<?php
namespace AskTamMCP\Tools;
defined('ABSPATH') || exit;

class RawSqlTools {

    private static array $BLOCKED = [
        '/\bDROP\b/i', '/\bTRUNCATE\b/i', '/\bDELETE\b/i',
        '/\bUPDATE\b/i', '/\bINSERT\b/i', '/\bALTER\b/i',
        '/\bCREATE\b/i', '/\bGRANT\b/i', '/\bREVOKE\b/i',
        '/\bLOAD\s+DATA\b/i', '/\bINTO\s+OUTFILE\b/i',
        '/\bINFORMATION_SCHEMA\b/i', '/\bmysql\b/i',
    ];

    public static function query(array $args): array {
        $settings = get_option('asktam_mcp_settings', []);
        if (empty($settings['allow_raw_sql'])) {
            throw new \RuntimeException("Raw SQL is disabled. Enable it in AskTam MCP → Settings.");
        }

        $sql   = trim($args['sql'] ?? '');
        $limit = min((int)($args['limit'] ?? 100), 500);

        if (empty($sql)) throw new \RuntimeException("SQL query is required.");

        // Only SELECT allowed
        if (!preg_match('/^\s*SELECT\b/i', $sql)) {
            throw new \RuntimeException("Only SELECT queries are allowed.");
        }

        // Block dangerous patterns
        foreach (self::$BLOCKED as $pattern) {
            if (preg_match($pattern, $sql)) {
                throw new \RuntimeException("Query contains blocked pattern.");
            }
        }

        // Inject LIMIT if not present
        if (!preg_match('/\bLIMIT\b/i', $sql)) {
            $sql .= " LIMIT $limit";
        }

        global $wpdb;
        $results = $wpdb->get_results($sql, ARRAY_A);

        if ($wpdb->last_error) {
            throw new \RuntimeException("SQL error: " . $wpdb->last_error);
        }

        return [
            'sql'     => $sql,
            'rows'    => $results,
            'count'   => count($results ?? []),
        ];
    }

    public static function listTables(array $args): array {
        global $wpdb;
        $prefix  = $args['prefix'] ?? $wpdb->prefix;
        $tables  = $wpdb->get_col("SHOW TABLES LIKE '{$wpdb->esc_like($prefix)}%'");
        $result  = [];
        foreach ($tables as $t) {
            $info = $wpdb->get_row("SELECT TABLE_ROWS, DATA_LENGTH+INDEX_LENGTH as SIZE FROM information_schema.TABLES WHERE TABLE_SCHEMA=DATABASE() AND TABLE_NAME='$t'", ARRAY_A);
            $result[] = [
                'table'    => $t,
                'rows'     => (int)($info['TABLE_ROWS'] ?? 0),
                'size'     => size_format((int)($info['SIZE'] ?? 0)),
            ];
        }
        return ['tables'=>$result,'count'=>count($result),'prefix'=>$prefix];
    }

    public static function describeTable(array $args): array {
        global $wpdb;
        $table   = sanitize_text_field($args['table']);
        // Must use allowed prefix
        if (strpos($table, $wpdb->prefix) !== 0) {
            throw new \RuntimeException("Table must use the WP prefix: $wpdb->prefix");
        }
        $columns = $wpdb->get_results("DESCRIBE `$table`", ARRAY_A);
        if ($wpdb->last_error) throw new \RuntimeException($wpdb->last_error);
        return ['table'=>$table,'columns'=>$columns,'count'=>count($columns)];
    }
}