/*
 * Copyright (C) 2015 The Android Open Source Project
 * Copyright (C) 2024 The LineageOS 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.messaging.util;

import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.os.UserHandle;
import android.os.UserManager;

import com.android.messaging.Factory;

import java.util.ArrayList;
import java.util.Hashtable;
import java.util.Set;

/**
 * Android OS version utilities
 */
public class OsUtil {

    private static Boolean sIsSecondaryUser = null;

    public static boolean isSecondaryUser() {
        if (sIsSecondaryUser == null) {
            final Context context = Factory.get().getApplicationContext();
            boolean isSecondaryUser = false;

            final UserHandle uh = android.os.Process.myUserHandle();
            final UserManager userManager =
                    (UserManager) context.getSystemService(Context.USER_SERVICE);
            if (userManager != null) {
                final long userSerialNumber = userManager.getSerialNumberForUser(uh);
                isSecondaryUser = (0 != userSerialNumber);
            }
            sIsSecondaryUser = isSecondaryUser;
        }
        return sIsSecondaryUser;
    }

    /**
     * Creates a joined string from a Set<String> using the given delimiter.
     * @param values
     * @param delimiter
     * @return
     */
    public static String joinFromSetWithDelimiter(
            final Set<String> values, final String delimiter) {
        if (values != null) {
            final StringBuilder joinedStringBuilder = new StringBuilder();
            boolean firstValue = true;
            for (final String value : values) {
                if (firstValue) {
                    firstValue = false;
                } else {
                    joinedStringBuilder.append(delimiter);
                }
                joinedStringBuilder.append(value);
            }
            return joinedStringBuilder.toString();
        }
        return null;
    }

    private static final Hashtable<String, Integer> sPermissions = new Hashtable<String, Integer>();

    /**
     * Check if the app has the specified permission. If it does not, the app needs to use
     * {@link android.app.Activity#requestPermission}. Note that if it
     * returns true, it cannot return false in the same process as the OS kills the process when
     * any permission is revoked.
     * @param permission A permission from {@link android.Manifest.permission}
     */
    public static boolean hasPermission(final String permission) {
        // It is safe to cache the PERMISSION_GRANTED result as the process gets killed if the
        // user revokes the permission setting. However, PERMISSION_DENIED should not be
        // cached as the process does not get killed if the user enables the permission setting.
        if (!sPermissions.containsKey(permission)
                || sPermissions.get(permission) == PackageManager.PERMISSION_DENIED) {
            final Context context = Factory.get().getApplicationContext();
            final int permissionState = context.checkSelfPermission(permission);
            sPermissions.put(permission, permissionState);
        }
        return sPermissions.get(permission) == PackageManager.PERMISSION_GRANTED;
    }

    /** Does the app have all the specified permissions */
    public static boolean hasPermissions(final String[] permissions) {
        for (final String permission : permissions) {
            if (!hasPermission(permission)) {
                return false;
            }
        }
        return true;
    }

    public static boolean hasPhonePermission() {
        return hasPermission(Manifest.permission.READ_PHONE_STATE);
    }

    public static boolean hasSmsPermission() {
        return hasPermission(Manifest.permission.READ_SMS);
    }

    public static boolean hasLocationPermission() {
        return OsUtil.hasPermission(Manifest.permission.ACCESS_FINE_LOCATION);
    }


    public static boolean hasStoragePermission() {
        // Note that READ_EXTERNAL_STORAGE and WRITE_EXTERNAL_STORAGE are granted or denied
        // together.
        return OsUtil.hasPermission(Manifest.permission.READ_EXTERNAL_STORAGE);
    }

    public static boolean hasRecordAudioPermission() {
        return OsUtil.hasPermission(Manifest.permission.RECORD_AUDIO);
    }

    /**
     * Returns array with the set of permissions that have not been granted from the given set.
     * The array will be empty if the app has all of the specified permissions. Note that calling
     * {@link Activity#requestPermissions} for an already granted permission can prompt the user
     * again, and its up to the app to only request permissions that are missing.
     */
    public static String[] getMissingPermissions(final String[] permissions) {
        final ArrayList<String> missingList = new ArrayList<String>();
        for (final String permission : permissions) {
            if (!hasPermission(permission)) {
                missingList.add(permission);
            }
        }

        final String[] missingArray = new String[missingList.size()];
        missingList.toArray(missingArray);
        return missingArray;
    }

    private static final String[] sRequiredPermissions = new String[] {
        // Required to read existing SMS threads
        Manifest.permission.READ_SMS,
        // Required for knowing the phone number, number of SIMs, etc.
        Manifest.permission.READ_PHONE_STATE,
        // This is not strictly required, but simplifies the contact picker scenarios
        Manifest.permission.READ_CONTACTS,
    };

    /** Does the app have the minimum set of permissions required to operate. */
    public static boolean hasRequiredPermissions() {
        return hasPermissions(sRequiredPermissions);
    }

    public static String[] getMissingRequiredPermissions() {
        return getMissingPermissions(sRequiredPermissions);
    }
}