using System;
using System.Data.OleDb;
using Serilog;

namespace SyncEngine.Access
{
    /// <summary>
    /// Grants Jet/ACE SELECT on system tables (same DDL as Access VBA CurrentProject.Connection.Execute).
    /// </summary>
    internal static class AccessSystemTablePermissions
    {
        private static readonly string[] SystemTables = { "MSysObjects", "MSysRelationships" };

        /// <summary>OleDb GRANT only works with user-level security (workgroup .mdw). Prefer Access.Application.</summary>
        public static bool TryGrantSelect(OleDbConnection conn, string userName, ILogger logger)
        {
            var user = string.IsNullOrWhiteSpace(userName) ? "Admin" : userName.Trim();
            var grantedAny = false;

            foreach (var table in SystemTables)
            {
                try
                {
                    // GRANT SELECT ON MSysObjects TO Admin;
                    var ddl = string.Format("GRANT SELECT ON {0} TO {1};", table, user);
                    using (var cmd = new OleDbCommand(ddl, conn))
                    {
                        cmd.ExecuteNonQuery();
                    }

                    logger.Information("Granted SELECT on {Table} to {User}", table, user);
                    grantedAny = true;
                }
                catch (Exception ex)
                {
                    logger.Debug(
                        "GRANT SELECT on {Table} via OleDb skipped (requires workgroup .mdw): {Message}",
                        table,
                        ex.Message);
                }
            }

            return grantedAny;
        }
    }
}