using Model;
using System;
using System.Collections.Generic;
using System.ComponentModel.Design;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp.Menu
{
    internal abstract class Menu<T> : IMenu
        where T : notnull
    {
        protected StringBuilder _screenDisplay;
        protected List<Selector<T>> _selectList = new List<Selector<T>>();

        public string Title { get; private set; }
        public StringBuilder InputStr { get; set; }

        private int _currentLine;
        public int CurrentLine {
            get => _currentLine;
            private set
            {
                _currentLine = value;
                if (_currentLine < 0) _currentLine = 0;
                if (_currentLine >= _selectList.Count) _currentLine = _selectList.Count-1;
            }
        }

        public T? CurrentSelected { get; protected set; }
        public bool WriteMode { get; set; }

        protected Menu(string title)
        {
            Title = title;
            CurrentLine = 0;
            WriteMode = false;
            _screenDisplay = new StringBuilder();
            InputStr = new StringBuilder();
        }

        protected Menu(string title, params Selector<T>[] selections ) : this(title)
        {
            if (selections == null || selections.Length == 0)
                throw new ArgumentException("Error: a menu must contain at least 1 selection");

            _selectList = selections.ToList();
            CurrentSelected = _selectList[0].Item;
        }

        public virtual void Display()
        {
            Console.Clear();
            Console.WriteLine(_screenDisplay);
        }

        public virtual void Update()
        {
            _screenDisplay.AppendLine($"[ {Title} ]");
            _screenDisplay.AppendLine("-------------------------------------------\n");

            for (int i = 0; i < _selectList.Count; i++)
            {
                if (CurrentLine == i)
                    _screenDisplay.Append($">  ");
                else
                    _screenDisplay.Append($"   ");

                _screenDisplay.AppendLine($"{_selectList[i].Line}");
            }
        }

        public void SelectNext()
        {
            CurrentSelected = _selectList[++CurrentLine].Item;
        }

        public void SelectPrevious()
        {
            CurrentSelected = _selectList[--CurrentLine].Item;
        }

        public void EnableWriteMode()
        {
            WriteMode = true;
        }

        public void DisableWriteMode()
        {
            WriteMode = false;
        }

        public abstract void Return();
    }
}