/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.nfc;

import android.nfc.technology.NfcA;
import android.nfc.technology.NfcB;
import android.nfc.technology.NfcF;
import android.nfc.technology.IsoDep;
import android.nfc.technology.TagTechnology;
import android.nfc.technology.Ndef;
import android.nfc.NdefMessage;
import android.os.Bundle;
import android.util.Log;

/**
 * Native interface to the NFC tag functions
 */
public class NativeNfcTag {
    static final boolean DBG = false;

    private int mHandle;

    private int[] mTechList;
    private int[] mTechHandles;
    private Bundle[] mTechExtras;
    private byte[][] mTechPollBytes;
    private byte[][] mTechActBytes;
    private byte[] mUid;

    private final String TAG = "NativeNfcTag";

    private PresenceCheckWatchdog mWatchdog;
    class PresenceCheckWatchdog extends Thread {

        private boolean isPresent = true;
        private boolean isRunning = true;

        public void reset() {
            this.interrupt();
        }

        public void end() {
            isRunning = false;
            this.interrupt();
        }

        @Override
        public void run() {
            if (DBG) Log.d(TAG, "Starting background presence check");
            while (isPresent && isRunning) {
                try {
                    Thread.sleep(1000);
                    isPresent = doPresenceCheck();
                } catch (InterruptedException e) {
                    // Activity detected, loop
                }
            }
            // Restart the polling loop if the tag is not here any more
            if (!isPresent) {
                Log.d(TAG, "Tag lost, restarting polling loop");
                doDisconnect();
            }
            if (DBG) Log.d(TAG, "Stopping background presence check");
        }
    }

    private native boolean doConnect();
    public synchronized boolean connect() {
        boolean isSuccess = doConnect();
        if (isSuccess) {
            mWatchdog = new PresenceCheckWatchdog();
            mWatchdog.start();
        }
        return isSuccess;
    }

    native boolean doDisconnect();
    public synchronized boolean disconnect() {
        if (mWatchdog != null) {
            mWatchdog.end();
        }
        return doDisconnect();
    }

    native boolean doReconnect();
    public synchronized boolean reconnect() {
        if (mWatchdog != null) {
            mWatchdog.reset();
        }
        return doReconnect();
    }

    private native byte[] doTransceive(byte[] data, boolean raw);
    public synchronized byte[] transceive(byte[] data, boolean raw) {
        if (mWatchdog != null) {
            mWatchdog.reset();
        }
        return doTransceive(data, raw);
    }

    private native boolean doCheckNdef(int[] ndefinfo);
    public synchronized boolean checkNdef(int[] ndefinfo) {
        if (mWatchdog != null) {
            mWatchdog.reset();
        }
        return doCheckNdef(ndefinfo);
    }

    private native byte[] doRead();
    public synchronized byte[] read() {
        if (mWatchdog != null) {
            mWatchdog.reset();
        }
        return doRead();
    }

    private native boolean doWrite(byte[] buf);
    public synchronized boolean write(byte[] buf) {
        if (mWatchdog != null) {
            mWatchdog.reset();
        }
        return doWrite(buf);
    }

    native boolean doPresenceCheck();
    public synchronized boolean presenceCheck() {
        if (mWatchdog != null) {
            mWatchdog.reset();
        }
        return doPresenceCheck();
    }

    native boolean doNdefFormat(byte[] key);
    public synchronized boolean formatNdef(byte[] key) {
        if (mWatchdog != null) {
            mWatchdog.reset();
        }
        return doNdefFormat(key);
    }

    private NativeNfcTag() {
    }

    public int getHandle() {
        return mHandle;
    }

    public byte[] getUid() {
        return mUid;
    }

    public int[] getTechList() {
        return mTechList;
    }

    // This method exists to "patch in" the ndef technologies,
    // which is done inside Java instead of the native JNI code.
    // To not create some nasty dependencies on the order on which things
    // are called (most notably getTechExtras()), it needs some additional
    // checking.
    public void addNdefTechnology(NdefMessage msg, int maxLength, int cardState) {
        synchronized (this) {
            int[] mNewTechList = new int[mTechList.length + 1];
            System.arraycopy(mTechList, 0, mNewTechList, 0, mTechList.length);
            mNewTechList[mTechList.length] = TagTechnology.NDEF;
            mTechList = mNewTechList;

            Bundle extras = new Bundle();
            extras.putParcelable(Ndef.EXTRA_NDEF_MSG, msg);
            extras.putInt(Ndef.EXTRA_NDEF_MAXLENGTH, maxLength);
            extras.putInt(Ndef.EXTRA_NDEF_CARDSTATE, cardState);

            if (mTechExtras == null) {
                // This will build the tech extra's for the first time,
                // including a NULL ref for the NDEF tech we generated above.
                Bundle[] builtTechExtras = getTechExtras();
                builtTechExtras[builtTechExtras.length - 1] = extras;
            }
            else {
                // Tech extras were built before, patch the NDEF one in
                Bundle[] oldTechExtras = getTechExtras();
                Bundle[] newTechExtras = new Bundle[oldTechExtras.length + 1];
                System.arraycopy(oldTechExtras, 0, newTechExtras, 0, oldTechExtras.length);
                newTechExtras[oldTechExtras.length] = extras;
                mTechExtras = newTechExtras;
            }

        }
    }

    private boolean hasTech(int tech) {
      boolean hasTech = false;
      for (int i = 0; i < mTechList.length; i++) {
          if (mTechList[i] == tech) {
              hasTech = true;
              break;
          }
      }
      return hasTech;
    }

    public Bundle[] getTechExtras() {
        synchronized (this) {
            if (mTechExtras != null) return mTechExtras;
            mTechExtras = new Bundle[mTechList.length];
            for (int i = 0; i < mTechList.length; i++) {
                Bundle extras = new Bundle();
                switch (mTechList[i]) {
                    case TagTechnology.NFC_A: {
                        byte[] actBytes = mTechActBytes[i];
                        if ((actBytes != null) && (actBytes.length > 0)) {
                            extras.putShort(NfcA.EXTRA_SAK, (short) (actBytes[0] & (short) 0xFF));
                        } else {
                            // Unfortunately Jewel doesn't have act bytes,
                            // ignore this case.
                        }
                        extras.putByteArray(NfcA.EXTRA_ATQA, mTechPollBytes[i]);
                        break;
                    }

                    case TagTechnology.NFC_B: {
                        extras.putByteArray(NfcB.EXTRA_ATQB, mTechPollBytes[i]);
                        break;
                    }
                    case TagTechnology.NFC_F: {
                        byte[] pmm = new byte[8];
                        byte[] sc = new byte[2];
                        if (mTechPollBytes[i].length >= 8) {
                            // At least pmm is present
                            System.arraycopy(mTechPollBytes[i], 0, pmm, 0, 8);
                            extras.putByteArray(NfcF.EXTRA_PMM, pmm);
                        }
                        if (mTechPollBytes[i].length == 10) {
                            System.arraycopy(mTechPollBytes[i], 8, sc, 0, 2);
                            extras.putByteArray(NfcF.EXTRA_SC, sc);
                        }
                        break;
                    }
                    case TagTechnology.ISO_DEP: {
                        if (hasTech(TagTechnology.NFC_A)) {
                            extras.putByteArray(IsoDep.EXTRA_HIST_BYTES, mTechActBytes[i]);
                        }
                        else {
                            extras.putByteArray(IsoDep.EXTRA_ATTRIB, mTechActBytes[i]);
                        }
                        break;
                    }

                    default: {
                        // Leave the entry in the array null
                        continue;
                    }
                }
                mTechExtras[i] = extras;
            }
            return mTechExtras;
        }
    }
}