using System.Collections;
using System.Collections.Generic;
using System;
using System.Linq;
using UnityEngine;
using UnityEngine.AddressableAssets;
using System.Runtime.CompilerServices;
using UnityEditor;

namespace NEG.Utils.Achievments
{
    using AchievmentTypes;

    public class AchievmentManager
    {
        public class Builder
        {
            public const string DefaultAchivmentsConfigLabel = "Achivments";

            private AchievmentManager manager = new AchievmentManager();
            private IAchivmentStorage storage;

            public static Builder FromDefaultConfig()
            {
                return FromLabeledConfig(DefaultAchivmentsConfigLabel);
            }

            public static Builder FromLabeledConfig(string label)
            {
                var builder = new Builder();
                
                var handle = Addressables.LoadAssetsAsync<IAchivmentManagerConfig>((IEnumerable)new string[] { label }, delegate { }, Addressables.MergeMode.Union, false);

                var configs = handle.WaitForCompletion();

                foreach (var config in configs)
                {
                    config.Apply(builder);
                }

                foreach (var config in configs)
                {
                    config.ApplyLast(builder);
                }

                Addressables.Release(handle);

                return builder;
            }

            public Builder WithLabeledDefinitions(string label)
            {
                var handle = Addressables.LoadAssetsAsync<AchivmentDefinitionCollection>((IEnumerable)new string[] { label }, delegate { }, Addressables.MergeMode.Union, false);

                var achivmentCollections = handle.WaitForCompletion();

                foreach (var achivmentCollection in achivmentCollections)
                    WithDefinitionsFrom(achivmentCollection);

                return this;
            }
            
            public Builder WithDefinitionsFrom(AchivmentDefinitionCollection collection)
            {
                foreach (var def in collection.Achivments)
                {
                    manager.RegisterAchivment(def);
                }

                return this;
            }

            public Builder LoadedFrom(IAchivmentStorage storageIn)
            {
                if (storage != null)
                {
                    throw new ApplicationException("Cannot Load achivment data from multiple storage instances");
                }

                this.storage = storageIn;

                return this;
            }

            public Builder WithCallbackReciever(IAchievmentCallbackReciever callbackReciever)
            {
                manager.AddCallbackReciever(callbackReciever);
                return this;
            }

            public AchievmentManager Build()
            {
                //TODO
                /*if (storage != null)
                {
                    manager.LoadFrom(storage);
                }*/
                return manager;
            }
        }

        public delegate void AchievmentCompletedCallback(AchievmentData achivment);
        public delegate void AchievmentStateChangedCallback(AchievmentData achivment);

        public event AchievmentCompletedCallback AchievmentCompleted;
        public event AchievmentStateChangedCallback AchievmentStateChanged;

        private Dictionary<string, AchievmentDefinition> definitionCache;
        private Dictionary<AchievmentDefinition, AchievmentData> dataCache;
        
        private AchievmentManager()
        {
            definitionCache = new Dictionary<string, AchievmentDefinition>();
            dataCache = new Dictionary<AchievmentDefinition, AchievmentData>();
        }

        private void RegisterAchivment(AchievmentDefinition definition)
        {
            if (!definitionCache.ContainsKey(definition.Id))
            {
                definitionCache.Add(definition.Id, definition);
                dataCache.Add(definition, definition.Construct());
            }
            else
            {
                Debug.LogWarning($"Duplicate Achivment with ID: {definition.Id}");
            }
        }

        /*private void LoadFrom(IAchivmentStorage achivmentStorage)
        {
            foreach (var entry in definitionCache)
            {
                var storedProgress = achivmentStorage.GetStoredAchivmentProgress(entry.Key);

                dataCache[entry.Value].ProgressLeft = storedProgress;
            }
        }*/

        public void AddCallbackRecievers(IEnumerable<IAchievmentCallbackReciever> initialCallbacks)
        {
            foreach (var callback in initialCallbacks)
            {
                AddCallbackReciever(callback);
            }
        }

        public void AddCallbackReciever(IAchievmentCallbackReciever callback)
        {
            AchievmentCompleted += callback.AchievmentCompleted;
            AchievmentStateChanged += callback.AchievmentStateChanged;
        }

        public void RemoveCallbackReciever(IAchievmentCallbackReciever callback)
        {
            AchievmentCompleted -= callback.AchievmentCompleted;
            AchievmentStateChanged -= callback.AchievmentStateChanged;
        }

        #region Achievment Manipulation (Sets, Gets)

        /// <summary>
        /// Returns if an achivment at a given id is completed
        /// </summary>
        /// <param name="id"></param>
        /// <returns></returns>
        /// <remarks>throws an <see cref="AchievmentException"/> if there is no achievment under id</remarks>
        public bool IsCompleted(string id)
        {
            return GetAchievmentForId(id).IsCompleted;
        }

        #region Toggle
        /// <summary>
        /// Sets a <see cref="ToggleAchievmentData"/> as completed, after which sends <see cref="AchievmentStateChanged"/>, also if the achievment is completed sends a <see cref="AchievmentCompleted"/>. <br/> 
        /// </summary>
        /// <seealso cref="ToggleAchievmentDefinition"/>
        /// <remarks>throws an <see cref="AchievmentException"/> if there is no achievment under id or an <see cref="AchievmentTypeException"/> if achievment under id is of a different type</remarks>
        public void SetToggleAchivment(string id)
        {
            ManipulateAchievment<ToggleAchievmentData>(id, (achievment) => achievment.CompletionState = true);
        }

        /// <summary>
        /// Gets a completion state from a <see cref="ToggleAchievmentData"/>.<br/> 
        /// </summary>
        /// <seealso cref="ToggleAchievmentDefinition"/>
        /// <remarks>throws an <see cref="AchievmentException"/> if there is no achievment under id or an <see cref="AchievmentTypeException"/> if achievment under id is of a different type</remarks>
        public bool GetToggleState(string id)
        {
            return GetAchievmentForId<ToggleAchievmentData>(id).CompletionState;
        }
        #endregion

        #region Int
        /// <summary>
        /// Sets progress of a given <see cref="IntAchievmentData"/> to <paramref name="progress"/>, after which sends <see cref="AchievmentStateChanged"/>, also if the achievment is completed sends a <see cref="AchievmentCompleted"/>. <br/> 
        /// </summary>
        /// <seealso cref="IntAchievmentDefinition"/>
        /// <remarks>throws an <see cref="AchievmentException"/> if there is no achievment under id or an <see cref="AchievmentTypeException"/> if achievment under id is of a different type</remarks>
        public void SetIntProgress(string id, int progress)
        {
            ManipulateAchievment<IntAchievmentData>(id, (achievment) => achievment.CurrentProgress = progress);
        }

        /// <summary>
        /// Changes progress of a given <see cref="IntAchievmentData"/> by <paramref name="delta"/>, after which sends <see cref="AchievmentStateChanged"/>, also if the achievment is completed sends a <see cref="AchievmentCompleted"/>. <br/> 
        /// </summary>
        /// <seealso cref="IntAchievmentDefinition"/>
        /// <remarks>throws an <see cref="AchievmentException"/> if there is no achievment under id or an <see cref="AchievmentTypeException"/> if achievment under id is of a different type</remarks>
        public void ChangeIntProgress(string id, int delta)
        {
            ManipulateAchievment<IntAchievmentData>(id, (achievment) => achievment.CurrentProgress += delta);
        }

        /// <summary>
        /// Gets current progress from a <see cref="IntAchievmentData"/>.<br/> 
        /// </summary>
        /// <seealso cref="ToggleAchievmentDefinition"/>
        /// <remarks>throws an <see cref="AchievmentException"/> if there is no achievment under id or an <see cref="AchievmentTypeException"/> if achievment under id is of a different type</remarks>
        public int GetIntProgress(string id)
        {
            return GetAchievmentForId<IntAchievmentData>(id).CurrentProgress;
        }
        #endregion

        #region Float
        /// <summary>
        /// Sets progress of a given <see cref="FloatAchievmentData"/> to <paramref name="progress"/>, after which sends <see cref="AchievmentStateChanged"/>, also if the achievment is completed sends a <see cref="AchievmentCompleted"/>. <br/> 
        /// </summary>
        /// <seealso cref="FloatAchievmentDefinition"/>
        /// <remarks>throws an <see cref="AchievmentException"/> if there is no achievment under id or an <see cref="AchievmentTypeException"/> if achievment under id is of a different type</remarks>
        public void SetFloatProgress(string id, float progress)
        {
            ManipulateAchievment<FloatAchievmentData>(id, (achievment) => achievment.CurrentProgress = progress);
        }

        /// <summary>
        /// Changes progress of a given <see cref="FloatAchievmentData"/> by <paramref name="delta"/>, after which sends <see cref="AchievmentStateChanged"/>, also if the achievment is completed sends a <see cref="AchievmentCompleted"/>. <br/> 
        /// </summary>
        /// <seealso cref="FloatAchievmentDefinition"/>
        /// <remarks>throws an <see cref="AchievmentException"/> if there is no achievment under id or an <see cref="AchievmentTypeException"/> if achievment under id is of a different type</remarks>
        public void ChangeFloatProgress(string id, float delta)
        {
            ManipulateAchievment<FloatAchievmentData>(id, (achievment) => achievment.CurrentProgress += delta);
        }

        /// <summary>
        /// Gets current progress from a <see cref="FloatAchievmentData"/>.<br/> 
        /// </summary>
        /// <seealso cref="FloatAchievmentDefinition"/>
        /// <remarks>throws an <see cref="AchievmentException"/> if there is no achievment under id or an <see cref="AchievmentTypeException"/> if achievment under id is of a different type</remarks>
        public float GetFloatProgress(string id)
        {
            return GetAchievmentForId<FloatAchievmentData>(id).CurrentProgress;
        }
        #endregion
        #endregion

        /// <summary>
        /// Returns an achievment of type <typeparamref name="T"/> under <paramref name="id"/>
        /// </summary>
        /// <typeparam name="T">Type of the achievment</typeparam>
        /// <param name="id">Id of requested achievment</param>
        /// <remarks>throws an <see cref="AchievmentException"/> if there is no achievment under id or an <see cref="AchievmentTypeException"/> if achievment under id is of a different type</remarks>
        public T GetAchievmentForId<T>(string id) where T : AchievmentData
        {
            return ValidateAchievmentType<T>(GetAchievmentForId(id));
        }

        /// <summary>
        /// Returns an achievment under <paramref name="id"/>
        /// </summary>
        /// <param name="id">Id of requested achievment</param>
        /// <remarks>throws an <see cref="ApplicationException"/> if there is no achievment under id</remarks>
        public AchievmentData GetAchievmentForId(string id)
        {
            var def = definitionCache.GetValueOrDefault(id);
            if (def != null)
            {
                return dataCache[def];
            }
            else
            {
                throw new AchievmentException($"Invalid achivment id {id}", id);
            }
        }

        private T ValidateAchievmentType<T>(AchievmentData data) where T : AchievmentData
        {
            if (data is not T convetred)
            {
                throw new AchievmentTypeException($"Attempting to perform an operation on an invalid achievment type. Expected {typeof(T)} got {data.GetType()}", data.Achivment.Id, typeof(T), data.GetType());
            }
            return convetred;
        }

        /// <summary>
        /// 
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="id"></param>
        /// <param name="manipulation">Action to perform on the achievment</param>
        private void ManipulateAchievment<T>(string id, Action<T> manipulation) where T : AchievmentData
        {
            var data = GetAchievmentForId<T>(id);

            if (CheckNotCompleted(data))
            {
                return;
            }

            manipulation(data);

            SendUpdateCallbacks(data);
        }

        /// <summary>
        /// Helper method to print a warning if an achievment is already completed
        /// </summary>
        /// <param name="data"></param>
        /// <returns>Completion state</returns>
        private bool CheckNotCompleted(AchievmentData data)
        {
            if (data.IsCompleted)
            {
                Debug.LogWarning($"Achievment already completed: {data.Achivment.Id}");
            }
            return data.IsCompleted;
        }

        private void SendUpdateCallbacks(AchievmentData data)
        {
            AchievmentStateChanged?.Invoke(data);

            if (data.IsCompleted)
            {
                AchievmentCompleted?.Invoke(data);
            }
        }
    }
}