<?php
if (!defined('ABSPATH')) exit;

/**
 * Aggregates buffered events into the database.
 *
 * @package Statinform
 */
class EISTAT_Aggregator {

    public static function run($force = false) {
        $buffer_dir = eistat_get_buffer_dir();
        $lock_file  = $buffer_dir . '.lock';

        // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fopen
        $lock_fp = @fopen($lock_file, 'c');
        if (!$lock_fp || !flock($lock_fp, LOCK_EX | LOCK_NB)) {
            return false;
        }

        try {
            $result = self::do_run($force);
        } catch (Throwable $e) {
            self::log('EXCEPTION: ' . $e->getMessage());
            flock($lock_fp, LOCK_UN);
            // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fclose
            fclose($lock_fp);
            return false;
        }

        flock($lock_fp, LOCK_UN);
        // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fclose
        fclose($lock_fp);
        return $result;
    }

    private static function log($message) {
        if (defined('WP_DEBUG') && WP_DEBUG && function_exists('wp_debug_log')) {
            wp_debug_log('EISTAT aggregator: ' . $message);
        }
    }

    private static function do_run($force = false) {
        global $wpdb;
        $eistat_p = $wpdb->prefix . 'eistat_';

        $buffer_dir = eistat_get_buffer_dir();
        $files = glob($buffer_dir . '*.jsonl');
        if (!$files) return 0;

        $events = [];
        foreach ($files as $file) {
            if (!$force) {
                $age = time() - filemtime($file);
                if ($age < 300) continue;
            }

            $tmp = $file . '.processing';
            // phpcs:ignore WordPress.WP.AlternativeFunctions.rename_rename
            if (!@rename($file, $tmp)) continue;

            $lines = file($tmp, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
            // phpcs:ignore WordPress.WP.AlternativeFunctions.unlink_unlink
            @unlink($tmp);

            foreach ($lines as $line) {
                $e = json_decode($line, true);
                if (is_array($e) && !empty($e['session_hash'])) {
                    $events[] = $e;
                }
            }
        }

        if (!$events) return 0;

        usort($events, function ($a, $b) { return $a['ts'] - $b['ts']; });

        // --- In-memory aggregation ---
        $pageviews      = [];
        $uniques        = [];
        $page_time      = [];
        $session_pages  = [];
        $session_times  = [];
        $session_data   = [];
        $clicks         = [];

        foreach ($events as $e) {
            $date  = wp_date('Y-m-d', $e['ts']);
            $ptype = self::valid_type($e['page_type'] ?? 'other');
            $pid   = (int)$e['page_id'];
            $sid   = $e['session_hash'];
            $key   = "$date|$ptype|$pid";

            if ($e['event'] === 'pageview') {
                if (!isset($pageviews[$key])) {
                    $pageviews[$key] = [
                        'date' => $date, 'ptype' => $ptype, 'pid' => $pid,
                        'url' => $e['page_url'], 'views' => 0,
                    ];
                }
                $pageviews[$key]['views']++;
                $uniques[$key][$sid] = true;

                if (!isset($session_pages[$sid])) $session_pages[$sid] = [];
                $last = end($session_pages[$sid]);
                if (!$last || $last[0] !== $ptype || $last[1] !== $pid) {
                    $session_pages[$sid][] = [$ptype, $pid, $e['page_url']];
                }

                if (!isset($session_data[$sid])) {
                    $utm_source   = $e['utm_source']   ?? '';
                    $utm_medium   = $e['utm_medium']   ?? '';
                    $utm_campaign = $e['utm_campaign'] ?? '';
                    $referrer     = $e['referrer']     ?? '';

                    list($source, $source_detail) = self::classify_source(
                        $referrer, $utm_source, $utm_medium
                    );

                    $session_data[$sid] = [
                        'sid' => $sid, 'date' => $date,
                        'first_ts' => $e['ts'], 'last_ts' => $e['ts'],
                        'entry_type' => $ptype, 'entry_id' => $pid, 'entry_url' => $e['page_url'],
                        'exit_type' => $ptype, 'exit_id' => $pid, 'exit_url' => $e['page_url'],
                        'pageviews' => 0,
                        'source' => $source, 'source_detail' => $source_detail,
                        'referrer_host' => self::host($referrer),
                        'utm_source' => substr((string)$utm_source, 0, 50),
                        'utm_medium' => substr((string)$utm_medium, 0, 50),
                        'utm_campaign' => substr((string)$utm_campaign, 0, 100),
                        'device' => $e['device'],
                        'is_bot' => (int)$e['is_bot'],
                        'ip_hash' => $e['ip_hash'] ?? '',
                    ];
                }
                $session_data[$sid]['pageviews']++;
                $session_data[$sid]['last_ts']   = max($session_data[$sid]['last_ts'], $e['ts']);
                $session_data[$sid]['exit_type'] = $ptype;
                $session_data[$sid]['exit_id']   = $pid;
                $session_data[$sid]['exit_url']  = $e['page_url'];
                $session_data[$sid]['is_bot']    = max($session_data[$sid]['is_bot'], (int)$e['is_bot']);

            } elseif ($e['event'] === 'unload') {
                $dur = (int)$e['duration'];
                if (!isset($page_time[$key])) $page_time[$key] = 0;
                $page_time[$key] += $dur;

                $skey = "$ptype|$pid";
                if (!isset($session_times[$sid][$skey])) $session_times[$sid][$skey] = 0;
                $session_times[$sid][$skey] += $dur;

                if (isset($session_data[$sid])) {
                    $session_data[$sid]['last_ts'] = max($session_data[$sid]['last_ts'], $e['ts']);
                }

            } elseif ($e['event'] === 'outbound_click') {
                $link_type = in_array($e['link_type'] ?? '', ['outbound','email','phone'], true)
                                ? $e['link_type'] : 'outbound';
                $link_url  = substr((string)($e['link_url'] ?? ''), 0, 500);
                $link_text = substr((string)($e['link_text'] ?? ''), 0, 120);

                $ckey = "$date|$ptype|$pid|$link_type|$link_url";
                if (!isset($clicks[$ckey])) {
                    $clicks[$ckey] = [
                        'date' => $date, 'ptype' => $ptype, 'pid' => $pid,
                        'link_type' => $link_type,
                        'link_url' => $link_url, 'link_text' => $link_text,
                        'count' => 0,
                    ];
                }
                $clicks[$ckey]['count']++;
            }
        }

        // --- Write pageviews ---
        foreach ($pageviews as $key => $row) {
            $uniq = count($uniques[$key] ?? []);
            $time = $page_time[$key] ?? 0;

            $sql = "INSERT INTO {$eistat_p}pageviews
                (date, page_type, page_id, page_url, views, unique_views, total_time)
             VALUES (%s, %s, %d, %s, %d, %d, %d)
             ON DUPLICATE KEY UPDATE
                views        = views + VALUES(views),
                unique_views = unique_views + VALUES(unique_views),
                total_time   = total_time + VALUES(total_time)";

            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
            $wpdb->query($wpdb->prepare($sql, $row['date'], $row['ptype'], $row['pid'], $row['url'], $row['views'], $uniq, $time));
        }

        // --- Write events ---
        foreach ($clicks as $row) {
            $sql = "INSERT INTO {$eistat_p}events
                (date, page_type, page_id, link_type, link_url, link_text, count)
             VALUES (%s, %s, %d, %s, %s, %s, %d)
             ON DUPLICATE KEY UPDATE count = count + VALUES(count)";

            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
            $wpdb->query($wpdb->prepare($sql, $row['date'], $row['ptype'], $row['pid'], $row['link_type'], $row['link_url'], $row['link_text'], $row['count']));
        }

        // --- Write sessions and transitions ---
        foreach ($session_data as $sid => $s) {
            $sql_prev = "SELECT exit_page_type, exit_page_id, pages_json
                         FROM {$eistat_p}sessions WHERE session_hash = %s";
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
            $prev = $wpdb->get_row($wpdb->prepare($sql_prev, $sid));

            $pages = $session_pages[$sid] ?? [];

            $pages_arr = [];
            foreach ($pages as $pg) {
                $skey = $pg[0] . '|' . $pg[1];
                $t    = $session_times[$sid][$skey] ?? 0;
                $pages_arr[] = [$pg[1], $t, self::type_to_char($pg[0])];
                if (count($pages_arr) >= 30) break;
            }

            $new_unique = count($pages);
            $new_time   = array_sum($session_times[$sid] ?? []);

            if ($prev && $prev->exit_page_id && !empty($pages)
                && ($prev->exit_page_id != $pages[0][1] || $prev->exit_page_type != $pages[0][0])) {
                self::transition($eistat_p, $s['date'], $prev->exit_page_type, $prev->exit_page_id, $pages[0][0], $pages[0][1]);
            }
            for ($i = 1; $i < count($pages); $i++) {
                self::transition($eistat_p, $s['date'], $pages[$i-1][0], $pages[$i-1][1], $pages[$i][0], $pages[$i][1]);
            }

            if ($prev === null) {
                // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching
                $wpdb->insert("{$eistat_p}sessions", [
                    'session_hash'    => $sid,
                    'ip_hash'         => $s['ip_hash'],
                    'date'            => $s['date'],
                    'first_seen'      => wp_date('Y-m-d H:i:s', $s['first_ts']),
                    'last_seen'       => wp_date('Y-m-d H:i:s', $s['last_ts']),
                    'entry_page_type' => $s['entry_type'],
                    'entry_page_id'   => $s['entry_id'],
                    'entry_page_url'  => $s['entry_url'],
                    'exit_page_type'  => $s['exit_type'],
                    'exit_page_id'    => $s['exit_id'],
                    'exit_page_url'   => $s['exit_url'],
                    'pageviews'       => $s['pageviews'],
                    'unique_pages'    => $new_unique,
                    'total_time'      => $new_time,
                    'pages_json'      => wp_json_encode($pages_arr),
                    'source'          => $s['source'],
                    'source_detail'   => $s['source_detail'],
                    'referrer_host'   => $s['referrer_host'],
                    'utm_source'      => $s['utm_source'],
                    'utm_medium'      => $s['utm_medium'],
                    'utm_campaign'    => $s['utm_campaign'],
                    'device'          => $s['device'],
                    'is_bot'          => $s['is_bot'],
                ]);
                if ($wpdb->last_error) {
                    self::log('INSERT session failed: ' . $wpdb->last_error);
                }
            } else {
                $existing = json_decode($prev->pages_json ?: '[]', true) ?: [];
                if (count($existing) < 30) {
                    $existing = array_slice(array_merge($existing, $pages_arr), 0, 30);
                }

                $sql_update = "UPDATE {$eistat_p}sessions SET
                    last_seen       = GREATEST(last_seen, %s),
                    exit_page_type  = %s,
                    exit_page_id    = %d,
                    exit_page_url   = %s,
                    pageviews       = pageviews + %d,
                    unique_pages    = unique_pages + %d,
                    total_time      = total_time + %d,
                    pages_json      = %s,
                    is_bot          = GREATEST(is_bot, %d)
                 WHERE session_hash = %s";

                // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
                $wpdb->query($wpdb->prepare($sql_update,
                    wp_date('Y-m-d H:i:s', $s['last_ts']),
                    $s['exit_type'], $s['exit_id'], $s['exit_url'],
                    $s['pageviews'], $new_unique, $new_time,
                    wp_json_encode($existing),
                    $s['is_bot'], $sid
                ));
                if ($wpdb->last_error) {
                    self::log('UPDATE session failed: ' . $wpdb->last_error);
                }
            }
        }

        // --- Rebuild summary tables ---
        $dates = array_unique(array_column($session_data, 'date'));
        foreach ($dates as $date) {
            $sql_del_sources = "DELETE FROM {$eistat_p}sources WHERE date = %s";
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
            $wpdb->query($wpdb->prepare($sql_del_sources, $date));

            $sql_ins_sources = "INSERT INTO {$eistat_p}sources
                (date, source, source_detail, referrer_host, sessions, pageviews, total_duration)
             SELECT date, source, source_detail, referrer_host, COUNT(*), SUM(pageviews), SUM(total_time)
             FROM {$eistat_p}sessions WHERE date = %s
             GROUP BY source, source_detail, referrer_host";
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
            $wpdb->query($wpdb->prepare($sql_ins_sources, $date));

            $sql_del_daily = "DELETE FROM {$eistat_p}daily WHERE date = %s";
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
            $wpdb->query($wpdb->prepare($sql_del_daily, $date));

            $sql_ins_daily = "INSERT INTO {$eistat_p}daily
                (date, sessions, unique_visitors, pageviews,
                 bounces, bounces_human, bot_sessions,
                 total_duration, total_duration_human,
                 total_duration_approx, total_duration_approx_human)
             SELECT
                date, COUNT(*), COUNT(DISTINCT ip_hash), SUM(pageviews),
                SUM(CASE WHEN unique_pages <= 1 AND total_time < 15 THEN 1 ELSE 0 END),
                SUM(CASE WHEN unique_pages <= 1 AND total_time < 15 AND is_bot = 0 THEN 1 ELSE 0 END),
                SUM(CASE WHEN is_bot = 1 THEN 1 ELSE 0 END),
                SUM(total_time),
                SUM(CASE WHEN is_bot = 0 THEN total_time ELSE 0 END),
                SUM(CASE WHEN total_time > 0 THEN total_time ELSE LEAST(TIMESTAMPDIFF(SECOND, first_seen, last_seen), 600) END),
                SUM(CASE WHEN is_bot = 1 THEN 0 WHEN total_time > 0 THEN total_time ELSE LEAST(TIMESTAMPDIFF(SECOND, first_seen, last_seen), 600) END)
             FROM {$eistat_p}sessions WHERE date = %s";
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
            $wpdb->query($wpdb->prepare($sql_ins_daily, $date));

            if ($wpdb->last_error) {
                self::log('daily rebuild failed: ' . $wpdb->last_error);
            }
        }

        return count($events);
    }

    private static function transition($eistat_p, $date, $from_t, $from_id, $to_t, $to_id) {
        global $wpdb;
        $sql = "INSERT INTO {$eistat_p}transitions
            (date, from_page_type, from_page_id, to_page_type, to_page_id, count)
         VALUES (%s, %s, %d, %s, %d, 1)
         ON DUPLICATE KEY UPDATE count = count + 1";
        // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
        $wpdb->query($wpdb->prepare($sql, $date, $from_t, $from_id, $to_t, $to_id));
    }

    private static function classify_source($referrer, $utm_source, $utm_medium) {
        $utm_source = strtolower(trim($utm_source));
        $utm_medium = strtolower(trim($utm_medium));

        if ($utm_source !== '') {
            $detail = $utm_source;
            if ($utm_medium === 'messenger' || $utm_medium === 'im') return ['social', $detail];
            if ($utm_medium === 'social')    return ['social', $detail];
            if ($utm_medium === 'email')     return ['referral', $detail];
            if ($utm_medium === 'cpc' || $utm_medium === 'paid' || $utm_medium === 'ads') return ['other', $detail];
            return ['other', $detail];
        }

        if (empty($referrer)) return ['direct', ''];

        $host = wp_parse_url($referrer, PHP_URL_HOST);
        if (!$host) return ['direct', ''];

        $home = wp_parse_url(home_url(), PHP_URL_HOST);
        if ($home && $host === $home) return ['internal', ''];

        if (preg_match('/google\./i', $host))     return ['google', ''];
        if (preg_match('/yandex\./i', $host))     return ['yandex', ''];
        if (preg_match('/bing\./i', $host))       return ['bing', ''];
        if (preg_match('/duckduckgo\./i', $host)) return ['other', 'duckduckgo'];

        if (preg_match('/(^|\.)t\.me$/i', $host)) return ['social', 'telegram'];
        if (preg_match('/telegram\./i', $host))   return ['social', 'telegram'];
        if (preg_match('/whatsapp\./i', $host))   return ['social', 'whatsapp'];
        if (preg_match('/viber\./i', $host))      return ['social', 'viber'];
        if (preg_match('/signal\./i', $host))     return ['social', 'signal'];

        if (preg_match('/vk\.com/i', $host))             return ['social', 'vk'];
        if (preg_match('/facebook\./i', $host))          return ['social', 'facebook'];
        if (preg_match('/instagram\./i', $host))         return ['social', 'instagram'];
        if (preg_match('/twitter\.com|x\.com/i', $host)) return ['social', 'twitter'];
        if (preg_match('/linkedin\./i', $host))          return ['social', 'linkedin'];
        if (preg_match('/reddit\./i', $host))            return ['social', 'reddit'];
        if (preg_match('/pinterest\./i', $host))         return ['social', 'pinterest'];

        return ['referral', ''];
    }

    private static function host($referrer) {
        if (empty($referrer)) return '';
        return substr((string)wp_parse_url($referrer, PHP_URL_HOST), 0, 100);
    }

    private static function valid_type($t) {
        static $valid = ['post','page','category','tag','tax','archive','home','search','404','other'];
        return in_array($t, $valid, true) ? $t : 'other';
    }

    private static function type_to_char($t) {
        static $map = [
            'post' => 'p', 'page' => 'g', 'category' => 'c', 'tag' => 't', 'tax' => 'x',
            'archive' => 'a', 'home' => 'h', 'search' => 's', '404' => '4', 'other' => 'o',
        ];
        return $map[$t] ?? 'o';
    }

    public static function char_to_type($c) {
        static $map = [
            'p' => 'post', 'g' => 'page', 'c' => 'category', 't' => 'tag', 'x' => 'tax',
            'a' => 'archive', 'h' => 'home', 's' => 'search', '4' => '404', 'o' => 'other',
        ];
        return $map[$c] ?? 'other';
    }
}