using System;
using System.Text;
using System.Windows.Forms;
using PCSC;
using PCSC.Exceptions;
using PCSC.Iso7816;
using PCSC.Monitoring;

namespace PasoriForm {
    public partial class Form1 : Form {

        // fields
        private string readerName;
        private ISCardContext context;
        private ISCardMonitor monitor;

        // constructor
        public Form1() {
            InitializeComponent();
            InitializePasori();
        }

        // pasori init
        private void InitializePasori() {
            try {
                // check connection
                context = ContextFactory.Instance.Establish(SCardScope.System);
                var readerNames = context.GetReaders();
                if(readerNames.Length < 1) {
                    throw new NoServiceException(SCardError.NoReadersAvailable); // Cannot find a smart card reader.
                }
                readerName = readerNames[0];
                // create monitor
                monitor = MonitorFactory.Instance.Create(SCardScope.System);
                monitor.CardInserted += Monitor_CardInserted;
                monitor.Start(readerName);
                textBoxLog.Text += "カードをかざしてください" + Environment.NewLine;
            } catch(NoServiceException ex) {
                textBoxLog.Text += ex.Message + Environment.NewLine;
            }
        }

        // monitor event
        private void Monitor_CardInserted(object sender, CardStatusEventArgs e) {
            Invoke(new Action(() => {
                ReadData();
            }));
        }

        // read data
        private void ReadData() {
            // reader
            using var reader = context.ConnectReader(readerName, SCardShareMode.Shared, SCardProtocol.Any);
            var apdu = new CommandApdu(IsoCase.Case2Short, reader.Protocol){
                CLA = 0xff,
                Instruction = InstructionCode.GetData,
                P1 = 0x00,
                P2 = 0x00,
                Le = 0
            };
            using (reader.Transaction(SCardReaderDisposition.Leave)) {
                // param
                var sendPci = SCardPCI.GetPci(reader.Protocol);
                var receivePci = new SCardPCI();
                var receiveBuffer = new Byte[256];
                var command = apdu.ToArray();
                // send
                var bytesReceived = reader.Transmit(
                    sendPci,
                    command,
                    command.Length,
                    receivePci,
                    receiveBuffer,
                    receiveBuffer.Length);
                // response
                var responseApdu = new ResponseApdu(receiveBuffer, bytesReceived, IsoCase.Case2Short, reader.Protocol);
                if (responseApdu.HasData) {
                    textBoxReadData.Text = new StringBuilder(BitConverter.ToString(responseApdu.GetData())).ToString();
                } else {
                    textBoxReadData.Text = string.Empty;
                }
            }
        }

        // form event
        private void Form1_FormClosing(object sender, FormClosingEventArgs e) {
            if(context != null) {
                context.Dispose();
            }
            if(monitor != null) {
                monitor.Dispose();
            }
        }

        // 更新button event
        private void ButtonReset_Click(object sender, EventArgs e) {
            InitializePasori();
        }
    }
}