using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using Tango.Core;
using Tango.FSE.Common;

namespace Tango.FSE.Procedures.Dialogs
{
    public class UserInputDialogViewVM : FSEDialogViewVM
    {
        public class Parameter
        {
            public PropertyInfo PropertyInfo { get; set; }
            public FieldInfo FieldInfo { get; set; }
            public String Name { get; set; }
            public String Value { get; set; }

            public String TypeName
            {
                get
                {
                    if (PropertyInfo != null)
                    {
                        return PropertyInfo.PropertyType.Name;
                    }
                    else if (FieldInfo != null)
                    {
                        return FieldInfo.FieldType.Name;
                    }

                    return null;
                }
            }

            public Type Type
            {
                get
                {
                    if (PropertyInfo != null)
                    {
                        return PropertyInfo.PropertyType;
                    }
                    else if (FieldInfo != null)
                    {
                        return FieldInfo.FieldType;
                    }
                    else
                    {
                        return null;
                    }
                }
            }

            public bool IsEnum
            {
                get { return Type == null?  false:  Type.IsEnum; }
            }

            public void SetValue(Object obj, Object value)
            {
                if (PropertyInfo != null)
                {
                    PropertyInfo.SetValue(obj, value);
                }
                else if (FieldInfo != null)
                {
                    FieldInfo.SetValue(obj, value);
                }
            }

            public Object GetValue(Object obj)
            {
                if (PropertyInfo != null)
                {
                    return PropertyInfo.GetValue(obj);
                }
                else if (FieldInfo != null)
                {
                    return FieldInfo.GetValue(obj);
                }

                return null;
            }
        }

        public String Title { get; set; }
        public String Message { get; set; }
        public List<Parameter> Parameters { get; set; }
        public Object Model { get; set; }

        public UserInputDialogViewVM(String title, String message, Object model)
        {
            CanClose = false;
            Title = title;
            Message = message;
            Parameters = new List<Parameter>();
            Model = model;
        }

        public void Init()
        {
            try
            {
                if (Model.GetType().IsValueTypeOrString())
                {
                    Parameter p = new Parameter();
                    p.Value = Model.ToStringSafe();
                    p.Name = "Value";
                    Parameters.Add(p);
                }
                else
                {
                    foreach (var prop in Model.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public))
                    {
                        var att = prop.GetCustomAttribute<UserInput>();

                        Parameter p = new Parameter();
                        p.PropertyInfo = prop;
                        p.Name = att != null ? att.Name : prop.Name.ToTitle();

                        if (typeof(IEnumerable).IsAssignableFrom(prop.PropertyType) && prop.PropertyType != typeof(String))
                        {
                            List<String> objects = new List<string>();

                            foreach (var item in prop.GetValue(Model) as IEnumerable)
                            {
                                objects.Add(item.ToStringSafe());
                            }

                            p.Value = String.Join(",", objects);
                        }
                        else
                        {
                            p.Value = prop.GetValue(Model).ToStringSafe();
                        }
                        Parameters.Add(p);
                    }

                    foreach (var field in Model.GetType().GetFields(BindingFlags.Instance | BindingFlags.Public))
                    {
                        var att = field.GetCustomAttribute<UserInput>();

                        Parameter p = new Parameter();
                        p.FieldInfo = field;
                        p.Name = att != null ? att.Name : field.Name.ToTitle();

                        if (typeof(IEnumerable).IsAssignableFrom(field.FieldType) && field.FieldType != typeof(String))
                        {
                            List<String> objects = new List<string>();

                            foreach (var item in field.GetValue(Model) as IEnumerable)
                            {
                                objects.Add(item.ToStringSafe());
                            }

                            p.Value = String.Join(",", objects);
                        }
                        else
                        {
                            p.Value = field.GetValue(Model).ToStringSafe();
                        }
                        Parameters.Add(p);
                    }
                }
            }
            catch (Exception ex)
            {
                throw new Exception("Error initializing the user input model.", ex);
            }
        }

        public void FinalizeModel()
        {
            if (Model.GetType().IsValueTypeOrString())
            {
                Model = Convert.ChangeType(Parameters.First().Value, Model.GetType());
            }
            else
            {
                foreach (var p in Parameters)
                {
                    try
                    {
                        if (typeof(IEnumerable).IsAssignableFrom(p.Type) && p.Type != typeof(String))
                        {
                            List<String> items = p.Value.Split(',').ToList();

                            Type genericType = p.Type.GenericTypeArguments[0];
                            IList list = p.GetValue(Model) as IList;
                            list.Clear();

                            foreach (var item in items)
                            {
                                list.Add(Convert.ChangeType(item, genericType));
                            }
                        }
                        else
                        {
                            if (p.Type.IsEnum)
                            {
                                var enumValue = Enum.Parse(p.Type, p.Value.ToString());
                                p.SetValue(Model, enumValue);
                            }
                            else
                            {
                                p.SetValue(Model, Convert.ChangeType(p.Value, p.Type));
                            }
                        }
                    }
                    catch (Exception ex)
                    {
                        throw new ArgumentException($"Error setting the value '{p.Value}' for parameter '{p.Name}' of type '{p.Type.Name}'.", ex);
                    }
                }
            }
        }
    }
}