#nullable enable
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

using Swan.Lite.Reflection;
using Swan.Mappers;
using Swan.Reflection;

namespace Swan {
  /// <summary>
  /// Extension methods.
  /// </summary>
  public static partial class Extensions {
    /// <summary>
    /// Iterates over the public, instance, readable properties of the source and
    /// tries to write a compatible value to a public, instance, writable property in the destination.
    /// </summary>
    /// <typeparam name="T">The type of the source.</typeparam>
    /// <param name="source">The source.</param>
    /// <param name="target">The target.</param>
    /// <param name="ignoreProperties">The ignore properties.</param>
    /// <returns>
    /// Number of properties that was copied successful.
    /// </returns>
    public static Int32 CopyPropertiesTo<T>(this T source, Object? target, params String[]? ignoreProperties) where T : class => ObjectMapper.Copy(source, target, GetCopyableProperties(target), ignoreProperties);

    /*/// <summary>
    /// Iterates over the public, instance, readable properties of the source and
    /// tries to write a compatible value to a public, instance, writable property in the destination.
    /// </summary>
    /// <param name="source">The source.</param>
    /// <param name="target">The destination.</param>
    /// <param name="propertiesToCopy">Properties to copy.</param>
    /// <returns>
    /// Number of properties that were successfully copied.
    /// </returns>
    public static Int32 CopyOnlyPropertiesTo(this Object source, Object target, params String[]? propertiesToCopy) => ObjectMapper.Copy(source, target, propertiesToCopy);*/

    /// <summary>
    /// Copies the properties to new instance of T.
    /// </summary>
    /// <typeparam name="T">The new object type.</typeparam>
    /// <param name="source">The source.</param>
    /// <param name="ignoreProperties">The ignore properties.</param>
    /// <returns>
    /// The specified type with properties copied.
    /// </returns>
    /// <exception cref="ArgumentNullException">source.</exception>
    public static T CopyPropertiesToNew<T>(this Object source, String[]? ignoreProperties = null) where T : class {
      if(source == null) {
        throw new ArgumentNullException(nameof(source));
      }

      T target = Activator.CreateInstance<T>();
      _ = ObjectMapper.Copy(source, target, GetCopyableProperties(target), ignoreProperties);

      return target;
    }

    /*/// <summary>
    /// Copies the only properties to new instance of T.
    /// </summary>
    /// <typeparam name="T">Object Type.</typeparam>
    /// <param name="source">The source.</param>
    /// <param name="propertiesToCopy">The properties to copy.</param>
    /// <returns>
    /// The specified type with properties copied.
    /// </returns>
    /// <exception cref="ArgumentNullException">source.</exception>
    public static T CopyOnlyPropertiesToNew<T>(this Object source, params String[] propertiesToCopy) where T : class {
      if(source == null) {
        throw new ArgumentNullException(nameof(source));
      }

      T target = Activator.CreateInstance<T>();
      _ = ObjectMapper.Copy(source, target, propertiesToCopy);

      return target;
    }

    /// <summary>
    /// Iterates over the keys of the source and tries to write a compatible value to a public, 
    /// instance, writable property in the destination.
    /// </summary>
    /// <param name="source">The source.</param>
    /// <param name="target">The target.</param>
    /// <param name="ignoreKeys">The ignore keys.</param>
    /// <returns>Number of properties that was copied successful.</returns>
    public static Int32 CopyKeyValuePairTo(this IDictionary<String, Object> source, Object? target, params String[] ignoreKeys) => source == null ? throw new ArgumentNullException(nameof(source)) : ObjectMapper.Copy(source, target, null, ignoreKeys);

    /// <summary>
    /// Iterates over the keys of the source and tries to write a compatible value to a public,
    /// instance, writable property in the destination.
    /// </summary>
    /// <typeparam name="T">Object Type.</typeparam>
    /// <param name="source">The source.</param>
    /// <param name="ignoreKeys">The ignore keys.</param>
    /// <returns>
    /// The specified type with properties copied.
    /// </returns>
    public static T CopyKeyValuePairToNew<T>(this IDictionary<String, Object> source, params String[] ignoreKeys) {
      if(source == null) {
        throw new ArgumentNullException(nameof(source));
      }

      T target = Activator.CreateInstance<T>();
      _ = source.CopyKeyValuePairTo(target, ignoreKeys);
      return target;
    }

    /// <summary>
    /// Does the specified action.
    /// </summary>
    /// <param name="action">The action.</param>
    /// <param name="retryInterval">The retry interval.</param>
    /// <param name="retryCount">The retry count.</param>
    public static void Retry(this Action action, TimeSpan retryInterval = default, Int32 retryCount = 3) {
      if(action == null) {
        throw new ArgumentNullException(nameof(action));
      }

      _ = Retry<Object?>(() => { action(); return null; }, retryInterval, retryCount);
    }

    /// <summary>
    /// Does the specified action.
    /// </summary>
    /// <typeparam name="T">The type of the source.</typeparam>
    /// <param name="action">The action.</param>
    /// <param name="retryInterval">The retry interval.</param>
    /// <param name="retryCount">The retry count.</param>
    /// <returns>
    /// The return value of the method that this delegate encapsulates.
    /// </returns>
    /// <exception cref="ArgumentNullException">action.</exception>
    /// <exception cref="AggregateException">Represents one or many errors that occur during application execution.</exception>
    public static T Retry<T>(this Func<T> action, TimeSpan retryInterval = default, Int32 retryCount = 3) {
      if(action == null) {
        throw new ArgumentNullException(nameof(action));
      }

      if(retryInterval == default) {
        retryInterval = TimeSpan.FromSeconds(1);
      }

      global::System.Collections.Generic.List<global::System.Exception> exceptions = new List<Exception>();

      for(Int32 retry = 0; retry < retryCount; retry++) {
        try {
          if(retry > 0) {
            Task.Delay(retryInterval).Wait();
          }

          return action();
        } catch(Exception ex) {
          exceptions.Add(ex);
        }
      }

      throw new AggregateException(exceptions);
    }*/

    /// <summary>
    /// Gets the copyable properties.
    ///
    /// If there is no properties with the attribute <c>AttributeCache</c> returns all the properties.
    /// </summary>
    /// <param name="this">The object.</param>
    /// <returns>
    /// Array of properties.
    /// </returns>
    /// <exception cref="ArgumentNullException">model.</exception>
    /// <seealso cref="AttributeCache"/>
    public static IEnumerable<String> GetCopyableProperties(this Object? @this) {
      if(@this == null) {
        throw new ArgumentNullException(nameof(@this));
      }

      global::System.Collections.Generic.IEnumerable<global::System.Reflection.PropertyInfo> collection = PropertyTypeCache.DefaultCache.Value.RetrieveAllProperties(@this.GetType(), true);

      global::System.Collections.Generic.IEnumerable<global::System.String> properties = collection.Select(x => new {
        x.Name,
        HasAttribute = AttributeCache.DefaultCache.Value.RetrieveOne<CopyableAttribute>(x) != null,
      }).Where(x => x.HasAttribute).Select(x => x.Name);

      return properties.Any() ? properties : collection.Select(x => x.Name);
    }

    internal static void CreateTarget(this Object source, Type targetType, Boolean includeNonPublic, ref Object? target) {
      switch(source) {
        // do nothing. Simply skip creation
        case String _:
          break;
        // When using arrays, there is no default constructor, attempt to build a compatible array
        case IList sourceObjectList when targetType.IsArray:
          Type? elementType = targetType.GetElementType();

          if(elementType != null) {
            target = Array.CreateInstance(elementType, sourceObjectList.Count);
          }

          break;
        default:
          IEnumerable<Tuple<System.Reflection.ConstructorInfo, System.Reflection.ParameterInfo[]>> constructors = ConstructorTypeCache.DefaultCache.Value.RetrieveAllConstructors(targetType, includeNonPublic);

          // Try to check if empty constructor is available
          if(constructors.Any(x => x.Item2.Length == 0)) {
            target = Activator.CreateInstance(targetType, includeNonPublic);
          } else {
            Tuple<System.Reflection.ConstructorInfo, System.Reflection.ParameterInfo[]> firstCtor = constructors.OrderBy(x => x.Item2.Length).FirstOrDefault();

            target = Activator.CreateInstance(targetType, firstCtor?.Item2.Select(arg => arg.GetType().GetDefault()).ToArray());
          }

          break;
      }
    }

    internal static String GetNameWithCase(this String name, JsonSerializerCase jsonSerializerCase) => jsonSerializerCase switch
    {
      JsonSerializerCase.PascalCase => Char.ToUpperInvariant(name[0]) + name.Substring(1),
      JsonSerializerCase.CamelCase => Char.ToLowerInvariant(name[0]) + name.Substring(1),
      JsonSerializerCase.None => name,
      _ => throw new ArgumentOutOfRangeException(nameof(jsonSerializerCase), jsonSerializerCase, null)
    };
  }
}