#region License
// Copyright (c) 2007 James Newton-King
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
#endregion

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using Newtonsoft.Json.Utilities;
using System.Diagnostics;
using System.Globalization;

namespace Newtonsoft.Json.Linq
{
  /// <summary>
  /// Represents a JSON property.
  /// </summary>
  public class JProperty : JContainer
  {
    private readonly string _name;

    /// <summary>
    /// Gets the property name.
    /// </summary>
    /// <value>The property name.</value>
    public string Name
    {
      [DebuggerStepThrough]
      get { return _name; }
    }

    /// <summary>
    /// Gets or sets the property value.
    /// </summary>
    /// <value>The property value.</value>
    public JToken Value
    {
      [DebuggerStepThrough]
      get { return Content; }
      set
      {
        CheckReentrancy();

        JToken newValue = value ?? new JValue((object) null);

        if (Content == null)
        {
          newValue = EnsureParentToken(newValue);

          Content = newValue;
          Content.Parent = this;
          Content.Next = Content;
        }
        else
        {
          Content.Replace(newValue);
        }
      }
    }

    internal override void ReplaceItem(JToken existing, JToken replacement)
    {
      if (IsTokenUnchanged(existing, replacement))
        return;

      if (Parent != null)
        ((JObject)Parent).InternalPropertyChanging(this);

      base.ReplaceItem(existing, replacement);

      if (Parent != null)
        ((JObject)Parent).InternalPropertyChanged(this);
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="JProperty"/> class from another <see cref="JProperty"/> object.
    /// </summary>
    /// <param name="other">A <see cref="JProperty"/> object to copy from.</param>
    public JProperty(JProperty other)
      : base(other)
    {
      _name = other.Name;
    }

    internal override void AddItem(bool isLast, JToken previous, JToken item)
    {
      if (Value != null)
        throw new Exception("{0} cannot have multiple values.".FormatWith(CultureInfo.InvariantCulture, typeof(JProperty)));

      Value = item;
    }

    internal override JToken GetItem(int index)
    {
      if (index != 0)
        throw new ArgumentOutOfRangeException();

      return Value;
    }

    internal override void SetItem(int index, JToken item)
    {
      if (index != 0)
        throw new ArgumentOutOfRangeException();
      
      Value = item;
    }

    internal override bool RemoveItem(JToken item)
    {
      throw new Exception("Cannot add or remove items from {0}.".FormatWith(CultureInfo.InvariantCulture, typeof(JProperty)));
    }

    internal override void RemoveItemAt(int index)
    {
      throw new Exception("Cannot add or remove items from {0}.".FormatWith(CultureInfo.InvariantCulture, typeof(JProperty)));
    }

    internal override void InsertItem(int index, JToken item)
    {
      throw new Exception("Cannot add or remove items from {0}.".FormatWith(CultureInfo.InvariantCulture, typeof(JProperty)));
    }

    internal override bool ContainsItem(JToken item)
    {
      return (Value == item);
    }

    internal override void ClearItems()
    {
      throw new Exception("Cannot add or remove items from {0}.".FormatWith(CultureInfo.InvariantCulture, typeof(JProperty)));
    }

    /// <summary>
    /// Returns a collection of the child tokens of this token, in document order.
    /// </summary>
    /// <returns>
    /// An <see cref="IEnumerable{T}"/> of <see cref="JToken"/> containing the child tokens of this <see cref="JToken"/>, in document order.
    /// </returns>
    public override JEnumerable<JToken> Children()
    {
      return new JEnumerable<JToken>(ChildrenInternal());
    }

    private IEnumerable<JToken> ChildrenInternal()
    {
      yield return Value;
    }

    internal override bool DeepEquals(JToken node)
    {
      JProperty t = node as JProperty;
      return (t != null && _name == t.Name && ContentsEqual(t));
    }

    internal override JToken CloneToken()
    {
      return new JProperty(this);
    }

    /// <summary>
    /// Gets the node type for this <see cref="JToken"/>.
    /// </summary>
    /// <value>The type.</value>
    public override JTokenType Type
    {
      [DebuggerStepThrough]
      get { return JTokenType.Property; }
    }

    internal JProperty(string name)
    {
      // called from JTokenWriter
      ValidationUtils.ArgumentNotNull(name, "name");

      _name = name;
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="JProperty"/> class.
    /// </summary>
    /// <param name="name">The property name.</param>
    /// <param name="content">The property content.</param>
    public JProperty(string name, params object[] content)
      : this(name, (object)content)
    {
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="JProperty"/> class.
    /// </summary>
    /// <param name="name">The property name.</param>
    /// <param name="content">The property content.</param>
    public JProperty(string name, object content)
    {
      ValidationUtils.ArgumentNotNull(name, "name");

      _name = name;

      Value = IsMultiContent(content)
        ? new JArray(content)
        : CreateFromContent(content);
    }

    /// <summary>
    /// Writes this token to a <see cref="JsonWriter"/>.
    /// </summary>
    /// <param name="writer">A <see cref="JsonWriter"/> into which this method will write.</param>
    /// <param name="converters">A collection of <see cref="JsonConverter"/> which will be used when writing the token.</param>
    public override void WriteTo(JsonWriter writer, params JsonConverter[] converters)
    {
      writer.WritePropertyName(_name);
      Value.WriteTo(writer, converters);
    }

    internal override int GetDeepHashCode()
    {
      return _name.GetHashCode() ^ ((Value != null) ? Value.GetDeepHashCode() : 0);
    }

    /// <summary>
    /// Loads an <see cref="JProperty"/> from a <see cref="JsonReader"/>. 
    /// </summary>
    /// <param name="reader">A <see cref="JsonReader"/> that will be read for the content of the <see cref="JProperty"/>.</param>
    /// <returns>A <see cref="JProperty"/> that contains the JSON that was read from the specified <see cref="JsonReader"/>.</returns>
    public static JProperty Load(JsonReader reader)
    {
      if (reader.TokenType == JsonToken.None)
      {
        if (!reader.Read())
          throw new Exception("Error reading JProperty from JsonReader.");
      }
      if (reader.TokenType != JsonToken.PropertyName)
        throw new Exception(
          "Error reading JProperty from JsonReader. Current JsonReader item is not a property: {0}".FormatWith(
            CultureInfo.InvariantCulture, reader.TokenType));

      JProperty p = new JProperty((string)reader.Value);
      p.SetLineInfo(reader as IJsonLineInfo);

      if (!reader.Read())
        throw new Exception("Error reading JProperty from JsonReader.");

      p.ReadContentFrom(reader);

      return p;
    }
  }
}