/*
 * Copyright (C) 2006 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;

import android.app.Activity;
import android.app.PendingIntent;
import android.app.PendingIntent.CanceledException;
import android.content.Intent;
import android.os.AsyncResult;
import android.os.Message;
import android.os.SystemProperties;
import android.provider.Telephony.Sms;
import android.provider.Telephony.Sms.Intents;
import android.telephony.PhoneNumberUtils;
import android.telephony.SmsCbLocation;
import android.telephony.SmsCbMessage;
import android.telephony.SmsManager;
import android.telephony.gsm.GsmCellLocation;
import android.util.Log;

import com.android.internal.telephony.CommandsInterface;
import com.android.internal.telephony.IccUtils;
import com.android.internal.telephony.PhoneBase;
import com.android.internal.telephony.SMSDispatcher;
import com.android.internal.telephony.SmsHeader;
import com.android.internal.telephony.SmsMessageBase;
import com.android.internal.telephony.SmsMessageBase.TextEncodingDetails;
import com.android.internal.telephony.SmsStorageMonitor;
import com.android.internal.telephony.SmsUsageMonitor;
import com.android.internal.telephony.TelephonyProperties;

import java.util.HashMap;
import java.util.Iterator;

import static android.telephony.SmsMessage.MessageClass;

public final class GsmSMSDispatcher extends SMSDispatcher {
    private static final String TAG = "GSM";

    /** Status report received */
    private static final int EVENT_NEW_SMS_STATUS_REPORT = 100;

    /** New broadcast SMS */
    private static final int EVENT_NEW_BROADCAST_SMS = 101;

    /** Result of writing SM to UICC (when SMS-PP service is not available). */
    private static final int EVENT_WRITE_SMS_COMPLETE = 102;

    /** Handler for SMS-PP data download messages to UICC. */
    private final UsimDataDownloadHandler mDataDownloadHandler;

    public GsmSMSDispatcher(PhoneBase phone, SmsStorageMonitor storageMonitor,
            SmsUsageMonitor usageMonitor) {
        super(phone, storageMonitor, usageMonitor);
        mDataDownloadHandler = new UsimDataDownloadHandler(mCm);
        mCm.setOnNewGsmSms(this, EVENT_NEW_SMS, null);
        mCm.setOnSmsStatus(this, EVENT_NEW_SMS_STATUS_REPORT, null);
        mCm.setOnNewGsmBroadcastSms(this, EVENT_NEW_BROADCAST_SMS, null);
    }

    @Override
    public void dispose() {
        mCm.unSetOnNewGsmSms(this);
        mCm.unSetOnSmsStatus(this);
        mCm.unSetOnNewGsmBroadcastSms(this);
    }

    @Override
    protected String getFormat() {
        return android.telephony.SmsMessage.FORMAT_3GPP;
    }

    /**
     * Handles 3GPP format-specific events coming from the phone stack.
     * Other events are handled by {@link SMSDispatcher#handleMessage}.
     *
     * @param msg the message to handle
     */
    @Override
    public void handleMessage(Message msg) {
        switch (msg.what) {
        case EVENT_NEW_SMS_STATUS_REPORT:
            handleStatusReport((AsyncResult) msg.obj);
            break;

        case EVENT_NEW_BROADCAST_SMS:
            handleBroadcastSms((AsyncResult)msg.obj);
            break;

        case EVENT_WRITE_SMS_COMPLETE:
            AsyncResult ar = (AsyncResult) msg.obj;
            if (ar.exception == null) {
                Log.d(TAG, "Successfully wrote SMS-PP message to UICC");
                mCm.acknowledgeLastIncomingGsmSms(true, 0, null);
            } else {
                Log.d(TAG, "Failed to write SMS-PP message to UICC", ar.exception);
                mCm.acknowledgeLastIncomingGsmSms(false,
                        CommandsInterface.GSM_SMS_FAIL_CAUSE_UNSPECIFIED_ERROR, null);
            }
            break;

        default:
            super.handleMessage(msg);
        }
    }

    /**
     * Called when a status report is received.  This should correspond to
     * a previously successful SEND.
     *
     * @param ar AsyncResult passed into the message handler.  ar.result should
     *           be a String representing the status report PDU, as ASCII hex.
     */
    private void handleStatusReport(AsyncResult ar) {
        String pduString = (String) ar.result;
        SmsMessage sms = SmsMessage.newFromCDS(pduString);

        if (sms != null) {
            int tpStatus = sms.getStatus();
            int messageRef = sms.messageRef;
            for (int i = 0, count = deliveryPendingList.size(); i < count; i++) {
                SmsTracker tracker = deliveryPendingList.get(i);
                if (tracker.mMessageRef == messageRef) {
                    // Found it.  Remove from list and broadcast.
                    if(tpStatus >= Sms.STATUS_FAILED || tpStatus < Sms.STATUS_PENDING ) {
                       deliveryPendingList.remove(i);
                    }
                    PendingIntent intent = tracker.mDeliveryIntent;
                    Intent fillIn = new Intent();
                    fillIn.putExtra("pdu", IccUtils.hexStringToBytes(pduString));
                    fillIn.putExtra("format", android.telephony.SmsMessage.FORMAT_3GPP);
                    try {
                        intent.send(mContext, Activity.RESULT_OK, fillIn);
                    } catch (CanceledException ex) {}

                    // Only expect to see one tracker matching this messageref
                    break;
                }
            }
        }
        acknowledgeLastIncomingSms(true, Intents.RESULT_SMS_HANDLED, null);
    }

    /** {@inheritDoc} */
    @Override
    public int dispatchMessage(SmsMessageBase smsb) {

        // If sms is null, means there was a parsing error.
        if (smsb == null) {
            Log.e(TAG, "dispatchMessage: message is null");
            return Intents.RESULT_SMS_GENERIC_ERROR;
        }

        SmsMessage sms = (SmsMessage) smsb;

        if (sms.isTypeZero()) {
            // As per 3GPP TS 23.040 9.2.3.9, Type Zero messages should not be
            // Displayed/Stored/Notified. They should only be acknowledged.
            Log.d(TAG, "Received short message type 0, Don't display or store it. Send Ack");
            return Intents.RESULT_SMS_HANDLED;
        }

        // Send SMS-PP data download messages to UICC. See 3GPP TS 31.111 section 7.1.1.
        if (sms.isUsimDataDownload()) {
            UsimServiceTable ust = mPhone.getUsimServiceTable();
            // If we receive an SMS-PP message before the UsimServiceTable has been loaded,
            // assume that the data download service is not present. This is very unlikely to
            // happen because the IMS connection will not be established until after the ISIM
            // records have been loaded, after the USIM service table has been loaded.
            if (ust != null && ust.isAvailable(
                    UsimServiceTable.UsimService.DATA_DL_VIA_SMS_PP)) {
                Log.d(TAG, "Received SMS-PP data download, sending to UICC.");
                return mDataDownloadHandler.startDataDownload(sms);
            } else {
                Log.d(TAG, "DATA_DL_VIA_SMS_PP service not available, storing message to UICC.");
                String smsc = IccUtils.bytesToHexString(
                        PhoneNumberUtils.networkPortionToCalledPartyBCDWithLength(
                                sms.getServiceCenterAddress()));
                mCm.writeSmsToSim(SmsManager.STATUS_ON_ICC_UNREAD, smsc,
                        IccUtils.bytesToHexString(sms.getPdu()),
                        obtainMessage(EVENT_WRITE_SMS_COMPLETE));
                return Activity.RESULT_OK;  // acknowledge after response from write to USIM
            }
        }

        if (mSmsReceiveDisabled) {
            // Device doesn't support SMS service,
            Log.d(TAG, "Received short message on device which doesn't support "
                    + "SMS service. Ignored.");
            return Intents.RESULT_SMS_HANDLED;
        }

        // Special case the message waiting indicator messages
        boolean handled = false;
        if (sms.isMWISetMessage()) {
            mPhone.setVoiceMessageWaiting(1, -1);  // line 1: unknown number of msgs waiting
            handled = sms.isMwiDontStore();
            if (false) {
                Log.d(TAG, "Received voice mail indicator set SMS shouldStore=" + !handled);
            }
        } else if (sms.isMWIClearMessage()) {
            mPhone.setVoiceMessageWaiting(1, 0);   // line 1: no msgs waiting
            handled = sms.isMwiDontStore();
            if (false) {
                Log.d(TAG, "Received voice mail indicator clear SMS shouldStore=" + !handled);
            }
        }

        if (handled) {
            return Intents.RESULT_SMS_HANDLED;
        }

        if (!mStorageMonitor.isStorageAvailable() &&
                sms.getMessageClass() != MessageClass.CLASS_0) {
            // It's a storable message and there's no storage available.  Bail.
            // (See TS 23.038 for a description of class 0 messages.)
            return Intents.RESULT_SMS_OUT_OF_MEMORY;
        }

        return dispatchNormalMessage(smsb);
    }

    /** {@inheritDoc} */
    @Override
    protected void sendData(String destAddr, String scAddr, int destPort,
            byte[] data, PendingIntent sentIntent, PendingIntent deliveryIntent) {
        SmsMessage.SubmitPdu pdu = SmsMessage.getSubmitPdu(
                scAddr, destAddr, destPort, data, (deliveryIntent != null));
        if (pdu != null) {
            sendRawPdu(pdu.encodedScAddress, pdu.encodedMessage, sentIntent, deliveryIntent,
                    destAddr);
        } else {
            Log.e(TAG, "GsmSMSDispatcher.sendData(): getSubmitPdu() returned null");
        }
    }

    /** {@inheritDoc} */
    @Override
    protected void sendText(String destAddr, String scAddr, String text,
            PendingIntent sentIntent, PendingIntent deliveryIntent) {
        SmsMessage.SubmitPdu pdu = SmsMessage.getSubmitPdu(
                scAddr, destAddr, text, (deliveryIntent != null));
        if (pdu != null) {
            sendRawPdu(pdu.encodedScAddress, pdu.encodedMessage, sentIntent, deliveryIntent,
                    destAddr);
        } else {
            Log.e(TAG, "GsmSMSDispatcher.sendText(): getSubmitPdu() returned null");
        }
    }

    /** {@inheritDoc} */
    @Override
    protected TextEncodingDetails calculateLength(CharSequence messageBody,
            boolean use7bitOnly) {
        return SmsMessage.calculateLength(messageBody, use7bitOnly);
    }

    /** {@inheritDoc} */
    @Override
    protected void sendNewSubmitPdu(String destinationAddress, String scAddress,
            String message, SmsHeader smsHeader, int encoding,
            PendingIntent sentIntent, PendingIntent deliveryIntent, boolean lastPart) {
        SmsMessage.SubmitPdu pdu = SmsMessage.getSubmitPdu(scAddress, destinationAddress,
                message, deliveryIntent != null, SmsHeader.toByteArray(smsHeader),
                encoding, smsHeader.languageTable, smsHeader.languageShiftTable);
        if (pdu != null) {
            sendRawPdu(pdu.encodedScAddress, pdu.encodedMessage, sentIntent, deliveryIntent,
                    destinationAddress);
        } else {
            Log.e(TAG, "GsmSMSDispatcher.sendNewSubmitPdu(): getSubmitPdu() returned null");
        }
    }

    /** {@inheritDoc} */
    @Override
    protected void sendSms(SmsTracker tracker) {
        HashMap<String, Object> map = tracker.mData;

        byte smsc[] = (byte[]) map.get("smsc");
        byte pdu[] = (byte[]) map.get("pdu");

        Message reply = obtainMessage(EVENT_SEND_SMS_COMPLETE, tracker);
        mCm.sendSMS(IccUtils.bytesToHexString(smsc), IccUtils.bytesToHexString(pdu), reply);
    }

    /** {@inheritDoc} */
    @Override
    protected void acknowledgeLastIncomingSms(boolean success, int result, Message response) {
        mCm.acknowledgeLastIncomingGsmSms(success, resultToCause(result), response);
    }

    private static int resultToCause(int rc) {
        switch (rc) {
            case Activity.RESULT_OK:
            case Intents.RESULT_SMS_HANDLED:
                // Cause code is ignored on success.
                return 0;
            case Intents.RESULT_SMS_OUT_OF_MEMORY:
                return CommandsInterface.GSM_SMS_FAIL_CAUSE_MEMORY_CAPACITY_EXCEEDED;
            case Intents.RESULT_SMS_GENERIC_ERROR:
            default:
                return CommandsInterface.GSM_SMS_FAIL_CAUSE_UNSPECIFIED_ERROR;
        }
    }

    /**
     * Holds all info about a message page needed to assemble a complete
     * concatenated message
     */
    private static final class SmsCbConcatInfo {

        private final SmsCbHeader mHeader;
        private final SmsCbLocation mLocation;

        public SmsCbConcatInfo(SmsCbHeader header, SmsCbLocation location) {
            mHeader = header;
            mLocation = location;
        }

        @Override
        public int hashCode() {
            return (mHeader.getSerialNumber() * 31) + mLocation.hashCode();
        }

        @Override
        public boolean equals(Object obj) {
            if (obj instanceof SmsCbConcatInfo) {
                SmsCbConcatInfo other = (SmsCbConcatInfo)obj;

                // Two pages match if they have the same serial number (which includes the
                // geographical scope and update number), and both pages belong to the same
                // location (PLMN, plus LAC and CID if these are part of the geographical scope).
                return mHeader.getSerialNumber() == other.mHeader.getSerialNumber()
                        && mLocation.equals(other.mLocation);
            }

            return false;
        }

        /**
         * Compare the location code for this message to the current location code. The match is
         * relative to the geographical scope of the message, which determines whether the LAC
         * and Cell ID are saved in mLocation or set to -1 to match all values.
         *
         * @param plmn the current PLMN
         * @param lac the current Location Area (GSM) or Service Area (UMTS)
         * @param cid the current Cell ID
         * @return true if this message is valid for the current location; false otherwise
         */
        public boolean matchesLocation(String plmn, int lac, int cid) {
            return mLocation.isInLocationArea(plmn, lac, cid);
        }
    }

    // This map holds incomplete concatenated messages waiting for assembly
    private final HashMap<SmsCbConcatInfo, byte[][]> mSmsCbPageMap =
            new HashMap<SmsCbConcatInfo, byte[][]>();

    /**
     * Handle 3GPP format SMS-CB message.
     * @param ar the AsyncResult containing the received PDUs
     */
    private void handleBroadcastSms(AsyncResult ar) {
        try {
            byte[] receivedPdu = (byte[])ar.result;

            if (false) {
                for (int i = 0; i < receivedPdu.length; i += 8) {
                    StringBuilder sb = new StringBuilder("SMS CB pdu data: ");
                    for (int j = i; j < i + 8 && j < receivedPdu.length; j++) {
                        int b = receivedPdu[j] & 0xff;
                        if (b < 0x10) {
                            sb.append('0');
                        }
                        sb.append(Integer.toHexString(b)).append(' ');
                    }
                    Log.d(TAG, sb.toString());
                }
            }

            SmsCbHeader header = new SmsCbHeader(receivedPdu);
            String plmn = SystemProperties.get(TelephonyProperties.PROPERTY_OPERATOR_NUMERIC);
            GsmCellLocation cellLocation = (GsmCellLocation) mPhone.getCellLocation();
            int lac = cellLocation.getLac();
            int cid = cellLocation.getCid();

            SmsCbLocation location;
            switch (header.getGeographicalScope()) {
                case SmsCbMessage.GEOGRAPHICAL_SCOPE_LA_WIDE:
                    location = new SmsCbLocation(plmn, lac, -1);
                    break;

                case SmsCbMessage.GEOGRAPHICAL_SCOPE_CELL_WIDE:
                case SmsCbMessage.GEOGRAPHICAL_SCOPE_CELL_WIDE_IMMEDIATE:
                    location = new SmsCbLocation(plmn, lac, cid);
                    break;

                case SmsCbMessage.GEOGRAPHICAL_SCOPE_PLMN_WIDE:
                default:
                    location = new SmsCbLocation(plmn);
                    break;
            }

            byte[][] pdus;
            int pageCount = header.getNumberOfPages();
            if (pageCount > 1) {
                // Multi-page message
                SmsCbConcatInfo concatInfo = new SmsCbConcatInfo(header, location);

                // Try to find other pages of the same message
                pdus = mSmsCbPageMap.get(concatInfo);

                if (pdus == null) {
                    // This is the first page of this message, make room for all
                    // pages and keep until complete
                    pdus = new byte[pageCount][];

                    mSmsCbPageMap.put(concatInfo, pdus);
                }

                // Page parameter is one-based
                pdus[header.getPageIndex() - 1] = receivedPdu;

                for (int i = 0; i < pdus.length; i++) {
                    if (pdus[i] == null) {
                        // Still missing pages, exit
                        return;
                    }
                }

                // Message complete, remove and dispatch
                mSmsCbPageMap.remove(concatInfo);
            } else {
                // Single page message
                pdus = new byte[1][];
                pdus[0] = receivedPdu;
            }

            SmsCbMessage message = GsmSmsCbMessage.createSmsCbMessage(header, location, pdus);
            dispatchBroadcastMessage(message);

            // Remove messages that are out of scope to prevent the map from
            // growing indefinitely, containing incomplete messages that were
            // never assembled
            Iterator<SmsCbConcatInfo> iter = mSmsCbPageMap.keySet().iterator();

            while (iter.hasNext()) {
                SmsCbConcatInfo info = iter.next();

                if (!info.matchesLocation(plmn, lac, cid)) {
                    iter.remove();
                }
            }
        } catch (RuntimeException e) {
            Log.e(TAG, "Error in decoding SMS CB pdu", e);
        }
    }
}