/*
 * Copyright (C) 2006 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.phone;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import com.android.internal.telephony.TelephonyIntents;
import com.android.internal.telephony.Phone;
import android.telephony.PhoneNumberUtils;
import android.util.Log;
import android.view.WindowManager;

import com.android.internal.telephony.TelephonyCapabilities;

/**
 * Helper class to listen for some magic dialpad character sequences
 * that are handled specially by the Phone app.
 *
 * Note the Contacts app also handles these sequences too, so there's a
 * separate version of this class under apps/Contacts.
 *
 * In fact, the most common use case for these special sequences is typing
 * them from the regular "Dialer" used for outgoing calls, which is part
 * of the contacts app; see DialtactsActivity and DialpadFragment.
 * *This* version of SpecialCharSequenceMgr is used for only a few
 * relatively obscure places in the UI:
 * - The "SIM network unlock" PIN entry screen (see
 *   IccNetworkDepersonalizationPanel.java)
 * - The emergency dialer (see EmergencyDialer.java).
 *
 * TODO: there's lots of duplicated code between this class and the
 * corresponding class under apps/Contacts.  Let's figure out a way to
 * unify these two classes (in the framework? in a common shared library?)
 */
public class SpecialCharSequenceMgr {
    private static final String TAG = PhoneGlobals.LOG_TAG;
    private static final boolean DBG = false;

    private static final String MMI_IMEI_DISPLAY = "*#06#";

    /** This class is never instantiated. */
    private SpecialCharSequenceMgr() {
    }

    /**
     * Check for special strings of digits from an input
     * string.
     * @param context input Context for the events we handle.
     * @param input the dial string to be examined.
     */
    static boolean handleChars(Context context, String input) {
        return handleChars(context, input, null);
    }

    /**
     * Generally used for the Personal Unblocking Key (PUK) unlocking
     * case, where we want to be able to maintain a handle to the
     * calling activity so that we can close it or otherwise display
     * indication if the PUK code is recognized.
     *
     * NOTE: The counterpart to this file in Contacts does
     * NOT contain the special PUK handling code, since it
     * does NOT need it.  When the device gets into PUK-
     * locked state, the keyguard comes up and the only way
     * to unlock the device is through the Emergency dialer,
     * which is still in the Phone App.
     *
     * @param context input Context for the events we handle.
     * @param input the dial string to be examined.
     * @param pukInputActivity activity that originated this
     * PUK call, tracked so that we can close it or otherwise
     * indicate that special character sequence is
     * successfully processed. Can be null.
     * @return true if the input was a special string which has been
     * handled.
     */
    static boolean handleChars(Context context,
                               String input,
                               Activity pukInputActivity) {

        //get rid of the separators so that the string gets parsed correctly
        String dialString = PhoneNumberUtils.stripSeparators(input);

        if (handleIMEIDisplay(context, dialString)
            || handlePinEntry(context, dialString, pukInputActivity)
            || handleAdnEntry(context, dialString)
            || handleSecretCode(context, dialString)) {
            return true;
        }

        return false;
    }

    /**
     * Variant of handleChars() that looks for the subset of "special
     * sequences" that are available even if the device is locked.
     *
     * (Specifically, these are the sequences that you're allowed to type
     * in the Emergency Dialer, which is accessible *without* unlocking
     * the device.)
     */
    static boolean handleCharsForLockedDevice(Context context,
                                              String input,
                                              Activity pukInputActivity) {
        // Get rid of the separators so that the string gets parsed correctly
        String dialString = PhoneNumberUtils.stripSeparators(input);

        // The only sequences available on a locked device are the "**04"
        // or "**05" sequences that allow you to enter PIN or PUK-related
        // codes.  (e.g. for the case where you're currently locked out of
        // your phone, and need to change the PIN!  The only way to do
        // that is via the Emergency Dialer.)

        if (handlePinEntry(context, dialString, pukInputActivity)) {
            return true;
        }

        return false;
    }

    /**
     * Handles secret codes to launch arbitrary activities in the form of *#*#<code>#*#*.
     * If a secret code is encountered an Intent is started with the android_secret_code://<code>
     * URI.
     *
     * @param context the context to use
     * @param input the text to check for a secret code in
     * @return true if a secret code was encountered
     */
    static private boolean handleSecretCode(Context context, String input) {
        // Secret codes are in the form *#*#<code>#*#*
        int len = input.length();
        if (len > 8 && input.startsWith("*#*#") && input.endsWith("#*#*")) {
            Intent intent = new Intent(TelephonyIntents.SECRET_CODE_ACTION,
                    Uri.parse("android_secret_code://" + input.substring(4, len - 4)));
            context.sendBroadcast(intent);
            return true;
        }

        return false;
    }

    static private boolean handleAdnEntry(Context context, String input) {
        /* ADN entries are of the form "N(N)(N)#" */

        // if the phone is keyguard-restricted, then just ignore this
        // input.  We want to make sure that sim card contacts are NOT
        // exposed unless the phone is unlocked, and this code can be
        // accessed from the emergency dialer.
        if (PhoneGlobals.getInstance().getKeyguardManager().inKeyguardRestrictedInputMode()) {
            return false;
        }

        int len = input.length();
        if ((len > 1) && (len < 5) && (input.endsWith("#"))) {
            try {
                int index = Integer.parseInt(input.substring(0, len-1));
                Intent intent = new Intent(Intent.ACTION_PICK);

                intent.setClassName("com.android.phone",
                                    "com.android.phone.SimContacts");
                intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                intent.putExtra("index", index);
                PhoneGlobals.getInstance().startActivity(intent);

                return true;
            } catch (NumberFormatException ex) {}
        }
        return false;
    }

    static private boolean handlePinEntry(Context context, String input,
                                          Activity pukInputActivity) {
        // TODO: The string constants here should be removed in favor
        // of some call to a static the MmiCode class that determines
        // if a dialstring is an MMI code.
        if ((input.startsWith("**04") || input.startsWith("**05"))
                && input.endsWith("#")) {
            PhoneGlobals app = PhoneGlobals.getInstance();
            boolean isMMIHandled = app.phone.handlePinMmi(input);

            // if the PUK code is recognized then indicate to the
            // phone app that an attempt to unPUK the device was
            // made with this activity.  The PUK code may still
            // fail though, but we won't know until the MMI code
            // returns a result.
            if (isMMIHandled && input.startsWith("**05")) {
                app.setPukEntryActivity(pukInputActivity);
            }
            return isMMIHandled;
        }
        return false;
    }

    static private boolean handleIMEIDisplay(Context context,
                                             String input) {
        if (input.equals(MMI_IMEI_DISPLAY)) {
            showDeviceIdPanel(context);
            return true;
        }

        return false;
    }

    static private void showDeviceIdPanel(Context context) {
        if (DBG) log("showDeviceIdPanel()...");

        Phone phone = PhoneGlobals.getPhone();
        int labelId = TelephonyCapabilities.getDeviceIdLabel(phone);
        String deviceId = phone.getDeviceId();

        AlertDialog alert = new AlertDialog.Builder(context)
                .setTitle(labelId)
                .setMessage(deviceId)
                .setPositiveButton(R.string.ok, null)
                .setCancelable(false)
                .create();
        alert.getWindow().setType(WindowManager.LayoutParams.TYPE_PRIORITY_PHONE);
        alert.show();
    }

    private static void log(String msg) {
        Log.d(TAG, "[SpecialCharSequenceMgr] " + msg);
    }
}