/*
 * Copyright (C) 2014 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.systemui.statusbar;

import com.android.internal.app.IBatteryStats;
import com.android.keyguard.KeyguardUpdateMonitor;
import com.android.keyguard.KeyguardUpdateMonitorCallback;
import com.android.systemui.R;
import com.android.systemui.statusbar.phone.KeyguardIndicationTextView;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.BatteryManager;
import android.os.BatteryStats;
import android.os.Handler;
import android.os.Message;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.os.UserHandle;
import android.text.TextUtils;
import android.text.format.Formatter;
import android.util.Log;
import android.view.View;

/**
 * Controls the little text indicator on the keyguard.
 */
public class KeyguardIndicationController {

    private static final String TAG = "KeyguardIndicationController";

    private static final int MSG_HIDE_TRANSIENT = 1;

    private final Context mContext;
    private final KeyguardIndicationTextView mTextView;
    private final IBatteryStats mBatteryInfo;

    private String mRestingIndication;
    private String mTransientIndication;
    private boolean mVisible;

    private boolean mPowerPluggedIn;
    private boolean mPowerCharged;

    public KeyguardIndicationController(Context context, KeyguardIndicationTextView textView) {
        mContext = context;
        mTextView = textView;

        mBatteryInfo = IBatteryStats.Stub.asInterface(
                ServiceManager.getService(BatteryStats.SERVICE_NAME));
        KeyguardUpdateMonitor.getInstance(context).registerCallback(mUpdateMonitor);
        context.registerReceiverAsUser(
                mReceiver, UserHandle.OWNER, new IntentFilter(Intent.ACTION_TIME_TICK), null, null);
    }

    public void setVisible(boolean visible) {
        mVisible = visible;
        mTextView.setVisibility(visible ? View.VISIBLE : View.GONE);
        if (visible) {
            hideTransientIndication();
            updateIndication();
        }
    }

    /**
     * Sets the indication that is shown if nothing else is showing.
     */
    public void setRestingIndication(String restingIndication) {
        mRestingIndication = restingIndication;
        updateIndication();
    }

    /**
     * Hides transient indication in {@param delayMs}.
     */
    public void hideTransientIndicationDelayed(long delayMs) {
        mHandler.sendMessageDelayed(
                mHandler.obtainMessage(MSG_HIDE_TRANSIENT), delayMs);
    }

    /**
     * Shows {@param transientIndication} until it is hidden by {@link #hideTransientIndication}.
     */
    public void showTransientIndication(int transientIndication) {
        showTransientIndication(mContext.getResources().getString(transientIndication));
    }

    /**
     * Shows {@param transientIndication} until it is hidden by {@link #hideTransientIndication}.
     */
    public void showTransientIndication(String transientIndication) {
        mTransientIndication = transientIndication;
        mHandler.removeMessages(MSG_HIDE_TRANSIENT);
        updateIndication();
    }

    /**
     * Hides transient indication.
     */
    public void hideTransientIndication() {
        if (mTransientIndication != null) {
            mTransientIndication = null;
            mHandler.removeMessages(MSG_HIDE_TRANSIENT);
            updateIndication();
        }
    }

    private void updateIndication() {
        if (mVisible) {
            mTextView.switchIndication(computeIndication());
        }
    }

    private String computeIndication() {
        if (!TextUtils.isEmpty(mTransientIndication)) {
            return mTransientIndication;
        }
        if (mPowerPluggedIn) {
            return computePowerIndication();
        }
        return mRestingIndication;
    }

    private String computePowerIndication() {
        if (mPowerCharged) {
            return mContext.getResources().getString(R.string.keyguard_charged);
        }

        // Try fetching charging time from battery stats.
        try {
            long chargingTimeRemaining = mBatteryInfo.computeChargeTimeRemaining();
            if (chargingTimeRemaining > 0) {
                String chargingTimeFormatted =
                        Formatter.formatShortElapsedTime(mContext, chargingTimeRemaining);
                return mContext.getResources().getString(
                        R.string.keyguard_indication_charging_time, chargingTimeFormatted);
            }
        } catch (RemoteException e) {
            Log.e(TAG, "Error calling IBatteryStats: ", e);
        }

        // Fall back to simple charging label.
        return mContext.getResources().getString(R.string.keyguard_plugged_in);
    }

    KeyguardUpdateMonitorCallback mUpdateMonitor = new KeyguardUpdateMonitorCallback() {
        @Override
        public void onRefreshBatteryInfo(KeyguardUpdateMonitor.BatteryStatus status) {
            mPowerPluggedIn = status.status == BatteryManager.BATTERY_STATUS_CHARGING
                    || status.status == BatteryManager.BATTERY_STATUS_FULL;
            mPowerCharged = status.isCharged();
            updateIndication();
        }
    };

    BroadcastReceiver mReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            if (mVisible) {
                updateIndication();
            }
        }
    };

    private final Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            if (msg.what == MSG_HIDE_TRANSIENT && mTransientIndication != null) {
                mTransientIndication = null;
                updateIndication();
            }
        }
    };
}