/*
 * Copyright (C) 2013 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.cdma;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.res.Resources;
import android.os.Message;
import android.os.RemoteCallback;
import android.os.SystemProperties;
import android.provider.Telephony.Sms.Intents;
import android.telephony.PhoneNumberUtils;
import android.telephony.cdma.CdmaSmsCbProgramResults;

import com.android.internal.telephony.CommandsInterface;
import com.android.internal.telephony.InboundSmsHandler;
import com.android.internal.telephony.InboundSmsTracker;
import com.android.internal.telephony.Phone;
import com.android.internal.telephony.SmsConstants;
import com.android.internal.telephony.SmsMessageBase;
import com.android.internal.telephony.SmsStorageMonitor;
import com.android.internal.telephony.TelephonyComponentFactory;
import com.android.internal.telephony.WspTypeDecoder;
import com.android.internal.telephony.cdma.sms.BearerData;
import com.android.internal.telephony.cdma.sms.CdmaSmsAddress;
import com.android.internal.telephony.cdma.sms.SmsEnvelope;
import com.android.internal.util.HexDump;

import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;

/**
 * Subclass of {@link InboundSmsHandler} for 3GPP2 type messages.
 */
public class CdmaInboundSmsHandler extends InboundSmsHandler {

    private final CdmaSMSDispatcher mSmsDispatcher;
    private static CdmaCbTestBroadcastReceiver sTestBroadcastReceiver;
    private static CdmaScpTestBroadcastReceiver sTestScpBroadcastReceiver;

    private byte[] mLastDispatchedSmsFingerprint;
    private byte[] mLastAcknowledgedSmsFingerprint;

    // Callback used to process the result of an SCP message
    private RemoteCallback mScpCallback;

    private final boolean mCheckForDuplicatePortsInOmadmWapPush = Resources.getSystem().getBoolean(
            com.android.internal.R.bool.config_duplicate_port_omadm_wappush);

    // When TEST_MODE is on we allow the test intent to trigger an SMS CB alert
    private static final boolean TEST_MODE = SystemProperties.getInt("ro.debuggable", 0) == 1;
    private static final String TEST_ACTION = "com.android.internal.telephony.cdma"
            + ".TEST_TRIGGER_CELL_BROADCAST";
    private static final String SCP_TEST_ACTION = "com.android.internal.telephony.cdma"
            + ".TEST_TRIGGER_SCP_MESSAGE";

    /**
     * Create a new inbound SMS handler for CDMA.
     */
    private CdmaInboundSmsHandler(Context context, SmsStorageMonitor storageMonitor,
            Phone phone, CdmaSMSDispatcher smsDispatcher) {
        super("CdmaInboundSmsHandler", context, storageMonitor, phone);
        mSmsDispatcher = smsDispatcher;
        phone.mCi.setOnNewCdmaSms(getHandler(), EVENT_NEW_SMS, null);

        mCellBroadcastServiceManager.enable();
        mScpCallback = new RemoteCallback(result -> {
            if (result == null) {
                loge("SCP results error: missing extras");
                return;
            }
            String sender = result.getString("sender");
            if (sender == null) {
                loge("SCP results error: missing sender extra.");
                return;
            }
            ArrayList<CdmaSmsCbProgramResults> results = result.getParcelableArrayList("results");
            if (results == null) {
                loge("SCP results error: missing results extra.");
                return;
            }

            BearerData bData = new BearerData();
            bData.messageType = BearerData.MESSAGE_TYPE_SUBMIT;
            bData.messageId = SmsMessage.getNextMessageId();
            bData.serviceCategoryProgramResults = results;
            byte[] encodedBearerData = BearerData.encode(bData);

            ByteArrayOutputStream baos = new ByteArrayOutputStream(100);
            DataOutputStream dos = new DataOutputStream(baos);
            try {
                dos.writeInt(SmsEnvelope.TELESERVICE_SCPT);
                dos.writeInt(0); //servicePresent
                dos.writeInt(0); //serviceCategory
                CdmaSmsAddress destAddr = CdmaSmsAddress.parse(
                        PhoneNumberUtils.cdmaCheckAndProcessPlusCodeForSms(sender));
                dos.write(destAddr.digitMode);
                dos.write(destAddr.numberMode);
                dos.write(destAddr.ton); // number_type
                dos.write(destAddr.numberPlan);
                dos.write(destAddr.numberOfDigits);
                dos.write(destAddr.origBytes, 0, destAddr.origBytes.length); // digits
                // Subaddress is not supported.
                dos.write(0); //subaddressType
                dos.write(0); //subaddr_odd
                dos.write(0); //subaddr_nbr_of_digits
                dos.write(encodedBearerData.length);
                dos.write(encodedBearerData, 0, encodedBearerData.length);
                // Ignore the RIL response. TODO: implement retry if SMS send fails.
                mPhone.mCi.sendCdmaSms(baos.toByteArray(), null);
            } catch (IOException e) {
                loge("exception creating SCP results PDU", e);
            } finally {
                try {
                    dos.close();
                } catch (IOException ignored) {
                }
            }
        });
        if (TEST_MODE) {
            if (sTestBroadcastReceiver == null) {
                sTestBroadcastReceiver = new CdmaCbTestBroadcastReceiver();
                IntentFilter filter = new IntentFilter();
                filter.addAction(TEST_ACTION);
                context.registerReceiver(sTestBroadcastReceiver, filter);
            }
            if (sTestScpBroadcastReceiver == null) {
                sTestScpBroadcastReceiver = new CdmaScpTestBroadcastReceiver();
                IntentFilter filter = new IntentFilter();
                filter.addAction(SCP_TEST_ACTION);
                context.registerReceiver(sTestScpBroadcastReceiver, filter);
            }
        }
    }

    /**
     * Unregister for CDMA SMS.
     */
    @Override
    protected void onQuitting() {
        mPhone.mCi.unSetOnNewCdmaSms(getHandler());

        if (DBG) log("unregistered for 3GPP2 SMS");
        super.onQuitting();
    }

    /**
     * Wait for state machine to enter startup state. We can't send any messages until then.
     */
    public static CdmaInboundSmsHandler makeInboundSmsHandler(Context context,
            SmsStorageMonitor storageMonitor, Phone phone, CdmaSMSDispatcher smsDispatcher) {
        CdmaInboundSmsHandler handler = new CdmaInboundSmsHandler(context, storageMonitor,
                phone, smsDispatcher);
        handler.start();
        return handler;
    }

    /**
     * Return true if this handler is for 3GPP2 messages; false for 3GPP format.
     *
     * @return true (3GPP2)
     */
    @Override
    protected boolean is3gpp2() {
        return true;
    }

    /**
     * Process Cell Broadcast, Voicemail Notification, and other 3GPP/3GPP2-specific messages.
     *
     * @param smsb the SmsMessageBase object from the RIL
     * @return true if the message was handled here; false to continue processing
     */
    @Override
    protected int dispatchMessageRadioSpecific(SmsMessageBase smsb) {
        SmsMessage sms = (SmsMessage) smsb;
        boolean isBroadcastType = (SmsEnvelope.MESSAGE_TYPE_BROADCAST == sms.getMessageType());

        // Handle CMAS emergency broadcast messages.
        if (isBroadcastType) {
            log("Broadcast type message");
            mCellBroadcastServiceManager.sendCdmaMessageToHandler(sms);
            return Intents.RESULT_SMS_HANDLED;
        }

        // Initialize fingerprint field, and see if we have a network duplicate SMS.
        mLastDispatchedSmsFingerprint = sms.getIncomingSmsFingerprint();
        if (mLastAcknowledgedSmsFingerprint != null &&
                Arrays.equals(mLastDispatchedSmsFingerprint, mLastAcknowledgedSmsFingerprint)) {
            return Intents.RESULT_SMS_HANDLED;
        }

        // Decode BD stream and set sms variables.
        sms.parseSms();
        int teleService = sms.getTeleService();

        switch (teleService) {
            case SmsEnvelope.TELESERVICE_VMN:
            case SmsEnvelope.TELESERVICE_MWI:
                // handle voicemail indication
                handleVoicemailTeleservice(sms);
                return Intents.RESULT_SMS_HANDLED;

            case SmsEnvelope.TELESERVICE_WMT:
            case SmsEnvelope.TELESERVICE_WEMT:
                if (sms.isStatusReportMessage()) {
                    mSmsDispatcher.sendStatusReportMessage(sms);
                    return Intents.RESULT_SMS_HANDLED;
                }
                break;

            case SmsEnvelope.TELESERVICE_SCPT:
                mCellBroadcastServiceManager.sendCdmaScpMessageToHandler(sms, mScpCallback);
                return Intents.RESULT_SMS_HANDLED;

            case SmsEnvelope.TELESERVICE_FDEA_WAP:
                if (!sms.preprocessCdmaFdeaWap()) {
                    return Intents.RESULT_SMS_HANDLED;
                }
                teleService = SmsEnvelope.TELESERVICE_WAP;
                // fall through
            case SmsEnvelope.TELESERVICE_WAP:
                // handled below, after storage check
                break;

            default:
                loge("unsupported teleservice 0x" + Integer.toHexString(teleService));
                return Intents.RESULT_SMS_UNSUPPORTED;
        }

        if (!mStorageMonitor.isStorageAvailable() &&
                sms.getMessageClass() != SmsConstants.MessageClass.CLASS_0) {
            // It's a storable message and there's no storage available.  Bail.
            // (See C.S0015-B v2.0 for a description of "Immediate Display"
            // messages, which we represent as CLASS_0.)
            return Intents.RESULT_SMS_OUT_OF_MEMORY;
        }

        if (SmsEnvelope.TELESERVICE_WAP == teleService) {
            return processCdmaWapPdu(sms.getUserData(), sms.mMessageRef,
                    sms.getOriginatingAddress(), sms.getDisplayOriginatingAddress(),
                    sms.getTimestampMillis());
        }

        return dispatchNormalMessage(smsb);
    }

    /**
     * Send an acknowledge message.
     *
     * @param success  indicates that last message was successfully received.
     * @param result   result code indicating any error
     * @param response callback message sent when operation completes.
     */
    @Override
    protected void acknowledgeLastIncomingSms(boolean success, int result, Message response) {
        int causeCode = resultToCause(result);
        mPhone.mCi.acknowledgeLastIncomingCdmaSms(success, causeCode, response);

        if (causeCode == 0) {
            mLastAcknowledgedSmsFingerprint = mLastDispatchedSmsFingerprint;
        }
        mLastDispatchedSmsFingerprint = null;
    }

    /**
     * Convert Android result code to CDMA SMS failure cause.
     *
     * @param rc the Android SMS intent result value
     * @return 0 for success, or a CDMA SMS failure cause value
     */
    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.CDMA_SMS_FAIL_CAUSE_RESOURCE_SHORTAGE;
            case Intents.RESULT_SMS_UNSUPPORTED:
                return CommandsInterface.CDMA_SMS_FAIL_CAUSE_INVALID_TELESERVICE_ID;
            case Intents.RESULT_SMS_GENERIC_ERROR:
            default:
                return CommandsInterface.CDMA_SMS_FAIL_CAUSE_OTHER_TERMINAL_PROBLEM;
        }
    }

    /**
     * Handle {@link SmsEnvelope#TELESERVICE_VMN} and {@link SmsEnvelope#TELESERVICE_MWI}.
     *
     * @param sms the message to process
     */
    private void handleVoicemailTeleservice(SmsMessage sms) {
        int voicemailCount = sms.getNumOfVoicemails();
        if (DBG) log("Voicemail count=" + voicemailCount);

        // range check
        if (voicemailCount < 0) {
            voicemailCount = -1;
        } else if (voicemailCount > 99) {
            // C.S0015-B v2, 4.5.12
            // range: 0-99
            voicemailCount = 99;
        }
        // update voice mail count in phone
        mPhone.setVoiceMessageCount(voicemailCount);
        // update metrics
        addVoicemailSmsToMetrics();
    }

    /**
     * Processes inbound messages that are in the WAP-WDP PDU format. See
     * wap-259-wdp-20010614-a section 6.5 for details on the WAP-WDP PDU format.
     * WDP segments are gathered until a datagram completes and gets dispatched.
     *
     * @param pdu The WAP-WDP PDU segment
     * @return a result code from {@link android.provider.Telephony.Sms.Intents}, or
     * {@link Activity#RESULT_OK} if the message has been broadcast
     * to applications
     */
    private int processCdmaWapPdu(byte[] pdu, int referenceNumber, String address, String dispAddr,
            long timestamp) {
        int index = 0;

        int msgType = (0xFF & pdu[index++]);
        if (msgType != 0) {
            log("Received a WAP SMS which is not WDP. Discard.");
            return Intents.RESULT_SMS_HANDLED;
        }
        int totalSegments = (0xFF & pdu[index++]);   // >= 1
        int segment = (0xFF & pdu[index++]);         // >= 0

        if (segment >= totalSegments) {
            loge("WDP bad segment #" + segment + " expecting 0-" + (totalSegments - 1));
            return Intents.RESULT_SMS_HANDLED;
        }

        // Only the first segment contains sourcePort and destination Port
        int sourcePort = 0;
        int destinationPort = 0;
        if (segment == 0) {
            //process WDP segment
            sourcePort = (0xFF & pdu[index++]) << 8;
            sourcePort |= 0xFF & pdu[index++];
            destinationPort = (0xFF & pdu[index++]) << 8;
            destinationPort |= 0xFF & pdu[index++];
            // Some carriers incorrectly send duplicate port fields in omadm wap pushes.
            // If configured, check for that here
            if (mCheckForDuplicatePortsInOmadmWapPush) {
                if (checkDuplicatePortOmadmWapPush(pdu, index)) {
                    index = index + 4; // skip duplicate port fields
                }
            }
        }

        // Lookup all other related parts
        log("Received WAP PDU. Type = " + msgType + ", originator = " + address
                + ", src-port = " + sourcePort + ", dst-port = " + destinationPort
                + ", ID = " + referenceNumber + ", segment# = " + segment + '/' + totalSegments);

        // pass the user data portion of the PDU to the shared handler in SMSDispatcher
        byte[] userData = new byte[pdu.length - index];
        System.arraycopy(pdu, index, userData, 0, pdu.length - index);
        InboundSmsTracker tracker = TelephonyComponentFactory.getInstance()
                .inject(InboundSmsTracker.class.getName()).makeInboundSmsTracker(mContext,
                        userData, timestamp, destinationPort, true, address, dispAddr,
                        referenceNumber,
                        segment, totalSegments, true, HexDump.toHexString(userData),
                        false /* isClass0 */,
                        mPhone.getSubId());

        // de-duping is done only for text messages
        return addTrackerToRawTableAndSendMessage(tracker, false /* don't de-dup */);
    }

    /**
     * Optional check to see if the received WapPush is an OMADM notification with erroneous
     * extra port fields.
     * - Some carriers make this mistake.
     * ex: MSGTYPE-TotalSegments-CurrentSegment
     * -SourcePortDestPort-SourcePortDestPort-OMADM PDU
     *
     * @param origPdu The WAP-WDP PDU segment
     * @param index   Current Index while parsing the PDU.
     * @return True if OrigPdu is OmaDM Push Message which has duplicate ports.
     * False if OrigPdu is NOT OmaDM Push Message which has duplicate ports.
     */
    private static boolean checkDuplicatePortOmadmWapPush(byte[] origPdu, int index) {
        index += 4;
        byte[] omaPdu = new byte[origPdu.length - index];
        System.arraycopy(origPdu, index, omaPdu, 0, omaPdu.length);

        WspTypeDecoder pduDecoder = new WspTypeDecoder(omaPdu);
        int wspIndex = 2;

        // Process header length field
        if (!pduDecoder.decodeUintvarInteger(wspIndex)) {
            return false;
        }

        wspIndex += pduDecoder.getDecodedDataLength();  // advance to next field

        // Process content type field
        if (!pduDecoder.decodeContentType(wspIndex)) {
            return false;
        }

        String mimeType = pduDecoder.getValueString();
        return (WspTypeDecoder.CONTENT_TYPE_B_PUSH_SYNCML_NOTI.equals(mimeType));
    }

    /**
     * Add voicemail indication SMS 0 to metrics.
     */
    private void addVoicemailSmsToMetrics() {
        mMetrics.writeIncomingVoiceMailSms(mPhone.getPhoneId(),
                android.telephony.SmsMessage.FORMAT_3GPP2);
    }

    /**
     * A broadcast receiver used for testing emergency cell broadcasts. To trigger test CDMA cell
     * broadcasts with adb run e.g:
     *
     * adb shell am broadcast -a com.android.internal.telephony.cdma.TEST_TRIGGER_CELL_BROADCAST \
     * --ei service_category 4097 \
     * --es bearer_data_string 00031303900801C00D0101015C02D00002BFD1931054D208119313D3D10815D05 \
     * 493925391C81193D48814D3D555120810D3D0D3D3925393C810D3D5539516480B481393D495120810D1539514 \
     * 9053081054925693D390481553951253080D0C4D481413481354D500
     *
     * adb shell am broadcast -a com.android.internal.telephony.cdma.TEST_TRIGGER_CELL_BROADCAST \
     * --ei service_category 4097 \
     * --es bearer_data_string 00031303900801C00D0101015C02D00002BFD1931054D208119313D3D10815D05 \
     * 493925391C81193D48814D3D555120810D3D0D3D3925393C810D3D5539516480B481393D495120810D1539514 \
     * 9053081054925693D390481553951253080D0C4D481413481354D500 \
     * --ei phone_id 0 \
     */
    private class CdmaCbTestBroadcastReceiver extends CbTestBroadcastReceiver {

        CdmaCbTestBroadcastReceiver() {
            super(TEST_ACTION);
        }

        @Override
        protected void handleTestAction(Intent intent) {
            SmsEnvelope envelope = new SmsEnvelope();
            // the CdmaSmsAddress is not used for a test cell broadcast message, but needs to be
            // supplied to avoid a null pointer exception in the platform
            CdmaSmsAddress nonNullAddress = new CdmaSmsAddress();
            nonNullAddress.origBytes = new byte[]{(byte) 0xFF};
            envelope.origAddress = nonNullAddress;

            // parse service category from intent
            envelope.serviceCategory = intent.getIntExtra("service_category", -1);
            if (envelope.serviceCategory == -1) {
                log("No service category, ignoring CB test intent");
                return;
            }

            // parse bearer data from intent
            String bearerDataString = intent.getStringExtra("bearer_data_string");
            envelope.bearerData = decodeHexString(bearerDataString);
            if (envelope.bearerData == null) {
                log("No bearer data, ignoring CB test intent");
                return;
            }

            SmsMessage sms = new SmsMessage(new CdmaSmsAddress(), envelope);
                mCellBroadcastServiceManager.sendCdmaMessageToHandler(sms);
        }
    }

    /**
     * A broadcast receiver used for testing CDMA SCP messages. To trigger test CDMA SCP messages
     * with adb run e.g:
     *
     * adb shell am broadcast -a com.android.internal.telephony.cdma.TEST_TRIGGER_SCP_MESSAGE \
     * --es originating_address_string 1234567890 \
     * --es bearer_data_string 00031007B0122610880080B2091C5F1D3965DB95054D1CB2E1E883A6F41334E \
     * 6CA830EEC882872DFC32F2E9E40
     */
    private class CdmaScpTestBroadcastReceiver extends CbTestBroadcastReceiver {

        CdmaScpTestBroadcastReceiver() {
            super(SCP_TEST_ACTION);
        }

        @Override
        protected void handleTestAction(Intent intent) {
            SmsEnvelope envelope = new SmsEnvelope();
            // the CdmaSmsAddress is not used for a test SCP message, but needs to be supplied to
            // avoid a null pointer exception in the platform
            CdmaSmsAddress nonNullAddress = new CdmaSmsAddress();
            nonNullAddress.origBytes = new byte[]{(byte) 0xFF};
            envelope.origAddress = nonNullAddress;

            // parse bearer data from intent
            String bearerDataString = intent.getStringExtra("bearer_data_string");
            envelope.bearerData = decodeHexString(bearerDataString);
            if (envelope.bearerData == null) {
                log("No bearer data, ignoring SCP test intent");
                return;
            }

            CdmaSmsAddress origAddr = new CdmaSmsAddress();
            String addressString = intent.getStringExtra("originating_address_string");
            origAddr.origBytes = decodeHexString(addressString);
            if (origAddr.origBytes == null) {
                log("No address data, ignoring SCP test intent");
                return;
            }
            SmsMessage sms = new SmsMessage(origAddr, envelope);
            sms.parseSms();
            mCellBroadcastServiceManager.sendCdmaScpMessageToHandler(sms, mScpCallback);
        }
    }
}