/*
 * Copyright (C) 2017 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.settings.notification;

import android.app.ActivityManager;
import android.app.AlarmManager;
import android.app.AlarmManager.AlarmClockInfo;
import android.app.NotificationManager;
import android.content.ContentResolver;
import android.content.Context;
import android.database.ContentObserver;
import android.net.Uri;
import android.os.Handler;
import android.os.UserHandle;
import android.provider.Settings;
import android.service.notification.ScheduleCalendar;
import android.service.notification.ZenModeConfig;
import android.support.v7.preference.Preference;
import android.support.v7.preference.PreferenceScreen;

import com.android.internal.annotations.VisibleForTesting;
import com.android.settings.core.PreferenceControllerMixin;
import com.android.settings.overlay.FeatureFactory;
import com.android.settingslib.core.AbstractPreferenceController;
import com.android.settingslib.core.instrumentation.MetricsFeatureProvider;
import com.android.settingslib.core.lifecycle.Lifecycle;
import com.android.settingslib.core.lifecycle.LifecycleObserver;
import com.android.settingslib.core.lifecycle.events.OnPause;
import com.android.settingslib.core.lifecycle.events.OnResume;

abstract public class AbstractZenModePreferenceController extends
        AbstractPreferenceController implements PreferenceControllerMixin, LifecycleObserver,
        OnResume, OnPause {

    @VisibleForTesting
    protected SettingObserver mSettingObserver;

    private final String KEY;
    final private NotificationManager mNotificationManager;
    protected static ZenModeConfigWrapper mZenModeConfigWrapper;
    protected MetricsFeatureProvider mMetricsFeatureProvider;
    protected final ZenModeBackend mBackend;
    protected PreferenceScreen mScreen;

    public AbstractZenModePreferenceController(Context context, String key,
            Lifecycle lifecycle) {
        super(context);
        mZenModeConfigWrapper = new ZenModeConfigWrapper(context);
        if (lifecycle != null) {
            lifecycle.addObserver(this);
        }
        KEY = key;
        mNotificationManager = (NotificationManager) context.getSystemService(
                Context.NOTIFICATION_SERVICE);

        final FeatureFactory featureFactory = FeatureFactory.getFactory(mContext);
        mMetricsFeatureProvider = featureFactory.getMetricsFeatureProvider();
        mBackend = ZenModeBackend.getInstance(context);
    }

    @Override
    public String getPreferenceKey() {
        return KEY;
    }

    @Override
    public void displayPreference(PreferenceScreen screen) {
        super.displayPreference(screen);
        mScreen = screen;
        Preference pref = screen.findPreference(KEY);
        if (pref != null) {
            mSettingObserver = new SettingObserver(pref);
        }
    }

    @Override
    public void onResume() {
        if (mSettingObserver != null) {
            mSettingObserver.register(mContext.getContentResolver());
            mSettingObserver.onChange(false, null);
        }
    }

    @Override
    public void onPause() {
        if (mSettingObserver != null) {
            mSettingObserver.unregister(mContext.getContentResolver());
        }
    }

    protected NotificationManager.Policy getPolicy() {
        return mNotificationManager.getNotificationPolicy();
    }

    protected ZenModeConfig getZenModeConfig() {
        return mNotificationManager.getZenModeConfig();
    }

    protected int getZenMode() {
        return Settings.Global.getInt(mContext.getContentResolver(), Settings.Global.ZEN_MODE,
                mBackend.mZenMode);
    }

    protected int getZenDuration() {
        return Settings.Global.getInt(mContext.getContentResolver(), Settings.Global.ZEN_DURATION,
                0);
    }

    class SettingObserver extends ContentObserver {
        private final Uri ZEN_MODE_URI = Settings.Global.getUriFor(Settings.Global.ZEN_MODE);
        private final Uri ZEN_MODE_CONFIG_ETAG_URI = Settings.Global.getUriFor(
                Settings.Global.ZEN_MODE_CONFIG_ETAG);
        private final Uri ZEN_MODE_DURATION_URI = Settings.Global.getUriFor(
                Settings.Global.ZEN_DURATION);

        private final Preference mPreference;

        public SettingObserver(Preference preference) {
            super(new Handler());
            mPreference = preference;
        }

        public void register(ContentResolver cr) {
            cr.registerContentObserver(ZEN_MODE_URI, false, this, UserHandle.USER_ALL);
            cr.registerContentObserver(ZEN_MODE_CONFIG_ETAG_URI, false, this, UserHandle.USER_ALL);
            cr.registerContentObserver(ZEN_MODE_DURATION_URI, false, this, UserHandle.USER_ALL);
        }

        public void unregister(ContentResolver cr) {
            cr.unregisterContentObserver(this);
        }

        @Override
        public void onChange(boolean selfChange, Uri uri) {
            super.onChange(selfChange, uri);
            if (uri == null || ZEN_MODE_URI.equals(uri) || ZEN_MODE_CONFIG_ETAG_URI.equals(uri)
                    || ZEN_MODE_DURATION_URI.equals(uri)) {
                mBackend.updatePolicy();
                mBackend.updateZenMode();
                if (mScreen != null) {
                    displayPreference(mScreen);
                }
                updateState(mPreference);
            }
        }
    }

    /**
     * Wrapper for testing compatibility
     */
    @VisibleForTesting
    static class ZenModeConfigWrapper {
        private final Context mContext;

        public ZenModeConfigWrapper(Context context) {
            mContext = context;
        }

        protected String getOwnerCaption(String owner) {
            return ZenModeConfig.getOwnerCaption(mContext, owner);
        }

        protected boolean isTimeRule(Uri id) {
            return ZenModeConfig.isValidEventConditionId(id) ||
                    ZenModeConfig.isValidScheduleConditionId(id);
        }

        protected CharSequence getFormattedTime(long time, int userHandle) {
            return ZenModeConfig.getFormattedTime(mContext, time, isToday(time), userHandle);
        }

        private boolean isToday(long time) {
            return ZenModeConfig.isToday(time);
        }

        protected long parseManualRuleTime(Uri id) {
            return ZenModeConfig.tryParseCountdownConditionId(id);
        }

        protected long parseAutomaticRuleEndTime(Uri id) {
            if (ZenModeConfig.isValidEventConditionId(id)) {
                // cannot look up end times for events
                return Long.MAX_VALUE;
            }

            if (ZenModeConfig.isValidScheduleConditionId(id)) {
                ScheduleCalendar schedule = ZenModeConfig.toScheduleCalendar(id);
                long endTimeMs = schedule.getNextChangeTime(System.currentTimeMillis());

                // check if automatic rule will end on next alarm
                if (schedule.exitAtAlarm()) {
                    long nextAlarm = getNextAlarm(mContext);
                    schedule.maybeSetNextAlarm(System.currentTimeMillis(), nextAlarm);
                    if (schedule.shouldExitForAlarm(endTimeMs)) {
                        return nextAlarm;
                    }
                }

                return endTimeMs;
            }

            return -1;
        }
    }

    private static long getNextAlarm(Context context) {
        final AlarmManager alarms = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
        final AlarmClockInfo info = alarms.getNextAlarmClock(ActivityManager.getCurrentUser());
        return info != null ? info.getTriggerTime() : 0;
    }
}