/*
 * Copyright (C) 2021 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.car.qc;

import static android.os.UserManager.SWITCHABILITY_STATUS_OK;
import static android.view.WindowInsets.Type.statusBars;

import static com.android.car.ui.utils.CarUiUtils.drawableToBitmap;

import android.annotation.Nullable;
import android.annotation.UserIdInt;
import android.app.ActivityManager;
import android.app.AlertDialog;
import android.car.Car;
import android.car.user.CarUserManager;
import android.car.user.UserCreationResult;
import android.car.user.UserSwitchResult;
import android.car.userlib.UserHelper;
import android.car.util.concurrent.AsyncFuture;
import android.content.Context;
import android.content.Intent;
import android.content.pm.UserInfo;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.Icon;
import android.os.AsyncTask;
import android.os.UserHandle;
import android.os.UserManager;
import android.sysprop.CarProperties;
import android.util.Log;
import android.view.Window;
import android.view.WindowManager;

import androidx.annotation.VisibleForTesting;
import androidx.core.graphics.drawable.RoundedBitmapDrawable;
import androidx.core.graphics.drawable.RoundedBitmapDrawableFactory;

import com.android.car.qc.QCItem;
import com.android.car.qc.QCList;
import com.android.car.qc.QCRow;
import com.android.car.qc.provider.BaseLocalQCProvider;
import com.android.internal.util.UserIcons;
import com.android.systemui.R;
import com.android.systemui.car.userswitcher.UserIconProvider;

import java.util.List;
import java.util.concurrent.TimeUnit;
import java.util.stream.Collectors;

/**
 * Local provider for the profile switcher panel.
 */
public class ProfileSwitcher extends BaseLocalQCProvider {
    private static final String TAG = ProfileSwitcher.class.getSimpleName();
    private static final int TIMEOUT_MS = CarProperties.user_hal_timeout().orElse(5_000) + 500;

    private final UserManager mUserManager;
    private final UserIconProvider mUserIconProvider;
    private final Car mCar;
    private final CarUserManager mCarUserManager;
    private boolean mPendingUserAdd;

    public ProfileSwitcher(Context context) {
        super(context);
        mUserManager = context.getSystemService(UserManager.class);
        mUserIconProvider = new UserIconProvider();
        mCar = Car.createCar(mContext);
        mCarUserManager = (CarUserManager) mCar.getCarManager(Car.CAR_USER_SERVICE);
    }

    @VisibleForTesting
    ProfileSwitcher(Context context, UserManager userManager, CarUserManager carUserManager) {
        super(context);
        mUserManager = userManager;
        mUserIconProvider = new UserIconProvider();
        mCar = null;
        mCarUserManager = carUserManager;
    }

    @Override
    public QCItem getQCItem() {
        QCList.Builder listBuilder = new QCList.Builder();

        int fgUserId = ActivityManager.getCurrentUser();
        UserHandle fgUserHandle = UserHandle.of(fgUserId);
        // If the foreground user CANNOT switch to other users, only display the foreground user.
        if (mUserManager.getUserSwitchability(fgUserHandle) != SWITCHABILITY_STATUS_OK) {
            UserInfo currentUser = mUserManager.getUserInfo(ActivityManager.getCurrentUser());
            return listBuilder.addRow(createUserProfileRow(currentUser)).build();
        }

        List<UserInfo> profiles = getProfileList();
        for (UserInfo profile : profiles) {
            listBuilder.addRow(createUserProfileRow(profile));
        }
        listBuilder.addRow(createGuestProfileRow());
        listBuilder.addRow(createAddProfileRow());
        return listBuilder.build();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        if (mCar != null) {
            mCar.disconnect();
        }
    }

    private List<UserInfo> getProfileList() {
        return mUserManager.getAliveUsers()
                .stream()
                .filter(userInfo -> userInfo.supportsSwitchToByUser() && !userInfo.isGuest())
                .collect(Collectors.toList());
    }

    private QCRow createUserProfileRow(UserInfo userInfo) {
        QCItem.ActionHandler actionHandler = (item, context, intent) -> {
            if (mPendingUserAdd) {
                return;
            }
            switchUser(userInfo.id);
        };

        return createProfileRow(userInfo.name,
                mUserIconProvider.getRoundedUserIcon(userInfo, mContext), actionHandler);
    }

    private QCRow createGuestProfileRow() {
        QCItem.ActionHandler actionHandler = (item, context, intent) -> {
            if (mPendingUserAdd) {
                return;
            }
            UserInfo guest = createNewOrFindExistingGuest(mContext);
            if (guest != null) {
                switchUser(guest.id);
            }
        };

        return createProfileRow(mContext.getString(R.string.start_guest_session),
                mUserIconProvider.getRoundedGuestDefaultIcon(mContext.getResources()),
                actionHandler);
    }

    private QCRow createAddProfileRow() {
        QCItem.ActionHandler actionHandler = (item, context, intent) -> {
            if (mPendingUserAdd) {
                return;
            }
            if (!mUserManager.canAddMoreUsers()) {
                showMaxUserLimitReachedDialog();
            } else {
                showConfirmAddUserDialog();
            }
        };

        return createProfileRow(mContext.getString(R.string.car_add_user), getCircularAddUserIcon(),
                actionHandler);
    }

    private QCRow createProfileRow(String title, Drawable iconDrawable,
            QCItem.ActionHandler actionHandler) {
        Icon icon = Icon.createWithBitmap(drawableToBitmap(iconDrawable));
        QCRow row = new QCRow.Builder()
                .setIcon(icon)
                .setIconTintable(false)
                .setTitle(title)
                .build();
        row.setActionHandler(actionHandler);
        return row;
    }

    private void switchUser(@UserIdInt int userId) {
        mContext.sendBroadcastAsUser(new Intent(Intent.ACTION_CLOSE_SYSTEM_DIALOGS),
                UserHandle.CURRENT);
        AsyncFuture<UserSwitchResult> userSwitchResultFuture =
                mCarUserManager.switchUser(userId);
        UserSwitchResult userSwitchResult;
        try {
            userSwitchResult = userSwitchResultFuture.get(TIMEOUT_MS, TimeUnit.MILLISECONDS);
        } catch (Exception e) {
            Log.w(TAG, "Could not switch user.", e);
            return;
        }
        if (userSwitchResult == null) {
            Log.w(TAG, "Timed out while switching user: " + TIMEOUT_MS + "ms");
        } else if (!userSwitchResult.isSuccess()) {
            Log.w(TAG, "Could not switch user: " + userSwitchResult);
        }
    }

    /**
     * Finds the existing Guest user, or creates one if it doesn't exist.
     *
     * @param context App context
     * @return UserInfo representing the Guest user
     */
    @Nullable
    private UserInfo createNewOrFindExistingGuest(Context context) {
        AsyncFuture<UserCreationResult> future = mCarUserManager.createGuest(
                context.getString(R.string.car_guest));
        // CreateGuest will return null if a guest already exists.
        UserInfo newGuest = getUserInfo(future);
        if (newGuest != null) {
            new UserIconProvider().assignDefaultIcon(
                    mUserManager, context.getResources(), newGuest);
            return newGuest;
        }
        return mUserManager.findCurrentGuestUser();
    }

    @Nullable
    private UserInfo getUserInfo(AsyncFuture<UserCreationResult> future) {
        UserCreationResult userCreationResult;
        try {
            userCreationResult = future.get(TIMEOUT_MS, TimeUnit.MILLISECONDS);
        } catch (Exception e) {
            Log.w(TAG, "Could not create user.", e);
            return null;
        }
        if (userCreationResult == null) {
            Log.w(TAG, "Timed out while creating user: " + TIMEOUT_MS + "ms");
            return null;
        }
        if (!userCreationResult.isSuccess() || userCreationResult.getUser() == null) {
            Log.w(TAG, "Could not create user: " + userCreationResult);
            return null;
        }
        return userCreationResult.getUser();
    }

    private RoundedBitmapDrawable getCircularAddUserIcon() {
        RoundedBitmapDrawable circleIcon = RoundedBitmapDrawableFactory.create(
                mContext.getResources(),
                UserIcons.convertToBitmap(mContext.getDrawable(R.drawable.car_add_circle_round)));
        circleIcon.setCircular(true);
        return circleIcon;
    }

    private int getMaxSupportedRealUsers() {
        int maxSupportedUsers = UserManager.getMaxSupportedUsers();
        if (UserManager.isHeadlessSystemUserMode()) {
            maxSupportedUsers -= 1;
        }
        List<UserInfo> users = mUserManager.getAliveUsers();
        // Count all users that are managed profiles of another user.
        int managedProfilesCount = 0;
        for (UserInfo user : users) {
            if (user.isManagedProfile()) {
                managedProfilesCount++;
            }
        }
        return maxSupportedUsers - managedProfilesCount;
    }

    private void showMaxUserLimitReachedDialog() {
        AlertDialog maxUsersDialog = new AlertDialog.Builder(mContext,
                com.android.internal.R.style.Theme_DeviceDefault_Dialog_Alert)
                .setTitle(R.string.profile_limit_reached_title)
                .setMessage(mContext.getResources().getQuantityString(
                        R.plurals.profile_limit_reached_message,
                        getMaxSupportedRealUsers(),
                        getMaxSupportedRealUsers()))
                .setPositiveButton(android.R.string.ok, null)
                .create();
        // Sets window flags for the SysUI dialog
        applyCarSysUIDialogFlags(maxUsersDialog);
        maxUsersDialog.show();
    }

    private void showConfirmAddUserDialog() {
        String message = mContext.getString(R.string.user_add_user_message_setup)
                .concat(System.getProperty("line.separator"))
                .concat(System.getProperty("line.separator"))
                .concat(mContext.getString(R.string.user_add_user_message_update));
        AlertDialog addUserDialog = new AlertDialog.Builder(mContext,
                com.android.internal.R.style.Theme_DeviceDefault_Dialog_Alert)
                .setTitle(R.string.user_add_profile_title)
                .setMessage(message)
                .setNegativeButton(android.R.string.cancel, null)
                .setPositiveButton(android.R.string.ok,
                        (dialog, which) -> new AddNewUserTask().execute(
                                mContext.getString(R.string.car_new_user)))
                .create();
        // Sets window flags for the SysUI dialog
        applyCarSysUIDialogFlags(addUserDialog);
        addUserDialog.show();
    }

    private void applyCarSysUIDialogFlags(AlertDialog dialog) {
        Window window = dialog.getWindow();
        window.setType(WindowManager.LayoutParams.TYPE_KEYGUARD_DIALOG);
        window.addFlags(WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM
                | WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);
        window.getAttributes().setFitInsetsTypes(
                window.getAttributes().getFitInsetsTypes() & ~statusBars());
    }

    private class AddNewUserTask extends AsyncTask<String, Void, UserInfo> {
        @Override
        protected UserInfo doInBackground(String... userNames) {
            AsyncFuture<UserCreationResult> future = mCarUserManager.createUser(userNames[0],
                    /* flags= */ 0);
            try {
                UserInfo user = getUserInfo(future);
                if (user != null) {
                    UserHelper.setDefaultNonAdminRestrictions(mContext, user,
                            /* enable= */ true);
                    UserHelper.assignDefaultIcon(mContext, user);
                    return user;
                } else {
                    Log.e(TAG, "Failed to create user in the background");
                    return user;
                }
            } catch (Exception e) {
                if (e instanceof InterruptedException) {
                    Thread.currentThread().interrupt();
                }
                Log.e(TAG, "Error creating new user: ", e);
            }
            return null;
        }

        @Override
        protected void onPreExecute() {
            mPendingUserAdd = true;
        }

        @Override
        protected void onPostExecute(UserInfo user) {
            mPendingUserAdd = false;
            if (user != null) {
                switchUser(user.id);
            }
        }
    }
}