/*
 * Copyright (C) 2009 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 android.bluetooth;

import android.annotation.NonNull;
import android.annotation.Nullable;
import android.annotation.SystemApi;
import android.compat.annotation.UnsupportedAppUsage;
import android.os.ParcelUuid;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.util.Arrays;
import java.util.HashSet;
import java.util.UUID;

/**
 * Static helper methods and constants to decode the ParcelUuid of remote devices.
 *
 * @hide
 */
@SystemApi
public final class BluetoothUuid {

    /* See Bluetooth Assigned Numbers document - SDP section, to get the values of UUIDs
     * for the various services.
     *
     * The following 128 bit values are calculated as:
     *  uuid * 2^96 + BASE_UUID
     */

    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid A2DP_SINK =
            ParcelUuid.fromString("0000110B-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid A2DP_SOURCE =
            ParcelUuid.fromString("0000110A-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid ADV_AUDIO_DIST =
            ParcelUuid.fromString("0000110D-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid HSP =
            ParcelUuid.fromString("00001108-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid HSP_AG =
            ParcelUuid.fromString("00001112-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid HFP =
            ParcelUuid.fromString("0000111E-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid HFP_AG =
            ParcelUuid.fromString("0000111F-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid AVRCP_CONTROLLER =
            ParcelUuid.fromString("0000110E-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid AVRCP_TARGET =
            ParcelUuid.fromString("0000110C-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid OBEX_OBJECT_PUSH =
            ParcelUuid.fromString("00001105-0000-1000-8000-00805f9b34fb");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid HID =
            ParcelUuid.fromString("00001124-0000-1000-8000-00805f9b34fb");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid HOGP =
            ParcelUuid.fromString("00001812-0000-1000-8000-00805f9b34fb");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid PANU =
            ParcelUuid.fromString("00001115-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid NAP =
            ParcelUuid.fromString("00001116-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid BNEP =
            ParcelUuid.fromString("0000000f-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid PBAP_PCE =
            ParcelUuid.fromString("0000112e-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid PBAP_PSE =
            ParcelUuid.fromString("0000112f-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid MAP =
            ParcelUuid.fromString("00001134-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid MNS =
            ParcelUuid.fromString("00001133-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid MAS =
            ParcelUuid.fromString("00001132-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid SAP =
            ParcelUuid.fromString("0000112D-0000-1000-8000-00805F9B34FB");
    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid HEARING_AID =
            ParcelUuid.fromString("0000FDF0-0000-1000-8000-00805f9b34fb");

    /** @hide */
    @NonNull
    @SystemApi
    public static final ParcelUuid BASE_UUID =
            ParcelUuid.fromString("00000000-0000-1000-8000-00805F9B34FB");

    /**
     * Length of bytes for 16 bit UUID
     *
     * @hide
     */
    @SystemApi
    public static final int UUID_BYTES_16_BIT = 2;
    /**
     * Length of bytes for 32 bit UUID
     *
     * @hide
     */
    @SystemApi
    public static final int UUID_BYTES_32_BIT = 4;
    /**
     * Length of bytes for 128 bit UUID
     *
     * @hide
     */
    @SystemApi
    public static final int UUID_BYTES_128_BIT = 16;

    /**
     * Returns true if there any common ParcelUuids in uuidA and uuidB.
     *
     * @param uuidA - List of ParcelUuids
     * @param uuidB - List of ParcelUuids
     *
     * @hide
     */
    @SystemApi
    public static boolean containsAnyUuid(@Nullable ParcelUuid[] uuidA,
            @Nullable ParcelUuid[] uuidB) {
        if (uuidA == null && uuidB == null) return true;

        if (uuidA == null) {
            return uuidB.length == 0;
        }

        if (uuidB == null) {
            return uuidA.length == 0;
        }

        HashSet<ParcelUuid> uuidSet = new HashSet<ParcelUuid>(Arrays.asList(uuidA));
        for (ParcelUuid uuid : uuidB) {
            if (uuidSet.contains(uuid)) return true;
        }
        return false;
    }

    /**
     * Extract the Service Identifier or the actual uuid from the Parcel Uuid.
     * For example, if 0000110B-0000-1000-8000-00805F9B34FB is the parcel Uuid,
     * this function will return 110B
     *
     * @param parcelUuid
     * @return the service identifier.
     */
    private static int getServiceIdentifierFromParcelUuid(ParcelUuid parcelUuid) {
        UUID uuid = parcelUuid.getUuid();
        long value = (uuid.getMostSignificantBits() & 0xFFFFFFFF00000000L) >>> 32;
        return (int) value;
    }

    /**
     * Parse UUID from bytes. The {@code uuidBytes} can represent a 16-bit, 32-bit or 128-bit UUID,
     * but the returned UUID is always in 128-bit format.
     * Note UUID is little endian in Bluetooth.
     *
     * @param uuidBytes Byte representation of uuid.
     * @return {@link ParcelUuid} parsed from bytes.
     * @throws IllegalArgumentException If the {@code uuidBytes} cannot be parsed.
     *
     * @hide
     */
    @NonNull
    @SystemApi
    public static ParcelUuid parseUuidFrom(@Nullable byte[] uuidBytes) {
        if (uuidBytes == null) {
            throw new IllegalArgumentException("uuidBytes cannot be null");
        }
        int length = uuidBytes.length;
        if (length != UUID_BYTES_16_BIT && length != UUID_BYTES_32_BIT
                && length != UUID_BYTES_128_BIT) {
            throw new IllegalArgumentException("uuidBytes length invalid - " + length);
        }

        // Construct a 128 bit UUID.
        if (length == UUID_BYTES_128_BIT) {
            ByteBuffer buf = ByteBuffer.wrap(uuidBytes).order(ByteOrder.LITTLE_ENDIAN);
            long msb = buf.getLong(8);
            long lsb = buf.getLong(0);
            return new ParcelUuid(new UUID(msb, lsb));
        }

        // For 16 bit and 32 bit UUID we need to convert them to 128 bit value.
        // 128_bit_value = uuid * 2^96 + BASE_UUID
        long shortUuid;
        if (length == UUID_BYTES_16_BIT) {
            shortUuid = uuidBytes[0] & 0xFF;
            shortUuid += (uuidBytes[1] & 0xFF) << 8;
        } else {
            shortUuid = uuidBytes[0] & 0xFF;
            shortUuid += (uuidBytes[1] & 0xFF) << 8;
            shortUuid += (uuidBytes[2] & 0xFF) << 16;
            shortUuid += (uuidBytes[3] & 0xFF) << 24;
        }
        long msb = BASE_UUID.getUuid().getMostSignificantBits() + (shortUuid << 32);
        long lsb = BASE_UUID.getUuid().getLeastSignificantBits();
        return new ParcelUuid(new UUID(msb, lsb));
    }

    /**
     * Parse UUID to bytes. The returned value is shortest representation, a 16-bit, 32-bit or
     * 128-bit UUID, Note returned value is little endian (Bluetooth).
     *
     * @param uuid uuid to parse.
     * @return shortest representation of {@code uuid} as bytes.
     * @throws IllegalArgumentException If the {@code uuid} is null.
     *
     * @hide
     */
    public static byte[] uuidToBytes(ParcelUuid uuid) {
        if (uuid == null) {
            throw new IllegalArgumentException("uuid cannot be null");
        }

        if (is16BitUuid(uuid)) {
            byte[] uuidBytes = new byte[UUID_BYTES_16_BIT];
            int uuidVal = getServiceIdentifierFromParcelUuid(uuid);
            uuidBytes[0] = (byte) (uuidVal & 0xFF);
            uuidBytes[1] = (byte) ((uuidVal & 0xFF00) >> 8);
            return uuidBytes;
        }

        if (is32BitUuid(uuid)) {
            byte[] uuidBytes = new byte[UUID_BYTES_32_BIT];
            int uuidVal = getServiceIdentifierFromParcelUuid(uuid);
            uuidBytes[0] = (byte) (uuidVal & 0xFF);
            uuidBytes[1] = (byte) ((uuidVal & 0xFF00) >> 8);
            uuidBytes[2] = (byte) ((uuidVal & 0xFF0000) >> 16);
            uuidBytes[3] = (byte) ((uuidVal & 0xFF000000) >> 24);
            return uuidBytes;
        }

        // Construct a 128 bit UUID.
        long msb = uuid.getUuid().getMostSignificantBits();
        long lsb = uuid.getUuid().getLeastSignificantBits();

        byte[] uuidBytes = new byte[UUID_BYTES_128_BIT];
        ByteBuffer buf = ByteBuffer.wrap(uuidBytes).order(ByteOrder.LITTLE_ENDIAN);
        buf.putLong(8, msb);
        buf.putLong(0, lsb);
        return uuidBytes;
    }

    /**
     * Check whether the given parcelUuid can be converted to 16 bit bluetooth uuid.
     *
     * @param parcelUuid
     * @return true if the parcelUuid can be converted to 16 bit uuid, false otherwise.
     *
     * @hide
     */
    @UnsupportedAppUsage
    public static boolean is16BitUuid(ParcelUuid parcelUuid) {
        UUID uuid = parcelUuid.getUuid();
        if (uuid.getLeastSignificantBits() != BASE_UUID.getUuid().getLeastSignificantBits()) {
            return false;
        }
        return ((uuid.getMostSignificantBits() & 0xFFFF0000FFFFFFFFL) == 0x1000L);
    }


    /**
     * Check whether the given parcelUuid can be converted to 32 bit bluetooth uuid.
     *
     * @param parcelUuid
     * @return true if the parcelUuid can be converted to 32 bit uuid, false otherwise.
     *
     * @hide
     */
    @UnsupportedAppUsage
    public static boolean is32BitUuid(ParcelUuid parcelUuid) {
        UUID uuid = parcelUuid.getUuid();
        if (uuid.getLeastSignificantBits() != BASE_UUID.getUuid().getLeastSignificantBits()) {
            return false;
        }
        if (is16BitUuid(parcelUuid)) {
            return false;
        }
        return ((uuid.getMostSignificantBits() & 0xFFFFFFFFL) == 0x1000L);
    }

    private BluetoothUuid() {}
}