using System;
using System.Collections.Generic;
using NewLife.Data;
using NewLife.Log;

namespace NewLife.Remoting
{
    /// <summary>编码器</summary>
    public interface IEncoder
    {
        /// <summary>编码对象</summary>
        /// <param name="obj"></param>
        /// <returns></returns>
        Byte[] Encode(Object obj);

        /// <summary>编码请求</summary>
        /// <param name="action"></param>
        /// <param name="args"></param>
        /// <param name="cookie">附加参数，位于顶级</param>
        /// <returns></returns>
        Byte[] Encode(String action, Object args, IDictionary<String, Object> cookie);

        /// <summary>编码响应</summary>
        /// <param name="code"></param>
        /// <param name="result"></param>
        /// <param name="cookie">附加参数，位于顶级</param>
        /// <returns></returns>
        Byte[] Encode(Int32 code, Object result, IDictionary<String, Object> cookie);

        /// <summary>解码成为字典</summary>
        /// <param name="pk">数据包</param>
        /// <returns></returns>
        IDictionary<String, Object> Decode(Packet pk);

        ///// <summary>解码请求</summary>
        ///// <param name="dic"></param>
        ///// <param name="action"></param>
        ///// <param name="args"></param>
        ///// <returns></returns>
        //Boolean TryGet(IDictionary<String, Object> dic, out String action, out Object args);

        ///// <summary>解码响应</summary>
        ///// <param name="dic"></param>
        ///// <param name="code"></param>
        ///// <param name="result"></param>
        ///// <returns></returns>
        //Boolean TryGet(IDictionary<String, Object> dic, out Int32 code, out Object result);

        /// <summary>转换为对象</summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="obj"></param>
        /// <returns></returns>
        T Convert<T>(Object obj);

        /// <summary>转换为目标类型</summary>
        /// <param name="obj"></param>
        /// <param name="targetType"></param>
        /// <returns></returns>
        Object Convert(Object obj, Type targetType);

        /// <summary>日志提供者</summary>
        ILog Log { get; set; }
    }

    /// <summary>编码器基类</summary>
    public abstract class EncoderBase : IEncoder
    {
        /// <summary>编码对象</summary>
        /// <param name="obj"></param>
        /// <returns></returns>
        public abstract Byte[] Encode(Object obj);

        /// <summary>编码请求</summary>
        /// <param name="action"></param>
        /// <param name="args"></param>
        /// <param name="cookie">附加参数，位于顶级</param>
        /// <returns></returns>
        public virtual Byte[] Encode(String action, Object args, IDictionary<String, Object> cookie)
        {
            var obj = new { action, args };
            return Encode(obj.ToDictionary().Merge(cookie));
        }

        /// <summary>编码响应</summary>
        /// <param name="code"></param>
        /// <param name="result"></param>
        /// <param name="cookie">附加参数，位于顶级</param>
        /// <returns></returns>
        public virtual Byte[] Encode(Int32 code, Object result, IDictionary<String, Object> cookie)
        {
            // 不支持序列化异常
            if (result is Exception ex) result = ex.GetTrue()?.Message;

            var obj = new { code, result };
            return Encode(obj.ToDictionary().Merge(cookie));
        }

        /// <summary>解码成为字典</summary>
        /// <param name="pk"></param>
        /// <returns></returns>
        public abstract IDictionary<String, Object> Decode(Packet pk);

        ///// <summary>解码请求</summary>
        ///// <param name="dic"></param>
        ///// <param name="action"></param>
        ///// <param name="args"></param>
        ///// <returns></returns>
        //public virtual Boolean TryGet(IDictionary<String, Object> dic, out String action, out Object args)
        //{
        //    action = null;
        //    args = null;

        //    Object act = null;
        //    if (!dic.TryGetValue("action", out act)) return false;

        //    // 参数可能不存在
        //    dic.TryGetValue("args", out args);

        //    action = act + "";

        //    return true;
        //}

        ///// <summary>解码响应</summary>
        ///// <param name="dic"></param>
        ///// <param name="code"></param>
        ///// <param name="result"></param>
        ///// <returns></returns>
        //public virtual Boolean TryGet(IDictionary<String, Object> dic, out Int32 code, out Object result)
        //{
        //    code = 0;
        //    result = null;

        //    Object cod = null;
        //    if (!dic.TryGetValue("code", out cod)) return false;

        //    // 参数可能不存在
        //    dic.TryGetValue("result", out result);

        //    code = cod.ToInt();

        //    return true;
        //}

        /// <summary>转换为对象</summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="obj"></param>
        /// <returns></returns>
        public virtual T Convert<T>(Object obj)
        {
            return (T)Convert(obj, typeof(T));
        }

        /// <summary>转换为目标类型</summary>
        /// <param name="obj"></param>
        /// <param name="targetType"></param>
        /// <returns></returns>
        public abstract Object Convert(Object obj, Type targetType);

        #region 日志
        /// <summary>日志提供者</summary>
        public ILog Log { get; set; } = Logger.Null;

        /// <summary>写日志</summary>
        /// <param name="format"></param>
        /// <param name="args"></param>
        public virtual void WriteLog(String format, params Object[] args)
        {
            Log.Info(format, args);
        }
        #endregion
    }
}