using System;
using System.Runtime.InteropServices;

namespace LrcTool
{
    public class HiraganaPhoneticHelper : IDisposable
    {
        private const string ProgId = "MSIME.Japan";

        private readonly IFELanguage _instance;

        public HiraganaPhoneticHelper()
        {
            if (!(Activator.CreateInstance(Type.GetTypeFromProgID(ProgId)) is IFELanguage ifelang))
            {
                throw new Exception($"Could not create object of {ProgId}, is STAThread attribute missing?");
            }

            var hr = ifelang.Open();
            if (hr != 0) throw Marshal.GetExceptionForHR(hr);

            hr = ifelang.GetPhonetic("東京は昨日雪が降りました。", 1, -1, out _);
            if (hr != 0) throw Marshal.GetExceptionForHR(hr);

            _instance = ifelang;
        }

        public string GetPhonetic(string input)
        {
            var hr = _instance.GetPhonetic(input, 1, -1, out var result);
            if (hr != 0) throw Marshal.GetExceptionForHR(hr);
            return result;
        }

        public void Dispose() => _instance?.Close();

        // IFELanguage2 Interface ID
        //[Guid("21164102-C24A-11d1-851A-00C04FCC6B14")]
        [ComImport]
        [Guid("019F7152-E6DB-11d0-83C3-00C04FDDB82E")]
        [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
        private interface IFELanguage
        {
            int Open();

            int Close();

            int GetJMorphResult(uint dwRequest, uint dwCMode, int cwchInput, [MarshalAs(UnmanagedType.LPWStr)] string pwchInput, IntPtr pfCInfo, out object ppResult);

            int GetConversionModeCaps(ref uint pdwCaps);

            int GetPhonetic([MarshalAs(UnmanagedType.BStr)] string @string, int start, int length, [MarshalAs(UnmanagedType.BStr)] out string result);

            int GetConversion([MarshalAs(UnmanagedType.BStr)] string @string, int start, int length, [MarshalAs(UnmanagedType.BStr)] out string result);
        }
    }
}