using System;
using System.Web;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;
using System.Threading.Tasks;

using SDKCSharp.Common;
using SDKCSharp.Request;
using SDKCSharp.Response;
using SDKCSharp.Utility;
using System.IO;

namespace SDKCSharp.Client
{
    /// <summary>
    /// 客户端
    /// </summary>
    public class OpenClient
    {

        private static OpenConfig DEFAULT_CONFIG = new OpenConfig();
        private const string ERROR_RESPONSE_KEY = "error_response";

        private Dictionary<string, string> header = new Dictionary<string, string>();


        private string url;
        private string appId;
        private string privateKey;

        private OpenConfig openConfig;
        private OpenRequest openRequest;
        private DataNameBuilder dataNameBuilder;


        public OpenClient(string url, string appId, string privateKey) : this(url, appId, privateKey,false, DEFAULT_CONFIG)
        {
            
        }

        public OpenClient(string url, string appId, string privateKey, bool priKeyFromFile) : this(url, appId, privateKey, priKeyFromFile, DEFAULT_CONFIG)
        {

        }

        public OpenClient(string url, string appId, string privateKey,bool priKeyFromFile, OpenConfig openConfig)
        {
            this.url = url;
            this.appId = appId;
            this.privateKey = privateKey;
            this.openConfig = openConfig;
            this.openRequest = new OpenRequest(openConfig);
            // 如果是从文件中加载私钥
            if (priKeyFromFile)
            {
                this.privateKey = LoadCertificateFile(privateKey);
            }
            this.dataNameBuilder = openConfig.DataNameBuilder;
        }

        /// <summary>
        /// 加载秘钥文件
        /// </summary>
        /// <returns>返回私钥内容.</returns>
        /// <param name="filename">文件路径.</param>
        private static string LoadCertificateFile(string filename)
        {
            if(!File.Exists(filename))
            {
                throw new SopException("文件不存在," + filename);
            }
            using (FileStream fs = File.OpenRead(filename))
            {
                byte[] data = new byte[fs.Length];
                fs.Read(data, 0, data.Length);
                return Encoding.UTF8.GetString(data);
            }
        }

        /// <summary>
        /// 发送请求
        /// </summary>
        /// <typeparam name="T">返回的Response类</typeparam>
        /// <param name="request">请求对象</param>
        /// <returns>返回Response类</returns>
        public virtual T Execute<T>(BaseRequest<T> request) where T : BaseResponse
        {
            return this.Execute<T>(request, null);
        }

        /// <summary>
        /// 发送请求
        /// </summary>
        /// <typeparam name="T">返回的Response类</typeparam>
        /// <param name="request">请求对象</param>
        /// <param name="accessToken">accessToken</param>
        /// <returns>返回Response类</returns>
        public virtual T Execute<T>(BaseRequest<T> request, string accessToken) where T : BaseResponse
        {
            RequestForm requestForm = request.CreateRequestForm(this.openConfig);
            Dictionary<string, string> form = requestForm.Form;
            if (!string.IsNullOrEmpty(accessToken))
            {
                form[this.openConfig.AccessTokenName] = accessToken;
            }
            form[this.openConfig.AppKeyName] = this.appId;
            string content = SopSignature.getSignContent(form);
            string sign = SignUtil.CreateSign(form, privateKey, request.Charset, request.SignType);
            form[this.openConfig.SignName] = sign;

            string resp = this.DoExecute(url, requestForm, header);

            return this.ParseResponse<T>(resp, request);
        }

        /// <summary>
        /// 执行请求
        /// </summary>
        /// <param name="url">请求url</param>
        /// <param name="requestForm">请求内容</param>
        /// <param name="header">请求header</param>
        /// <returns>返回服务器响应内容</returns>
        protected virtual string DoExecute(string url, RequestForm requestForm, Dictionary<string, string> header)
        {
            return openRequest.Request(this.url, requestForm, header);
        }

        /// <summary>
        /// 解析返回结果
        /// </summary>
        /// <typeparam name="T">返回的Response</typeparam>
        /// <param name="resp">服务器响应内容</param>
        /// <param name="request">请求Request</param>
        /// <returns>返回Response</returns>
        protected virtual T ParseResponse<T>(string resp, BaseRequest<T> request) where T: BaseResponse {
            string method = request.Method;
            string dataName = this.dataNameBuilder.Build(method);
            Dictionary<string, object> jsonObject = JsonUtil.ParseToDictionary(resp);
            bool errorResponse = jsonObject.ContainsKey(ERROR_RESPONSE_KEY);
            if (errorResponse)
            {
                dataName = ERROR_RESPONSE_KEY;
            }
            object data = jsonObject[dataName];
            string jsonData = data == null ? "{}" : data.ToString();           
            T t = JsonUtil.ParseObject<T>(jsonData);
            t.Body = jsonData;
            return t;
        }


    }
}