using System.Collections;
using System.Collections.Generic;
using System.Linq;
using UnityEngine;
using Unity.VisualScripting;



#if UNITY_EDITOR
using UnityEditor;

[CustomEditor(typeof(SkillTreeManager))]
public class SkillTreeManagerEditor : Editor
{
    public override void OnInspectorGUI()
    {
        DrawDefaultInspector();
        if (GUILayout.Button("Generate"))
        {
            (target as SkillTreeManager).Generate();
        }
    }
}
#endif

public class SkillTreeManager : MonoBehaviour
{
    //[SerializeField]
    //private 
    [SerializeField]
    private float _lineColorVariation = 0.2f;
    [SerializeField]
    private float _lineOffset = 5f;
    [SerializeField]
    private float _lineThickness = 10f;
    [SerializeField]
    private Vector2 _startPositionOffset = new Vector2(200, 0);
    [SerializeField]
    Vector2 _distanceBetweenItems = Vector2.one * 200;
    [SerializeField]
    List<SkillTreeItem> _skillTreeItems;
    [SerializeField]
    GameObject _skillTreeItemPrefab;
    [SerializeField]
    GameObject _uiLineRendererPrefab;
    [SerializeField]
    GameObject _popUpConfigPrefab;
    [SerializeField]
    GameObject _skillTreeInfoItemPrefab;

    [SerializeField]
    Transform _nodeContainer;
    [SerializeField]
    Transform _lineContainer;

    private List<SkillTreeItemDisplay> DrawColumn(List<SkillTreeItem> items, List<SkillTreeItemDisplay> created)
    {
        var testList = new List<SkillSO>();
        var returnList = new List<SkillTreeItemDisplay>();
        var ancestors = items.Max(current => GetAncestorCount(current));
        for (int i = 0; i < items.Count; i++)
        {            
            var item = items[i];

            var comp = created.Find(x => x.Data == item);
            if (comp)
            {
                returnList.Add(comp);
                continue;
            }

            var x = _startPositionOffset.x + ancestors * _distanceBetweenItems.x;
            var y = _startPositionOffset.y + _distanceBetweenItems.y * i - (items.Count / 2) * _distanceBetweenItems.y;
            var pos = new Vector2(x, y);

            
            var instance = Instantiate(_skillTreeItemPrefab, _nodeContainer.transform);
            instance.GetComponent<RectTransform>().anchoredPosition = pos;
            comp = instance.GetComponent<SkillTreeItemDisplay>();
            comp.Data = item;
            comp._popUpConf = _popUpConfigPrefab;
            created.Add(comp);
            returnList.Add(comp);
        }
        return returnList;

        static int GetAncestorCount(SkillTreeItem item, int start = 0)
        {
            var max = start;
            foreach(var ancestor in item.Prerequisites)
            {
                var count = GetAncestorCount(ancestor, start + 1);
                if (count > max) max = count;
            }
            return max;
        }


    }

    private void Start()
    {
        Generate();
    }

    public void Generate()
    {
        foreach (Transform t in _nodeContainer) DestroyImmediate(t.gameObject);
        foreach (Transform t in _lineContainer) DestroyImmediate(t.gameObject);

        var dict = new Dictionary<int, HashSet<int>>();
        var created = new List<SkillTreeItemDisplay>();
        var choices = _skillTreeItems.FindAll(x => x.Prerequisites.Count <= 0);
        
        DrawColumn(choices, created);

        for (int i = 0; i < created.Count; i++)
        {
            var current = created[i];

            choices = _skillTreeItems.FindAll(x => x.Prerequisites.Contains(current.Data));
            if (choices.Count <= 0) continue;

            var column = DrawColumn(choices, created);
        }

        foreach (var node in created)
        {
            dict.TryAdd(node.Data.GetHashCode(), new());
            Vector2 colorVariation = new Vector2(Random.value - 0.5f, Random.value - 0.5f) * _lineColorVariation;
            var rect1 = node.GetComponent<RectTransform>();
            
            var prereqs = created.FindAll(x => x.Data.Prerequisites.Contains(node.Data));

            for (int p = 0; p < prereqs.Count; p++)
            {
                var prereq = prereqs[p];

                if (dict[node.Data.GetHashCode()].Contains(prereq.Data.GetHashCode())) continue;
                dict[node.Data.GetHashCode()].Add(prereq.Data.GetHashCode());

                var rect2 = prereq.GetComponent<RectTransform>();
                var delta = rect2.anchoredPosition - rect1.anchoredPosition;

                var lineObj = Instantiate(_uiLineRendererPrefab, _lineContainer);
                var line = lineObj.GetComponent<UILineRenderer>();

                node.RelatedLines.Add(line);
                prereq.RelatedLines.Add(line);

                line.points.Clear();
                line.points.Add(rect1.anchoredPosition + (p * _lineOffset - prereqs.Count * _lineOffset / 2) * Vector2.one);
                line.points.Add(rect1.anchoredPosition + (p * _lineOffset - prereqs.Count * _lineOffset / 2) * Vector2.one + Vector2.right * delta.x / 2);
                line.points.Add(rect2.anchoredPosition + (p * _lineOffset - prereqs.Count * _lineOffset / 2) * Vector2.one + Vector2.left * delta.x / 2);
                line.points.Add(rect2.anchoredPosition + (p * _lineOffset - prereqs.Count * _lineOffset / 2) * Vector2.one);
                line.transform.SetAsFirstSibling();

                Color.RGBToHSV(line.color, out float H, out float S, out float V);
                line.thickness = _lineThickness;
                line.color = Color.HSVToRGB(H, S + colorVariation.x, V + colorVariation.y);
            }
        }
    }
}