using System;
using System.Collections;
using System.Linq;
using System.Reflection;
using ToolsModule.ManagmentSecurity;

namespace ToolsModule.ManagmentMapping
{
    /// <summary>
    /// Маппер сущностей
    /// </summary>
    public class Mapper
    {
        /// <summary>
        /// Преобразование из одного класса в другой
        /// </summary>
        /// <typeparam name="From"></typeparam>
        /// <typeparam name="To"></typeparam>
        /// <param name="obj"></param>
        /// <param name="haveRigth"></param>
        /// <returns></returns>
        public static To MapToClass<From, To>(From obj, bool haveRigth) where To : class => FillObject(obj, (To)Activator.CreateInstance(typeof(To)), haveRigth);

        /// <summary>
        /// Преобразование из одного класса в другой
        /// </summary>
        /// <typeparam name="From"></typeparam>
        /// <typeparam name="To"></typeparam>
        /// <param name="obj"></param>
        /// <param name="newObject"></param>
        /// <returns></returns>
        public static To MapToClass<From, To>(From obj, To newObject, bool haveRigth) where To : class => FillObject(obj, newObject, haveRigth, true);

        /// <summary>
        /// Заполнение объекта
        /// </summary>
        /// <typeparam name="From"></typeparam>
        /// <typeparam name="To"></typeparam>
        /// <param name="obj"></param>
        /// <param name="newObject"></param>
        /// <param name="haveRigth"></param>
        /// <param name="exsistRecord"></param>
        /// <returns></returns>
        private static To FillObject<From, To>(From obj, To newObject, bool haveRigth, bool exsistRecord = false)
            where To : class
        {
            if (obj == null)
            {
                return null;
            }
            if (newObject == null)
            {
                return null;
            }

            var typeFrom = typeof(From);
            var typeTo = typeof(To);
            var properties = typeTo.GetProperties().Where(x => x.CanWrite);
            foreach (var property in properties)
            {
                if (property.Name == "Id" && exsistRecord)
                {
                    continue;
                }
                var checkRight = property.GetCustomAttribute<CheckRigthForMapAttribute>();
                if (!haveRigth && checkRight != null)
                {
                    continue;
                }

                object value = null;
                var customAttribute = property.GetCustomAttribute<MapConfigurationAttribute>();
                if (customAttribute != null)
                {
                    if (!haveRigth && !customAttribute.AllowCopyWithoutRigth)
                    {
                        continue;
                    }
                    value = GetValueFromCustomAttribute(customAttribute, typeFrom, obj);
                }
                else
                {
                    var bindingProperty = typeFrom.GetProperty(property.Name);
                    if (bindingProperty != null)
                    {
                        value = bindingProperty.GetValue(obj);
                    }
                }
                if (value is null)
                {
                    continue;
                }

                if (property.PropertyType.Name.StartsWith("Nullable") && Nullable.GetUnderlyingType(property.PropertyType).IsEnum)
                {
                    property.SetValue(newObject, Enum.Parse(Nullable.GetUnderlyingType(property.PropertyType), value.ToString()));
                    continue;
                }
                property.SetValue(newObject, value);
            }

            return newObject;
        }

        private static object GetValueFromCustomAttribute(MapConfigurationAttribute customAttribute, Type typeFrom, object obj)
        {
            object value = obj;
            var props = customAttribute.PropertyNameFromModel.Split('.');
            foreach (var prop in props)
            {
                if (prop == "ToString")
                {
                    value = value.ToString();
                    break;
                }
                else if (prop == "Count")
                {
                    value = (value as ICollection)?.Count;
                    break;
                }
                else if (prop == "Method")
                {
                    int index = 0;
                    while (true)
                    {
                        if (props[index++] == "Method")
                            break;
                        if (index == props.Length)
                        {
                            break;
                        }
                    }
                    var methodName = props[index].Split('[')?[0];
                    if (string.IsNullOrEmpty(methodName))
                    {
                        break;
                    }
                    var parameters = props[index].Split(new char[] { '[', ']' }, StringSplitOptions.RemoveEmptyEntries)?[1].Split(',');
                    var objs = new object[parameters.Length];
                    for (int i = 0; i < parameters.Length; ++i)
                    {
                        var type = parameters[i].Split(':')[0];
                        switch (type)
                        {
                            case "Enum":
                                objs[i] = Enum.Parse(customAttribute.MethodParams[i], parameters[i].Split(':')[1]);
                                break;
                        }
                    }
                    value = typeFrom.InvokeMember(methodName, BindingFlags.InvokeMethod | BindingFlags.Public | BindingFlags.Instance, null, value, objs);
                    break;

                }
                var bindingProperty = value.GetType().GetProperty(prop);
                if (bindingProperty != null)
                {
                    value = bindingProperty.GetValue(value);
                    if (value is null)
                    {
                        break;
                    }
                }
                else
                {
                    value = null;
                    break;
                }
            }
            return value;
        }
    }
}