/*
 * Copyright (C) 2016 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.incallui;

import com.google.common.base.Preconditions;

import com.android.contacts.common.ContactsUtils;
import com.android.contacts.common.compat.CallSdkCompat;
import com.android.contacts.common.preference.ContactsPreferences;
import com.android.contacts.common.util.BitmapUtil;
import com.android.contacts.common.util.ContactDisplayUtils;
import com.android.dialer.R;
import com.android.incallui.util.TelecomCallUtil;

import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.net.Uri;
import android.support.annotation.Nullable;
import android.telecom.Call;
import android.telecom.PhoneAccount;
import android.text.BidiFormatter;
import android.text.TextDirectionHeuristics;
import android.text.TextUtils;
import android.util.ArrayMap;

import java.util.Map;

/**
 * Handles the display of notifications for "external calls".
 *
 * External calls are a representation of a call which is in progress on the user's other device
 * (e.g. another phone, or a watch).
 */
public class ExternalCallNotifier implements ExternalCallList.ExternalCallListener {

    /**
     * Tag used with the notification manager to uniquely identify external call notifications.
     */
    private static final String NOTIFICATION_TAG = "EXTERNAL_CALL";

    /**
     * Represents a call and associated cached notification data.
     */
    private static class NotificationInfo {
        private final Call mCall;
        private final int mNotificationId;
        @Nullable private String mContentTitle;
        @Nullable private Bitmap mLargeIcon;
        @Nullable private String mPersonReference;

        public NotificationInfo(Call call, int notificationId) {
            Preconditions.checkNotNull(call);
            mCall = call;
            mNotificationId = notificationId;
        }

        public Call getCall() {
            return mCall;
        }

        public int getNotificationId() {
            return mNotificationId;
        }

        public @Nullable String getContentTitle() {
            return mContentTitle;
        }

        public @Nullable Bitmap getLargeIcon() {
            return mLargeIcon;
        }

        public @Nullable String getPersonReference() {
            return mPersonReference;
        }

        public void setContentTitle(@Nullable String contentTitle) {
            mContentTitle = contentTitle;
        }

        public void setLargeIcon(@Nullable Bitmap largeIcon) {
            mLargeIcon = largeIcon;
        }

        public void setPersonReference(@Nullable String personReference) {
            mPersonReference = personReference;
        }
    }

    private final Context mContext;
    private final ContactInfoCache mContactInfoCache;
    private Map<Call, NotificationInfo> mNotifications = new ArrayMap<>();
    private int mNextUniqueNotificationId;
    private ContactsPreferences mContactsPreferences;

    /**
     * Initializes a new instance of the external call notifier.
     */
    public ExternalCallNotifier(Context context, ContactInfoCache contactInfoCache) {
        mContext = Preconditions.checkNotNull(context);
        mContactsPreferences = ContactsPreferencesFactory.newContactsPreferences(mContext);
        mContactInfoCache = Preconditions.checkNotNull(contactInfoCache);
    }

    /**
     * Handles the addition of a new external call by showing a new notification.
     * Triggered by {@link CallList#onCallAdded(android.telecom.Call)}.
     */
    @Override
    public void onExternalCallAdded(android.telecom.Call call) {
        Log.i(this, "onExternalCallAdded " + call);
        Preconditions.checkArgument(!mNotifications.containsKey(call));
        NotificationInfo info = new NotificationInfo(call, mNextUniqueNotificationId++);
        mNotifications.put(call, info);

        showNotifcation(info);
    }

    /**
     * Handles the removal of an external call by hiding its associated notification.
     * Triggered by {@link CallList#onCallRemoved(android.telecom.Call)}.
     */
    @Override
    public void onExternalCallRemoved(android.telecom.Call call) {
        Log.i(this, "onExternalCallRemoved " + call);

        dismissNotification(call);
    }

    /**
     * Handles updates to an external call.
     */
    @Override
    public void onExternalCallUpdated(Call call) {
        Preconditions.checkArgument(mNotifications.containsKey(call));
        postNotification(mNotifications.get(call));
    }

    /**
     * Initiates a call pull given a notification ID.
     *
     * @param notificationId The notification ID associated with the external call which is to be
     *                       pulled.
     */
    public void pullExternalCall(int notificationId) {
        for (NotificationInfo info : mNotifications.values()) {
            if (info.getNotificationId() == notificationId) {
                CallSdkCompat.pullExternalCall(info.getCall());
                return;
            }
        }
    }

    /**
     * Shows a notification for a new external call.  Performs a contact cache lookup to find any
     * associated photo and information for the call.
     */
    private void showNotifcation(final NotificationInfo info) {
        // We make a call to the contact info cache to query for supplemental data to what the
        // call provides.  This includes the contact name and photo.
        // This callback will always get called immediately and synchronously with whatever data
        // it has available, and may make a subsequent call later (same thread) if it had to
        // call into the contacts provider for more data.
        com.android.incallui.Call incallCall = new com.android.incallui.Call(info.getCall(),
                false /* registerCallback */);

        mContactInfoCache.findInfo(incallCall, false /* isIncoming */,
                new ContactInfoCache.ContactInfoCacheCallback() {
                    @Override
                    public void onContactInfoComplete(String callId,
                            ContactInfoCache.ContactCacheEntry entry) {

                        // Ensure notification still exists as the external call could have been
                        // removed during async contact info lookup.
                        if (mNotifications.containsKey(info.getCall())) {
                            saveContactInfo(info, entry);
                        }
                    }

                    @Override
                    public void onImageLoadComplete(String callId,
                            ContactInfoCache.ContactCacheEntry entry) {

                        // Ensure notification still exists as the external call could have been
                        // removed during async contact info lookup.
                        if (mNotifications.containsKey(info.getCall())) {
                            savePhoto(info, entry);
                        }
                    }

                    @Override
                    public void onContactInteractionsInfoComplete(String callId,
                            ContactInfoCache.ContactCacheEntry entry) {
                    }
                });
    }

    /**
     * Dismisses a notification for an external call.
     */
    private void dismissNotification(Call call) {
        Preconditions.checkArgument(mNotifications.containsKey(call));

        NotificationManager notificationManager =
                (NotificationManager) mContext.getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.cancel(NOTIFICATION_TAG, mNotifications.get(call).getNotificationId());

        mNotifications.remove(call);
    }

    /**
     * Attempts to build a large icon to use for the notification based on the contact info and
     * post the updated notification to the notification manager.
     */
    private void savePhoto(NotificationInfo info, ContactInfoCache.ContactCacheEntry entry) {
        Bitmap largeIcon = getLargeIconToDisplay(mContext, entry, info.getCall());
        if (largeIcon != null) {
            largeIcon = getRoundedIcon(mContext, largeIcon);
        }
        info.setLargeIcon(largeIcon);
        postNotification(info);
    }

    /**
     * Builds and stores the contact information the notification will display and posts the updated
     * notification to the notification manager.
     */
    private void saveContactInfo(NotificationInfo info, ContactInfoCache.ContactCacheEntry entry) {
        info.setContentTitle(getContentTitle(mContext, mContactsPreferences,
                entry, info.getCall()));
        info.setPersonReference(getPersonReference(entry, info.getCall()));
        postNotification(info);
    }

    /**
     * Rebuild an existing or show a new notification given {@link NotificationInfo}.
     */
    private void postNotification(NotificationInfo info) {
        Log.i(this, "postNotification : " + info.getContentTitle());
        Notification.Builder builder = new Notification.Builder(mContext);
        // Set notification as ongoing since calls are long-running versus a point-in-time notice.
        builder.setOngoing(true);
        // Make the notification prioritized over the other normal notifications.
        builder.setPriority(Notification.PRIORITY_HIGH);
        // Set the content ("Ongoing call on another device")
        builder.setContentText(mContext.getString(R.string.notification_external_call));
        builder.setSmallIcon(R.drawable.ic_call_white_24dp);
        builder.setContentTitle(info.getContentTitle());
        builder.setLargeIcon(info.getLargeIcon());
        builder.setColor(mContext.getResources().getColor(R.color.dialer_theme_color));
        builder.addPerson(info.getPersonReference());

        // Where the external call supports being transferred to the local device, add an action
        // to the notification to initiate the call pull process.
        if ((info.getCall().getDetails().getCallCapabilities()
                & CallSdkCompat.Details.CAPABILITY_CAN_PULL_CALL)
                == CallSdkCompat.Details.CAPABILITY_CAN_PULL_CALL) {

            Intent intent = new Intent(
                    NotificationBroadcastReceiver.ACTION_PULL_EXTERNAL_CALL, null, mContext,
                    NotificationBroadcastReceiver.class);
            intent.putExtra(NotificationBroadcastReceiver.EXTRA_NOTIFICATION_ID,
                    info.getNotificationId());

            builder.addAction(new Notification.Action.Builder(R.drawable.ic_call_white_24dp,
                    mContext.getText(R.string.notification_transfer_call),
                    PendingIntent.getBroadcast(mContext, 0, intent, 0)).build());
        }

        /**
         * This builder is used for the notification shown when the device is locked and the user
         * has set their notification settings to 'hide sensitive content'
         * {@see Notification.Builder#setPublicVersion}.
         */
        Notification.Builder publicBuilder = new Notification.Builder(mContext);
        publicBuilder.setSmallIcon(R.drawable.ic_call_white_24dp);
        publicBuilder.setColor(mContext.getResources().getColor(R.color.dialer_theme_color));

        builder.setPublicVersion(publicBuilder.build());
        Notification notification = builder.build();

        NotificationManager notificationManager =
                (NotificationManager) mContext.getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.notify(NOTIFICATION_TAG, info.getNotificationId(), notification);
    }

    /**
     * Finds a large icon to display in a notification for a call.  For conference calls, a
     * conference call icon is used, otherwise if contact info is specified, the user's contact
     * photo or avatar is used.
     *
     * @param context The context.
     * @param contactInfo The contact cache info.
     * @param call The call.
     * @return The large icon to use for the notification.
     */
    private @Nullable Bitmap getLargeIconToDisplay(Context context,
            ContactInfoCache.ContactCacheEntry contactInfo, android.telecom.Call call) {

        Bitmap largeIcon = null;
        if (call.getDetails().hasProperty(android.telecom.Call.Details.PROPERTY_CONFERENCE) &&
                !call.getDetails()
                        .hasProperty(android.telecom.Call.Details.PROPERTY_GENERIC_CONFERENCE)) {

            largeIcon = BitmapFactory.decodeResource(context.getResources(),
                    R.drawable.img_conference);
        }
        if (contactInfo.photo != null && (contactInfo.photo instanceof BitmapDrawable)) {
            largeIcon = ((BitmapDrawable) contactInfo.photo).getBitmap();
        }
        return largeIcon;
    }

    /**
     * Given a bitmap, returns a rounded version of the icon suitable for display in a notification.
     *
     * @param context The context.
     * @param bitmap The bitmap to round.
     * @return The rounded bitmap.
     */
    private @Nullable Bitmap getRoundedIcon(Context context, @Nullable Bitmap bitmap) {
        if (bitmap == null) {
            return null;
        }
        final int height = (int) context.getResources().getDimension(
                android.R.dimen.notification_large_icon_height);
        final int width = (int) context.getResources().getDimension(
                android.R.dimen.notification_large_icon_width);
        return BitmapUtil.getRoundedBitmap(bitmap, width, height);
    }

    /**
     * Builds a notification content title for a call.  If the call is a conference call, it is
     * identified as such.  Otherwise an attempt is made to show an associated contact name or
     * phone number.
     *
     * @param context The context.
     * @param contactsPreferences Contacts preferences, used to determine the preferred formatting
     *                            for contact names.
     * @param contactInfo The contact info which was looked up in the contact cache.
     * @param call The call to generate a title for.
     * @return The content title.
     */
    private @Nullable String getContentTitle(Context context,
            @Nullable ContactsPreferences contactsPreferences,
            ContactInfoCache.ContactCacheEntry contactInfo, android.telecom.Call call) {

        if (call.getDetails().hasProperty(android.telecom.Call.Details.PROPERTY_CONFERENCE) &&
                !call.getDetails()
                        .hasProperty(android.telecom.Call.Details.PROPERTY_GENERIC_CONFERENCE)) {

            return context.getResources().getString(R.string.card_title_conf_call);
        }

        String preferredName = ContactDisplayUtils.getPreferredDisplayName(contactInfo.namePrimary,
                contactInfo.nameAlternative, contactsPreferences);
        if (TextUtils.isEmpty(preferredName)) {
            return TextUtils.isEmpty(contactInfo.number) ? null : BidiFormatter.getInstance()
                    .unicodeWrap(contactInfo.number, TextDirectionHeuristics.LTR);
        }
        return preferredName;
    }

    /**
     * Gets a "person reference" for a notification, used by the system to determine whether the
     * notification should be allowed past notification interruption filters.
     *
     * @param contactInfo The contact info from cache.
     * @param call The call.
     * @return the person reference.
     */
    private String getPersonReference(ContactInfoCache.ContactCacheEntry contactInfo,
            Call call) {

        String number = TelecomCallUtil.getNumber(call);
        // Query {@link Contacts#CONTENT_LOOKUP_URI} directly with work lookup key is not allowed.
        // So, do not pass {@link Contacts#CONTENT_LOOKUP_URI} to NotificationManager to avoid
        // NotificationManager using it.
        if (contactInfo.lookupUri != null && contactInfo.userType != ContactsUtils.USER_TYPE_WORK) {
            return contactInfo.lookupUri.toString();
        } else if (!TextUtils.isEmpty(number)) {
            return Uri.fromParts(PhoneAccount.SCHEME_TEL, number, null).toString();
        }
        return "";
    }
}