using System;
using InABox.Core;
using InABox.Mobile;
using Xamarin.Forms;

namespace PRS.Mobile
{
    public abstract class DigitalFormLookupView : ContentView,
        IDigitalFormField<DFLayoutLookupField, DFLayoutLookupFieldProperties, Guid>
    {
        private DFLayoutLookupField _definition;
        public DFLayoutLookupField Definition
        {
            get => _definition;
            set
            {
                _definition = value;
                Initialize(value ??  new DFLayoutLookupField());
            } 
        }

        protected DFLayoutLookupValue _value;
        public Guid Value
        {
            get => _value.ID;
            set =>_value.ID = value;
        }

        public bool IsEmpty => Value == Guid.Empty;

        protected abstract void UpdateUI();
        
        private bool _readOnly;
        public bool ReadOnly
        {
            get => _readOnly;
            set
            {
                _readOnly = value;
                UpdateStatus();
            }
        }

        public object OtherValue(String property)
        {
            if ((_value?.Values != null) && _value.Values.TryGetValue(property, out object result))
                return result;
            return null;
        }
        
        public void Deserialize(string serialized)
        {
            _value = new DFLayoutLookupValue(serialized);
            UpdateUI();
        }

        public string Serialize()
        {
            return _value?.ToString() ?? "";
        }

        public event DigitalFormViewChangedHandler ValueChanged;

        protected DigitalFormLookupView()
        {
            _value = new DFLayoutLookupValue();
        }
        
        protected void DoLookup(object sender, MobileButtonClickEventArgs args)
        {
            var entityType = CoreUtils.GetEntity(Definition.Properties.LookupType);
            var modeltype = typeof(SelectionViewModel<>).MakeGenericType(entityType);
            var model = (ISelectionViewModel)Activator.CreateInstance(modeltype);
            foreach (var additionalcolumn in Definition.Properties.AdditionalPropertiesList)
                model.VisibleColumns.Add(additionalcolumn);
            GenericSelectionPage _selector = new GenericSelectionPage("Select Value", model);
            _selector.OnItemSelected += (o,e) =>
            {
                _value.ID = e.Row.Get<Guid>("ID");
                _value.Text = e.Formatted;
                _value.Values = e.Row.ToDictionary();
                UpdateUI();
                ValueChanged?.Invoke(this, new DigitalFormViewChangedArgs(Definition,Value));
            };
            Navigation.PushAsync(_selector);
        }

        private void Initialize(DFLayoutLookupField definition)
        {
            UpdateStatus();
        }

        protected abstract void UpdateStatus();

    }
}