<?php
/**
 * Analytics storage: tables and event writing.
 *
 * @package KarmaDocs
 */

namespace KarmaDocs\Analytics;

use KarmaDocs\Features;

defined( 'ABSPATH' ) || exit;

/**
 * Reader events are stored with a few typed columns instead of JSON, so the
 * nightly rollups stay plain SQL:
 *
 * - `label`: search term, feedback vote / reason, rating (yes / no), link host or 404 path
 * - `n1`: result count (search), click position (search_click), read depth % (read)
 * - `n2`: active reading seconds (read)
 */
class Store {

	/**
	 * Event types collected on every plan.
	 */
	const FREE_TYPES = array( 'view', 'feedback' );

	/**
	 * Event types collected with Pro analytics.
	 */
	const PRO_TYPES = array( 'read', 'search', 'search_click', 'feedback_reason', 'toc_click', 'code_copy', 'link_out', 'contact_click', 'widget_open', 'widget_search', 'ai_question', 'ai_rating', 'summary_rating', '404' );

	/**
	 * Table name.
	 *
	 * @param string $name events|stats_daily|search_daily.
	 * @return string
	 */
	public static function table( $name ) {
		global $wpdb;
		return $wpdb->prefix . 'kdocs_' . $name;
	}

	/**
	 * Event types accepted on this site.
	 *
	 * @return string[]
	 */
	public static function types() {
		return Features::is_pro() ? array_merge( self::FREE_TYPES, self::PRO_TYPES ) : self::FREE_TYPES;
	}

	/**
	 * Writes events.
	 *
	 * @param array[] $events Events: type, kb_id, article_id, session, search_id, label, n1, n2, ref.
	 * @return int Number written.
	 */
	public static function insert( array $events ) {
		global $wpdb;
		if ( ! $events ) {
			return 0;
		}
		$now     = current_time( 'mysql' );
		$day     = substr( $now, 0, 10 );
		$visitor = Identity::visitor();
		$device  = Identity::device();
		$country = Identity::country();
		$member  = Identity::member();
		$rows    = array();
		$values  = array();
		foreach ( $events as $event ) {
			$rows[] = '(%s,%s,%s,%d,%d,%s,%s,%s,%s,%d,%d,%s,%s,%s,%s)';
			array_push(
				$values,
				$now,
				$day,
				$event['type'],
				(int) ( $event['kb_id'] ?? 0 ),
				(int) ( $event['article_id'] ?? 0 ),
				$visitor,
				(string) ( $event['session'] ?? '' ),
				(string) ( $event['search_id'] ?? '' ),
				mb_substr( (string) ( $event['label'] ?? '' ), 0, 191 ),
				(int) ( $event['n1'] ?? 0 ),
				(int) ( $event['n2'] ?? 0 ),
				$device,
				(string) ( $event['ref'] ?? '' ),
				$country,
				$member
			);
		}
		$table = esc_sql( self::table( 'events' ) );
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery,WordPress.DB.PreparedSQL.InterpolatedNotPrepared,WordPress.DB.PreparedSQL.NotPrepared,WordPress.DB.PreparedSQLPlaceholders.UnfinishedPrepare,PluginCheck.Security.DirectDB.UnescapedDBParameter -- Placeholders are built above.
		$done = $wpdb->query( $wpdb->prepare( "INSERT INTO {$table} (ts, day, type, kb_id, article_id, visitor, session, search_id, label, n1, n2, device, ref, country, member) VALUES " . implode( ',', $rows ), $values ) );
		return (int) $done;
	}

	/**
	 * Writes one server-side event (feedback, AI questions) for the current reader.
	 *
	 * @param string $type  Type.
	 * @param array  $event Fields (see insert()).
	 */
	public static function log( $type, array $event = array() ) {
		if ( ! in_array( $type, self::types(), true ) || ! Identity::countable() ) {
			return;
		}
		$event['type'] = $type;
		self::insert( array( $event ) );
	}
}