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

namespace UnityEngine.Perception.GroundTruth
{
    [Serializable]
    public struct IdLabelEntry : ILabelEntry
    {
        string ILabelEntry.label => this.label;
        public string label;
        public int id;
    }
    /// <summary>
    /// A definition for how a <see cref="Labeling"/> should be resolved to a single label and id for ground truth generation.
    /// </summary>
    [CreateAssetMenu(fileName = "IdLabelingConfiguration", menuName = "Perception/ID Labeling Configuration", order = 1)]
    public class IdLabelConfig : LabelingConfiguration2<IdLabelEntry>
    {
    }

    [Serializable]
    public struct SemanticSegmentationLabelEntry : ILabelEntry
    {
        string ILabelEntry.label => this.label;
        public string label;
        public int pixelValue;
    }
    /// <summary>
    /// A definition for how a <see cref="Labeling"/> should be resolved to a single label and id for ground truth generation.
    /// </summary>
    [CreateAssetMenu(fileName = "SemanticSegmentationLabelingConfiguration", menuName = "Perception/Semantic Segmentation Label Config", order = 1)]
    public class SemanticSegmentationLabelConfig : LabelingConfiguration2<SemanticSegmentationLabelEntry>
    {
        /// <summary>
        /// Whether the inspector will auto-assign ids based on the id of the first element.
        /// </summary>
        public bool AutoAssignIds = true;

        /// <summary>
        /// Whether the inspector will start label ids at zero or one when <see cref="AutoAssignIds"/> is enabled.
        /// </summary>
        public StartingLabelId StartingLabelId = StartingLabelId.One;
    }
    /// <summary>
    /// A definition for how a <see cref="Labeling"/> should be resolved to a single label and id for ground truth generation.
    /// </summary>
    [CreateAssetMenu(fileName = "LabelingConfiguration2", menuName = "Perception/Labeling Configuration 2", order = 1)]
    public class LabelingConfiguration2<T> : ScriptableObject where T : ILabelEntry
    {
        /// <summary>
        /// A sequence of <see cref="LabelEntry"/> which defines the labels relevant for this configuration and their values.
        /// </summary>
        [FormerlySerializedAs("LabelingConfigurations")]
        [SerializeField]
        public List<T> LabelEntries = new List<T>();

        /// <summary>
        /// Attempts to find the matching index in <see cref="LabelEntries"/> for the given <see cref="Labeling"/>.
        /// </summary>
        /// <remarks>
        /// The matching index is the first class name in the given Labeling which matches an entry in <see cref="LabelEntries"/>.
        /// </remarks>
        /// <param name="labeling">The <see cref="Labeling"/> to match </param>
        /// <param name="labelEntry">When this method returns, contains the matching <see cref="LabelEntry"/>, or <code>default</code> if no match was found.</param>
        /// <returns>Returns true if a match was found. False if not.</returns>
        public bool TryGetMatchingConfigurationEntry(Labeling labeling, out T labelEntry)
        {
            return TryGetMatchingConfigurationEntry(labeling, out labelEntry, out int _);
        }

        /// <summary>
        /// Attempts to find the matching index in <see cref="LabelEntries"/> for the given <see cref="Labeling"/>.
        /// </summary>
        /// <remarks>
        /// The matching index is the first class name in the given Labeling which matches an entry in <see cref="LabelEntries"/>.
        /// </remarks>
        /// <param name="labeling">The <see cref="Labeling"/> to match </param>
        /// <param name="labelEntry">When this method returns, contains the matching <see cref="LabelEntry"/>, or <code>default</code> if no match was found.</param>
        /// <param name="labelEntryIndex">When this method returns, contains the index of the matching <see cref="LabelEntry"/>, or <code>-1</code> if no match was found.</param>
        /// <returns>Returns true if a match was found. False if not.</returns>
        public bool TryGetMatchingConfigurationEntry(Labeling labeling, out T labelEntry, out int labelEntryIndex)
        {
            foreach (var labelingClass in labeling.labels)
            {
                for (var i = 0; i < LabelEntries.Count; i++)
                {
                    var entry = LabelEntries[i];
                    if (string.Equals(entry, labelingClass))
                    {
                        labelEntry = LabelEntries[i];
                        labelEntryIndex = i;
                        return true;
                    }
                }
            }

            labelEntryIndex = -1;
            labelEntry = default;
            return false;
        }
    }

    public interface ILabelEntry
    {
        string label { get; }
    }
}