( ! is_array( $people ) ) {
			$people = array();
		}

		$this->people = wp_json_encode( $people );

		return $this;
	}

	/**
	 * Set the email headers.
	 * We require array here.
	 *
	 * @since 1.5.0
	 *
	 * @param array $headers
	 *
	 * @return Email
	 */
	public function set_headers( $headers ) {

		if ( ! is_array( $headers ) ) {
			$headers = [];
		}

		$filtered_headers = array_filter(
			$headers,
			function ( $header ) {
				return strpos( $header, ':' ) !== false;
			}
		);

		$this->headers = wp_json_encode( array_values( $filtered_headers ) );

		return $this;
	}

	/**
	 * Set the email error text.
	 *
	 * @since 2.5.0
	 *
	 * @param string $error_text The email error text to be set.
	 *
	 * @return Email
	 */
	public function set_error_text( $error_text ) {

		$this->error_text = sanitize_textarea_field( $error_text );

		return $this;
	}

	/**
	 * Set the email content and try to define whether it has HTML or not.
	 *
	 * @since 1.5.0
	 *
	 * @param string $content The email content.
	 *
	 * @return Email
	 */
	public function set_content( $content ) {

		// TODO: this check is NOT reliable.
		if ( $content === wp_strip_all_tags( $content ) ) {
			$this->set_content_plain( wp_strip_all_tags( $content ) );
		} else {
			$this->set_content_html( $content );
		}

		return $this;
	}

	/**
	 * Set the email plain text content.
	 *
	 * @since 1.5.0
	 *
	 * @param string $plain
	 *
	 * @return Email
	 */
	public function set_content_plain( $plain ) {

		$this->content_plain = $plain;

		return $this;
	}

	/**
	 * Set the email HTML content.
	 *
	 * @since 1.5.0
	 *
	 * @param string $html
	 *
	 * @return Email
	 */
	public function set_content_html( $html ) {

		$this->content_html = $html;

		return $this;
	}

	/**
	 * Set the date when the email was sent.
	 * Date validation is taken from wp_insert_post().
	 * Date should be set in this format: Y-m-d H:i:s.
	 * DateTime object will be set in property, on save it will be converted to string.
	 *
	 * @since 1.5.0
	 * @since 2.6.0 Added UTC timezone.
	 *
	 * @param string $date_sent
	 *
	 * @return Email
	 *
	 * @throws \Exception When date is incorrectly generated on PHP side.
	 */
	public function set_date_sent( $date_sent ) {

		// Validate the date. Time is ignored.
		$mm = substr( $date_sent, 5, 2 );
		$jj = substr( $date_sent, 8, 2 );
		$aa = substr( $date_sent, 0, 4 );

		$valid_date = wp_checkdate( $mm, $jj, $aa, $date_sent );
		$timezone   = new \DateTimeZone( 'UTC' );

		if ( $valid_date ) {
			$date_sent = \DateTime::createFromFormat( WP::datetime_mysql_format(), $date_sent, $timezone );
		} else {
			$date_sent = new \DateTime( 'now', $timezone );
		}

		$this->date_sent = $date_sent;

		return $this;
	}

	/**
	 * Set whether the email had attachments.
	 *
	 * @since 1.5.0
	 *
	 * @param int $attachments
	 *
	 * @return Email
	 */
	public function set_attachments( $attachments ) {

		$this->attachments = (int) $attachments;

		return $this;
	}

	/**
	 * Set the mailer key that was used to send this email.
	 *
	 * @since 1.5.0
	 *
	 * @param string $mailer
	 *
	 * @return Email
	 */
	public function set_mailer( $mailer ) {

		$this->mailer = sanitize_key( $mailer );

		return $this;
	}

	/**
	 * Set the status of the email: was it successfully sent or not?
	 * We do not insist on exact default statuses, as developers may want to change that.
	 * We do insist on an integer.
	 *
	 * @since 1.5.0
	 *
	 * @param int $status
	 *
	 * @return Email
	 */
	public function set_status( $status ) {

		$this->status = (int) $status;

		return $this;
	}

	/**
	 * Set the initiator by checking the backtrace for the wp_mail function call.
	 *
	 * @since 3.0.0
	 *
	 * @return Email
	 */
	public function set_initiator() {

		$backtrace = $this->get_wpmail_backtrace();

		if ( empty( $backtrace['file'] ) ) {
			return $this;
		}

		$this->initiator_file = $backtrace['file'];

		if ( ! empty( $backtrace['line'] ) ) {
			$this->initiator_file .= ':' . $backtrace['line'];
		}

		$this->initiator_name = WP::get_initiator_name( $backtrace['file'] );

		return $this;
	}

	/**
	 * Save a new or modified email in DB.
	 *
	 * @since 1.5.0
	 *
	 * @return Email New or updated email class instance.
	 * @throws \Exception When email init fails.
	 */
	public function save() {

		global $wpdb;

		$table = Logs::get_table_name();

		if ( (bool) $this->get_id() ) {
			// Update the existing DB table record.
			$wpdb->update( // phpcs:ignore WordPress.DB.DirectDatabaseQuery.NoCaching
				$table,
				[
					'message_id'     => $this->message_id,
					'subject'        => $this->subject,
					'people'         => $this->people,
					'headers'        => $this->headers,
					'error_text'     => $this->error_text,
					'content_plain'  => $this->content_plain,
					'content_html'   => $this->content_html,
					'status'         => $this->status,
					'date_sent'      => $this->get_date_sent()->format( WP::datetime_mysql_format() ),
					'mailer'         => $this->mailer,
					'attachments'    => $this->attachments,
					'initiator_name' => $this->initiator_name,
					'initiator_file' => $this->initiator_file,
				],
				[
					'id' => $this->get_id(),
				],
				[
					'%s', // message ID.
					'%s', // subject.
					'%s', // people.
					'%s', // headers.
					'%s', // error_text.
					'%s', // content_plain.
					'%s', // content_html.
					'%s', // status.
					'%s', // date_sent.
					'%s', // mailer.
					'%d', // attachments.
					'%s', // initiator_name.
					'%s', // initiator_file.
				],
				[
					'%d',
				]
			);

			$email_id = $this->get_id();
		} else {
			// Create a new DB table record.
			$wpdb->insert(
				$table,
				[
					'message_id'     => $this->message_id,
					'subject'        => $this->subject,
					'people'         => $this->people,
					'headers'        => $this->headers,
					'error_text'     => $this->error_text,
					'content_plain'  => $this->content_plain,
					'content_html'   => $this->content_html,
					'status'         => $this->status,
					'date_sent'      => $this->get_date_sent()->format( WP::datetime_mysql_format() ),
					'mailer'         => $this->mailer,
					'attachments'    => $this->attachments,
					'initiator_name' => $this->initiator_name,
					'initiator_file' => $this->initiator_file,
				],
				[
					'%s', // message ID.
					'%s', // subject.
					'%s', // people.
					'%s', // headers.
					'%s', // error_text.
					'%s', // content_plain.
					'%s', // content_html.
					'%s', // status.
					'%s', // date_sent.
					'%s', // mailer.
					'%d', // attachments.
					'%s', // initiator_name.
					'%s', // initiator_file.
				]
			);

			$email_id = $wpdb->insert_id;
		}

		try {
			$email = new Email( $email_id );
		} catch ( \Exception $e ) {
			$email = new Email();
		}

		return $email;
	}

	/**
	 * Delete the current email.
	 * Usage:
	 *     $email = new Email( $email_id );
	 *     $email->delete();
	 *
	 * @since 1.5.0
	 *
	 * @return int|false Integer on successful deletion (number of rows), false on failure.
	 */
	public function delete() {

		global $wpdb;

		return $wpdb->delete(
			Logs::get_table_name(),
			array(
				'id' => $this->get_id(),
			),
			array(
				'%d',
			)
		);
	}

	/**
	 * Whether the email instance is a valid entity to work with.
	 *
	 * @since 1.5.0
	 */
	public function is_valid() {

		if (
			empty( $this->id ) ||
			empty( $this->headers ) ||
			empty( $this->date_sent )
		) {
			return false;
		}

		return true;
	}

	/**
	 * Whether the email was successfully sent or not.
	 *
	 * @since 1.5.0
	 *
	 * @return bool
	 */
	public function is_sent() {

		return self::STATUS_SENT === $this->get_status();
	}

	/**
	 * Whether the email sending has failed.
	 *
	 * @since 2.5.0
	 *
	 * @return bool
	 */
	public function has_failed() {

		return self::STATUS_UNSENT === $this->get_status();
	}

	/**
	 * Whether the email content has HTML or not.
	 *
	 * @since 1.5.0
	 *
	 * @return bool
	 */
	public function is_html() {

		return ! empty( $this->get_content_html() );
	}

	/**
	 * If the email has an error text.
	 *
	 * @since 2.5.0
	 *
	 * @return bool
	 */
	public function has_error() {

		return ! empty( $this->get_error_text() );
	}

	/**
	 * Get the wpmail function backtrace, if it exists.
	 *
	 * @since 3.0.0
	 *
	 * @return array
	 */
	private function get_wpmail_backtrace() {

		$backtrace = debug_backtrace( DEBUG_BACKTRACE_IGNORE_ARGS ); // phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_debug_backtrace

		foreach ( $backtrace as $item ) {
			if ( $item['function'] === 'wp_mail' ) {
				if ( isset( $item['function'] ) ) {
					unset( $item['function'] );
				}

				return $item;
			}
		}

		return [];
	}
}
