using System;
using System.Runtime.ConstrainedExecution;
using System.Runtime.InteropServices;

namespace Foodsoft.Alpm
{
    internal sealed class SafeAlpmHandle : SafeHandle
    {
        private SafeAlpmHandle() : base(IntPtr.Zero, true) { }

        public override bool IsInvalid
        {
            [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
            [PrePrepareMethod]
            get => handle == IntPtr.Zero;
        }

        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
        [PrePrepareMethod]
        protected override bool ReleaseHandle()
        {
            return alpm.alpm_release(handle) == 0;
        }
    }
}