using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;

namespace FelicaLib
{
    // システムコード
    public enum SystemCode : int
    {
        Any = 0xffff,       // ANY
        Common = 0xfe00,    // 共通領域
        Cyberne = 0x0003,   // サイバネ領域

        Edy = 0xfe00,       // Edy (=共通領域)
        Suica = 0x0003,     // Suica (=サイバネ領域)
    }

    public interface IFelica : IDisposable
    {
        void Polling(int systemcode);
        byte[] IDm();
        byte[] PMm();
        byte[] ReadWithoutEncryption(int servicecode, int addr);
    }

    public class Felica : IFelica
    {
        [DllImport("felicalib.dll")]
        private extern static IntPtr pasori_open(String dummy);
        [DllImport("felicalib.dll")]
        private extern static void pasori_close(IntPtr p);
        [DllImport("felicalib.dll")]
        private extern static int pasori_init(IntPtr p);
        [DllImport("felicalib.dll")]
        private extern static IntPtr felica_polling(IntPtr p, ushort systemcode, byte rfu, byte time_slot);
        [DllImport("felicalib.dll")]
        private extern static void felica_free(IntPtr f);
        [DllImport("felicalib.dll")]
        private extern static void felica_getidm(IntPtr f, byte[] data);
        [DllImport("felicalib.dll")]
        private extern static void felica_getpmm(IntPtr f, byte[] data);
        [DllImport("felicalib.dll")]
        private extern static int felica_read_without_encryption02(IntPtr f, int servicecode, int mode, byte addr, byte[] data);

        private IntPtr pasorip = IntPtr.Zero;
        private IntPtr felicap = IntPtr.Zero;

        public Felica()
        {
            pasorip = pasori_open(null);
            if (pasorip == IntPtr.Zero)
            {
                throw new Exception("felicalib.dll を開けません");
            }
            if (pasori_init(pasorip) != 0)
            {
                throw new Exception("PaSoRi に接続できません");
            }
        }

        public void Dispose()
        {
            if (pasorip != IntPtr.Zero)
            {
                pasori_close(pasorip);
                pasorip = IntPtr.Zero;
            }
        }

        ~Felica()
        {
            Dispose();
        }

        public void Polling(int systemcode)
        {
            felica_free(felicap);

            felicap = felica_polling(pasorip, (ushort)systemcode, 0, 0);
            if (felicap == IntPtr.Zero)
            {
                throw new Exception("カード読み取り失敗");
            }
        }

        public byte[] IDm()
        {
            if (felicap == IntPtr.Zero)
            {
                throw new Exception("no polling executed.");
            }

            byte[] buf = new byte[8];
            felica_getidm(felicap, buf);
            return buf;
        }    

        public byte[] PMm()
        {
            if (felicap == IntPtr.Zero)
            {
                throw new Exception("no polling executed.");
            }

            byte[] buf = new byte[8];
            felica_getpmm(felicap, buf);
            return buf;
        }    

        public byte[] ReadWithoutEncryption(int servicecode, int addr)
        {
            if (felicap == IntPtr.Zero)
            {
                throw new Exception("no polling executed.");
            }

            byte[] data = new byte[16];
            int ret = felica_read_without_encryption02(felicap, servicecode, 0, (byte)addr, data);
            if (ret != 0)
            {
                return null;
            }
            return data;
        }
    }
}