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

namespace PRS.Mobile
{
    public abstract class DigitalFormLookupView : ContentView,
        IDigitalFormField<DFLayoutLookupField, DFLayoutLookupFieldProperties, Guid, DFLayoutLookupValue>
    {
        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 void Deserialize(DFLoadStorageEntry entry)
        {
            _value = Definition?.Properties.DeserializeValue(entry) ?? new DFLayoutLookupValue();
            UpdateUI();
        }

        public void Serialize(DFSaveStorageEntry entry)
            => Definition?.Properties.SerializeValue(entry, _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.TryGetValue(property, out object? result))
                return result;
            return null;
        }
        
        public event DigitalFormViewChangedHandler? ValueChanged;

        protected DigitalFormLookupView()
        {
            _value = new DFLayoutLookupValue();
        }

        public void DoLookup(Guid id)
        {
            if (Definition == null)
                return;
            var lookupType = CoreUtils.GetEntity(Definition.Properties.LookupType);
            var filter = Filter.Create(lookupType, "ID").IsEqualTo(id);
            var columns = Columns.Create(lookupType, ColumnTypeFlags.None)
                .Add("ID")
                .Add(Definition.Properties.Property)
                .Add(Definition.Properties.AdditionalPropertiesList)
                .Add(LookupFactory.DefineColumns(lookupType).ColumnNames());
            
            var row = Client.Create(lookupType).Query(filter, columns).Rows.FirstOrDefault();
            if (row == null)
                return;
            
            _value.ID = row.Get<Guid>("ID");
            _value.Text = LookupFactory.FormatLookup(lookupType, row.ToDictionary(), new[] { "ID" });
            _value.Values = row.ToDictionary();
            UpdateUI();

        }
        
        protected void DoLookup(object sender, MobileButtonClickEventArgs args)
        {
            if (Definition == null)
                return;
            var entityType = CoreUtils.GetEntity(Definition.Properties.LookupType);
            var modeltype = typeof(SelectionViewModel<>).MakeGenericType(entityType);
            var model = (ISelectionViewModel)Activator.CreateInstance(modeltype);
            
            if (!String.IsNullOrWhiteSpace(Definition.Properties.Filter))
            {
                var filtertype = typeof(Filter<>).MakeGenericType(entityType);
                model.Filter = Serialization.Deserialize(filtertype, Definition.Properties.Filter) as IFilter;
            }

            foreach (var additionalcolumn in Definition.Properties.AdditionalPropertiesList)
                model.VisibleColumns.Add(additionalcolumn);

            model.VisibleColumns.Add(Definition.Properties.Property);
            
            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();
                var field = Definition.Properties.Property.Split('.').Last();
                var value = e.Row[field];
                ValueChanged?.Invoke(this, new DigitalFormViewChangedArgs(Definition,value));
            };
            Navigation.PushAsync(_selector);
        }

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

        protected abstract void UpdateStatus();

    }
}