using System;
using System.Runtime.CompilerServices;
using System.Runtime.ConstrainedExecution;

namespace Foodsoft.Alpm
{
    internal sealed class SafeCachePackageHandle : SafePackageHandle
    {
        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
        [PrePrepareMethod]
        internal SafeCachePackageHandle(IntPtr ptr, SafeDatabaseHandle parentHandle)
            : base(parentHandle.SafeAlpmHandle)
        {
            var success = false;

            RuntimeHelpers.PrepareConstrainedRegions();
            try { }
            finally
            {
                parentHandle.DangerousAddRef(ref success);
                if (success)
                {
                    SafeDatabaseHandle = parentHandle;
                    handle = ptr;
                }
            }

            if (!success) throw new ObjectDisposedException(GetType().FullName);
        }

        internal SafeDatabaseHandle SafeDatabaseHandle
        {
            [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
            [PrePrepareMethod]
            get;
        } = null!;

        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
        [PrePrepareMethod]
        protected override bool ReleaseHandle()
        {
            SafeDatabaseHandle.DangerousRelease();
            return true;
        }
    }
}