using OAuthApp.Data;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System.Linq;
using System.Net.Http;
using System.Web;

namespace OAuthApp.Controllers
{
 public class OpenWechatController : Controller
 {
 readonly HttpContext _httpContext;
 readonly AppDbContext _dbContext;

 // 微信开放平台网站应用专用
 const string Authorize_url = "https://open.weixin.qq.com/connect/qrconnect";

 public OpenWechatController(IHttpContextAccessor contextAccessor,
 AppDbContext dbContext)
 {
 _httpContext = contextAccessor.HttpContext;
 _dbContext = dbContext;
 }

 public const string default_scope = "snsapi_login";

 [HttpGet]
 public ActionResult Authorize([FromQuery] string code, [FromQuery] long state, [FromQuery] string jxwechat)
 {
 var props = _dbContext.PropertySettings
 .Where(x => x.ChannelCode.Equals(ChannelCodes.App) && x.ChannelAppId == state).ToList();

 if (props.Count <1)
 {
 return NotFound("请先配置应用");
 }

 var OpenWechatClientID = props
 .FirstOrDefault(x => x.Name.Equals(PropKeyConst.OpenWechatClientID)).Value;

 //if (string.IsNullOrWhiteSpace(OpenWechatClientID))
 //{
 // OpenWechatClientID = default_client_id;
 //}

 var OpenWechatClientSecret = props
 .FirstOrDefault(x => x.Name.Equals(PropKeyConst.OpenWechatClientSecret)).Value;

 //if (string.IsNullOrWhiteSpace(OpenWechatClientSecret))
 //{
 // OpenWechatClientSecret = default_client_secret;
 //}

 var OpenWechatScope = props
 .FirstOrDefault(x => x.Name.Equals(PropKeyConst.OpenWechatScope)).Value;

 //if (string.IsNullOrWhiteSpace(OpenWechatScope))
 //{
 // OpenWechatScope = default_scope;
 //}

 var OpenWechatRedirectUri = props
 .FirstOrDefault(x => x.Name.Equals(PropKeyConst.OpenWechatRedirectUri)).Value;

 if (string.IsNullOrWhiteSpace(code) && string.IsNullOrWhiteSpace(jxwechat))
 {
 var host = _httpContext.Request.Scheme + "://" + _httpContext.Request.Host.ToString();

 var redirect_uri = $"{host}/OpenWechat/Authorize";

 var queryStrings = $"appid={OpenWechatClientID}&redirect_uri={redirect_uri}&response_type=code&scope={OpenWechatScope}&state={state}#wechat_redirect";

 var redirectTo = Authorize_url + "?" + queryStrings;

 return new RedirectResult(redirectTo);
 }

 else
 {
 var OAuthorizeResult = GetAccessToken(OpenWechatClientID, OpenWechatClientSecret, code, OpenWechatScope);

 var redirectTo = OpenWechatRedirectUri + $"?id={state}&app_wechat={HttpUtility.UrlEncode(OAuthorizeResult)}";

 return new RedirectResult(redirectTo);
 }
 }

 private string GetAccessToken(string client_id, string client_secret, string code, string scope)
 {
 var result = string.Empty;

 using (var hc = new HttpClient())
 {
 var url = $"https://api.weixin.qq.com/sns/oauth2/access_token?appid={client_id}&secret={client_secret}&code={code}&grant_type=authorization_code";

 result = hc.GetStringAsync(url).Result;
 }

 var responseJson = JsonConvert.DeserializeObject<JObject>(result);

 #region 报错
 if (responseJson["errcode"] != null && responseJson["errcode"].HasValues)
 {
 return responseJson["errcode"].Value<string>();
 }
 #endregion

 #region 如果scope是snsapi_userinfo 
 if (scope.Equals(default_scope))
 {
 var access_token = responseJson["access_token"].Value<string>();

 var openid = responseJson["openid"].Value<string>();

 using (var hc = new HttpClient())
 {
 var url = $"https://api.weixin.qq.com/sns/userinfo?access_token={access_token}&openid={openid}&lang=zh_CN";

 result = hc.GetStringAsync(url).Result;
 }

 responseJson = JsonConvert.DeserializeObject<JObject>(result);

 #region 报错
 if (responseJson["errcode"] != null && responseJson["errcode"].HasValues)
 {
 return responseJson["errcode"].Value<string>();
 }
 #endregion

 responseJson.Add("access_token", access_token);

 return JsonConvert.SerializeObject(responseJson);
 }
 #endregion

 //scope是snsapi_base
 return result;
 }

 }
}