using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Text;

namespace Model
{
    /// <summary>
    /// Define a collection of <see cref="Recipe"/>.
    /// <br/>This class implement <see cref="IList"/> and <see cref="IEquatable{T}"/>.
    /// </summary>
    public class RecipeCollection : IList<Recipe>, IEquatable<RecipeCollection>
    {
        #region Attributes
        private readonly List<Recipe> _recipes;
        private string _description = "";
        #endregion

        #region Properties
        /// <summary>
        /// A short description of what this collection contain. <br/>
        /// Set to "No description." when the value passed is null, empty or contain white spaces.
        /// </summary>
        public string Description
        {
            get => _description;
            set
            {
                if (string.IsNullOrWhiteSpace(value))
                    _description = "No description.";
                else
                    _description = value;
            }
        }

        #region IList Prperties
        public int Count => _recipes.Count;
        public bool IsReadOnly => false;
        public Recipe this[int index] { get => _recipes[index]; set => _recipes[index] = value; }
        #endregion
        #endregion

        #region Constructors
        /// <summary>
        /// Construct a new collection of _recipes.
        /// </summary>
        /// <param name="description">A short description of what this list will contain</param>
        /// <param name="recipes">Recipes to add in this new collection</param>
        public RecipeCollection(string description, params Recipe[] recipes)
        {
            _recipes = new List<Recipe>(recipes);
            Description = description;
        }
        #endregion

        #region Methods
        /// <summary>
        /// Find a recipe in this list by giving the id.
        /// </summary>
        /// <param name="id">The id of the list we are looking for</param>
        /// <returns>The recipe of the id given</returns>
        /// <exception cref="ArgumentException"/>
        public Recipe? GetRecipeById(int id)
        {
            Recipe? recipe = _recipes.Find(r => r.Id == id);
            if (recipe == null) throw new ArgumentException("No _recipes match the given id.");
            return recipe;
        }

        public RecipeCollection ResearchByName(string str)
        {
            return new RecipeCollection(
                description: $"Results of the research: {str}",
                recipes: _recipes.FindAll(x => x.Title.ToLower().Contains(str.ToLower())).ToArray());
        }

        #region IList Methods
        public int IndexOf(Recipe item)
        {
            return _recipes.IndexOf(item);
        }

        public void Insert(int index, Recipe item)
        {
            _recipes.Insert(index, item);
        }

        public void RemoveAt(int index)
        {
            _recipes.RemoveAt(index);
        }

        public void Add(Recipe item)
        {
            _recipes.Add(item);
        }

        public void Clear()
        {
            _recipes.Clear();
        }

        public bool Contains(Recipe item)
        {
            return _recipes.Contains(item);
        }

        public void CopyTo(Recipe[] array, int arrayIndex)
        {
            _recipes.CopyTo(array, arrayIndex);
        }

        public bool Remove(Recipe item)
        {
            return _recipes.Remove(item);
        }

        public IEnumerator<Recipe> GetEnumerator()
        {
            return _recipes.GetEnumerator();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return _recipes.GetEnumerator();
        }
        #endregion

        public virtual bool Equals(RecipeCollection? other)
        {
            
            if (other == null) return false;
            if (other == this) return true;
            return _description.Equals(other.Description) && _recipes.Equals(other._recipes);
        }

        public override bool Equals(object? obj)
        {
            var item = obj as RecipeCollection;
            if (item == null) return false;
            return Equals(obj);
        }

        public override int GetHashCode()
        {
            return _recipes.GetHashCode();
        }

        public override string ToString()
        {
            StringBuilder sb = new StringBuilder($"[RecipeCollection] - {Description}:\n");
            foreach (Recipe r in _recipes)
            {
                sb.AppendFormat("\t - {0}\n", r.ToString());
            }
            return sb.ToString();
        }
        #endregion
    }
}