ChatBot.cs

using UnityEngine;
using System.Collections.Generic;
using System.Threading.Tasks;
using LLMUnity;

namespace LLMUnitySamples
{
    public class ChatBot : MonoBehaviour
    {
        public Transform chatContainer;
        public Color playerColor = new Color32(81, 164, 81, 255);
        public Color aiColor = new Color32(29, 29, 73, 255);
        public Color fontColor = Color.white;
        public Font font;
        public int fontSize = 16;
        public int bubbleWidth = 600;
        public LLMClient llm;
        public float textPadding = 10f;
        public float bubbleSpacing = 10f;
        public Sprite sprite;

        private InputBubble inputBubble;
        private List<Bubble> chatBubbles = new List<Bubble>();
        private bool blockInput = true;
        private BubbleUI playerUI, aiUI;
        private bool updatePositions = false;
        private bool warmUpDone = false;

        void Start()
        {
            if (font == null) font =  Resources.GetBuiltinResource<Font>("LegacyRuntime.ttf");
            playerUI = new BubbleUI {
                sprite=sprite,
                font=font,
                fontSize=fontSize,
                fontColor=fontColor,
                bubbleColor=playerColor,
                bottomPosition=0,
                leftPosition=0,
                textPadding=textPadding,
                bubbleOffset=bubbleSpacing,
                bubbleWidth=bubbleWidth,
                bubbleHeight=-1
            };
            aiUI = playerUI;
            aiUI.bubbleColor = aiColor;
            aiUI.leftPosition = 1;
            
            inputBubble = new InputBubble(chatContainer, playerUI, "InputBubble", "Loading...", 4);
            inputBubble.AddSubmitListener(onInputFieldSubmit);
            inputBubble.AddValueChangedListener(onValueChanged);
            inputBubble.setInteractable(false);
            _ = llm.Warmup(WarmUpCallback);
        }

        void onInputFieldSubmit(string newText){
            inputBubble.ActivateInputField();
            if (blockInput || newText.Trim() == "" || Input.GetKey(KeyCode.LeftShift) || Input.GetKey(KeyCode.RightShift)){
                StartCoroutine(BlockInteraction());
                return;
            }
            blockInput = true;
            // replace vertical_tab
            string message = inputBubble.GetText().Replace("\v", "\n");

            Bubble playerBubble = new Bubble(chatContainer, playerUI, "PlayerBubble", message);
            Bubble aiBubble = new Bubble(chatContainer, aiUI, "AIBubble", "...");
            chatBubbles.Add(playerBubble);
            chatBubbles.Add(aiBubble);
            SetUpdatePositions();

            BubbleTextSetter aiBubbleTextSetter = new BubbleTextSetter(this, aiBubble);
            Task chatTask = llm.Chat(message, aiBubbleTextSetter.SetText, AllowInput);

            inputBubble.SetText("");
        }

        public void WarmUpCallback(){
            warmUpDone = true;
            inputBubble.SetPlaceHolderText("Message me");
            AllowInput();
        }

        public void AllowInput(){
            blockInput = false;
            inputBubble.ReActivateInputField();
        }

        IEnumerator<string> BlockInteraction()
        {
            // prevent from change until next frame
            inputBubble.setInteractable(false);
            yield return null;
            inputBubble.setInteractable(true);
            // change the caret position to the end of the text
            inputBubble.MoveTextEnd();
        }

        void onValueChanged(string newText){
            // Get rid of newline character added when we press enter
            if (Input.GetKey(KeyCode.Return)){
                if(inputBubble.GetText().Trim() == "")
                    inputBubble.SetText("");
            }
        }

        public void SetUpdatePositions(){
            updatePositions = true;
        }

        public void UpdateBubblePositions()
        {
            float y = inputBubble.GetSize().y + inputBubble.GetRectTransform().offsetMin.y + bubbleSpacing;
            int lastBubbleOutsideFOV = -1;
            float containerHeight = chatContainer.GetComponent<RectTransform>().rect.height;
            for (int i = chatBubbles.Count - 1; i >= 0; i--) {
                Bubble bubble = chatBubbles[i];
                RectTransform childRect = bubble.GetRectTransform();
                childRect.anchoredPosition = new Vector2(childRect.anchoredPosition.x, y);

                // last bubble outside the container
                if (y > containerHeight && lastBubbleOutsideFOV == -1){
                    lastBubbleOutsideFOV = i;
                }
                y += bubble.GetSize().y + bubbleSpacing;
            }
            // destroy bubbles outside the container
            for (int i = 0; i <= lastBubbleOutsideFOV; i++) {
                chatBubbles[i].Destroy();
            }
            chatBubbles.RemoveRange(0, lastBubbleOutsideFOV+1);
        }

        void Update()
        {
            if(!inputBubble.inputFocused() && warmUpDone)
            {
                inputBubble.ActivateInputField();
                StartCoroutine(BlockInteraction());
            }
            if(updatePositions){
                UpdateBubblePositions();
                updatePositions=false;
            }
        }
    }
}