<?php

if ( ! defined( 'ABSPATH' ) ) { exit; }

if ( ! class_exists( 'AIEO_Submission_Trail', false ) ) {

class AIEO_Submission_Trail {

	
	const CAP = 50;

	
	const SKEW_TOLERANCE = 900;

	
	const SKEW_FLOOR = 15;

	
	const WINDOW = 21600;

	
	const MAX_DWELL = 14400;

	
	const PAGE_TYPES = array( 'page_view', 'product_view', 'category_view', 'page_exit', 'tab_hidden' );

	
	
	

	
	public static function for_submission( array $s ) {
		$created = isset( $s['created'] ) ? $s['created'] : 0;
		$created = is_numeric( $created ) ? (int) $created : (int) strtotime( (string) $created . ' UTC' );
		if ( $created <= 0 ) { $created = time(); }
		$window = isset( $s['window'] ) && (int) $s['window'] > 0 ? (int) $s['window'] : (int) apply_filters( 'aieo_submission_trail_window', self::WINDOW );
		$ids    = isset( $s['session_ids'] ) && is_array( $s['session_ids'] ) ? array_values( array_filter( array_map( 'strval', $s['session_ids'] ) ) ) : array();

		$before  = array();
		$after   = array();
		$queried = false;
		$hit     = false;
		if ( $ids && self::sessions_available() ) {
			$queried = true;
			foreach ( self::page_views( $ids, $created, $window ) as $page ) {
				$hit = true;
				if ( $page['ts'] < $created ) {
					$before[] = $page;
				} else {
					$after[] = $page;
				}
			}
		}
		return array(
			'before'       => array_slice( $before, -self::CAP ),
			'after'        => array_slice( $after, 0, self::CAP ),
			'source_flags' => self::flags( false, $hit, $queried, false ),
		);
	}

	
	public static function page_views( array $session_ids, $created, $window ) {
		$rows = self::events( $session_ids, $created, $window, self::PAGE_TYPES );
		if ( ! $rows ) { return array(); }
		$skew  = self::clock_skew( $rows );
		$pages = array();
		foreach ( $rows as $r ) {
			$type = (string) $r->event_type;
			if ( 'page_exit' === $type || 'tab_hidden' === $type ) { continue; }
			$key = self::visit_key( (string) $r->page_url );
			if ( '' === $key ) { continue; }
			$ts = (int) floor( ( (float) $r->timestamp ) / 1000 ) + $skew;
			if ( $ts < $created - $window || $ts > $created + $window ) { continue; }
			$dwell = max( (int) $r->time_on_page, self::dwell_from_data( $r->event_data ) );
			if ( isset( $pages[ $key ] ) ) {
				$pages[ $key ]['dwell'] = max( $pages[ $key ]['dwell'], $dwell );
				continue;
			}
			$pid           = 'product_view' === $type ? self::product_id_from_event( $r ) : 0;
			$pages[ $key ] = array(
				'url'        => (string) $r->page_url,
				'path'       => (string) wp_parse_url( (string) $r->page_url, PHP_URL_PATH ),
				'title'      => self::title_of( (string) $r->page_url, $pid ),
				'product_id' => $pid,
				'ts'         => $ts,
				'at'         => gmdate( 'Y-m-d H:i:s', $ts ),
				'dwell'      => $dwell,
			);
		}
		foreach ( $rows as $r ) {
			$type = (string) $r->event_type;
			if ( 'page_exit' !== $type && 'tab_hidden' !== $type ) { continue; }
			$key = self::visit_key( (string) $r->page_url );
			if ( '' === $key || ! isset( $pages[ $key ] ) ) { continue; }
			$dwell = max( (int) $r->time_on_page, self::dwell_from_data( $r->event_data ) );
			if ( $dwell > $pages[ $key ]['dwell'] ) { $pages[ $key ]['dwell'] = $dwell; }
		}
		uasort( $pages, static function ( $a, $b ) { return $a['ts'] <=> $b['ts']; } );
		return array_values( $pages );
	}

	
	const TRACKING_ARGS = '/^(utm_[a-z]+|gclid|gbraid|wbraid|fbclid|msclkid|ttclid|twclid|li_fat_id|mc_cid|mc_eid|_ga|_gl|_hsenc|_hsmi|srsltid)$/';

	
	public static function visit_key( $url ) {
		$base = self::page_key( $url );
		if ( '' === $base ) { return ''; }
		$query = (string) wp_parse_url( trim( (string) $url ), PHP_URL_QUERY );
		if ( '' === $query ) { return $base; }
		parse_str( $query, $args );
		$keep = array();
		foreach ( (array) $args as $k => $v ) {
			if ( ! preg_match( self::TRACKING_ARGS, strtolower( (string) $k ) ) && is_scalar( $v ) ) { $keep[ (string) $k ] = (string) $v; }
		}
		if ( ! $keep ) { return $base; }
		ksort( $keep );
		return $base . '?' . http_build_query( $keep );
	}

	
	private static function title_of( $url, $product_id ) {
		static $memo = array();
		$key = self::visit_key( $url );
		if ( isset( $memo[ $key ] ) ) { return $memo[ $key ]; }
		$title = '';
		$pid   = $product_id > 0 ? $product_id : (int) url_to_postid( strtok( $url, '#' ) );
		if ( $pid > 0 ) {
			$title = wp_strip_all_tags( get_the_title( $pid ) );
		} elseif ( self::visit_key( $url ) === self::visit_key( home_url( '/' ) ) ) {
			$title = wp_strip_all_tags( get_bloginfo( 'name' ) );
		}
		if ( '' === $title ) {
			$title = (string) wp_parse_url( $url, PHP_URL_PATH );
		}
		$memo[ $key ] = $title;
		return $title;
	}

	
	
	

	
	public static function product_views( array $session_ids, $created, $window ) {
		$rows = self::events( $session_ids, $created, $window, array( 'product_view', 'page_exit', 'tab_hidden' ) );
		if ( ! $rows ) { return array(); }

		$skew = self::clock_skew( $rows );

		$out     = array();
		$by_page = array();
		foreach ( $rows as $r ) {
			if ( 'product_view' !== (string) $r->event_type ) { continue; }
			$pid = self::product_id_from_event( $r );
			if ( $pid <= 0 ) { continue; }
			$ts = (int) floor( ( (float) $r->timestamp ) / 1000 ) + $skew;
			if ( $ts < $created - $window || $ts > $created + $window ) { continue; }
			$key = self::page_key( (string) $r->page_url );
			if ( '' !== $key ) { $by_page[ $key ] = $pid; }
			$dwell = max( (int) $r->time_on_page, self::dwell_from_data( $r->event_data ) );
			if ( isset( $out[ $pid ] ) ) {
				$out[ $pid ]['dwell'] = max( $out[ $pid ]['dwell'], $dwell );
				if ( $ts < $out[ $pid ]['ts'] ) { $out[ $pid ]['ts'] = $ts; $out[ $pid ]['at'] = gmdate( 'Y-m-d H:i:s', $ts ); }
				continue;
			}
			$out[ $pid ] = array(
				'ts'    => $ts,
				'at'    => gmdate( 'Y-m-d H:i:s', $ts ),
				'dwell' => $dwell,
			);
		}
		if ( ! $out ) { return array(); }

		
		
		foreach ( $rows as $r ) {
			$type = (string) $r->event_type;
			if ( 'page_exit' !== $type && 'tab_hidden' !== $type ) { continue; }
			$pid = (int) $r->product_id;
			if ( $pid <= 0 || ! isset( $out[ $pid ] ) ) {
				$key = self::page_key( (string) $r->page_url );
				$pid = ( '' !== $key && isset( $by_page[ $key ] ) ) ? (int) $by_page[ $key ] : 0;
			}
			if ( $pid <= 0 || ! isset( $out[ $pid ] ) ) { continue; }
			$dwell = max( (int) $r->time_on_page, self::dwell_from_data( $r->event_data ) );
			if ( $dwell > $out[ $pid ]['dwell'] ) { $out[ $pid ]['dwell'] = $dwell; }
		}

		if ( count( $out ) > self::CAP ) {
			uasort( $out, static function ( $a, $b ) { return $a['ts'] <=> $b['ts']; } );
			$out = array_slice( $out, 0, self::CAP, true );
		}
		return $out;
	}

	
	
	

	
	public static function events( array $session_ids, $created, $window, array $types ) {
		global $wpdb;
		$hot     = $wpdb->prefix . 'aieo_sessions';
		$archive = $wpdb->prefix . 'aieo_sessions_archive';

		$session_ids = array_values( array_unique( array_filter( array_map( 'strval', $session_ids ) ) ) );
		$types       = array_values( array_filter( array_map( static function ( $t ) { return preg_replace( '/[^a-z_]/', '', (string) $t ); }, $types ) ) );
		if ( ! $session_ids || ! $types ) { return array(); }
		$in    = implode( ',', array_fill( 0, count( $session_ids ), '%s' ) );
		$types = "('" . implode( "','", $types ) . "')";

		$from_ms = ( $created - $window - self::SKEW_TOLERANCE ) * 1000;
		$to_ms   = ( $created + $window + self::SKEW_TOLERANCE ) * 1000;

		$sql = "SELECT event_type, product_id, event_data, page_url, timestamp, time_on_page, UNIX_TIMESTAMP(created_at) AS ingested
				  FROM `{$hot}`
				 WHERE session_id IN ({$in}) AND event_type IN {$types} AND timestamp BETWEEN %d AND %d";
		$params = array_merge( $session_ids, array( $from_ms, $to_ms ) );

		if ( self::archive_available() ) {
			$sql .= " UNION ALL
				SELECT event_type, product_id, event_data, page_url, timestamp, time_on_page, UNIX_TIMESTAMP(created_at) AS ingested
				  FROM `{$archive}`
				 WHERE session_id IN ({$in}) AND event_type IN {$types} AND timestamp BETWEEN %d AND %d";
			$params = array_merge( $params, $session_ids, array( $from_ms, $to_ms ) );
		}
		$sql = 'SELECT * FROM (' . $sql . ') u ORDER BY ABS(CAST(u.timestamp AS SIGNED) - %d) ASC LIMIT ' . ( self::CAP * 10 );
		$params[] = $created * 1000;

		$rows = (array) $wpdb->get_results( $wpdb->prepare( $sql, $params ) ); 
		if ( ! $rows ) { return array(); }
		usort( $rows, static function ( $a, $b ) { return (float) $a->timestamp <=> (float) $b->timestamp; } );
		return $rows;
	}

	
	public static function flags( $beacon, $sessions_hit, $sessions_queried, $recent ) {
		return array(
			'beacon'           => (bool) $beacon,
			'sessions'         => (bool) $sessions_hit,
			'sessions_queried' => (bool) $sessions_queried,
			'recent'           => (bool) $recent,
			'tracking_on'      => self::tracking_enabled(),
			'consent_gated'    => self::consent_gated(),
		);
	}

	
	public static function tracking_enabled() {
		return '1' === (string) get_option( 'aieo_session_tracking_enabled', '0' );
	}

	
	public static function consent_gated() {
		$bypass = get_option( 'aieo_session_bypass_consent', '1' );
		if ( '1' == $bypass ) { return false; } 
		$require = get_option( 'aieo_session_tracking_require_consent', '1' );
		return '1' == $require; 
	}

	
	public static function sessions_available() {
		global $wpdb;
		static $memo = null;
		if ( null !== $memo ) { return $memo; }
		$t    = $wpdb->prefix . 'aieo_sessions';
		$memo = ( (string) $wpdb->get_var( $wpdb->prepare( 'SHOW TABLES LIKE %s', $t ) ) === $t );
		return $memo;
	}

	
	public static function archive_available() {
		global $wpdb;
		static $memo = null;
		if ( null !== $memo ) { return $memo; }
		$t    = $wpdb->prefix . 'aieo_sessions_archive';
		$memo = ( (string) $wpdb->get_var( $wpdb->prepare( 'SHOW TABLES LIKE %s', $t ) ) === $t );
		return $memo;
	}

	
	public static function clock_skew( array $rows ) {
		$diffs = array();
		foreach ( $rows as $r ) {
			$ingested = isset( $r->ingested ) ? (int) $r->ingested : 0;
			if ( $ingested <= 0 ) { continue; }
			$diffs[] = $ingested - (int) floor( ( (float) $r->timestamp ) / 1000 );
		}
		if ( count( $diffs ) < 2 ) { return 0; }
		sort( $diffs );
		$n    = count( $diffs );
		$q    = static function ( $p ) use ( $diffs, $n ) { return $diffs[ min( $n - 1, max( 0, (int) floor( $p * ( $n - 1 ) ) ) ) ]; };
		$mid  = (int) floor( $n / 2 );
		$skew = ( $n % 2 ) ? $diffs[ $mid ] : (int) floor( ( $diffs[ $mid - 1 ] + $diffs[ $mid ] ) / 2 );
		
		
		if ( abs( $skew ) > self::SKEW_TOLERANCE ) { return 0; }
		
		if ( $skew < 0 ) { return $skew; }
		
		if ( $skew < self::SKEW_FLOOR ) { return 0; }
		$low  = (int) $q( 0.25 );
		$high = (int) $q( 0.75 );
		if ( ( $high - $low ) > self::SKEW_FLOOR ) { return 0; }
		return max( 0, $low );
	}

	
	public static function dwell_from_data( $event_data ) {
		$data = json_decode( (string) $event_data, true );
		if ( ! is_array( $data ) ) { return 0; }
		$n = 0;
		foreach ( array( 'time_on_page', 'time_active', 'dwell' ) as $k ) {
			if ( isset( $data[ $k ] ) && is_numeric( $data[ $k ] ) ) { $n = max( $n, (int) $data[ $k ] ); }
		}
		return min( $n, self::MAX_DWELL );
	}

	
	public static function page_key( $url ) {
		$url = trim( $url );
		if ( '' === $url ) { return ''; }
		$p = wp_parse_url( $url );
		if ( ! is_array( $p ) ) { return ''; }
		$host = isset( $p['host'] ) ? strtolower( preg_replace( '/^www\./', '', (string) $p['host'] ) ) : '';
		$path = isset( $p['path'] ) ? rtrim( (string) $p['path'], '/' ) : '';
		return $host . $path;
	}

	
	public static function product_id_from_event( $row ) {
		if ( isset( $row->product_id ) && (int) $row->product_id > 0 ) { return (int) $row->product_id; }
		$data = json_decode( (string) $row->event_data, true );
		if ( is_array( $data ) ) {
			foreach ( array( 'product_id', 'productId', 'post_id' ) as $k ) {
				if ( ! empty( $data[ $k ] ) && is_numeric( $data[ $k ] ) ) { return (int) $data[ $k ]; }
			}
		}
		$url = (string) $row->page_url;
		if ( '' === $url ) { return 0; }
		static $memo = array();
		$key = self::page_key( $url );
		if ( isset( $memo[ $key ] ) ) { return $memo[ $key ]; }
		$pid = (int) url_to_postid( strtok( $url, '#' ) );
		$memo[ $key ] = ( $pid > 0 && 'product' === get_post_type( $pid ) ) ? $pid : 0;
		return $memo[ $key ];
	}
}

}