using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using UnityEditor;
using UnityEngine;
using UnityEngine.Analytics;
using UnityEngine.Perception.GroundTruth;
using UnityEngine.Perception.Randomization.Parameters;
using UnityEngine.Perception.Randomization.Randomizers;
using UnityEngine.Perception.Randomization.Samplers;

namespace UnityEngine.Perception
{
    public static class PerceptionEngineAnalytics
    {
        const string k_VendorKey = "unity.perception";
        const int k_MaxElementsInStruct = 100;
        const int k_MaxEventsPerHour = 100;
        static bool s_AllEventsRegistered;

        // Runtime Events
        static string[] allEvents => new[] { k_EventScenarioCompleted };
        const string k_EventScenarioCompleted = "perceptionScenarioCompleted";

        #region Event: Scenario Completed

        /// <summary>
        /// Which labelers will be identified and included in the analytics information.
        /// </summary>
        static readonly Type[] k_LabelerAllowList = new[]
        {
            typeof(BoundingBox3DLabeler), typeof(BoundingBox2DLabeler), typeof(InstanceSegmentationLabeler),
            typeof(KeypointLabeler), typeof(ObjectCountLabeler), typeof(SemanticSegmentationLabeler)
        };

        #region Data Structures

        [Serializable]
        public class PerceptionCameraData
        {
            public string captureTriggerMode;
            public int startAtFrame;
            public int framesBetweenCaptures;
        }

        [Serializable]
        public class LabelerData
        {
            public string name;
            public int labelConfigCount;
            public string objectFilter;
            public int animationPoseCount;

            public static LabelerData FromLabeler(CameraLabeler labeler)
            {
                var labelerType = labeler.GetType();
                if (!k_LabelerAllowList.Contains(labelerType))
                    return null;

                var labelerData = new LabelerData()
                {
                    name = labeler.GetType().Name
                };

                switch (labeler)
                {
                    case BoundingBox3DLabeler bb3dl:
                        labelerData.labelConfigCount = bb3dl.idLabelConfig.labelEntries.Count;
                        break;
                    case BoundingBox2DLabeler bb2dl:
                        labelerData.labelConfigCount = bb2dl.idLabelConfig.labelEntries.Count;
                        break;
                    case InstanceSegmentationLabeler isl:
                        labelerData.labelConfigCount = isl.idLabelConfig.labelEntries.Count;
                        break;
                    case KeypointLabeler kpl:
                        labelerData.labelConfigCount = kpl.idLabelConfig.labelEntries.Count;
                        labelerData.objectFilter = kpl.objectFilter.ToString();
                        labelerData.animationPoseCount = kpl.animationPoseConfigs.Count;
                        break;
                    case ObjectCountLabeler ocl:
                        labelerData.labelConfigCount = ocl.labelConfig.labelEntries.Count;
                        break;
                    case SemanticSegmentationLabeler ssl:
                        labelerData.labelConfigCount = ssl.labelConfig.labelEntries.Count;
                        break;
                }

                return labelerData;
            }
        }

        [Serializable]
        public class MemberData
        {
            public string name;
            public string value;
            public string type;
        }

        [Serializable]
        public class ParameterField
        {
            public string name;
            public string distribution;
            public float value = int.MinValue;
            public float rangeMinimum = int.MinValue;
            public float rangeMaximum = int.MinValue;
            public float mean = int.MinValue;
            public float stdDev = int.MinValue;
            public int categoricalParameterCount = int.MinValue;

            public static ParameterField ExtractSamplerInformation(ISampler sampler, string fieldName = "value")
            {
                switch (sampler)
                {
                    case AnimationCurveSampler _:
                        return new ParameterField()
                        {
                            name = fieldName,
                            distribution = "AnimationCurve"
                        };
                    case ConstantSampler cs:
                        return new ParameterField()
                        {
                            name = fieldName,
                            distribution = "Constant",
                            value = cs.value
                        };
                    case NormalSampler ns:
                        return new ParameterField()
                        {
                            name = fieldName,
                            distribution = "Normal",
                            mean = ns.mean,
                            stdDev = ns.standardDeviation,
                            rangeMinimum = ns.range.minimum,
                            rangeMaximum = ns.range.maximum
                        };
                    case UniformSampler us:
                        return new ParameterField()
                        {
                            name = fieldName,
                            distribution = "Uniform",
                            rangeMinimum = us.range.minimum,
                            rangeMaximum = us.range.maximum
                        };
                    default:
                        return null;
                }
            }

            public static List<ParameterField> ExtractSamplersInformation(IEnumerable<ISampler> samplers, IEnumerable<string> indexToNameMapping)
            {
                var samplersList = samplers.ToList();
                var indexToNameMappingList = indexToNameMapping.ToList();
                if (samplersList.Count > indexToNameMappingList.Count)
                    throw new Exception("Insufficient names provided for mapping ParameterFields");
                return samplersList.Select((t, i) => ExtractSamplerInformation(t, indexToNameMappingList[i])).ToList();
            }
        }

        [Serializable]
        public class ParameterData
        {
            public string name;
            public string type;
            public List<ParameterField> fields;
        }

        [Serializable]
        public class RandomizerData
        {
            public string name;
            public MemberData[] members;
            public ParameterData[] parameters;

            public static RandomizerData FromRandomizer(Randomizer randomizer)
            {
                if (randomizer == null)
                    return null;

                var data = new RandomizerData()
                {
                    name = randomizer.GetType().Name,
                };

                var randomizerType = randomizer.GetType();

                // Only looks for randomizers included by the Perception package.
                if (randomizerType.Namespace == null || !randomizerType.Namespace.StartsWith("UnityEngine.Perception"))
                    return null;

                // Naming configuration
                var vectorFieldNames = new[] { "x", "y", "z", "w" };
                var hsvaFieldNames = new[] { "hue", "saturation", "value", "alpha" };
                var rgbFieldNames = new[] { "red", "green", "blue" };

                // Add member fields and parameters separately
                var members = new List<MemberData>();
                var parameters = new List<ParameterData>();
                foreach (var field in randomizerType.GetFields(BindingFlags.Public | BindingFlags.Instance))
                {
                    var member = field.GetValue(randomizer);
                    var memberType = member.GetType();

                    // If member is either a categorical or numeric parameter
                    if (memberType.IsSubclassOf(typeof(Parameter)))
                    {
                        var pd = new ParameterData()
                        {
                            name = field.Name,
                            type = memberType.Name,
                            fields = new List<ParameterField>()
                        };

                        // All included parameter types
                        switch (member)
                        {
                            case CategoricalParameterBase cp:
                                pd.fields.Add(new ParameterField()
                                {
                                    name = "values",
                                    distribution = "Categorical",
                                    categoricalParameterCount = cp.probabilities.Count
                                });
                                break;
                            case BooleanParameter bP:
                                pd.fields.Add(ParameterField.ExtractSamplerInformation(bP.value));
                                break;
                            case FloatParameter fP:
                                pd.fields.Add(ParameterField.ExtractSamplerInformation(fP.value));
                                break;
                            case IntegerParameter iP:
                                pd.fields.Add(ParameterField.ExtractSamplerInformation(iP.value));
                                break;
                            case Vector2Parameter v2P:
                                pd.fields.AddRange(ParameterField.ExtractSamplersInformation(v2P.samplers, vectorFieldNames));
                                break;
                            case Vector3Parameter v3P:
                                pd.fields.AddRange(ParameterField.ExtractSamplersInformation(v3P.samplers, vectorFieldNames));
                                break;
                            case Vector4Parameter v4P:
                                pd.fields.AddRange(ParameterField.ExtractSamplersInformation(v4P.samplers, vectorFieldNames));
                                break;
                            case ColorHsvaParameter hsvaP:
                                pd.fields.AddRange(ParameterField.ExtractSamplersInformation(hsvaP.samplers, hsvaFieldNames));
                                break;
                            case ColorRgbParameter rgbP:
                                pd.fields.AddRange(ParameterField.ExtractSamplersInformation(rgbP.samplers, rgbFieldNames));
                                break;
                        }

                        parameters.Add(pd);
                    }
                    else
                    {
                        members.Add(new MemberData()
                        {
                            name = field.Name,
                            type = memberType.FullName,
                            value = member.ToString()
                        });
                    }
                }

                data.members = members.ToArray();
                data.parameters = parameters.ToArray();
                return data;
            }
        }

        [Serializable]
        public class ScenarioCompletedData
        {
            public string platform;
            public PerceptionCameraData perceptionCamera;
            public LabelerData[] labelers;
            public RandomizerData[] randomizers;
        }

        #endregion

        internal static void ReportScenarioCompleted(PerceptionCamera cam, IEnumerable<Randomizer> randomizers)
        {
            if (!TryRegisterEvents())
                return;

            var data = new ScenarioCompletedData();
            if (cam != null)
            {
                // Perception Camera Data
                data.perceptionCamera = new PerceptionCameraData()
                {
                    captureTriggerMode = cam.captureTriggerMode.ToString(),
                    startAtFrame = cam.firstCaptureFrame,
                    framesBetweenCaptures = cam.framesBetweenCaptures
                };

                // Labeler Data
                data.labelers = cam.labelers
                    .Select(LabelerData.FromLabeler)
                    .Where(labeler => labeler != null).ToArray();
            }

            var randomizerList = randomizers.ToArray();
            if (randomizerList.Any())
            {
                data.randomizers = randomizerList
                    .Select(RandomizerData.FromRandomizer)
                    .Where(x => x != null).ToArray();
            }

            EditorAnalytics.SendEventWithLimit(k_EventScenarioCompleted, data);
        }

        #endregion

        static bool TryRegisterEvents()
        {
            if (s_AllEventsRegistered)
                return true;

            var success = true;
            foreach (var eventName in allEvents)
            {
                success &= EditorAnalytics.RegisterEventWithLimit(eventName, k_MaxEventsPerHour, k_MaxElementsInStruct, k_VendorKey) == AnalyticsResult.Ok;
            }

            s_AllEventsRegistered = success;

            return success;
        }
    }
}