using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;

namespace Store.Framework.Models
{
    /// <summary>
    /// Cookie集合，支持普通 Cookie 字符串和 API 返回的 Cookie JSON。
    /// </summary>
    [JsonConverter(typeof(CookiesJsonConverter))]
    public class Cookies : Dictionary<string, string>
    {
        private readonly string oldCookie;

        public Cookies(string cookie)
        {
            oldCookie = cookie;
            Load(cookie);
        }

        /// <summary>
        /// Cookie字符串
        /// </summary>
        public string CookieString
        {
            get
            {
                return GetCookieString();
            }
        }

        /// <summary>
        /// 获取指定值
        /// </summary>
        /// <param name="key"></param>
        /// <param name="defvalue">默认值</param>
        /// <returns></returns>
        public string GetValue(string key, string defvalue)
        {
            if (ContainsKey(key))
            {
                return this[key];
            }
            return defvalue;
        }

        /// <summary>
        /// 添加或修改
        /// </summary>
        /// <param name="key"></param>
        /// <param name="value"></param>
        public void AddOrUpdate(string key, string value)
        {
            if (!this.ContainsKey(key))
            {
                Add(key, value);
            }
            else
            {
                this[key] = value;
            }
        }

        /// <summary>
        /// 获取Cookies字符串
        /// </summary>
        /// <returns></returns>
        public virtual string GetCookieString()
        {
            var list = this.Select(a => { return $"{a.Key}={a.Value}"; });
            return string.Join(";", list);
        }

        /// <summary>
        /// 转为浏览器 Cookie 字符串。
        /// </summary>
        public override string ToString()
        {
            var list = this.Select(a => { return $"{a.Key}={a.Value}"; });
            return string.Join("; ", list);
        }
        /// <summary>
        /// 隐式转换
        /// </summary>
        /// <param name="cookie"></param>
        public static implicit operator string(Cookies cookie)
        {
            return cookie.GetCookieString();
        }

        internal static Cookies FromToken(JToken token)
        {
            Cookies cookies = new Cookies(string.Empty);
            if (token == null || token.Type == JTokenType.Null)
                return cookies;

            if (token.Type == JTokenType.String)
                return new Cookies(token.ToString());

            cookies.AddToken(token);
            return cookies;
        }

        private void Load(string cookie)
        {
            Clear();
            if (string.IsNullOrWhiteSpace(cookie))
                return;

            try
            {
                AddToken(JToken.Parse(cookie));
                if (Count > 0)
                    return;
            }
            catch (JsonException)
            {
            }

            SplitCookie(Decode(cookie));
        }

        private void AddToken(JToken token)
        {
            if (token == null || token.Type == JTokenType.Null)
                return;

            if (token is JArray array)
            {
                foreach (JToken item in array)
                {
                    AddCookie(item);
                }
                return;
            }

            AddCookie(token);
        }

        private void AddCookie(JToken token)
        {
            if (token == null || token.Type == JTokenType.Null)
                return;

            if (token.Type == JTokenType.String)
            {
                string value = token.ToString();
                int index = value.IndexOf('=');
                if (index <= 0)
                    return;

                AddOrUpdate(value.Substring(0, index).Trim(), value.Substring(index + 1).Trim());
                return;
            }

            JToken name = token["Name"] ?? token["name"];
            JToken valueToken = token["Value"] ?? token["value"];
            if (name == null || valueToken == null)
                return;

            AddOrUpdate(name.ToString(), valueToken.ToString());
        }

        /// <summary>
        /// 拆分普通 Cookie 字符串。
        /// </summary>
        private void SplitCookie(string cookie)
        {
            Clear();
            if (string.IsNullOrEmpty(cookie))
                return;

            Regex regCookie = new Regex("(?<key>.+?)=(?<value>.+?)(;|$)");
            if (regCookie.IsMatch(cookie))
            {
                MatchCollection matchs = regCookie.Matches(cookie);
                foreach (Match item in matchs)
                {
                    string key = item.Groups["key"].Value.Trim();
                    string value = item.Groups["value"].Value.Trim();
                    if (!ContainsKey(key))
                    {
                        this.Add(key, value);
                    }
                }
            }
        }

        private static string Decode(string value)
        {
            return (value ?? string.Empty)
                .Replace("＆", "&")
                .Replace("％", "%")
                .Replace("＋", "+")
                .Replace("＂", "\"");
        }
    }

    /// <summary>
    /// Cookie JSON 转换器。
    /// </summary>
    public class CookiesJsonConverter : JsonConverter
    {
        public override bool CanConvert(Type objectType)
        {
            return typeof(Cookies).IsAssignableFrom(objectType);
        }

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        {
            if (reader.TokenType == JsonToken.Null)
                return null;

            if (reader.TokenType == JsonToken.String)
                return new Cookies(reader.Value?.ToString());

            return Cookies.FromToken(JToken.Load(reader));
        }

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            Cookies cookies = value as Cookies;
            writer.WriteValue(cookies?.GetCookieString());
        }
    }
}