/*
 * Copyright (C) 2010 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.internal.policy.impl;

import java.util.List;

import android.app.admin.DevicePolicyManager;
import android.content.Context;
import android.content.res.Configuration;
import android.graphics.Rect;

import com.android.internal.widget.LockPatternUtils;
import com.android.internal.widget.PasswordEntryKeyboardView;

import android.os.CountDownTimer;
import android.os.SystemClock;
import android.provider.Settings;
import android.security.KeyStore;
import android.text.Editable;
import android.text.InputType;
import android.text.TextWatcher;
import android.text.method.DigitsKeyListener;
import android.text.method.TextKeyListener;
import android.view.Gravity;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.view.inputmethod.EditorInfo;
import android.view.inputmethod.InputMethodInfo;
import android.view.inputmethod.InputMethodManager;
import android.view.inputmethod.InputMethodSubtype;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.Space;
import android.widget.TextView;
import android.widget.TextView.OnEditorActionListener;

import com.android.internal.R;
import com.android.internal.widget.PasswordEntryKeyboardHelper;

/**
 * Displays a dialer-like interface or alphanumeric (latin-1) key entry for the user to enter
 * an unlock password
 */
public class PasswordUnlockScreen extends LinearLayout implements KeyguardScreen,
        OnEditorActionListener {

    private static final String TAG = "PasswordUnlockScreen";
    private final KeyguardUpdateMonitor mUpdateMonitor;
    private final KeyguardScreenCallback mCallback;

    private final boolean mIsAlpha;

    private final EditText mPasswordEntry;
    private final LockPatternUtils mLockPatternUtils;
    private final PasswordEntryKeyboardView mKeyboardView;
    private final PasswordEntryKeyboardHelper mKeyboardHelper;

    private final int mCreationOrientation;
    private final int mCreationHardKeyboardHidden;

    private final KeyguardStatusViewManager mStatusViewManager;
    private final boolean mUseSystemIME = true; // TODO: Make configurable
    private boolean mResuming; // used to prevent poking the wakelock during onResume()

    // To avoid accidental lockout due to events while the device in in the pocket, ignore
    // any passwords with length less than or equal to this length.
    private static final int MINIMUM_PASSWORD_LENGTH_BEFORE_REPORT = 3;

    public PasswordUnlockScreen(Context context, Configuration configuration,
            LockPatternUtils lockPatternUtils, KeyguardUpdateMonitor updateMonitor,
            KeyguardScreenCallback callback) {
        super(context);

        mCreationHardKeyboardHidden = configuration.hardKeyboardHidden;
        mCreationOrientation = configuration.orientation;
        mUpdateMonitor = updateMonitor;
        mCallback = callback;
        mLockPatternUtils = lockPatternUtils;

        LayoutInflater layoutInflater = LayoutInflater.from(context);
        if (mCreationOrientation != Configuration.ORIENTATION_LANDSCAPE) {
            layoutInflater.inflate(R.layout.keyguard_screen_password_portrait, this, true);
        } else {
            layoutInflater.inflate(R.layout.keyguard_screen_password_landscape, this, true);
        }

        mStatusViewManager = new KeyguardStatusViewManager(this, mUpdateMonitor, mLockPatternUtils,
                mCallback, true);

        final int quality = lockPatternUtils.getKeyguardStoredPasswordQuality();
        mIsAlpha = DevicePolicyManager.PASSWORD_QUALITY_ALPHABETIC == quality
                || DevicePolicyManager.PASSWORD_QUALITY_ALPHANUMERIC == quality
                || DevicePolicyManager.PASSWORD_QUALITY_COMPLEX == quality;

        mKeyboardView = (PasswordEntryKeyboardView) findViewById(R.id.keyboard);
        mPasswordEntry = (EditText) findViewById(R.id.passwordEntry);
        mPasswordEntry.setOnEditorActionListener(this);

        mKeyboardHelper = new PasswordEntryKeyboardHelper(context, mKeyboardView, this, false);
        mKeyboardHelper.setEnableHaptics(
                Settings.Secure.getInt(mContext.getContentResolver(),
                        Settings.Secure.LOCK_PATTERN_TACTILE_FEEDBACK_ENABLED, 0)
                        != 0);
        boolean imeOrDeleteButtonVisible = false;
        if (mIsAlpha) {
            // We always use the system IME for alpha keyboard, so hide lockscreen's soft keyboard
            mKeyboardHelper.setKeyboardMode(PasswordEntryKeyboardHelper.KEYBOARD_MODE_ALPHA);
            mKeyboardView.setVisibility(View.GONE);
        } else {
            // Use lockscreen's numeric keyboard if the physical keyboard isn't showing
            mKeyboardHelper.setKeyboardMode(PasswordEntryKeyboardHelper.KEYBOARD_MODE_NUMERIC);
            mKeyboardView.setVisibility(mCreationHardKeyboardHidden
                    == Configuration.HARDKEYBOARDHIDDEN_NO ? View.INVISIBLE : View.VISIBLE);

            // The delete button is of the PIN keyboard itself in some (e.g. tablet) layouts,
            // not a separate view
            View pinDelete = findViewById(R.id.pinDel);
            if (pinDelete != null) {
                pinDelete.setVisibility(View.VISIBLE);
                imeOrDeleteButtonVisible = true;
                pinDelete.setOnClickListener(new OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        mKeyboardHelper.handleBackspace();
                    }
                });
            }
        }

        mPasswordEntry.requestFocus();

        // This allows keyboards with overlapping qwerty/numeric keys to choose just numeric keys.
        if (mIsAlpha) {
            mPasswordEntry.setKeyListener(TextKeyListener.getInstance());
            mPasswordEntry.setInputType(InputType.TYPE_CLASS_TEXT
                    | InputType.TYPE_TEXT_VARIATION_PASSWORD);
            //mStatusViewManager.setHelpMessage(R.string.keyguard_password_enter_password_code,
                    //KeyguardStatusViewManager.LOCK_ICON);
        } else {
            mPasswordEntry.setKeyListener(DigitsKeyListener.getInstance());
            mPasswordEntry.setInputType(InputType.TYPE_CLASS_NUMBER
                    | InputType.TYPE_NUMBER_VARIATION_PASSWORD);
            //mStatusViewManager.setHelpMessage(R.string.keyguard_password_enter_pin_code,
                    //KeyguardStatusViewManager.LOCK_ICON);
        }

        // Poke the wakelock any time the text is selected or modified
        mPasswordEntry.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                mCallback.pokeWakelock();
            }
        });
        mPasswordEntry.addTextChangedListener(new TextWatcher() {
            public void onTextChanged(CharSequence s, int start, int before, int count) {
            }

            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            }

            public void afterTextChanged(Editable s) {
                if (!mResuming) {
                    mCallback.pokeWakelock();
                }
            }
        });

        // If there's more than one IME, enable the IME switcher button
        View switchImeButton = findViewById(R.id.switch_ime_button);
        final InputMethodManager imm = (InputMethodManager) getContext().getSystemService(
                Context.INPUT_METHOD_SERVICE);
        if (mIsAlpha && switchImeButton != null && hasMultipleEnabledIMEsOrSubtypes(imm, false)) {
            switchImeButton.setVisibility(View.VISIBLE);
            imeOrDeleteButtonVisible = true;
            switchImeButton.setOnClickListener(new OnClickListener() {
                public void onClick(View v) {
                    mCallback.pokeWakelock(); // Leave the screen on a bit longer
                    imm.showInputMethodPicker();
                }
            });
        }

        // If no icon is visible, reset the left margin on the password field so the text is
        // still centered.
        if (!imeOrDeleteButtonVisible) {
            android.view.ViewGroup.LayoutParams params = mPasswordEntry.getLayoutParams();
            if (params instanceof MarginLayoutParams) {
                ((MarginLayoutParams)params).leftMargin = 0;
                mPasswordEntry.setLayoutParams(params);
            }
        }
    }

    /**
     * Method adapted from com.android.inputmethod.latin.Utils
     *
     * @param imm The input method manager
     * @param shouldIncludeAuxiliarySubtypes
     * @return true if we have multiple IMEs to choose from
     */
    private boolean hasMultipleEnabledIMEsOrSubtypes(InputMethodManager imm,
            final boolean shouldIncludeAuxiliarySubtypes) {
        final List<InputMethodInfo> enabledImis = imm.getEnabledInputMethodList();

        // Number of the filtered IMEs
        int filteredImisCount = 0;

        for (InputMethodInfo imi : enabledImis) {
            // We can return true immediately after we find two or more filtered IMEs.
            if (filteredImisCount > 1) return true;
            final List<InputMethodSubtype> subtypes =
                    imm.getEnabledInputMethodSubtypeList(imi, true);
            // IMEs that have no subtypes should be counted.
            if (subtypes.isEmpty()) {
                ++filteredImisCount;
                continue;
            }

            int auxCount = 0;
            for (InputMethodSubtype subtype : subtypes) {
                if (subtype.isAuxiliary()) {
                    ++auxCount;
                }
            }
            final int nonAuxCount = subtypes.size() - auxCount;

            // IMEs that have one or more non-auxiliary subtypes should be counted.
            // If shouldIncludeAuxiliarySubtypes is true, IMEs that have two or more auxiliary
            // subtypes should be counted as well.
            if (nonAuxCount > 0 || (shouldIncludeAuxiliarySubtypes && auxCount > 1)) {
                ++filteredImisCount;
                continue;
            }
        }

        return filteredImisCount > 1
        // imm.getEnabledInputMethodSubtypeList(null, false) will return the current IME's enabled
        // input method subtype (The current IME should be LatinIME.)
                || imm.getEnabledInputMethodSubtypeList(null, false).size() > 1;
    }

    @Override
    protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) {
        // send focus to the password field
        return mPasswordEntry.requestFocus(direction, previouslyFocusedRect);
    }

    /** {@inheritDoc} */
    public boolean needsInput() {
        return mUseSystemIME && mIsAlpha;
    }

    /** {@inheritDoc} */
    public void onPause() {
        mStatusViewManager.onPause();
    }

    /** {@inheritDoc} */
    public void onResume() {
        mResuming = true;
        // reset status
        mStatusViewManager.onResume();

        // start fresh
        mPasswordEntry.setText("");
        mPasswordEntry.requestFocus();

        // if the user is currently locked out, enforce it.
        long deadline = mLockPatternUtils.getLockoutAttemptDeadline();
        if (deadline != 0) {
            handleAttemptLockout(deadline);
        }
        mResuming = false;
    }

    /** {@inheritDoc} */
    public void cleanUp() {
        mUpdateMonitor.removeCallback(this);
    }

    private void verifyPasswordAndUnlock() {
        String entry = mPasswordEntry.getText().toString();
        if (mLockPatternUtils.checkPassword(entry)) {
            mCallback.keyguardDone(true);
            mCallback.reportSuccessfulUnlockAttempt();
            mStatusViewManager.setInstructionText(null);
            KeyStore.getInstance().password(entry);
        } else if (entry.length() > MINIMUM_PASSWORD_LENGTH_BEFORE_REPORT ) {
            // to avoid accidental lockout, only count attempts that are long enough to be a
            // real password. This may require some tweaking.
            mCallback.reportFailedUnlockAttempt();
            if (0 == (mUpdateMonitor.getFailedAttempts()
                    % LockPatternUtils.FAILED_ATTEMPTS_BEFORE_TIMEOUT)) {
                long deadline = mLockPatternUtils.setLockoutAttemptDeadline();
                handleAttemptLockout(deadline);
            }
            mStatusViewManager.setInstructionText(
                    mContext.getString(R.string.lockscreen_password_wrong));
        } else if (entry.length() > 0) {
            mStatusViewManager.setInstructionText(
                    mContext.getString(R.string.lockscreen_password_wrong));
        }
        mPasswordEntry.setText("");
    }

    // Prevent user from using the PIN/Password entry until scheduled deadline.
    private void handleAttemptLockout(long elapsedRealtimeDeadline) {
        mPasswordEntry.setEnabled(false);
        mKeyboardView.setEnabled(false);
        long elapsedRealtime = SystemClock.elapsedRealtime();
        new CountDownTimer(elapsedRealtimeDeadline - elapsedRealtime, 1000) {

            @Override
            public void onTick(long millisUntilFinished) {
                int secondsRemaining = (int) (millisUntilFinished / 1000);
                String instructions = getContext().getString(
                        R.string.lockscreen_too_many_failed_attempts_countdown,
                        secondsRemaining);
                mStatusViewManager.setInstructionText(instructions);
            }

            @Override
            public void onFinish() {
                mPasswordEntry.setEnabled(true);
                mKeyboardView.setEnabled(true);
                mStatusViewManager.resetStatusInfo();
            }
        }.start();
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        mCallback.pokeWakelock();
        return false;
    }

    @Override
    protected void onAttachedToWindow() {
        super.onAttachedToWindow();
        Configuration config = getResources().getConfiguration();
        if (config.orientation != mCreationOrientation
                || config.hardKeyboardHidden != mCreationHardKeyboardHidden) {
            mCallback.recreateMe(config);
        }
    }

    /** {@inheritDoc} */
    @Override
    protected void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        if (newConfig.orientation != mCreationOrientation
                || newConfig.hardKeyboardHidden != mCreationHardKeyboardHidden) {
            mCallback.recreateMe(newConfig);
        }
    }

    public void onKeyboardChange(boolean isKeyboardOpen) {
        // Don't show the soft keyboard when the real keyboard is open
        mKeyboardView.setVisibility(isKeyboardOpen ? View.INVISIBLE : View.VISIBLE);
    }

    public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
        // Check if this was the result of hitting the enter key
        if (actionId == EditorInfo.IME_NULL || actionId == EditorInfo.IME_ACTION_DONE
                || actionId == EditorInfo.IME_ACTION_NEXT) {
            verifyPasswordAndUnlock();
            return true;
        }
        return false;
    }
}