<?php
/**
 * Request logger.
 */

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

class AICRG_Logger {

    /** @var wpdb */
    private $db;

    /** @var string */
    private $table;

    public function __construct( wpdb $db, string $table ) {
        $this->db    = $db;
        $this->table = $table;
    }

    public function log( string $bot_slug, string $bot_name, string $ua, string $url, string $action ): void {
        $settings = aicrg_get_settings();

        if ( empty( $settings['log_enabled'] ) ) {
            return;
        }

        $data = [
            'time'       => current_time( 'mysql' ),
            'bot_slug'   => sanitize_title( $bot_slug ),
            'bot_name'   => sanitize_text_field( $bot_name ),
            'user_agent' => aicrg_truncate( sanitize_textarea_field( $ua ), 500 ),
            'url'        => aicrg_truncate( esc_url_raw( $url ), 500 ),
            'action'     => in_array( $action, [ 'allowed', 'blocked' ], true ) ? $action : 'allowed',
        ];

        $formats = [ '%s', '%s', '%s', '%s', '%s', '%s' ];

        $inserted = $this->db->insert( $this->table, $data, $formats );

        if ( false !== $inserted ) {
            $this->prune_logs( absint( $settings['log_limit'] ?? 500 ) );
        }
    }

    public function get_logs( array $args = [] ): array {
        $defaults = [ 'limit' => 50, 'offset' => 0 ];
        $args     = wp_parse_args( $args, $defaults );
        $limit    = absint( $args['limit'] );
        $offset   = absint( $args['offset'] );

        $query = $this->db->prepare(
            "SELECT * FROM {$this->table} ORDER BY time DESC LIMIT %d OFFSET %d",
            $limit,
            $offset
        );

        return $this->db->get_results( $query, ARRAY_A ) ?: [];
    }

    public function count_logs(): int {
        return (int) $this->db->get_var( "SELECT COUNT(*) FROM {$this->table}" );
    }

    public function clear_logs(): void {
        $this->db->query( "DELETE FROM {$this->table}" );
    }

    public function get_activity_trend( int $days = 7 ): array {
        $days = max( 1, $days );
        $query = $this->db->prepare(
            "SELECT DATE(time) as day,
                    SUM(CASE WHEN action = 'blocked' THEN 1 ELSE 0 END) as blocked,
                    SUM(CASE WHEN action = 'allowed' THEN 1 ELSE 0 END) as allowed,
                    COUNT(*) as total
             FROM {$this->table}
             WHERE time >= DATE_SUB( %s, INTERVAL %d DAY )
             GROUP BY DATE(time)
             ORDER BY day DESC",
            current_time( 'mysql' ),
            $days
        );

        $rows = $this->db->get_results( $query, ARRAY_A ) ?: [];
        return array_reverse( $rows );
    }

    private function prune_logs( int $limit ): void {
        if ( $limit <= 0 ) {
            return;
        }

        $count = (int) $this->db->get_var( "SELECT COUNT(*) FROM {$this->table}" );
        if ( $count <= $limit ) {
            return;
        }

        $ids = $this->db->get_col(
            $this->db->prepare(
                "SELECT id FROM {$this->table} ORDER BY time DESC LIMIT %d, 18446744073709551615",
                $limit
            )
        );

        if ( ! empty( $ids ) ) {
            $placeholders = implode( ',', array_fill( 0, count( $ids ), '%d' ) );
            $query        = $this->db->prepare( "DELETE FROM {$this->table} WHERE id IN ($placeholders)", ...array_map( 'intval', $ids ) );
            $this->db->query( $query );
        }
    }
}