#nullable enable
using System;
using UnityEngine.UIElements;

namespace UVC.UIToolkit
{
    /// <summary>
    /// 날짜시간 범위 속성 아이템
    /// 시작, 종료 두 개의 DateTimePicker
    /// </summary>
    public class UTKDateTimeRangePropertyItem : UTKPropertyItemBase<UTKDateTimeRange>
    {
        #region Fields
        private UTKInputField? _startField;
        private UTKInputField? _endField;
        private UTKButton? _startPickerBtn;
        private UTKButton? _endPickerBtn;
        private UTKDatePicker? _currentPicker;
        private bool _isEditingStart;
        private string _dateTimeFormat = "yyyy-MM-dd HH:mm";
        #endregion

        #region Properties
        public override UTKPropertyType PropertyType => UTKPropertyType.DateTimeRange;

        public string DateTimeFormat
        {
            get => _dateTimeFormat;
            set
            {
                _dateTimeFormat = value ?? "yyyy-MM-dd HH:mm";
                RefreshUI();
            }
        }
        #endregion

        #region Constructor
        public UTKDateTimeRangePropertyItem(string id, string name, UTKDateTimeRange initialValue = default, bool isReadOnly = false)
            : base(id, name, initialValue.Start == default ? new UTKDateTimeRange(DateTime.Now, DateTime.Now) : initialValue)
        {
            base._isReadOnly = isReadOnly;
        }

        public UTKDateTimeRangePropertyItem(string id, string name, DateTime start, DateTime end, bool isReadOnly = false)
            : base(id, name, new UTKDateTimeRange(start, end))
        {
            base._isReadOnly = isReadOnly;
        }
        #endregion

        #region Override Methods
        public override VisualElement CreateUI()
        {
            var container = CreateUIFromUxml("UTKDateTimeRangePropertyItem");
            if (container == null)
            {
                return CreateUIFallback();
            }

            _startField = container.Q<UTKInputField>("start-field");
            _endField = container.Q<UTKInputField>("end-field");
            _startPickerBtn = container.Q<UTKButton>("start-picker-btn");
            _endPickerBtn = container.Q<UTKButton>("end-picker-btn");

            if (_startField != null)
            {
                _startField.Value = Value.Start.ToString(_dateTimeFormat);
                _startField.isReadOnly = IsReadOnly;
            }

            if (_endField != null)
            {
                _endField.Value = Value.End.ToString(_dateTimeFormat);
                _endField.isReadOnly = IsReadOnly;
            }

            if (_startPickerBtn != null)
            {
                _startPickerBtn.IsEnabled = !IsReadOnly;
            }

            if (_endPickerBtn != null)
            {
                _endPickerBtn.IsEnabled = !IsReadOnly;
            }

            return container;
        }

        private VisualElement CreateUIFallback()
        {
            var container = CreateContainer();

            var label = CreateNameLabel();
            container.Add(label);

            var valueContainer = new VisualElement();
            valueContainer.AddToClassList("utk-property-item__value");
            valueContainer.style.flexDirection = FlexDirection.Row;

            // Start field
            _startField = new UTKInputField();
            _startField.name = "start-field";
            _startField.Value = Value.Start.ToString(_dateTimeFormat);
            _startField.style.flexGrow = 1;
            _startField.isReadOnly = IsReadOnly;
            valueContainer.Add(_startField);

            _startPickerBtn = new UTKButton("...", "", UTKButton.ButtonVariant.Secondary);
            _startPickerBtn.name = "start-picker-btn";
            _startPickerBtn.IsEnabled = !IsReadOnly;
            _startPickerBtn.AddToClassList("utk-property-item__picker-btn");
            valueContainer.Add(_startPickerBtn);

            var separator = new UTKLabel("~", UTKLabel.LabelSize.Body2);
            separator.AddToClassList("utk-property-item__range-separator");
            valueContainer.Add(separator);

            // End field
            _endField = new UTKInputField();
            _endField.name = "end-field";
            _endField.Value = Value.End.ToString(_dateTimeFormat);
            _endField.style.flexGrow = 1;
            _endField.isReadOnly = IsReadOnly;
            valueContainer.Add(_endField);

            _endPickerBtn = new UTKButton("...", "", UTKButton.ButtonVariant.Secondary);
            _endPickerBtn.name = "end-picker-btn";
            _endPickerBtn.IsEnabled = !IsReadOnly;
            _endPickerBtn.AddToClassList("utk-property-item__picker-btn");
            valueContainer.Add(_endPickerBtn);

            container.Add(valueContainer);

            return container;
        }

        public override void BindUI(VisualElement element)
        {
            base.BindUI(element);

            _startField = element.Q<UTKInputField>("start-field");
            _endField = element.Q<UTKInputField>("end-field");
            _startPickerBtn = element.Q<UTKButton>("start-picker-btn");
            _endPickerBtn = element.Q<UTKButton>("end-picker-btn");

            if (_startField != null)
            {
                _startField.Value = Value.Start.ToString(_dateTimeFormat);
                _startField.isReadOnly = IsReadOnly;
                _startField.OnValueChanged += OnStartTextChanged;
            }

            if (_endField != null)
            {
                _endField.Value = Value.End.ToString(_dateTimeFormat);
                _endField.isReadOnly = IsReadOnly;
                _endField.OnValueChanged += OnEndTextChanged;
            }

            if (_startPickerBtn != null)
            {
                _startPickerBtn.IsEnabled = !IsReadOnly;
                _startPickerBtn.OnClicked += OnStartPickerClicked;
            }

            if (_endPickerBtn != null)
            {
                _endPickerBtn.IsEnabled = !IsReadOnly;
                _endPickerBtn.OnClicked += OnEndPickerClicked;
            }
        }

        public override void UnbindUI(VisualElement element)
        {
            if (_startField != null)
            {
                _startField.OnValueChanged -= OnStartTextChanged;
                _startField = null;
            }

            if (_endField != null)
            {
                _endField.OnValueChanged -= OnEndTextChanged;
                _endField = null;
            }

            if (_startPickerBtn != null)
            {
                _startPickerBtn.OnClicked -= OnStartPickerClicked;
                _startPickerBtn = null;
            }

            if (_endPickerBtn != null)
            {
                _endPickerBtn.OnClicked -= OnEndPickerClicked;
                _endPickerBtn = null;
            }

            ClosePicker();
            base.UnbindUI(element);
        }

        public override void RefreshUI()
        {
            if (_startField != null)
            {
                var formatted = Value.Start.ToString(_dateTimeFormat);
                if (_startField.Value != formatted)
                {
                    _startField.SetValue(formatted, false);
                }
            }

            if (_endField != null)
            {
                var formatted = Value.End.ToString(_dateTimeFormat);
                if (_endField.Value != formatted)
                {
                    _endField.SetValue(formatted, false);
                }
            }
        }

        protected override void UpdateReadOnlyState()
        {
            base.UpdateReadOnlyState();

            if (_startField != null) _startField.isReadOnly = IsReadOnly;
            if (_endField != null) _endField.isReadOnly = IsReadOnly;
            if (_startPickerBtn != null) _startPickerBtn.IsEnabled = !IsReadOnly;
            if (_endPickerBtn != null) _endPickerBtn.IsEnabled = !IsReadOnly;
        }
        #endregion

        #region Private Methods
        private void OnStartPickerClicked()
        {
            _isEditingStart = true;
            OpenPicker(Value.Start);
        }

        private void OnEndPickerClicked()
        {
            _isEditingStart = false;
            OpenPicker(Value.End);
        }

        private void OpenPicker(DateTime initialDateTime)
        {
            if (_currentPicker != null || _rootElement == null) return;

            var root = _rootElement;
            while (root.parent != null) root = root.parent;

            string title = _isEditingStart ? $"{Name} - 시작" : $"{Name} - 종료";
            _currentPicker = UTKDatePicker.Show(root, initialDateTime, UTKDatePicker.PickerMode.DateAndTime, title);
            _currentPicker.OnDateSelected += OnPickerDateSelected;
            _currentPicker.OnClosed += OnPickerClosed;
        }

        private void ClosePicker()
        {
            if (_currentPicker != null)
            {
                _currentPicker.OnDateSelected -= OnPickerDateSelected;
                _currentPicker.OnClosed -= OnPickerClosed;
                _currentPicker.Close();
                _currentPicker = null;
            }
        }

        private void OnPickerDateSelected(DateTime dateTime)
        {
            if (_isEditingStart)
            {
                Value = new UTKDateTimeRange(dateTime, Value.End);
            }
            else
            {
                Value = new UTKDateTimeRange(Value.Start, dateTime);
            }
            ClosePicker();
        }

        private void OnPickerClosed() => _currentPicker = null;

        private void OnStartTextChanged(string newValue)
        {
            if (DateTime.TryParse(newValue, out DateTime dateTime))
            {
                var range = new UTKDateTimeRange(dateTime, Value.End);
                DebounceValueChange(range, 500).Forget();
            }
        }

        private void OnEndTextChanged(string newValue)
        {
            if (DateTime.TryParse(newValue, out DateTime dateTime))
            {
                var range = new UTKDateTimeRange(Value.Start, dateTime);
                DebounceValueChange(range, 500).Forget();
            }
        }
        #endregion

        #region IDisposable
        protected override void Dispose(bool disposing)
        {
            if (disposing) ClosePicker();
            base.Dispose(disposing);
        }
        #endregion
    }
}