using System;
using System.Collections.Generic;
using System.Linq;
using UnityEditor;

namespace UnityEngine.Perception.GroundTruth {
    /// <summary>
    /// A definition for how a <see cref="Labeling"/> should be resolved to a single label and color for semantic segmentation generation.
    /// </summary>
    [CreateAssetMenu(fileName = "SemanticSegmentationLabelConfig", menuName = "Perception/Semantic Segmentation Label Config", order = 1)]
    public class SemanticSegmentationLabelConfig : LabelConfig<SemanticSegmentationLabelEntry>
    {
        public static readonly List<Color> s_StandardColors = new List<Color>()
        {
            Color.blue,
            Color.green,
            Color.red,
            Color.white,
            Color.yellow,
            Color.gray
        };

        public override void AddLabel(string labelToAdd)
        {
            m_LabelEntries.Add(new SemanticSegmentationLabelEntry
            {
                label = labelToAdd,
                color = FindNewColor()
            });
        }

        Color FindNewColor()
        {
            var standardColorList = new List<Color>(s_StandardColors);
            foreach (var item in m_LabelEntries)
            {
                standardColorList.Remove(item.color);
            }
            if (standardColorList.Any())
                return standardColorList.First();

            return Random.ColorHSV(0, 1, .5f, 1, 1, 1);
        }
    }

    /// <summary>
    /// LabelEntry for <see cref="SemanticSegmentationLabelConfig"/>. Maps a label to a color.
    /// </summary>
    [Serializable]
    public struct SemanticSegmentationLabelEntry : ILabelEntry
    {
        string ILabelEntry.label => this.label;
        /// <summary>
        /// The label this entry should match.
        /// </summary>
        public string label;
        /// <summary>
        /// The color to be drawn in the semantic segmentation image
        /// </summary>
        public Color color;
    }
}