using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;

namespace Pilz.Plugins.Advanced
{
    public sealed class PluginFeatureController
    {
        public delegate void PluginFeatureEventHandler(PluginFeatureController controller, PluginFeature feature);

        /// <summary>
        /// Fires when a new <see cref="PluginFeature"/> has been registred.
        /// </summary>
        public static event PluginFeatureEventHandler? OnPluginFeatureReistred;

        /// <summary>
        /// Fires when a <see cref="PluginFeature"/> has been unregistred.
        /// </summary>
        public static event PluginFeatureEventHandler? OnPluginFeatureUnregistred;

        /// <summary>
        /// The default public instance that can be used by plugins and the interface providing software.
        /// </summary>
        public static PluginFeatureController Instance { get; private set; } = new();

        private readonly HashSet<PluginFeature> features = [];

        /// <summary>
        /// A wrapper of all registred <see cref="PluginFeature"/> instances.
        /// </summary>
        public FeatureController Features { get; init; }
        
        /// <summary>
        /// A wrapper for all registred <see cref="PluginModule"/> instances.
        /// </summary>
        public ModuleController Modules { get; init; }

        /// <summary>
        /// A wrapper for all registred <see cref="PluginFunction"/> instances.
        /// </summary>
        public FunctionController Functions { get; init; }

        public PluginFeatureController()
        {
            Features = new(this);
            Functions = new(this);
            Modules = new(this);
        }

        public void RegisterAllFromMyAssembly()
        {
            RegisterAllFromAssembly(Assembly.GetCallingAssembly());
        }

        public void RegisterAllFromAssembly(Assembly assembly)
        {
            const string nameGetFeatures = $"{nameof(IPluginFeaturesProvider.GetFeatures)}";
            const string nameGetFeaturesExplicit = $"{nameof(IPluginFeaturesProvider)}.{nameof(IPluginFeaturesProvider.GetFeatures)}";
            const string nameInstance = $"get_{nameof(IPluginFeatureProvider.Instance)}";
            const string nameInstnaceExplicit = $"get_{nameof(IPluginFeatureProvider)}.{nameof(IPluginFeatureProvider.Instance)}";

            foreach (var type in assembly.GetTypes())
            {
                if (type.IsAssignableTo(typeof(IPluginFeaturesProvider)))
                {
                    var methods = type.GetMethods(BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
                    var method = methods.FirstOrDefault(n => n.Name == nameGetFeaturesExplicit || n.Name == nameGetFeatures);

                    if (method != null && method.Invoke(null, null) is PluginFeature[] features)
                    {
                        foreach (var feature in features)
                            Register(feature);
                    }
                }
                else if (type.IsAssignableTo(typeof(IPluginFeatureProvider)))
                {
                    var methods = type.GetMethods(BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
                    var method = methods.FirstOrDefault(n => n.Name == nameInstnaceExplicit || n.Name == nameInstance);

                    if (method != null && method.Invoke(null, null) is PluginFeature feature)
                        Register(feature);
                }
            }
        }

        public void Register<TProvider>() where TProvider : IPluginFeatureProvider
        {
            Register(TProvider.Instance);
        }

        public void RegisterAll<TProvider>() where TProvider : IPluginFeaturesProvider
        {
            foreach (var feature in TProvider.GetFeatures())
                Register(feature);
        }

        public void Register(PluginFeature module)
        {
            if (!features.Contains(module))
            {
                features.Add(module);
                OnPluginFeatureReistred?.Invoke(this, module);
            }
        }

        public void Unregister(PluginFeature module)
        {
            features.Remove(module);
            OnPluginFeatureUnregistred?.Invoke(this, module);
        }

        public class FeatureController(PluginFeatureController controller)
        {
            protected readonly PluginFeatureController controller = controller;

            public virtual IEnumerable<PluginFeature> GetAll()
            {
                return controller.features.ToArray();
            }

            public virtual IEnumerable<PluginFeature> Get(string featureType)
            {
                return controller.features.Where(n => n.Type == featureType);
            }

            public virtual PluginFeature? GetFirst(string featureType)
            {
                return controller.features.FirstOrDefault(n => n.Type == featureType);
            }

            public virtual PluginFeature? GetByIdentifier(string fullIdentifier)
            {
                return controller.features.FirstOrDefault(n => n.FullIdentifier == fullIdentifier);
            }

            public virtual PluginFeature? GetByIdentifier(string featureType, string identifier)
            {
                return controller.features.FirstOrDefault(n => n.Type == featureType && n.Identifier == identifier);
            }
        }

        public class FeatureController<T>(PluginFeatureController controller) : FeatureController(controller) where T : PluginFeature
        {
            public override IEnumerable<T> GetAll()
            {
                return controller.features.OfType<T>();
            }

            public override IEnumerable<T> Get(string moduleType)
            {
                return GetAll().Where(n => n.Type == moduleType);
            }

            public override T? GetFirst(string moduleType)
            {
                return base.GetFirst(moduleType) as T;
            }

            public override T? GetByIdentifier(string fullIdentifier)
            {
                return base.GetByIdentifier(fullIdentifier) as T;
            }

            public override T? GetByIdentifier(string featureType, string identifier)
            {
                return base.GetByIdentifier(featureType, identifier) as T;
            }
        }

        public class ModuleController(PluginFeatureController controller) : FeatureController<PluginModuleBase>(controller)
        {
        }

        public class FunctionController(PluginFeatureController controller) : FeatureController<PluginFunction>(controller)
        {
            public void ExecuteAll(string functionType)
            {
                foreach (var function in Get(functionType))
                    function.Execute();
            }

            public void ExecuteAll(string functionType, params object?[]? @params)
            {
                foreach (var function in Get(functionType))
                    function.Execute(@params);
            }

            public void ExecuteAll(string functionType, PluginFunctionParameter @params)
            {
                foreach (var function in Get(functionType))
                    function.Execute(@params);
            }

            public IEnumerable<object?> ExcuteAndGetResults(string functionType)
            {
                return Get(functionType).Select(n => n.Execute());
            }

            public IEnumerable<object?> ExcuteAndGetResults(string functionType, params object?[]? @params)
            {
                return Get(functionType).Select(n => n.Execute(@params));
            }

            public IEnumerable<object?> ExcuteAndGetResults(string functionType, PluginFunctionParameter @params)
            {
                return Get(functionType).Select(n => n.Execute(@params));
            }
        }
    }
}