scrcpy/server/src/main/java/com/genymobile/scrcpy/DeviceMessage.java

package com.genymobile.scrcpy;

import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;

public abstract class DeviceMessage {
    private static final int MESSAGE_MAX_SIZE = 1 << 18; // 256k
    public static final int MAX_EVENT_SIZE = 4096;
    public static final int TYPE_CLIPBOARD = 0;
    public static final int TYPE_PUSH_RESPONSE = 101;

    public static final int TYPE_ACK_CLIPBOARD = 1;
    public static final int TYPE_UHID_OUTPUT = 2;

    private int type;
    private String text;
    private long sequence;
    private int id;
    private byte[] data;

    private DeviceMessage(int type) {
        this.type = type;
    }

    private DeviceMessage(int type, int sequence) {
        this.type = type;
        this.sequence = sequence;
    }

    private static final class ClipboardMessage extends DeviceMessage {
        public static final int CLIPBOARD_TEXT_MAX_LENGTH = MESSAGE_MAX_SIZE - 5; // type: 1 byte; length: 4 bytes
        private byte[] raw;
        private int len;
        private ClipboardMessage(String text) {
            super(TYPE_CLIPBOARD);
            this.raw = text.getBytes(StandardCharsets.UTF_8);
            this.len = StringUtils.getUtf8TruncationIndex(raw, CLIPBOARD_TEXT_MAX_LENGTH);
        }

        private ClipboardMessage(long sequence) {
            super(TYPE_ACK_CLIPBOARD);
        }

        public void writeToByteArray(byte[] array, int offset) {
            ByteBuffer buffer = ByteBuffer.wrap(array, offset, array.length - offset);
            buffer.put((byte) this.getType());
            buffer.putInt(len);
            buffer.put(raw, 0, len);
        }
        public int getLen() {
            return 5 + len;
        }
    }

    private static final class FilePushResponseMessage extends DeviceMessage {
        private short id;
        private int result;

        private FilePushResponseMessage(short id, int result) {
            super(TYPE_PUSH_RESPONSE);
            this.id = id;
            this.result = result;
        }

        @Override
        public void writeToByteArray(byte[] array, int offset) {
            ByteBuffer buffer = ByteBuffer.wrap(array, offset, array.length - offset);
            buffer.put((byte) this.getType());
            buffer.putShort(id);
            buffer.put((byte) result);
        }

        @Override
        public int getLen() {
            return 4;
        }
    }

    public static DeviceMessage createClipboard(String text) {
        return new ClipboardMessage(text);
    }

    public static DeviceMessage createPushResponse(short id, int result) {
        return new FilePushResponseMessage(id, result);
    }

    public static DeviceMessage createAckClipboard(long sequence) {
        return new ClipboardMessage(sequence);
    }

    // public static DeviceMessage createUhidOutput(int id, byte[] data) {
    //     // DeviceMessage event = new DeviceMessage();
    //     // event.type = TYPE_UHID_OUTPUT;
    //     // event.id = id;
    //     // event.data = data;
    //     // return event;
    // }

    public int getType() {
        return type;
    }

    public void writeToByteArray(byte[] array) {
        writeToByteArray(array, 0);
    }

    public byte[] writeToByteArray(int offset) {
        byte[] temp = new byte[offset + this.getLen()];
        writeToByteArray(temp, offset);
        return temp;
    }
    
    public abstract void writeToByteArray(byte[] array, int offset);
    public abstract int getLen();

    public long getSequence() {
        return sequence;
    }

    public int getId() {
        return id;
    }

    public byte[] getData() {
        return data;
    }
}