<?php
/**
 * Analytics tracking for the Add as Preferred Source plugin.
 *
 * Records per-day impressions, clicks, and dismissals in a single
 * WordPress option and exposes a static helper to read them back.
 *
 * @since      1.2
 *
 * @package    Add_As_Preferred_Source
 * @subpackage Add_As_Preferred_Source/includes
 */

// If this file is called directly, abort.
if ( ! defined( 'WPINC' ) ) {
	die;
}

/**
 * ADASPRSO_Analytics class
 */
class ADASPRSO_Analytics {

	/**
	 * Constructor — registers AJAX handlers for both logged-in and guest users.
	 */
	public function __construct() {
		add_action( 'wp_ajax_adasprso_track_event',        array( $this, 'track_event' ) );
		add_action( 'wp_ajax_nopriv_adasprso_track_event', array( $this, 'track_event' ) );
	}

	/**
	 * AJAX handler — increments the counter for the given event type.
	 */
	public function track_event() {
		check_ajax_referer( 'adasprso_track_nonce', 'nonce' );

		$valid_events = array( 'impression', 'click', 'dismiss' );
		$event        = isset( $_POST['event'] ) ? sanitize_text_field( wp_unslash( $_POST['event'] ) ) : '';

		if ( ! in_array( $event, $valid_events, true ) ) {
			wp_send_json_error( 'invalid_event' );
			wp_die();
		}

		$field_map = array(
			'impression' => 'impressions',
			'click'      => 'clicks',
			'dismiss'    => 'dismissals',
		);

		$today = gmdate( 'Y-m-d' );
		$data  = get_option( 'adasprso_analytics_data', array() );

		if ( ! isset( $data[ $today ] ) ) {
			$data[ $today ] = array( 'impressions' => 0, 'clicks' => 0, 'dismissals' => 0 );
		}

		$data[ $today ][ $field_map[ $event ] ]++;

		// Keep only the most recent 60 days to prevent unbounded growth.
		krsort( $data );
		$data = array_slice( $data, 0, 60, true );

		update_option( 'adasprso_analytics_data', $data, false );
		wp_send_json_success();
	}

	/**
	 * Return per-day stats for the given number of days (newest last).
	 *
	 * @param  int   $days  Number of days to return (default 30).
	 * @return array        Associative array keyed YYYY-MM-DD => ['impressions','clicks','dismissals'].
	 */
	public static function get_stats( $days = 30 ) {
		$data   = get_option( 'adasprso_analytics_data', array() );
		$result = array();

		for ( $i = $days - 1; $i >= 0; $i-- ) {
			$date            = gmdate( 'Y-m-d', strtotime( "-{$i} days" ) );
			$result[ $date ] = isset( $data[ $date ] )
				? $data[ $date ]
				: array( 'impressions' => 0, 'clicks' => 0, 'dismissals' => 0 );
		}

		return $result;
	}
}