<?php
/**
 * Event registry and dispatcher.
 *
 * @package PingPush
 */

defined( 'ABSPATH' ) || exit;

/**
 * Holds event definitions and turns triggered events into queued notifications.
 */
class PingPush_Events {

	/**
	 * Registered events.
	 *
	 * @var array<string,array>
	 */
	private static $events = array();

	/**
	 * Dedupe keys seen in this request.
	 *
	 * @var array<string,bool>
	 */
	private static $seen = array();

	/**
	 * Groups in display order.
	 *
	 * @return array<string,string>
	 */
	public static function groups() {
		return array(
			'core'      => __( 'WordPress', 'pingpush' ),
			'forms'     => __( 'Forms', 'pingpush' ),
			'ecommerce' => __( 'Ecommerce', 'pingpush' ),
			'other'     => __( 'Other', 'pingpush' ),
		);
	}

	/**
	 * Register an event.
	 *
	 * @param string $id   Unique id (a-z, 0-9, _).
	 * @param array  $args Arguments (keys below).
	 *     - label (string): Label in settings.
	 *     - description (string): Help text.
	 *     - group (string): core|forms|ecommerce|other.
	 *     - source (string): Plugin name that provides the event.
	 *     - title (string): Default title template.
	 *     - message (string): Default message template.
	 *     - priority (int): Default priority (-2..1).
	 *     - sound (string): Default sound ('' = device default).
	 *     - enabled (bool): Enabled by default.
	 *     - placeholders (array): Placeholder names (without braces).
	 *     - options (array): Extra settings: key => [type, label, choices, default].
	 */
	public static function register( $id, array $args ) {
		$id = sanitize_key( $id );
		if ( '' === $id ) {
			return;
		}
		self::$events[ $id ] = wp_parse_args(
			$args,
			array(
				'label'        => $id,
				'description'  => '',
				'group'        => 'other',
				'source'       => '',
				'title'        => '{event}',
				'message'      => '{event}',
				'priority'     => 0,
				'sound'        => '',
				'enabled'      => false,
				'placeholders' => array(),
				'options'      => array(),
			)
		);
	}

	/**
	 * All events.
	 *
	 * @return array<string,array>
	 */
	public static function all() {
		return self::$events;
	}

	/**
	 * One event definition.
	 *
	 * @param string $id Id.
	 * @return array|null
	 */
	public static function get( $id ) {
		return self::$events[ $id ] ?? null;
	}

	/**
	 * Effective settings for an event (saved values over defaults).
	 *
	 * @param string $id Id.
	 * @return array
	 */
	public static function settings_for( $id ) {
		$def = self::get( $id );
		if ( ! $def ) {
			return array();
		}
		$all   = PingPush_Settings::get();
		$saved = $all['events'][ $id ] ?? array();

		$defaults = array(
			'enabled'  => $def['enabled'],
			'priority' => 'default' === ( $def['priority'] ?? '' ) ? 'default' : (int) $def['priority'],
			'sound'    => (string) $def['sound'],
			'title'    => $def['title'],
			'message'  => $def['message'],
		);
		foreach ( $def['options'] as $key => $opt ) {
			$defaults[ $key ] = $opt['default'] ?? '';
		}

		$out = array_merge( $defaults, is_array( $saved ) ? $saved : array() );
		if ( '' === trim( (string) $out['title'] ) ) {
			$out['title'] = $def['title'];
		}
		if ( '' === trim( (string) $out['message'] ) ) {
			$out['message'] = $def['message'];
		}
		return $out;
	}

	/**
	 * Whether an event is turned on and keys exist.
	 *
	 * @param string $id Id.
	 * @return bool
	 */
	public static function is_enabled( $id ) {
		if ( ! self::get( $id ) ) {
			return false;
		}
		$settings = PingPush_Settings::get();
		if ( empty( $settings['token'] ) || empty( $settings['user_key'] ) ) {
			return false;
		}
		$event = self::settings_for( $id );
		return ! empty( $event['enabled'] );
	}

	/**
	 * Trigger an event.
	 *
	 * @param string $id   Event id.
	 * @param array  $data Placeholder data. 'fields' may hold form fields.
	 * @param array  $args Arguments (keys below).
	 *     - url (string): Supplementary URL.
	 *     - url_title (string): URL title.
	 *     - dedupe (string): Dedupe key; same id + key is sent once.
	 *     - dedupe_ttl (int): Seconds to remember the key across requests (0 = this request only).
	 *     - sync (bool): Send immediately instead of queueing.
	 * @return bool Whether a notification was queued/sent.
	 */
	public static function trigger( $id, array $data = array(), array $args = array() ) {
		if ( ! self::is_enabled( $id ) ) {
			return false;
		}

		$args = wp_parse_args(
			$args,
			array(
				'url'        => '',
				'url_title'  => '',
				'dedupe'     => '',
				'dedupe_ttl' => 120,
				'sync'       => false,
			)
		);

		if ( '' !== (string) $args['dedupe'] ) {
			$key = $id . '|' . $args['dedupe'];
			if ( isset( self::$seen[ $key ] ) ) {
				return false;
			}
			self::$seen[ $key ] = true;

			if ( (int) $args['dedupe_ttl'] > 0 ) {
				$transient = 'pingpush_dd_' . md5( $key );
				if ( get_transient( $transient ) ) {
					return false;
				}
				set_transient( $transient, 1, (int) $args['dedupe_ttl'] );
			}
		}

		$def      = self::get( $id );
		$event    = self::settings_for( $id );
		$settings = PingPush_Settings::get();

		$data['event'] = $def['label'];

		/**
		 * Last chance to stop a notification.
		 *
		 * @param bool   $send Whether to send.
		 * @param string $id   Event id.
		 * @param array  $data Placeholder data.
		 */
		if ( ! apply_filters( 'pingpush_should_send', true, $id, $data ) ) {
			return false;
		}

		$title   = PingPush_Templates::render( (string) $event['title'], $data );
		$message = PingPush_Templates::render( (string) $event['message'], $data );

		if ( ! empty( $settings['include_site_name'] ) ) {
			$site  = wp_specialchars_decode( get_bloginfo( 'name' ), ENT_QUOTES );
			$title = '' !== $site ? $site . ' – ' . $title : $title;
		}

		$priority = ( 'default' === $event['priority'] || '' === $event['priority'] ) ? $settings['default_priority'] : $event['priority'];
		$priority = PingPush_API::sanitize_priority( $priority );

		/** Filters the title. */
		$title = (string) apply_filters( 'pingpush_title', $title, $id, $data );
		/** Filters the message. */
		$message = (string) apply_filters( 'pingpush_message', $message, $id, $data );
		/** Filters the priority: -2 (lowest), -1 (low), 0 (normal) or 1 (high). Other values become 0. */
		$priority = PingPush_API::sanitize_priority( apply_filters( 'pingpush_priority', $priority, $id, $data ) );

		$payload = array(
			'event'     => $id,
			'title'     => PingPush_Templates::truncate( $title, PingPush_API::MAX_TITLE ),
			'message'   => PingPush_Templates::truncate( $message, PingPush_API::MAX_MESSAGE ),
			'priority'  => $priority,
			'sound'     => (string) $event['sound'],
			'timestamp' => time(),
		);

		$url = esc_url_raw( (string) $args['url'] );
		if ( '' !== $url && strlen( $url ) <= PingPush_API::MAX_URL ) {
			$payload['url']       = $url;
			$payload['url_title'] = PingPush_Templates::truncate( '' !== $args['url_title'] ? $args['url_title'] : __( 'Open', 'pingpush' ), PingPush_API::MAX_URL_TITLE );
		}

		/**
		 * Filters the full payload sent to Pushover (credentials are added at send time).
		 *
		 * @param array  $payload Payload.
		 * @param string $id      Event id.
		 * @param array  $data    Placeholder data.
		 */
		$payload = (array) apply_filters( 'pingpush_payload', $payload, $id, $data );

		if ( $args['sync'] ) {
			PingPush_Queue::handle( $payload, PingPush_Queue::MAX_RETRIES );
		} else {
			PingPush_Queue::push( $payload );
		}
		return true;
	}
}