using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;
using Netron.NetronLight;
namespace Netron.Diagramming.Core {
  /// <summary>
  /// CollectionBase is a base class that can be used to more easily implement the
  /// generic ICollection&lt;T&gt; and non-generic ICollection interfaces.
  /// </summary>
  /// <remarks>
  /// <para>To use CollectionBase as a base class, the derived class must override
  /// the Count, GetEnumerator, Add, Clear, and Remove methods. </para>
  /// <para>ICollection&lt;T&gt;.Contains need not be implemented by the
  /// derived class, but it should be strongly considered, because the CollectionBase implementation
  /// may not be very efficient.</para>
  /// </remarks>
  /// <typeparam name="T">The item type of the collection.</typeparam>

  [DebuggerDisplay("{DebuggerDisplayString()}")]
  public partial class CollectionBase<T> : ICollection<T>, ICollection, IList<T>, ICollectionBase<T>, IShowable {
    #region Events
    /// <summary>
    /// Occurs when an item is added to the collection.
    /// </summary>
    public event EventHandler<CollectionEventArgs<T>> OnItemAdded;
    /// <summary>
    /// Occurs when an item is removed from the collection.
    /// </summary>
    public event EventHandler<CollectionEventArgs<T>> OnItemRemoved;
    /// <summary>
    /// Occurs when the collection is cleared.
    /// </summary>
    public event EventHandler OnClear;
    #endregion

    #region Fields
    /// <summary>
    /// the internal generic list on which this collection is based
    /// </summary>                                                                    
    protected List<T> innerList;
    /// <summary>
    /// whether this collection is readonly
    /// </summary>
    bool mReadOnly = false;
    #endregion

    #region Properties
    /// <summary>
    /// Indicates whether the collection is read-only. 
    /// </summary>
    bool ICollection<T>.IsReadOnly {
      get {
        return mReadOnly;
      }
    }

    /// <summary>
    /// Gets a value indicating whether this instance is empty.
    /// </summary>
    /// <value><c>true</c> if this instance is empty; otherwise, <c>false</c>.</value>
    public virtual bool IsEmpty {
      get { return this.innerList.Count == 0; }
    }
    #endregion



    #region Constructor

    /// <summary>
    /// Creates a new CollectionBase. 
    /// </summary>
    public CollectionBase() {
      innerList = new List<T>();
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="T:CollectionBase&lt;T&gt;"/> class.
    /// </summary>
    /// <param name="baseCollection">The base collection.</param>
    public CollectionBase(ICollectionBase<T> baseCollection)
      : this() {
      innerList.AddRange(baseCollection);
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="T:CollectionBase&lt;T&gt;"/> class.
    /// </summary>
    /// <param name="baseCollection">The base collection.</param>
    /// <param name="readOnly">if set to <c>true</c> [read only].</param>
    public CollectionBase(ICollectionBase<T> baseCollection, bool readOnly)
      : this() {
      mReadOnly = readOnly;
      //innerList = new System.Collections.ObjectModel.ReadOnlyCollection<T>(baseCollection);
      innerList.AddRange(baseCollection);
    }




    #endregion

    /// <summary>
    /// Shows the string representation of the collection. The string representation contains
    /// a list of the items in the collection. Contained collections (except string) are expanded
    /// recursively.
    /// </summary>
    /// <returns>The string representation of the collection.</returns>
    public override string ToString() {
      return Algorithms.ToString(this);
    }
    /// <summary>
    /// Returns a string representation of this collection.
    /// </summary>
    /// <param name="format">The format.</param>
    /// <param name="formatProvider">The format provider.</param>
    /// <returns></returns>
    public virtual string ToString(string format, IFormatProvider formatProvider) {
      return Showing.ShowString(this, format, formatProvider);
    }

    #region ICollection<T> Members

    /// <summary>
    /// Must be overridden to allow adding items to this collection.
    /// </summary>
    /// <remarks><p>This method is not abstract, although derived classes should always
    /// override it. It is not abstract because some derived classes may wish to reimplement
    /// Add with a different return type (typically bool). In C#, this can be accomplished
    /// with code like the following:</p>
    /// <code>
    ///     public class MyCollection&lt;T&gt;: CollectionBase&lt;T&gt;, ICollection&lt;T&gt;
    ///     {
    ///         public new bool Add(T item) {
    ///             /* Add the item */
    ///         }
    ///  
    ///         void ICollection&lt;T&gt;.Add(T item) {
    ///             Add(item);
    ///         }
    ///     }
    /// </code>
    /// </remarks>
    /// <param name="item">Item to be added to the collection.</param>
    /// <exception cref="NotImplementedException">Always throws this exception to indicated
    /// that the method must be overridden or re-implemented in the derived class.</exception>
    public virtual void Add(T item) {
      if (item == null) throw new InconsistencyException("Adding 'null' to the collection is not allowed.");
      if (mReadOnly)
        throw new InconsistencyException("The collection is read only");
      this.innerList.Add(item);
      RaiseOnItemAdded(item);

    }
    /// <summary>
    /// Determines the index of a specific item in the <see cref="T:System.Collections.Generic.IList`1"></see>.
    /// </summary>
    /// <param name="item">The object to locate in the <see cref="T:System.Collections.Generic.IList`1"></see>.</param>
    /// <returns>
    /// The index of item if found in the list; otherwise, -1.
    /// </returns>
    public int IndexOf(T item) {
      return this.innerList.IndexOf(item);
    }

    /// <summary>
    /// Inserts the specified item at the specified index.
    /// </summary>
    /// <param name="index">The index.</param>
    /// <param name="item">A parameter of the generics Type T</param>
    public virtual void Insert(int index, T item) {
      if (mReadOnly)
        throw new InconsistencyException("The collection is read only");
      if (item.Equals(default(T)))
        return;
      this.innerList.Insert(index, item);
      RaiseOnItemAdded(item);
    }

    /// <summary>
    /// Adds a collection range to this collection.
    /// </summary>
    /// <param name="items">The items.</param>
    public virtual void AddRange(CollectionBase<T> items) {
      if (mReadOnly)
        throw new InconsistencyException("The collection is read only");
      this.innerList.AddRange(items);
      foreach (T item in items) {
        RaiseOnItemAdded(item);
      }
    }

    private void RaiseOnItemAdded(T item) {
      if (OnItemAdded != null)
        OnItemAdded(this, new CollectionEventArgs<T>(item));
    }

    private void RaiseOnItemRemoved(T item) {
      if (OnItemRemoved != null)
        OnItemRemoved(this, new CollectionEventArgs<T>(item));
    }
    private void RaiseOnClear() {
      if (OnClear != null)
        OnClear(this, EventArgs.Empty);
    }



    /// <summary>
    /// Must be overridden to allow clearing this collection.
    /// </summary>
    public virtual void Clear() {
      RaiseOnClear();
      innerList.Clear();
    }

    /// <summary>
    /// Must be overridden to allow removing items from this collection.
    /// </summary>
    /// <returns>True if <paramref name="item"/> existed in the collection and
    /// was removed. False if <paramref name="item"/> did not exist in the collection.</returns>
    public virtual bool Remove(T item) {

      bool result = this.innerList.Remove(item);
      if (result) {
        RaiseOnItemRemoved(item);
      }
      return result;
    }

    /// <summary>
    /// Determines if the collection contains a particular item. This default implementation
    /// iterates all of the items in the collection via GetEnumerator, testing each item
    /// against <paramref name="item"/> using IComparable&lt;T&gt;.Equals or
    /// Object.Equals.
    /// </summary>
    /// <remarks>You should strongly consider overriding this method to provide
    /// a more efficient implementation, or if the default equality comparison
    /// is inappropriate.</remarks>
    /// <param name="item">The item to check for in the collection.</param>
    /// <returns>True if the collection contains <paramref name="item"/>, false otherwise.</returns>
    public virtual bool Contains(T item) {
      return this.innerList.Contains(item);

    }

    /// <summary>
    /// Copies all the items in the collection into an array. Implemented by
    /// using the enumerator returned from GetEnumerator to get all the items
    /// and copy them to the provided array.
    /// </summary>
    /// <param name="array">Array to copy to.</param>
    /// <param name="arrayIndex">Starting index in <paramref name="array"/> to copy to.</param>
    public virtual void CopyTo(T[] array, int arrayIndex) {
      int count = this.Count;

      if (count == 0)
        return;

      if (array == null)
        throw new ArgumentNullException("array");
      if (count < 0)
        throw new ArgumentOutOfRangeException("count", count, Resource1.ArgumentOutOfRange);
      if (arrayIndex < 0)
        throw new ArgumentOutOfRangeException("arrayIndex", arrayIndex, Resource1.ArgumentOutOfRange);
      if (arrayIndex >= array.Length || count > array.Length - arrayIndex)
        throw new ArgumentException("arrayIndex", Resource1.ArrayTooSmall);

      int index = arrayIndex, i = 0;
      foreach (T item in (ICollection<T>)this) {
        if (i >= count)
          break;

        array[index] = item;
        ++index;
        ++i;
      }
    }

    /// <summary>
    /// Creates an array of the correct size, and copies all the items in the 
    /// collection into the array, by calling CopyTo.
    /// </summary>
    /// <returns>An array containing all the elements in the collection, in order.</returns>
    public virtual T[] ToArray() {
      int count = this.Count;

      T[] array = new T[count];
      CopyTo(array, 0);
      return array;
    }

    /// <summary>
    /// Must be overridden to provide the number of items in the collection.
    /// </summary>
    /// <value>The number of items in the collection.</value>
    public virtual int Count { get { return innerList.Count; } }



    #endregion

    #region Delegate operations

    /// <summary>
    /// Determines if the collection contains any item that satisfies the condition
    /// defined by <paramref name="predicate"/>.
    /// </summary>
    /// <param name="predicate">A delegate that defines the condition to check for.</param>
    /// <returns>True if the collection contains one or more items that satisfy the condition
    /// defined by <paramref name="predicate"/>. False if the collection does not contain
    /// an item that satisfies <paramref name="predicate"/>.</returns>
    public virtual bool Exists(Predicate<T> predicate) {
      if (predicate == null)
        throw new ArgumentNullException("predicate");

      return Algorithms.Exists(this, predicate);
    }

    /// <summary>
    /// Determines if all of the items in the collection satisfy the condition
    /// defined by <paramref name="predicate"/>.
    /// </summary>
    /// <param name="predicate">A delegate that defines the condition to check for.</param>
    /// <returns>True if all of the items in the collection satisfy the condition
    /// defined by <paramref name="predicate"/>, or if the collection is empty. False if one or more items
    /// in the collection do not satisfy <paramref name="predicate"/>.</returns>
    public virtual bool TrueForAll(Predicate<T> predicate) {
      if (predicate == null)
        throw new ArgumentNullException("predicate");

      return Algorithms.TrueForAll(this, predicate);
    }
    /*
   /// <summary>
   /// Counts the number of items in the collection that satisfy the condition
   /// defined by <paramref name="predicate"/>.
   /// </summary>
   /// <param name="predicate">A delegate that defines the condition to check for.</param>
   /// <returns>The number of items in the collection that satisfy <paramref name="predicate"/>.</returns>
   public virtual int CountWhere(Predicate<T> predicate)
   {
       if (predicate == null)
           throw new ArgumentNullException("predicate");

       return Algorithms.CountWhere(this, predicate);
   }
     */
    /// <summary>
    /// Finds the first item in the collection satisfying the given predicate
    /// </summary>
    /// <param name="predicate">a searching predictae</param>
    /// <returns>an item satisfying the criteria (if any)</returns>
    public virtual T Find(Predicate<T> predicate) {
      foreach (T item in this.innerList) {
        if (predicate(item))
          return item;
      }
      return default(T);
    }


    /// <summary>
    /// Removes all the items in the collection that satisfy the condition
    /// defined by <paramref name="predicate"/>.
    /// </summary>
    /// <param name="predicate">A delegate that defines the condition to check for.</param>
    /// <returns>Returns a collection of the items that were removed, in sorted order.</returns>
    public virtual ICollection<T> RemoveAll(Predicate<T> predicate) {
      if (predicate == null)
        throw new ArgumentNullException("predicate");

      return Algorithms.RemoveWhere(this, predicate);
    }

    /// <summary>
    /// Performs the specified action on each item in this collection.
    /// </summary>
    /// <param name="action">An Action delegate which is invoked for each item in this collection.</param>
    public virtual void ForEach(Action<T> action) {
      if (action == null)
        throw new ArgumentNullException("action");

      Algorithms.ForEach(this, action);
    }



    #endregion

    #region IEnumerable<T> Members

    /// <summary>
    /// Must be overridden to enumerate all the members of the collection.
    /// </summary>
    /// <returns>A generic IEnumerator&lt;T&gt; that can be used
    /// to enumerate all the items in the collection.</returns>
    public virtual IEnumerator<T> GetEnumerator() {
      return this.innerList.GetEnumerator();
    }


    #endregion

    #region ICollection Members

    /// <summary>
    /// Copies all the items in the collection into an array. Implemented by
    /// using the enumerator returned from GetEnumerator to get all the items
    /// and copy them to the provided array.
    /// </summary>
    /// <param name="array">Array to copy to.</param>
    /// <param name="index">Starting index in <paramref name="array"/> to copy to.</param>
    void ICollection.CopyTo(Array array, int index) {
      int count = this.Count;

      if (count == 0)
        return;

      if (array == null)
        throw new ArgumentNullException("array");
      if (index < 0)
        throw new ArgumentOutOfRangeException("index", index, Resource1.ArgumentOutOfRange);
      if (index >= array.Length || count > array.Length - index)
        throw new ArgumentException("index", Resource1.ArrayTooSmall);

      int i = 0;
      foreach (object o in (ICollection)this) {
        if (i >= count)
          break;

        array.SetValue(o, index);
        ++index;
        ++i;
      }
    }

    /// <summary>
    /// Indicates whether the collection is synchronized.
    /// </summary>
    /// <value>Always returns false, indicating that the collection is not synchronized.</value>
    bool ICollection.IsSynchronized {
      get { return IsSynchronized; }
    }

    /// <summary>
    /// See code analysis CA1033
    /// </summary>
    protected bool IsSynchronized {
      get { return false; }
    }
    /// <summary>
    /// Indicates the synchronization object for this collection.
    /// </summary>
    /// <value>Always returns this.</value>
    object ICollection.SyncRoot {
      get { return SyncRoot; }
    }

    /// <summary>
    /// See code analysis CA1033
    /// </summary>
    protected object SyncRoot {
      get { return this; }
    }

    #endregion

    #region IEnumerable Members

    /// <summary>
    /// Provides an IEnumerator that can be used to iterate all the members of the
    /// collection. This implementation uses the IEnumerator&lt;T&gt; that was overridden
    /// by the derived classes to enumerate the members of the collection.
    /// </summary>
    /// <returns>An IEnumerator that can be used to iterate the collection.</returns>
    IEnumerator IEnumerable.GetEnumerator() {
      foreach (T item in this) {
        yield return item;
      }
    }

    #endregion

    /// <summary>
    /// Display the contents of the collection in the debugger. This is intentionally private, it is called
    /// only from the debugger due to the presence of the DebuggerDisplay attribute. It is similar
    /// format to ToString(), but is limited to 250-300 characters or so, so as not to overload the debugger.
    /// </summary>
    /// <returns>The string representation of the items in the collection, similar in format to ToString().</returns>
    internal string DebuggerDisplayString() {
      const int MAXLENGTH = 250;

      System.Text.StringBuilder builder = new System.Text.StringBuilder();

      builder.Append('{');

      // Call ToString on each item and put it in.
      bool firstItem = true;
      foreach (T item in this) {
        if (builder.Length >= MAXLENGTH) {
          builder.Append(",...");
          break;
        }

        if (!firstItem)
          builder.Append(',');

        if (item == null)
          builder.Append("null");
        else
          builder.Append(item.ToString());

        firstItem = false;
      }

      builder.Append('}');
      return builder.ToString();
    }
    /// <summary>
    /// Removes an item at the given index
    /// </summary>
    /// <param name="index"></param>
    public void RemoveAt(int index) {
      this.innerList.RemoveAt(index);
    }
    /// <summary>
    /// Integer indexer
    /// </summary>
    /// <param name="index"></param>
    /// <returns></returns>
    public T this[int index] {
      get {
        return this.innerList[index];
      }
      set {
        this.innerList[index] = value;
      }
    }

    /// <summary>
    /// Returns a deep copy of this collection.
    /// <remarks>The returned collection is not attached to the <see cref="Model"/>
    /// and is as such on an in-memory collection of instances. You need to 'unwrap' the collection 
    /// in the model and, to make it visible, deploy it in the paintables collection of the model.
    /// </remarks>
    /// </summary>
    /// <returns></returns>
    public CollectionBase<T> DeepCopy() {
      /* This doesn't work seemingly....
      if (!typeof(T).IsSerializable)
          throw new InconsistencyException("The generic type on which the collection is based is not serializable, the collection cannot generate a deep copy.");
      */

      try {

        CollectionBase<T> newobj = null;
        MemoryStream stream = new MemoryStream();
        GenericFormatter<BinaryFormatter> f = new GenericFormatter<BinaryFormatter>();
        f.Serialize(stream, this);
        stream.Seek(0, SeekOrigin.Begin);
        newobj = f.Deserialize<CollectionBase<T>>(stream);
        stream.Close();
        return newobj;
      }
      catch (Exception exc) {
        throw new InconsistencyException("The copy operation failed.", exc);
      }

    }
    /// <summary>
    /// Returns a copy of this instance.
    /// </summary>
    /// <returns></returns>
    public CollectionBase<T> Copy() {
      CollectionBase<T> copy = new CollectionBase<T>();
      foreach (T item in this.innerList) {
        copy.Add(item);
      }
      return copy;
    }
    /// <summary>
    /// This method creates first a deep copy of the collection and puts 
    /// the result in a <see cref="MemoryStream"/>. 
    /// See the <see cref="CopyTool"/> for details.
    /// </summary>
    /// <returns></returns>
    public MemoryStream ToStream() {
      try {

        MemoryStream stream = new MemoryStream();
        GenericFormatter<BinaryFormatter> f =
            new GenericFormatter<BinaryFormatter>();
        f.Serialize(stream, this);
        return stream;
      }
      catch (Exception exc) {
        throw new InconsistencyException(
            "The ToStream() operation failed.",
            exc);
      }

    }

    /// <summary>
    /// Format <code>this</code> using at most approximately <code>rest</code> chars and
    /// append the result, possibly truncated, to stringbuilder.
    /// Subtract the actual number of used chars from <code>rest</code>.
    /// </summary>
    /// <param name="stringbuilder"></param>
    /// <param name="rest"></param>
    /// <param name="formatProvider"></param>
    /// <returns>
    /// True if the appended formatted string was complete (not truncated).
    /// </returns>
    public virtual bool Show(System.Text.StringBuilder stringbuilder, ref int rest, IFormatProvider formatProvider) {
      return true;
    }

  }






}