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

namespace Amanotes.Core
{
    partial class Widget2D // ComputedRects
    {
        [FormerlySerializedAs("_derivedRects")]
        [SerializeField] internal List<ComputedRect> _computedRects = new List<ComputedRect>();

        internal void ComputeAllRects()
        {
            if (_computedRects == null || _computedRects.Count == 0) return;

            var srcSize = (Vector2)_size;
            var srcPivot = _size.pivot;

            for (int i = 0; i < _computedRects.Count; i++)
            {
                var dr = _computedRects[i];
                if (dr == null) continue;
                dr.Compute(srcSize, srcPivot);
            }
        }

        /// <summary>
        /// Get the computed rect by ID.
        /// Returns the source rect (centered on pivot) if id is null/empty or not found.
        /// </summary>
        public Rect GetRect(string id)
        {
            if (string.IsNullOrEmpty(id)) return GetSourceRect();

            for (int i = 0; i < _computedRects.Count; i++)
            {
                var dr = _computedRects[i];
                if (dr != null && dr.id == id) return dr.cachedRect;
            }

            return GetSourceRect();
        }

        /// <summary>
        /// Get the computed size of a rect by ID.
        /// Returns source size if id is null/empty or not found.
        /// </summary>
        public Vector2 GetRectSize(string id)
        {
            if (string.IsNullOrEmpty(id)) return _size;

            for (int i = 0; i < _computedRects.Count; i++)
            {
                var dr = _computedRects[i];
                if (dr != null && dr.id == id) return dr.cachedRect.size;
            }

            return _size;
        }

        /// <summary>
        /// Get the ComputedRect definition by ID (for runtime param mutation).
        /// </summary>
        public ComputedRect GetComputedRect(string id)
        {
            if (string.IsNullOrEmpty(id)) return null;

            for (int i = 0; i < _computedRects.Count; i++)
            {
                var dr = _computedRects[i];
                if (dr != null && dr.id == id) return dr;
            }

            return null;
        }

        [System.Obsolete("Use GetComputedRect instead")]
        public ComputedRect GetDerivedRectDef(string id) => GetComputedRect(id);

        public void AddComputedRect(ComputedRect rect)
        {
            if (rect == null) return;
            _computedRects ??= new List<ComputedRect>();
            _computedRects.Add(rect);
        }

        [System.Obsolete("Use AddComputedRect instead")]
        public void AddDerivedRect(ComputedRect rect) => AddComputedRect(rect);

        /// <summary>
        /// Collects all computed rect IDs into the provided list (for editor dropdown).
        /// </summary>
        internal void GetComputedRectIds(List<string> ids)
        {
            ids.Clear();
            if (_computedRects == null) return;
            for (int i = 0; i < _computedRects.Count; i++)
            {
                var dr = _computedRects[i];
                if (dr != null && !string.IsNullOrEmpty(dr.id))
                    ids.Add(dr.id);
            }
        }

        private Rect GetSourceRect()
        {
            var s = (Vector2)_size;
            var p = _size.pivot;
            return new Rect(-p.x * s.x, -p.y * s.y, s.x, s.y);
        }

#if UNITY_EDITOR
        private static readonly Color[] _rectColors = {
            new Color(0.2f, 0.8f, 0.4f, 0.8f),
            new Color(0.3f, 0.6f, 0.9f, 0.8f),
            new Color(0.9f, 0.5f, 0.2f, 0.8f),
            new Color(0.8f, 0.2f, 0.7f, 0.8f),
            new Color(0.9f, 0.9f, 0.2f, 0.8f),
        };

        internal void DrawComputedRectGizmos()
        {
            if (_computedRects == null || _computedRects.Count == 0) return;

            var srcSize = (Vector2)_size;
            var srcPivot = _size.pivot;
            var t = transform;

            for (int i = 0; i < _computedRects.Count; i++)
            {
                var dr = _computedRects[i];
                if (dr == null || string.IsNullOrEmpty(dr.id)) continue;

                var rect = dr.Compute(srcSize, srcPivot);
                var color = _rectColors[i % _rectColors.Length];
                Gizmos.color = color;

                var center = new Vector3(rect.x + rect.width * 0.5f, rect.y + rect.height * 0.5f, 0f);
                var size3 = _size.useZ
                    ? new Vector3(rect.width, 0f, rect.height)
                    : new Vector3(rect.width, rect.height, 0f);

                var worldCenter = t.TransformPoint(_size.useZ
                    ? new Vector3(center.x, 0f, center.y)
                    : center);

                Gizmos.matrix = Matrix4x4.TRS(worldCenter, t.rotation, Vector3.one);
                Gizmos.DrawWireCube(Vector3.zero, size3);
            }

            Gizmos.matrix = Matrix4x4.identity;
        }
#endif
    }
}