using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

namespace OTGIntegrated.Dialogue
{
    public sealed class DialogueUI : MonoBehaviour
    {
        public GameObject panelRoot;
        public Text speakerText;
        public Text lineText;
        public Transform responseRoot;
        public Button closeButton;
        public Font uiFont;

        private readonly List<GameObject> spawnedResponses = new List<GameObject>();

        private void Awake()
        {
            ConfigureResponseLayout();

            if (closeButton != null)
            {
                closeButton.onClick.RemoveAllListeners();
                closeButton.onClick.AddListener(() => FindObjectOfType<DialogueManager>()?.EndDialogue());
            }

            Hide();
        }

        public void Show(string speaker, string line, IReadOnlyList<DialogueChoice> choices)
        {
            if (panelRoot != null)
            {
                panelRoot.SetActive(true);
            }

            if (speakerText != null)
            {
                speakerText.text = speaker;
            }

            if (lineText != null)
            {
                lineText.text = line;
            }

            ClearResponses();
            if (choices == null || responseRoot == null)
            {
                return;
            }

            for (int i = 0; i < choices.Count; i++)
            {
                CreateChoiceButton(choices[i]);
            }
        }

        public void Hide()
        {
            ClearResponses();
            if (panelRoot != null)
            {
                panelRoot.SetActive(false);
            }
        }

        private void CreateChoiceButton(DialogueChoice choice)
        {
            if (choice == null)
            {
                return;
            }

            GameObject root = new GameObject("DialogueChoice", typeof(RectTransform), typeof(Image), typeof(Button));
            root.transform.SetParent(responseRoot, false);
            spawnedResponses.Add(root);
            root.GetComponent<RectTransform>().sizeDelta = new Vector2(0f, 42f);
            LayoutElement layoutElement = root.AddComponent<LayoutElement>();
            layoutElement.preferredHeight = 42f;
            layoutElement.minHeight = 42f;
            layoutElement.flexibleWidth = 1f;
            root.GetComponent<Image>().color = new Color(0.11f, 0.14f, 0.18f, 0.94f);

            Text label = CreateText(root.transform, "Text", choice.Text, 16, TextAnchor.MiddleLeft);
            label.rectTransform.anchorMin = Vector2.zero;
            label.rectTransform.anchorMax = Vector2.one;
            label.rectTransform.offsetMin = new Vector2(14f, 0f);
            label.rectTransform.offsetMax = new Vector2(-8f, 0f);

            Button button = root.GetComponent<Button>();
            button.onClick.AddListener(() => choice.Callback?.Invoke());
        }

        private void ConfigureResponseLayout()
        {
            if (responseRoot == null)
            {
                return;
            }

            VerticalLayoutGroup layout = responseRoot.GetComponent<VerticalLayoutGroup>();
            if (layout == null)
            {
                return;
            }

            layout.childControlWidth = true;
            layout.childForceExpandWidth = true;
            layout.childControlHeight = false;
            layout.childForceExpandHeight = false;
        }

        private Text CreateText(Transform parent, string name, string value, int fontSize, TextAnchor anchor)
        {
            GameObject textObject = new GameObject(name, typeof(RectTransform), typeof(Text));
            textObject.transform.SetParent(parent, false);
            Text text = textObject.GetComponent<Text>();
            text.font = uiFont != null ? uiFont : Resources.GetBuiltinResource<Font>("Arial.ttf");
            text.fontSize = fontSize;
            text.alignment = anchor;
            text.color = new Color(0.94f, 0.93f, 0.88f, 1f);
            text.text = value;
            return text;
        }

        private void ClearResponses()
        {
            for (int i = 0; i < spawnedResponses.Count; i++)
            {
                if (spawnedResponses[i] != null)
                {
                    Destroy(spawnedResponses[i]);
                }
            }

            spawnedResponses.Clear();
        }
    }
}