using System;
using System.Collections;
using System.Collections.Generic;
using System.Runtime.Serialization;
using System.Xml;
using System.Xml.Schema;
using System.Xml.Serialization;
using UnityEngine;

/// <summary>
/// 解决原生字典无法被序列化XML的问题
/// </summary>
/// <typeparam name="TKey"></typeparam>
/// <typeparam name="TValue"></typeparam>
[Serializable]
public class XDictionary<TKey, TValue>: Dictionary<TKey, TValue>, IXmlSerializable, ISerializable
{
    #region 构造函数

    #region 默认构造函数 + public DictionaryEx()
    /// <summary>
    /// 默认构造函数
    /// </summary>
    public XDictionary()
        : base()
    {

    }
    #endregion

    #region 构造函数 + public DictionaryEx(int capacity)
    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="capacity">可包含的初始元素数</param>
    public XDictionary(int capacity)
        : base(capacity)
    {

    }
    #endregion

    #region 构造函数 + public DictionaryEx(IEqualityComparer<TKey> comparer)
    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="comparer">比较键时要使用的 比较器 实现，或者为 null，以便为键类型使用默认的 比较器</param>
    public XDictionary(IEqualityComparer<TKey> comparer)
        : base(comparer)
    {

    }
    #endregion

    #region 构造函数 + public DictionaryEx(IDictionary<TKey, TValue> dictionary)
    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="dictionary">初始数据</param>
    public XDictionary(IDictionary<TKey, TValue> dictionary)
        : base(dictionary)
    {

    }
    #endregion

    #region 构造函数 + public DictionaryEx(int capacity, IEqualityComparer<TKey> comparer)
    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="capacity">可包含的初始元素数</param>
    /// <param name="comparer">比较键时要使用的 比较器 实现，或者为 null，以便为键类型使用默认的 比较器</param>
    public XDictionary(int capacity, IEqualityComparer<TKey> comparer)
        : base(capacity, comparer)
    {

    }
    #endregion

    #region 构造函数 + public DictionaryEx(IDictionary<TKey, TValue> dictionary, IEqualityComparer<TKey> comparer)
    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="dictionary">初始数据</param>
    /// <param name="comparer">比较键时要使用的 比较器 实现，或者为 null，以便为键类型使用默认的 比较器</param>
    public XDictionary(IDictionary<TKey, TValue> dictionary, IEqualityComparer<TKey> comparer)
        : base(dictionary, comparer)
    {

    }
    #endregion

    //二进制反序列化构造函数
    public XDictionary(SerializationInfo info, StreamingContext context):base(info, context)
    {
        
    }

    #endregion

    #region 取得概要 + public XmlSchema GetSchema()
    /// <summary>
    /// 取得概要
    /// 注：根据MSDN的文档，此方法为保留方法，一定返回 null。
    /// </summary>
    /// <returns>Xml概要</returns>
    public XmlSchema GetSchema()
    {
        return null;
    }
    #endregion

    #region 从 XML 对象中反序列化生成本对象 + public void ReadXml(XmlReader reader)
    /// <summary>  
    /// 从 XML 对象中反序列化生成本对象
    /// </summary>  
    /// <param name="reader">包含反序列化对象的 XmlReader 流</param>  
    public void ReadXml(XmlReader reader)
    {
        XmlSerializer keySerializer = new XmlSerializer(typeof(TKey));
        XmlSerializer valueSerializer = new XmlSerializer(typeof(TValue));
        bool wasEmpty = reader.IsEmptyElement;
        reader.Read();
        if (wasEmpty) return;

        while (reader.NodeType != XmlNodeType.EndElement)
        {
            reader.ReadStartElement("Item");
            reader.ReadStartElement("Key");
            TKey key = (TKey)keySerializer.Deserialize(reader);
            reader.ReadEndElement();
            reader.ReadStartElement("Value");
            TValue value = (TValue)valueSerializer.Deserialize(reader);
            reader.ReadEndElement();
            this.Add(key, value);
            reader.ReadEndElement();
            reader.MoveToContent();
        }

        reader.ReadEndElement();
    }
    #endregion

    #region 将本对象序列化为 XML 对象 + public void WriteXml(XmlWriter writer)
    /// <summary>  
    /// 将本对象序列化为 XML 对象
    /// </summary>  
    /// <param name="writer">待写入的 XmlWriter 对象</param>  
    public void WriteXml(XmlWriter writer)
    {
        XmlSerializer keySerializer = new XmlSerializer(typeof(TKey));
        XmlSerializer valueSerializer = new XmlSerializer(typeof(TValue));
        foreach (TKey key in this.Keys)
        {
            writer.WriteStartElement("Item");
            writer.WriteStartElement("Key");
            keySerializer.Serialize(writer, key);
            writer.WriteEndElement();
            writer.WriteStartElement("Value");
            TValue value = this[key];
            valueSerializer.Serialize(writer, value);
            writer.WriteEndElement();
            writer.WriteEndElement();
        }
    }
    #endregion
}