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

public class Constellation : MonoBehaviour
{
    [Header("Режим малювання")]
    public bool editMode = false;
    [Header("Максимальна кількіссть зірок")]
    public int maxStars = 10;

    [Header("Матеріали")]
    [SerializeField] private GameObject starPrefab;
    [SerializeField] private Material lineMaterial;

    [Header("Відстань")]
    [SerializeField] private float planeDistance = 8f;

    [Header("Розміри")]
    [SerializeField] private float starScaleMin = 0.06f;
    [SerializeField] private float starScaleMax = 0.14f;
    [SerializeField] private float lineWidth = 0.02f;

    private readonly List<Transform> _stars = new List<Transform>();
    private readonly List<LineRenderer> _lines = new List<LineRenderer>();

    private Transform _root;
    private Camera _cam;

    private void Awake()
    {
        EnsureCameraAndRoot();
    }

    private void Update()
    {
        if (!editMode) return;

        EnsureCameraAndRoot();

        if (_cam == null)
        {
            return;
        }

        if (Input.GetMouseButtonDown(0))
        {
            TryAddStarByClick(Input.mousePosition);
        }

        UpdateAllLines();
    }

    private void EnsureCameraAndRoot()
    {
        if (_cam == null || !_cam.enabled)
        {
            _cam = FindEnabledCamera();
        }

        if (_cam != null && (_root == null || _root.parent != _cam.transform))
        {
            if (_root == null)
            {
                GameObject go = new GameObject("ConstellationRoot");
                _root = go.transform;
            }

            _root.SetParent(_cam.transform);
            _root.localPosition = new Vector3(0f, 0f, planeDistance);
            _root.localRotation = Quaternion.identity;
            _root.localScale = Vector3.one;
        }
    }

    private Camera FindEnabledCamera()
    {
        Camera[] cams = Camera.allCameras;
        for (int i = 0; i < cams.Length; i++)
        {
            if (cams[i] != null && cams[i].enabled && cams[i].gameObject.activeInHierarchy)
                return cams[i];
        }

        if (Camera.main != null && Camera.main.enabled)
            return Camera.main;

        return null;
    }

    private void TryAddStarByClick(Vector3 screenPos)
    {
        Ray ray = _cam.ScreenPointToRay(screenPos);

        Plane plane = new Plane(_cam.transform.forward, _cam.transform.position + _cam.transform.forward * planeDistance);

        if (!plane.Raycast(ray, out float enter))
        {
            return;
        }

        Vector3 worldHit = ray.GetPoint(enter);
        Vector3 localHit = _root.InverseTransformPoint(worldHit);

        GameObject starGo = Instantiate(starPrefab, _root);
        starGo.name = "Star_" + _stars.Count;

        Transform starT = starGo.transform;
        starT.localPosition = localHit;

        float rndScale = Random.Range(starScaleMin, starScaleMax);
        starT.localScale = Vector3.one * rndScale;

        _stars.Add(starT);

        if (_stars.Count >= 2)
        {
            CreateLine(_stars[_stars.Count - 2], _stars[_stars.Count - 1]);
        }
    }

    private void CreateLine(Transform a, Transform b)
    {
        if (a == null || b == null) return;

        GameObject lineGo = new GameObject("Line_" + _lines.Count);
        lineGo.transform.SetParent(_root);
        lineGo.transform.localPosition = Vector3.zero;
        lineGo.transform.localRotation = Quaternion.identity;
        lineGo.transform.localScale = Vector3.one;

        LineRenderer lr = lineGo.AddComponent<LineRenderer>();

        if (lineMaterial != null)
        {
            lr.material = lineMaterial;
        }
        else
        {
            Material fallback = new Material(Shader.Find("Unlit/Color"));
            fallback.color = new Color(0.7f, 0.85f, 1f, 1f);
            lr.material = fallback;
        }

        lr.useWorldSpace = false;
        lr.positionCount = 2;
        lr.startWidth = lineWidth;
        lr.endWidth = lineWidth;

        lr.numCapVertices = 6;
        lr.numCornerVertices = 6;

        _lines.Add(lr);

        lr.SetPosition(0, a.localPosition);
        lr.SetPosition(1, b.localPosition);
    }

    private void UpdateAllLines()
    {
        int needed = Mathf.Max(0, _stars.Count - 1);
        if (_lines.Count < needed) return;

        for (int i = 0; i < needed; i++)
        {
            LineRenderer lr = _lines[i];
            if (lr == null) continue;

            Transform a = _stars[i];
            Transform b = _stars[i + 1];

            if (a == null || b == null) continue;

            lr.SetPosition(0, a.localPosition);
            lr.SetPosition(1, b.localPosition);
        }
    }

    public void ClearAll()
    {
        for (int i = 0; i < _lines.Count; i++)
        {
            if (_lines[i] != null) Destroy(_lines[i].gameObject);
        }

        for (int i = 0; i < _stars.Count; i++)
        {
            if (_stars[i] != null) Destroy(_stars[i].gameObject);
        }

        _lines.Clear();
        _stars.Clear();

    }

}