using System;
using System.Runtime.InteropServices;
using Gst.GLib;

namespace Gst {
  internal static class Marshaller {

    public static IntPtr StringArrayToNullTermPointer (string[] strs) {
      if (strs == null)
        return IntPtr.Zero;

      IntPtr result = Gst.GLib.Marshaller.Malloc ( (ulong) ( (strs.Length + 1) * IntPtr.Size));

      for (int i = 0; i < strs.Length; i++)
        Marshal.WriteIntPtr (result, i * IntPtr.Size, Gst.GLib.Marshaller.StringToPtrGStrdup (strs [i]));

      Marshal.WriteIntPtr (result, strs.Length * IntPtr.Size, IntPtr.Zero);

      return result;
    }

    [DllImport ("libglib-2.0-0.dll") ]
    static extern void g_strfreev (IntPtr mem);

    public static string[] NullTermPtrToStringArray (IntPtr null_term_array, bool owned) {
      if (null_term_array == IntPtr.Zero)
        return new string [0];

      int count = 0;
      System.Collections.ArrayList result = new System.Collections.ArrayList ();
      IntPtr s = Marshal.ReadIntPtr (null_term_array, count++ * IntPtr.Size);
      while (s != IntPtr.Zero) {
        result.Add (Gst.GLib.Marshaller.Utf8PtrToString (s));
        s = Marshal.ReadIntPtr (null_term_array, count++ * IntPtr.Size);
      }

      if (owned)
        g_strfreev (null_term_array);

      return (string[]) result.ToArray (typeof (string));
    }
  }
}