/*
 * Copyright (C) 2018 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 android.telephony.ims.stub;

import android.annotation.IntDef;
import android.annotation.SystemApi;
import android.os.RemoteException;
import android.telephony.SmsManager;
import android.telephony.SmsMessage;
import android.telephony.ims.aidl.IImsSmsListener;
import android.util.Log;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

/**
 * Base implementation for SMS over IMS.
 *
 * Any service wishing to provide SMS over IMS should extend this class and implement all methods
 * that the service supports.
 *
 * @hide
 */
@SystemApi
public class ImsSmsImplBase {
    private static final String LOG_TAG = "SmsImplBase";

    /** @hide */
    @IntDef({
            SEND_STATUS_OK,
            SEND_STATUS_ERROR,
            SEND_STATUS_ERROR_RETRY,
            SEND_STATUS_ERROR_FALLBACK
        })
    @Retention(RetentionPolicy.SOURCE)
    public @interface SendStatusResult {}
    /**
     * Message was sent successfully.
     */
    public static final int SEND_STATUS_OK = 1;

    /**
     * IMS provider failed to send the message and platform should not retry falling back to sending
     * the message using the radio.
     */
    public static final int SEND_STATUS_ERROR = 2;

    /**
     * IMS provider failed to send the message and platform should retry again after setting TP-RD
     * bit to high.
     */
    public static final int SEND_STATUS_ERROR_RETRY = 3;

    /**
     * IMS provider failed to send the message and platform should retry falling back to sending
     * the message using the radio.
     */
    public static final int SEND_STATUS_ERROR_FALLBACK = 4;

    /** @hide */
    @IntDef({
            DELIVER_STATUS_OK,
            DELIVER_STATUS_ERROR_GENERIC,
            DELIVER_STATUS_ERROR_NO_MEMORY,
            DELIVER_STATUS_ERROR_REQUEST_NOT_SUPPORTED
        })
    @Retention(RetentionPolicy.SOURCE)
    public @interface DeliverStatusResult {}
    /**
     * Message was delivered successfully.
     */
    public static final int DELIVER_STATUS_OK = 1;

    /**
     * Message was not delivered.
     */
    public static final int DELIVER_STATUS_ERROR_GENERIC = 2;

    /**
     * Message was not delivered due to lack of memory.
     */
    public static final int DELIVER_STATUS_ERROR_NO_MEMORY = 3;

    /**
     * Message was not delivered as the request is not supported.
     */
    public static final int DELIVER_STATUS_ERROR_REQUEST_NOT_SUPPORTED = 4;

    /** @hide */
    @IntDef({
            STATUS_REPORT_STATUS_OK,
            STATUS_REPORT_STATUS_ERROR
        })
    @Retention(RetentionPolicy.SOURCE)
    public @interface StatusReportResult {}

    /**
     * Status Report was set successfully.
     */
    public static final int STATUS_REPORT_STATUS_OK = 1;

    /**
     * Error while setting status report.
     */
    public static final int STATUS_REPORT_STATUS_ERROR = 2;

    // Lock for feature synchronization
    private final Object mLock = new Object();
    private IImsSmsListener mListener;

    /**
     * Registers a listener responsible for handling tasks like delivering messages.
     *
     * @param listener listener to register.
     *
     * @hide
     */
    public final void registerSmsListener(IImsSmsListener listener) {
        synchronized (mLock) {
            mListener = listener;
        }
    }

    /**
     * This method will be triggered by the platform when the user attempts to send an SMS. This
     * method should be implemented by the IMS providers to provide implementation of sending an SMS
     * over IMS.
     *
     * @param token unique token generated by the platform that should be used when triggering
     *             callbacks for this specific message.
     * @param messageRef the message reference.
     * @param format the format of the message. Valid values are {@link SmsMessage#FORMAT_3GPP} and
     *               {@link SmsMessage#FORMAT_3GPP2}.
     * @param smsc the Short Message Service Center address.
     * @param isRetry whether it is a retry of an already attempted message or not.
     * @param pdu PDUs representing the contents of the message.
     */
    public void sendSms(int token, int messageRef, String format, String smsc, boolean isRetry,
            byte[] pdu) {
        // Base implementation returns error. Should be overridden.
        try {
            onSendSmsResult(token, messageRef, SEND_STATUS_ERROR,
                    SmsManager.RESULT_ERROR_GENERIC_FAILURE);
        } catch (RuntimeException e) {
            Log.e(LOG_TAG, "Can not send sms: " + e.getMessage());
        }
    }

    /**
     * This method will be triggered by the platform after
     * {@link #onSmsReceived(int, String, byte[])} has been called to deliver the result to the IMS
     * provider.
     *
     * @param token token provided in {@link #onSmsReceived(int, String, byte[])}
     * @param result result of delivering the message. Valid values are:
     *  {@link #DELIVER_STATUS_OK},
     *  {@link #DELIVER_STATUS_ERROR_GENERIC},
     *  {@link #DELIVER_STATUS_ERROR_NO_MEMORY},
     *  {@link #DELIVER_STATUS_ERROR_REQUEST_NOT_SUPPORTED}
     * @param messageRef the message reference
     */
    public void acknowledgeSms(int token, @DeliverStatusResult int messageRef, int result) {
        Log.e(LOG_TAG, "acknowledgeSms() not implemented.");
    }

    /**
     * This method will be triggered by the platform after
     * {@link #onSmsStatusReportReceived(int, int, String, byte[])} has been called to provide the
     * result to the IMS provider.
     *
     * @param token token provided in {@link #sendSms(int, int, String, String, boolean, byte[])}
     * @param result result of delivering the message. Valid values are:
     *  {@link #STATUS_REPORT_STATUS_OK},
     *  {@link #STATUS_REPORT_STATUS_ERROR}
     * @param messageRef the message reference
     */
    public void acknowledgeSmsReport(int token, int messageRef, @StatusReportResult int result) {
        Log.e(LOG_TAG, "acknowledgeSmsReport() not implemented.");
    }

    /**
     * This method should be triggered by the IMS providers when there is an incoming message. The
     * platform will deliver the message to the messages database and notify the IMS provider of the
     * result by calling {@link #acknowledgeSms(int, int, int)}.
     *
     * This method must not be called before {@link #onReady()} is called or the call will fail. If
     * the platform is not available, {@link #acknowledgeSms(int, int, int)} will be called with the
     * {@link #DELIVER_STATUS_ERROR_GENERIC} result code.
     * @param token unique token generated by IMS providers that the platform will use to trigger
     *              callbacks for this message.
     * @param format the format of the message. Valid values are {@link SmsMessage#FORMAT_3GPP} and
     * {@link SmsMessage#FORMAT_3GPP2}.
     * @param pdu PDUs representing the contents of the message.
     * @throws RuntimeException if called before {@link #onReady()} is triggered.
     */
    public final void onSmsReceived(int token, String format, byte[] pdu) throws RuntimeException {
        synchronized (mLock) {
            if (mListener == null) {
                throw new RuntimeException("Feature not ready.");
            }
            try {
                mListener.onSmsReceived(token, format, pdu);
            } catch (RemoteException e) {
                Log.e(LOG_TAG, "Can not deliver sms: " + e.getMessage());
                SmsMessage message = SmsMessage.createFromPdu(pdu, format);
                if (message != null && message.mWrappedSmsMessage != null) {
                    acknowledgeSms(token, message.mWrappedSmsMessage.mMessageRef,
                            DELIVER_STATUS_ERROR_GENERIC);
                } else {
                    Log.w(LOG_TAG, "onSmsReceived: Invalid pdu entered.");
                    acknowledgeSms(token, 0, DELIVER_STATUS_ERROR_GENERIC);
                }
            }
        }
    }

    /**
     * This method should be triggered by the IMS providers to pass the result of the sent message
     * to the platform.
     *
     * @param token token provided in {@link #sendSms(int, int, String, String, boolean, byte[])}
     * @param messageRef the message reference. Should be between 0 and 255 per TS.123.040
     * @param status result of sending the SMS. Valid values are:
     *  {@link #SEND_STATUS_OK},
     *  {@link #SEND_STATUS_ERROR},
     *  {@link #SEND_STATUS_ERROR_RETRY},
     *  {@link #SEND_STATUS_ERROR_FALLBACK},
     * @param reason reason in case status is failure. Valid values are:
     *  {@link SmsManager#RESULT_ERROR_NONE},
     *  {@link SmsManager#RESULT_ERROR_GENERIC_FAILURE},
     *  {@link SmsManager#RESULT_ERROR_RADIO_OFF},
     *  {@link SmsManager#RESULT_ERROR_NULL_PDU},
     *  {@link SmsManager#RESULT_ERROR_NO_SERVICE},
     *  {@link SmsManager#RESULT_ERROR_LIMIT_EXCEEDED},
     *  {@link SmsManager#RESULT_ERROR_FDN_CHECK_FAILURE},
     *  {@link SmsManager#RESULT_ERROR_SHORT_CODE_NOT_ALLOWED},
     *  {@link SmsManager#RESULT_ERROR_SHORT_CODE_NEVER_ALLOWED},
     *  {@link SmsManager#RESULT_RADIO_NOT_AVAILABLE},
     *  {@link SmsManager#RESULT_NETWORK_REJECT},
     *  {@link SmsManager#RESULT_INVALID_ARGUMENTS},
     *  {@link SmsManager#RESULT_INVALID_STATE},
     *  {@link SmsManager#RESULT_NO_MEMORY},
     *  {@link SmsManager#RESULT_INVALID_SMS_FORMAT},
     *  {@link SmsManager#RESULT_SYSTEM_ERROR},
     *  {@link SmsManager#RESULT_MODEM_ERROR},
     *  {@link SmsManager#RESULT_NETWORK_ERROR},
     *  {@link SmsManager#RESULT_ENCODING_ERROR},
     *  {@link SmsManager#RESULT_INVALID_SMSC_ADDRESS},
     *  {@link SmsManager#RESULT_OPERATION_NOT_ALLOWED},
     *  {@link SmsManager#RESULT_INTERNAL_ERROR},
     *  {@link SmsManager#RESULT_NO_RESOURCES},
     *  {@link SmsManager#RESULT_CANCELLED},
     *  {@link SmsManager#RESULT_REQUEST_NOT_SUPPORTED}
     *
     * @throws RuntimeException if called before {@link #onReady()} is triggered or if the
     * connection to the framework is not available. If this happens attempting to send the SMS
     * should be aborted.
     */
    public final void onSendSmsResult(int token, int messageRef,  @SendStatusResult int status,
            int reason) throws RuntimeException {
        synchronized (mLock) {
            if (mListener == null) {
                throw new RuntimeException("Feature not ready.");
            }
            try {
                mListener.onSendSmsResult(token, messageRef, status, reason);
            } catch (RemoteException e) {
                e.rethrowFromSystemServer();
            }
        }
    }

    /**
     * Sets the status report of the sent message.
     *
     * @param token token provided in {@link #sendSms(int, int, String, String, boolean, byte[])}
     * @param messageRef the message reference.
     * @param format the format of the message. Valid values are {@link SmsMessage#FORMAT_3GPP} and
     * {@link SmsMessage#FORMAT_3GPP2}.
     * @param pdu PDUs representing the content of the status report.
     * @throws RuntimeException if called before {@link #onReady()} is triggered
     */
    public final void onSmsStatusReportReceived(int token, int messageRef, String format,
            byte[] pdu) throws RuntimeException{
        synchronized (mLock) {
            if (mListener == null) {
                throw new RuntimeException("Feature not ready.");
            }
            try {
                mListener.onSmsStatusReportReceived(token, messageRef, format, pdu);
            } catch (RemoteException e) {
                Log.e(LOG_TAG, "Can not process sms status report: " + e.getMessage());
                acknowledgeSmsReport(token, messageRef, STATUS_REPORT_STATUS_ERROR);
            }
        }
    }

    /**
     * Returns the SMS format. Default is {@link SmsMessage#FORMAT_3GPP} unless overridden by IMS
     * Provider.
     *
     * @return  the format of the message. Valid values are {@link SmsMessage#FORMAT_3GPP} and
     * {@link SmsMessage#FORMAT_3GPP2}.
     */
    public String getSmsFormat() {
      return SmsMessage.FORMAT_3GPP;
    }

    /**
     * Called when ImsSmsImpl has been initialized and communication with the framework is set up.
     * Any attempt by this class to access the framework before this method is called will return
     * with a {@link RuntimeException}.
     */
    public void onReady() {
        // Base Implementation - Should be overridden
    }
}