using Fiddler;
using FiddlerDecryption.Utils;
using Flurl.Http;
using Newtonsoft.Json.Linq;
using System;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace Util
{
    class DecodeUtil
    {

        static Uri GetAPIUri(string path)
        {
            Setting setting = Setting.Instance;
            Uri uri = new Uri(setting.ApiHost);
            string scheme = uri.Scheme.ToLower();
            if (scheme != "http" && scheme != "https")
            {
                setting.ApiHost = Setting.DEFAULT_API_HOST;
                uri = new Uri(setting.ApiHost);
            }
            UriBuilder builder = new UriBuilder(uri);
            builder.Path += path;
            return builder.Uri;
        }

        /// <summary>
        /// 清除返回 JObject 中 cachedSize 和 serializedSize 字段
        /// </summary>
        /// <param name="j"></param>
        /// <returns></returns>
        public static JToken ClearSizeInfo(JToken j)
        {
            if (j == null) return null;
            if (j is JArray ja) {
                for (int i = 0; i < ja.Count; i++)
                {
                    ja[i] = ClearSizeInfo(ja[i]);
                }
                return ja;
            }
            if (j is JObject jo)
            {
                jo.Remove("cachedSize");
                jo.Remove("serializedSize");
                foreach (var p in jo)
                {
                    string key = p.Key;
                    JToken val = p.Value;
                    jo[key] = ClearSizeInfo(val);
                }
                return jo;
            }
            return j;
        }

        public static async Task<JObject> DoDecryptionNew(HTTPRequestHeaders headers, byte[] mBody)
        {
            if (NeedToDecrypt(headers))
            {
                var url = "http://localhost:7790/api/v1/proto/request/decode";
                try
                {
                    string r = await url.PostJsonAsync(new
                    {
                        protocolId = Convert.ToInt32(headers["X-Protocol-Id"]),
                        protocolBody = Convert.ToBase64String(mBody)
                    }).Result.GetStringAsync();
                    if (r != null)
                    {
                        JObject jo = JObject.Parse(r);
                        return ClearSizeInfo(jo) as JObject;
                    }
                    else
                    {
                        return null;
                    }
                }
                catch (Exception ex)
                {
                    return new JObject()
                    {
                        new JProperty("ok", false),
                        new JProperty("resultCode", 502),
                        new JProperty("message", ex.InnerException?.Message ?? ex.Message)
                    };
                }
            }
            return null;
        }

        public static async Task<byte[]> DoDecryption(HTTPRequestHeaders headers, byte[] mBody)
        {
            // 判断是否是对应内容
            string showBody = "";
            if (NeedToDecrypt(headers))
            {
                var url = "http://localhost:7790/api/v1/proto/request/decode";
                try
                {
                    string r = await url.PostJsonAsync(new
                    {
                        protocolId = Convert.ToInt32(headers["X-Protocol-Id"]),
                        protocolBody = Convert.ToBase64String(mBody)
                    }).Result.GetStringAsync();
                    if (r != null)
                    {
                        JObject jo = JObject.Parse(r);
                        if (jo["ok"].Value<bool>())
                        {
                            JObject result = jo["data"].Value<JObject>();
                            result = ClearSizeInfo(result) as JObject;
                            jo["data"] = result;
                        }
                        showBody = jo.ToString();
                    }
                    else
                    {
                        return null;
                    }
                }
                catch (Exception ex)
                {
                    showBody = ex.Message;
                }
            }

            return Encoding.UTF8.GetBytes(showBody);
        }

        public static async Task<byte[]> DoDecryption(HTTPResponseHeaders headers, byte[] mBody)
        {
            // 判断是否是对应内容
            string showBody = "";
            if (NeedToDecrypt(headers))
            {
                var url = "http://localhost:7790/api/v1/proto/response/decode";
                try
                {
                    int? protocolId = headers["X-Protocol-Id"] == null ? (int?)null : Convert.ToInt32(headers["X-Protocol-Id"]);
                    string r = await url.PostJsonAsync(new
                    {
                        protocolId,
                        protocolBody = Convert.ToBase64String(mBody)
                    }).Result.GetStringAsync();
                    if (r != null)
                    {
                        JObject jo = JObject.Parse(r);
                        if (jo["ok"].Value<bool>())
                        {
                            JObject result = jo["data"].Value<JObject>();
                            result = ClearSizeInfo(result) as JObject;
                            jo["data"] = result;
                        }
                        showBody = jo.ToString();
                    }
                    else
                    {
                        return null;
                    }
                }
                catch (Exception ex)
                {
                    showBody = ex.Message;
                }
            }

            return Encoding.UTF8.GetBytes(showBody);
        }

        /// <summary>
        /// 请求是否需要做益盟解密
        /// </summary>
        /// <param name="headers">请求的 Headers</param>
        /// <returns></returns>
        public static bool NeedToDecrypt(HTTPRequestHeaders headers)
        {
            if (headers.Exists("Host") && headers.Exists("Content-Type") && headers.Exists("X-Protocol-Id"))
            {
                var host = headers["Host"];
                var contentType = headers["Content-Type"];
                var protocolId = headers["X-Protocol-Id"];

                return Regex.IsMatch(protocolId, "^\\d+$") 
                    && host.ToLower().EndsWith(".emoney.cn") 
                    && contentType.ToLower().Contains("application/x-protobuf-v3");
            }
            return false;
        }

        /// <summary>
        /// 响应是否需要做益盟解密
        /// </summary>
        /// <param name="headers">返回的 Headers</param>
        /// <returns></returns>
        public static bool NeedToDecrypt(HTTPResponseHeaders headers)
        {
            if (headers.Exists("Content-Type") && headers.Exists("X-Protocol-Id"))
            {
                var contentType = headers["Content-Type"];
                var protocolId = headers["X-Protocol-Id"];

                return Regex.IsMatch(protocolId, "^\\d+$") 
                    && contentType.ToLower().Contains("application/x-protobuf-v3");
            }
            return false;
        }
    }
}