/*
 * Copyright (C) 2007 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.internal.telephony.gsm.stk;

import android.content.Context;
import android.content.Intent;
import android.os.AsyncResult;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Message;

import com.android.internal.telephony.IccUtils;
import com.android.internal.telephony.CommandsInterface;
import com.android.internal.telephony.EncodeException;
import com.android.internal.telephony.GsmAlphabet;
import com.android.internal.telephony.gsm.SimCard;
import com.android.internal.telephony.gsm.SIMFileHandler;
import com.android.internal.telephony.gsm.SIMRecords;

import android.util.Config;

import java.io.ByteArrayOutputStream;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;

/**
 * Enumeration for representing the tag value of COMPREHENSION-TLV objects. If
 * you want to get the actual value, call {@link #value() value} method.
 *
 * {@hide}
 */
enum ComprehensionTlvTag {
  COMMAND_DETAILS(0x01),
  DEVICE_IDENTITIES(0x02),
  RESULT(0x03),
  DURATION(0x04),
  ALPHA_ID(0x05),
  USSD_STRING(0x0a),
  TEXT_STRING(0x0d),
  TONE(0x0e),
  ITEM(0x0f),
  ITEM_ID(0x10),
  RESPONSE_LENGTH(0x11),
  FILE_LIST(0x12),
  HELP_REQUEST(0x15),
  DEFAULT_TEXT(0x17),
  EVENT_LIST(0x19),
  ICON_ID(0x1e),
  ITEM_ICON_ID_LIST(0x1f),
  IMMEDIATE_RESPONSE(0x2b),
  LANGUAGE(0x2d),
  URL(0x31),
  BROWSER_TERMINATION_CAUSE(0x34),
  TEXT_ATTRIBUTE(0x50);

    private int mValue;

    ComprehensionTlvTag(int value) {
        mValue = value;
    }

    /**
     * Returns the actual value of this COMPREHENSION-TLV object.
     *
     * @return Actual tag value of this object
     */
        public int value() {
            return mValue;
        }

    public static ComprehensionTlvTag fromInt(int value) {
        for (ComprehensionTlvTag e : ComprehensionTlvTag.values()) {
            if (e.mValue == value) {
                return e;
            }
        }
        return null;
    }
}

class RilMessage {
    int mId;
    Object mData;
    ResultCode mResCode;

    RilMessage(int msgId, String rawData) {
        mId = msgId;
        mData = rawData;
    }

    RilMessage(RilMessage other) {
        this.mId = other.mId;
        this.mData = other.mData;
        this.mResCode = other.mResCode;
    }
}

/**
 * Class that implements SIM Toolkit Telephony Service. Interacts with the RIL
 * and application.
 *
 * {@hide}
 */
public class StkService extends Handler implements AppInterface {

    // Class members
    private static SIMRecords mSimRecords;
    
    // Service members.
    private static StkService sInstance;
    private CommandsInterface mCmdIf;
    private Context mContext;
    private StkCmdMessage mCurrntCmd = null;
    private StkCmdMessage mMenuCmd = null;

    private RilMessageDecoder mMsgDecoder = null;

    // Service constants.
    static final int MSG_ID_SESSION_END              = 1;
    static final int MSG_ID_PROACTIVE_COMMAND        = 2;
    static final int MSG_ID_EVENT_NOTIFY             = 3;
    static final int MSG_ID_CALL_SETUP               = 4;
    static final int MSG_ID_REFRESH                  = 5;
    static final int MSG_ID_RESPONSE                 = 6;

    static final int MSG_ID_RIL_MSG_DECODED          = 10;

    // Events to signal SIM presence or absent in the device.
    private static final int MSG_ID_SIM_LOADED       = 20;

    private static final int DEV_ID_KEYPAD      = 0x01;
    private static final int DEV_ID_DISPLAY     = 0x02;
    private static final int DEV_ID_EARPIECE    = 0x03;
    private static final int DEV_ID_UICC        = 0x81;
    private static final int DEV_ID_TERMINAL    = 0x82;
    private static final int DEV_ID_NETWORK     = 0x83;

    /* Intentionally private for singleton */
    private StkService(CommandsInterface ci, SIMRecords sr, Context context,
            SIMFileHandler fh, SimCard sc) {
        if (ci == null || sr == null || context == null || fh == null
                || sc == null) {
            throw new NullPointerException(
                    "Service: Input parameters must not be null");
        }
        mCmdIf = ci;
        mContext = context;

        // Get the RilMessagesDecoder for decoding the messages.
        mMsgDecoder = RilMessageDecoder.getInstance(this, fh);

        // Register ril events handling.
        mCmdIf.setOnStkSessionEnd(this, MSG_ID_SESSION_END, null);
        mCmdIf.setOnStkProactiveCmd(this, MSG_ID_PROACTIVE_COMMAND, null);
        mCmdIf.setOnStkEvent(this, MSG_ID_EVENT_NOTIFY, null);
        mCmdIf.setOnStkCallSetUp(this, MSG_ID_CALL_SETUP, null);
        //mCmdIf.setOnSimRefresh(this, MSG_ID_REFRESH, null);

        mSimRecords = sr;

        // Register for SIM ready event.
        mSimRecords.registerForRecordsLoaded(this, MSG_ID_SIM_LOADED, null);
    }

    public void dispose() {
        mSimRecords.unregisterForRecordsLoaded(this);
        mCmdIf.unSetOnStkSessionEnd(this);
        mCmdIf.unSetOnStkProactiveCmd(this);
        mCmdIf.unSetOnStkEvent(this);
        mCmdIf.unSetOnStkCallSetUp(this);

        this.removeCallbacksAndMessages(null);

        //removing instance
        sInstance = null;
    }

    protected void finalize() {
        StkLog.d(this, "Service finalized");
    }

    private void handleRilMsg(RilMessage rilMsg) {
        if (rilMsg == null) {
            return;
        }

        // dispatch messages
        CommandParams cmdParams = null;
        switch (rilMsg.mId) {
        case MSG_ID_EVENT_NOTIFY:
            if (rilMsg.mResCode == ResultCode.OK) {
                cmdParams = (CommandParams) rilMsg.mData;
                if (cmdParams != null) {
                    handleProactiveCommand(cmdParams);
                }
            }
            break;
        case MSG_ID_PROACTIVE_COMMAND:
            cmdParams = (CommandParams) rilMsg.mData;
            if (cmdParams != null) {
                if (rilMsg.mResCode == ResultCode.OK) {
                    handleProactiveCommand(cmdParams);
                } else {
                    // for proactive commands that couldn't be decoded
                    // successfully respond with the code generated by the
                    // message decoder.
                    sendTerminalResponse(cmdParams.cmdDet, rilMsg.mResCode,
                            false, 0, null);
                }
            }
            break;
        case MSG_ID_REFRESH:
            cmdParams = (CommandParams) rilMsg.mData;
            if (cmdParams != null) {
                handleProactiveCommand(cmdParams);
            }
            break;
        case MSG_ID_SESSION_END:
            handleSessionEnd();
            break;
        case MSG_ID_CALL_SETUP:
            // prior event notify command supplied all the information
            // needed for set up call processing.
            break;
        }
    }

    /**
     * Handles RIL_UNSOL_STK_PROACTIVE_COMMAND unsolicited command from RIL.
     * Sends valid proactive command data to the application using intents.
     *
     */
    private void handleProactiveCommand(CommandParams cmdParams) {
        StkLog.d(this, cmdParams.getCommandType().name());

        StkCmdMessage cmdMsg = new StkCmdMessage(cmdParams);
        switch (cmdParams.getCommandType()) {
        case SET_UP_MENU:
            if (removeMenu(cmdMsg.getMenu())) {
                mMenuCmd = null;
            } else {
                mMenuCmd = cmdMsg;
            }
            sendTerminalResponse(cmdParams.cmdDet, ResultCode.OK, false, 0,
                    null);
            break;
        case DISPLAY_TEXT:
            // when application is not required to respond, send an immediate
            // response.
            if (!cmdMsg.geTextMessage().responseNeeded) {
                sendTerminalResponse(cmdParams.cmdDet, ResultCode.OK, false,
                        0, null);
            }
            break;
        case REFRESH:
            // ME side only handles refresh commands which meant to remove IDLE
            // MODE TEXT.
            cmdParams.cmdDet.typeOfCommand = CommandType.SET_UP_IDLE_MODE_TEXT
                    .value();
            break;
        case SET_UP_IDLE_MODE_TEXT:
            sendTerminalResponse(cmdParams.cmdDet, ResultCode.OK, false,
                    0, null);
            break;
        case LAUNCH_BROWSER:
        case SELECT_ITEM:
        case GET_INPUT:
        case GET_INKEY:
        case SEND_DTMF:
        case SEND_SMS:
        case SEND_SS:
        case SEND_USSD:
        case PLAY_TONE:
        case SET_UP_CALL:
            // nothing to do on telephony!
            break;
        default:
            StkLog.d(this, "Unsupported command");
            return;
        }
        mCurrntCmd = cmdMsg;
        Intent intent = new Intent(AppInterface.STK_CMD_ACTION);
        intent.putExtra("STK CMD", cmdMsg);
        mContext.sendBroadcast(intent);
    }

    /**
     * Handles RIL_UNSOL_STK_SESSION_END unsolicited command from RIL.
     *
     */
    private void handleSessionEnd() {
        StkLog.d(this, "SESSION END");

        mCurrntCmd = mMenuCmd;
        Intent intent = new Intent(AppInterface.STK_SESSION_END_ACTION);
        mContext.sendBroadcast(intent);
    }

    private void sendTerminalResponse(CommandDetails cmdDet,
            ResultCode resultCode, boolean includeAdditionalInfo,
            int additionalInfo, ResponseData resp) {

        if (cmdDet == null) {
            return;
        }
        ByteArrayOutputStream buf = new ByteArrayOutputStream();

        // command details
        int tag = ComprehensionTlvTag.COMMAND_DETAILS.value();
        if (cmdDet.compRequired) {
            tag |= 0x80;
        }
        buf.write(tag);
        buf.write(0x03); // length
        buf.write(cmdDet.commandNumber);
        buf.write(cmdDet.typeOfCommand);
        buf.write(cmdDet.commandQualifier);

        // device identities
        tag = 0x80 | ComprehensionTlvTag.DEVICE_IDENTITIES.value();
        buf.write(tag);
        buf.write(0x02); // length
        buf.write(DEV_ID_TERMINAL); // source device id
        buf.write(DEV_ID_UICC); // destination device id

        // result
        tag = 0x80 | ComprehensionTlvTag.RESULT.value();
        buf.write(tag);
        int length = includeAdditionalInfo ? 2 : 1;
        buf.write(length);
        buf.write(resultCode.value());

        // additional info
        if (includeAdditionalInfo) {
            buf.write(additionalInfo);
        }

        // Fill optional data for each corresponding command
        if (resp != null) {
            resp.format(buf);
        }

        byte[] rawData = buf.toByteArray();
        String hexString = IccUtils.bytesToHexString(rawData);
        if (Config.LOGD) {
            StkLog.d(this, "TERMINAL RESPONSE: " + hexString);
        }

        mCmdIf.sendTerminalResponse(hexString, null);
    }


    private void sendMenuSelection(int menuId, boolean helpRequired) {

        ByteArrayOutputStream buf = new ByteArrayOutputStream();

        // tag
        int tag = BerTlv.BER_MENU_SELECTION_TAG;
        buf.write(tag);

        // length
        buf.write(0x00); // place holder

        // device identities
        tag = 0x80 | ComprehensionTlvTag.DEVICE_IDENTITIES.value();
        buf.write(tag);
        buf.write(0x02); // length
        buf.write(DEV_ID_KEYPAD); // source device id
        buf.write(DEV_ID_UICC); // destination device id

        // item identifier
        tag = 0x80 | ComprehensionTlvTag.ITEM_ID.value();
        buf.write(tag);
        buf.write(0x01); // length
        buf.write(menuId); // menu identifier chosen

        // help request
        if (helpRequired) {
            tag = ComprehensionTlvTag.HELP_REQUEST.value();
            buf.write(tag);
            buf.write(0x00); // length
        }

        byte[] rawData = buf.toByteArray();

        // write real length
        int len = rawData.length - 2; // minus (tag + length)
        rawData[1] = (byte) len;

        String hexString = IccUtils.bytesToHexString(rawData);

        mCmdIf.sendEnvelope(hexString, null);
    }

    private void eventDownload(int event, int sourceId, int destinationId,
            byte[] additionalInfo, boolean oneShot) {

        ByteArrayOutputStream buf = new ByteArrayOutputStream();

        // tag
        int tag = BerTlv.BER_EVENT_DOWNLOAD_TAG;
        buf.write(tag);

        // length
        buf.write(0x00); // place holder, assume length < 128.

        // event list
        tag = 0x80 | ComprehensionTlvTag.EVENT_LIST.value();
        buf.write(tag);
        buf.write(0x01); // length
        buf.write(event); // event value

        // device identities
        tag = 0x80 | ComprehensionTlvTag.DEVICE_IDENTITIES.value();
        buf.write(tag);
        buf.write(0x02); // length
        buf.write(sourceId); // source device id
        buf.write(destinationId); // destination device id

        // additional information
        if (additionalInfo != null) {
            for (byte b : additionalInfo) {
                buf.write(b);
            }
        }

        byte[] rawData = buf.toByteArray();

        // write real length
        int len = rawData.length - 2; // minus (tag + length)
        rawData[1] = (byte) len;

        String hexString = IccUtils.bytesToHexString(rawData);

        mCmdIf.sendEnvelope(hexString, null);
    }

    /**
     * Used for instantiating the Service from the GsmPhone constructor.
     *
     * @param ci CommandsInterface object
     * @param sr SIMRecords object
     * @param context phone app context
     * @param fh SIM file handler
     * @param sc GSM SIM card
     * @return The only Service object in the system
     */
    public static StkService getInstance(CommandsInterface ci, SIMRecords sr,
            Context context, SIMFileHandler fh, SimCard sc) {
        if (sInstance == null) {
            if (ci == null || sr == null || context == null || fh == null
                    || sc == null) {
                return null;
            }
            HandlerThread thread = new HandlerThread("Stk Telephony service");
            thread.start();
            sInstance = new StkService(ci, sr, context, fh, sc);
            StkLog.d(sInstance, "NEW sInstance");
        } else if ((sr != null) && (mSimRecords != sr)) {
            StkLog.d(sInstance, String.format(
                    "Reinitialize the Service with SIMRecords sr=0x%x.", sr));
            mSimRecords = sr;

            // re-Register for SIM ready event.
            mSimRecords.registerForRecordsLoaded(sInstance, MSG_ID_SIM_LOADED, null);
            StkLog.d(sInstance, "sr changed reinitialize and return current sInstance");
        } else {
            StkLog.d(sInstance, "Return current sInstance");
        }
        return sInstance;
    }

    /**
     * Used by application to get an AppInterface object.
     *
     * @return The only Service object in the system
     */
    public static AppInterface getInstance() {
        return getInstance(null, null, null, null, null);
    }

    @Override
    public void handleMessage(Message msg) {

        switch (msg.what) {
        case MSG_ID_SESSION_END:
        case MSG_ID_PROACTIVE_COMMAND:
        case MSG_ID_EVENT_NOTIFY:
        case MSG_ID_REFRESH:
            StkLog.d(this, "ril message arrived");
            String data = null;
            if (msg.obj != null) {
                AsyncResult ar = (AsyncResult) msg.obj;
                if (ar != null && ar.result != null) {
                    try {
                        data = (String) ar.result;
                    } catch (ClassCastException e) {
                        break;
                    }
                }
            }
            mMsgDecoder.sendStartDecodingMessageParams(new RilMessage(msg.what, data));
            break;
        case MSG_ID_CALL_SETUP:
            mMsgDecoder.sendStartDecodingMessageParams(new RilMessage(msg.what, null));
            break;
        case MSG_ID_SIM_LOADED:
            break;
        case MSG_ID_RIL_MSG_DECODED:
            handleRilMsg((RilMessage) msg.obj);
            break;
        case MSG_ID_RESPONSE:
            handleCmdResponse((StkResponseMessage) msg.obj);
            break;
        default:
            throw new AssertionError("Unrecognized STK command: " + msg.what);
        }
    }

    public synchronized void onCmdResponse(StkResponseMessage resMsg) {
        if (resMsg == null) {
            return;
        }
        // queue a response message.
        Message msg = this.obtainMessage(MSG_ID_RESPONSE, resMsg);
        msg.sendToTarget();
    }

    private boolean validateResponse(StkResponseMessage resMsg) {
        if (mCurrntCmd != null) {
            return (resMsg.cmdDet.compareTo(mCurrntCmd.mCmdDet));
        }
        return false;
    }

    private boolean removeMenu(Menu menu) {
        try {
            if (menu.items.size() == 1 && menu.items.get(0) == null) {
                return true;
            }
        } catch (NullPointerException e) {
            StkLog.d(this, "Unable to get Menu's items size");
            return true;
        }
        return false;
    }

    private void handleCmdResponse(StkResponseMessage resMsg) {
        // Make sure the response details match the last valid command. An invalid 
        // response is a one that doesn't have a corresponding proactive command
        // and sending it can "confuse" the baseband/ril. 
        // One reason for out of order responses can be UI glitches. For example, 
        // if the application launch an activity, and that activity is stored  
        // by the framework inside the history stack. That activity will be
        // available for relaunch using the latest application dialog 
        // (long press on the home button). Relaunching that activity can send 
        // the same command's result again to the StkService and can cause it to  
        // get out of sync with the SIM.
        if (!validateResponse(resMsg)) {
            return;
        }
        ResponseData resp = null;
        boolean helpRequired = false;
        CommandDetails cmdDet = resMsg.getCmdDetails();

        switch (resMsg.resCode) {
        case HELP_INFO_REQUIRED:
            helpRequired = true;
            // fall through
        case OK:
        case PRFRMD_WITH_PARTIAL_COMPREHENSION:
        case PRFRMD_WITH_MISSING_INFO:
        case PRFRMD_WITH_ADDITIONAL_EFS_READ:
        case PRFRMD_ICON_NOT_DISPLAYED:
        case PRFRMD_MODIFIED_BY_NAA:
        case PRFRMD_LIMITED_SERVICE:
        case PRFRMD_WITH_MODIFICATION:
        case PRFRMD_NAA_NOT_ACTIVE:
        case PRFRMD_TONE_NOT_PLAYED:
            switch (AppInterface.CommandType.fromInt(cmdDet.typeOfCommand)) {
            case SET_UP_MENU:
                helpRequired = resMsg.resCode == ResultCode.HELP_INFO_REQUIRED;
                sendMenuSelection(resMsg.usersMenuSelection, helpRequired);
                return;
            case SELECT_ITEM:
                resp = new SelectItemResponseData(resMsg.usersMenuSelection);
                break;
            case GET_INPUT:
            case GET_INKEY:
                Input input = mCurrntCmd.geInput();
                if (!input.yesNo) {
                    // when help is requested there is no need to send the text
                    // string object.
                    if (!helpRequired) {
                        resp = new GetInkeyInputResponseData(resMsg.usersInput,
                                input.ucs2, input.packed);
                    }
                } else {
                    resp = new GetInkeyInputResponseData(
                            resMsg.usersYesNoSelection);
                }
                break;
            case DISPLAY_TEXT:
            case LAUNCH_BROWSER:
                break;
            case SET_UP_CALL:
                mCmdIf.handleCallSetupRequestFromSim(resMsg.usersConfirm, null);
                // No need to send terminal response for SET UP CALL. The user's
                // confirmation result is send back using a dedicated ril message
                // invoked by the CommandInterface call above. 
                mCurrntCmd = null;
                return;
            }
            break;
        case NO_RESPONSE_FROM_USER:
        case UICC_SESSION_TERM_BY_USER:
        case BACKWARD_MOVE_BY_USER:
            resp = null;
            break;
        default:
            return;
        }
        sendTerminalResponse(cmdDet, resMsg.resCode, false, 0, resp);
        mCurrntCmd = null;
    }
}
