<?php
/**
 * Tracks crawler stats.
 */

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

class AICRG_Crawler_Registry {

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

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

    /** @var array */
    private $allowed_statuses = [ 'trusted', 'blocked', 'unknown' ];

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

    public function get_or_create( string $slug, string $name, string $default_status = 'unknown' ): ?array {
        $record = $this->get_by_slug( $slug );

        if ( $record ) {
            return $record;
        }

        if ( ! in_array( $default_status, $this->allowed_statuses, true ) ) {
            $default_status = 'unknown';
        }

        $inserted = $this->db->insert(
            $this->table,
            [
                'bot_slug'     => $slug,
                'display_name' => $name,
                'status'       => $default_status,
                'first_seen'   => current_time( 'mysql' ),
                'last_seen'    => current_time( 'mysql' ),
                'total_hits'   => 0,
                'allowed_hits' => 0,
                'blocked_hits' => 0,
            ],
            [ '%s', '%s', '%s', '%s', '%s', '%d', '%d', '%d' ]
        );

        if ( false === $inserted ) {
            return null;
        }

        return $this->get_by_slug( $slug );
    }

    public function update_stats( string $slug, string $action ): void {
        $action = 'blocked' === $action ? 'blocked' : 'allowed';

        $this->db->query(
            $this->db->prepare(
                "UPDATE {$this->table} SET last_seen = %s, total_hits = total_hits + 1, allowed_hits = allowed_hits + %d, blocked_hits = blocked_hits + %d WHERE bot_slug = %s",
                current_time( 'mysql' ),
                'allowed' === $action ? 1 : 0,
                'blocked' === $action ? 1 : 0,
                $slug
            )
        );
    }

    public function set_status( string $slug, string $status ): bool {
        if ( ! in_array( $status, $this->allowed_statuses, true ) ) {
            $status = 'unknown';
        }

        return false !== $this->db->update(
            $this->table,
            [ 'status' => $status ],
            [ 'bot_slug' => $slug ],
            [ '%s' ],
            [ '%s' ]
        );
    }

    public function get_status( string $slug ): string {
        $record = $this->get_by_slug( $slug );
        return $record['status'] ?? 'unknown';
    }

    public function get_all_crawlers( array $args = [] ): array {
        $defaults = [
            'limit'  => 50,
            'offset' => 0,
            'search' => '',
            'order'  => 'last_seen',
            'order_direction' => 'DESC',
        ];
        $args   = wp_parse_args( $args, $defaults );
        $limit  = absint( $args['limit'] );
        $offset = absint( $args['offset'] );
        $search = sanitize_text_field( $args['search'] );
        $order  = in_array( $args['order'], [ 'last_seen', 'first_seen', 'display_name', 'total_hits' ], true ) ? $args['order'] : 'last_seen';
        $direction = 'ASC' === strtoupper( $args['order_direction'] ) ? 'ASC' : 'DESC';

        $sql    = "SELECT * FROM {$this->table}";
        $where  = [];
        $params = [];

        if ( $search ) {
            $like    = '%' . $this->db->esc_like( $search ) . '%';
            $where[] = '(display_name LIKE %s OR bot_slug LIKE %s)';
            $params[] = $like;
            $params[] = $like;
        }

        if ( $where ) {
            $sql .= ' WHERE ' . implode( ' AND ', $where );
        }

        $sql .= " ORDER BY {$order} {$direction} LIMIT %d OFFSET %d";
        $params[] = $limit;
        $params[] = $offset;

        $query = $this->db->prepare( $sql, ...$params );

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

    public function get_summary_stats(): array {
        $row = $this->db->get_row( "SELECT SUM(total_hits) AS total_hits, SUM(allowed_hits) AS allowed_hits, SUM(blocked_hits) AS blocked_hits FROM {$this->table}", ARRAY_A );
        return [
            'total_hits'   => isset( $row['total_hits'] ) ? (int) $row['total_hits'] : 0,
            'allowed_hits' => isset( $row['allowed_hits'] ) ? (int) $row['allowed_hits'] : 0,
            'blocked_hits' => isset( $row['blocked_hits'] ) ? (int) $row['blocked_hits'] : 0,
        ];
    }

    public function get_status_counts(): array {
        $rows = $this->db->get_results( "SELECT status, COUNT(*) as total FROM {$this->table} GROUP BY status", ARRAY_A );
        $counts = [ 'trusted' => 0, 'blocked' => 0, 'unknown' => 0 ];
        foreach ( (array) $rows as $row ) {
            $status = $row['status'];
            if ( isset( $counts[ $status ] ) ) {
                $counts[ $status ] = (int) $row['total'];
            }
        }
        return $counts;
    }

    public function count_crawlers( array $args = [] ): int {
        $defaults = [ 'search' => '' ];
        $args     = wp_parse_args( $args, $defaults );
        $search   = sanitize_text_field( $args['search'] );

        $sql    = "SELECT COUNT(*) FROM {$this->table}";
        $params = [];

        if ( $search ) {
            $like    = '%' . $this->db->esc_like( $search ) . '%';
            $sql    .= ' WHERE (display_name LIKE %s OR bot_slug LIKE %s)';
            $params = [ $like, $like ];
        }

        if ( $params ) {
            return (int) $this->db->get_var( $this->db->prepare( $sql, ...$params ) );
        }

        return (int) $this->db->get_var( $sql );
    }

    private function get_by_slug( string $slug ): ?array {
        $query = $this->db->prepare(
            "SELECT * FROM {$this->table} WHERE bot_slug = %s LIMIT 1",
            $slug
        );

        $row = $this->db->get_row( $query, ARRAY_A );
        return $row ?: null;
    }
}