using System.Text;
using NewLife.Collections;
using NewLife.Reflection;

namespace NewLife.Serialization;

/// <summary>Json序列化</summary>
/// <remarks>
/// 文档 https://newlifex.com/core/json
/// </remarks>
public class Json : FormatterBase, IJson
{
    #region 属性
    /// <summary>是否缩进</summary>
    public Boolean Indented { get; set; }

    /// <summary>处理器列表</summary>
    public IList<IJsonHandler> Handlers { get; private set; }
    #endregion

    #region 构造
    /// <summary>实例化</summary>
    public Json()
    {
        UseProperty = true;

        // 遍历所有处理器实现
        var list = new List<IJsonHandler>
        {
            new JsonGeneral { Host = this },
            new JsonComposite { Host = this },
            new JsonArray { Host = this }
        };
        //list.Add(new JsonDictionary { Host = this });
        // 根据优先级排序
        Handlers = list.OrderBy(e => e.Priority).ToList();
    }
    #endregion

    #region 处理器
    /// <summary>添加处理器</summary>
    /// <param name="handler"></param>
    /// <returns></returns>
    public Json AddHandler(IJsonHandler handler)
    {
        if (handler != null)
        {
            handler.Host = this;
            Handlers.Add(handler);
            // 根据优先级排序
            Handlers = Handlers.OrderBy(e => e.Priority).ToList();
        }

        return this;
    }

    /// <summary>添加处理器</summary>
    /// <typeparam name="THandler"></typeparam>
    /// <param name="priority"></param>
    /// <returns></returns>
    public Json AddHandler<THandler>(Int32 priority = 0) where THandler : IJsonHandler, new()
    {
        var handler = new THandler
        {
            Host = this
        };
        if (priority != 0) handler.Priority = priority;

        return AddHandler(handler);
    }

    /// <summary>获取处理器</summary>
    /// <typeparam name="T"></typeparam>
    /// <returns></returns>
    public T? GetHandler<T>() where T : class, IJsonHandler
    {
        foreach (var item in Handlers)
        {
            if (item is T) return item as T;
        }

        return default;
    }
    #endregion

    #region 写入
    /// <summary>写入一个对象</summary>
    /// <param name="value">目标对象</param>
    /// <param name="type">类型</param>
    /// <returns></returns>
    public virtual Boolean Write(Object? value, Type? type = null)
    {
        if (type == null)
        {
            if (value == null) return true;

            type = value.GetType();

            // 一般类型为空是顶级调用
            if (Hosts.Count == 0 && Log != null && Log.Enable) WriteLog("JsonWrite {0} {1}", type.Name, value);
        }

        if (value == null) return true;

        //foreach (var item in Handlers)
        //{
        //    if (item.Write(value, type)) return true;
        //}

        var sb = Pool.StringBuilder.Get();
        Write(sb, value);

        Stream.Write(sb.Put(true).GetBytes());

        return true;
    }

    /// <summary>写入字符串</summary>
    /// <param name="value"></param>
    public virtual void Write(String value)
    {
        //_builder.Append(value);
    }

    /// <summary>写入</summary>
    /// <param name="sb"></param>
    /// <param name="value"></param>
    public virtual void Write(StringBuilder sb, Object value)
    {
        if (value == null) return;

        var type = value.GetType();
        foreach (var item in Handlers)
        {
            if (item.Write(value, type)) return;
        }
    }
    #endregion

    #region 读取
    /// <summary>读取指定类型对象</summary>
    /// <param name="type"></param>
    /// <returns></returns>
    public virtual Object? Read(Type type)
    {
        var value = type.CreateInstance();
        return !TryRead(type, ref value) ? throw new Exception("Read failed!") : value;
    }

    /// <summary>读取指定类型对象</summary>
    /// <typeparam name="T"></typeparam>
    /// <returns></returns>
    public T? Read<T>() => (T?)Read(typeof(T));

    /// <summary>尝试读取指定类型对象</summary>
    /// <param name="type"></param>
    /// <param name="value"></param>
    /// <returns></returns>
    public virtual Boolean TryRead(Type type, ref Object? value)
    {
        if (Hosts.Count == 0 && Log != null && Log.Enable) WriteLog("JsonRead {0} {1}", type.Name, value);

        foreach (var item in Handlers)
        {
            if (item.TryRead(type, ref value)) return true;
        }

        return false;
    }

    /// <summary>读取</summary>
    /// <param name="value"></param>
    /// <returns></returns>
    public virtual Boolean Read(String value) => true;

    /// <summary>读取字节</summary>
    /// <returns></returns>
    public virtual Byte ReadByte()
    {
        var b = Stream.ReadByte();
        return b < 0 ? throw new Exception("The data stream is out of range!") : (Byte)b;
    }
    #endregion

    #region 辅助函数

    #endregion
}