using System.Runtime.InteropServices;

namespace MoonlightServers.Daemon.Helpers;

internal static partial class NativeMethods
{
    [StructLayout(LayoutKind.Sequential)]
    internal struct StatVfsResult
    {
        public ulong bsize;
        public ulong frsize;
        public ulong blocks;
        public ulong bfree;
        public ulong bavail;
        public ulong files;
        public ulong ffree;
        public ulong favail;
        public ulong fsid;
        public ulong flag;
        public ulong namemax;
        private ulong __spare0;  // } kernel reserved padding —
        private ulong __spare1;  // } never read, exist only to
        private ulong __spare2;  // } match the 112-byte struct
        private ulong __spare3;  // } statvfs layout on x86-64
        private ulong __spare4;  // } Linux so the fields above
        private ulong __spare5;  // } land at the right offsets
    }

    // SetLastError = true tells the marshaller to capture errno immediately
    // after the call, before any other code can clobber it. Retrieve it with
    // Marshal.GetLastPInvokeError() which maps to the thread-local errno value.
    [LibraryImport("libc", EntryPoint = "statvfs",
        StringMarshalling = StringMarshalling.Utf8,
        SetLastError = true)]
    internal static partial int StatVfs(string path, out StatVfsResult buf);
}