using Flurl.Http;
using Insurance.Web.Models;
using Microsoft.IdentityModel.Tokens;
using System;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
using System.Web.Mvc;

namespace Insurance.Web.Controllers
{
    public class TestController : Controller
    {
        public async Task<ActionResult> Index()
        {
            try
            {
                var aes = new AesCryptography();
                var course = new InsuranceCourse(aes);

                //1 呼叫認證api，以確認使用者身份
                ResponseResult loginResult = await course.Login("voxel", "000", "A123456789");
                if (loginResult.Success == false)
                    throw new Exception("認證失敗,錯誤訊息=>" + loginResult.Message);

                //2 認證成功後，呼叫完訓api執行完訓動作
                ResponseResult finishResult = await course.Finish(loginResult.Token,"A123456789", "A012");
                if (finishResult.Success==false)
                    throw new Exception("完訓失敗,錯誤訊息=>" + finishResult.Message);

                return Content("完訓成功");
            }
            catch(Exception ex)
            {
                return Content(ex.Message);
            }
        }
    }

    public class InsuranceCourse
    {
        private AesCryptography _Aes;
        public InsuranceCourse(AesCryptography aesCryptography)
        {
            this._Aes = aesCryptography;
        }

        /// <summary>
        /// 登入
        /// </summary>
        /// <param name="account">帳號</param>
        /// <param name="password">密碼</param>
        /// <param name="insuranceNo">業務員登錄證字號</param>
        public async Task<ResponseResult> Login(string account, string password, string insuranceNo)
        {           
            //1 產生認證資料
            string user = $"{account}|{password}|{insuranceNo}";

            //2 對認證資料進行Aes加密
            byte[] userArray = this._Aes.Encrypt(user);

            //3 將Aes資料進行Base64Url編碼
            string userBase64Url = Base64UrlEncoder.Encode(userArray);

            //4 呼叫登入api進行身份認證,同時將認證資料以查詢字串方式傳遞
            string url = "https://localhost:44381/api/verify/login?user=" + userBase64Url;
            
            //5 傳回結果為json物件
            ResponseResult response = await url.AllowHttpStatus("1XX-6XX").GetJsonAsync<ResponseResult>();
           
            //6 判斷傳回結果  
            if (response == null) 
                throw new Exception("API/Login 無回應");

            if (response.Success == false)
                throw new Exception("認證失敗,錯誤訊息=" + response.Message);

            //7 認證成功
            return response;
        }

        /// <summary>
        /// 完訓
        /// </summary>
        /// <param name="token">登入認證時取得的jwt token</param>
        /// <param name="insuranceNo">業務員登錄證字號</param>
        /// <param name="code">完訓碼</param>
        public async Task<ResponseResult> Finish(string token, string insuranceNo, string code) 
        {
            //1 產生完訓資料
            string info = $"{insuranceNo}|{code}";

            //2 對完訓資料進行Aes加密
            byte[] infoArray = this._Aes.Encrypt(info);

            //3 將Aes資料進行Base64Url編碼
            string infoBase64Url = Base64UrlEncoder.Encode(infoArray);

            //4 呼叫完訓api進行,同時將完訓資料以查詢字串方式傳遞
            string url = "https://localhost:44381/api/Verify/Finish?info=" + infoBase64Url;                        
            ResponseResult response = await url.AllowHttpStatus("1XX-6XX")
                                               .WithOAuthBearerToken(token)    //header加上『Authorization』並指定jwt token
                                               .GetJsonAsync<ResponseResult>();//傳回結果為json物件

            //5 判斷傳回結果
            if (response == null)
                throw new Exception("API/Login 無回應");

            if (response.Success == false)
                throw new Exception("認證失敗,錯誤訊息=" + response.Message);

            //6 認證成功
            return response;
        }

    }

    public class AesCryptography
    {
        public string Key = "B04412AC311B413087B1DAF37B1B8562";
        public string IV = "1234567812345679";

        public byte[] Encrypt(string plain_text)
        {   
            Aes aes = Aes.Create();
            ICryptoTransform transform = aes.CreateEncryptor(Encoding.UTF8.GetBytes(this.Key), Encoding.UTF8.GetBytes(this.IV));
            byte[] bPlainText = Encoding.UTF8.GetBytes(plain_text);
            return transform.TransformFinalBlock(bPlainText, 0, bPlainText.Length);
        }
      
        public string Decrypt(byte[] aesArray)
        {
            Aes aes = Aes.Create();
            ICryptoTransform transform = aes.CreateDecryptor(Encoding.UTF8.GetBytes(this.Key), Encoding.UTF8.GetBytes(this.IV));
            byte[] outputData = null;
            try
            {
                outputData = transform.TransformFinalBlock(aesArray, 0, aesArray.Length);
                return Encoding.UTF8.GetString(outputData);
            }
            catch (Exception ex)
            {
                throw new Exception($@"解密失敗:{ex.Message}");
            }
        }
    }

}