Add exchange api endpoint, fix jwt authtoken var type error

Signed-off-by: Asai Neko <sugar@sne.moe>

service/auth/exchange.go

@@ -0,0 +1,65 @@
+package auth
+
+import (
+	"net/url"
+	"nixcn-cms/data"
+	"nixcn-cms/pkgs/authcode"
+	"nixcn-cms/utils"
+
+	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
+)
+
+func Exchange(c *gin.Context) {
+	var exchangeReq struct {
+		ClientId    string `json:"client_id"`
+		RedirectUri string `json:"redirect_uri"`
+		State       string `json:"state"`
+	}
+
+	err := c.BindJSON(exchangeReq)
+	if err != nil {
+		utils.HttpResponse(c, 400, "", "invalid request")
+		return
+	}
+
+	userIdOrig, ok := c.Get("user_id")
+	if !ok {
+		utils.HttpResponse(c, 401, "", "unauthorized")
+		return
+	}
+
+	userId, err := uuid.Parse(userIdOrig.(string))
+	if err != nil {
+		utils.HttpResponse(c, 500, "", "failed to parse uuid")
+		return
+	}
+
+	userData := new(data.User)
+	user, err := userData.GetByUserId(userId)
+	if err != nil {
+		utils.HttpResponse(c, 500, "", "failed to get user id")
+		return
+	}
+
+	code, err := authcode.NewAuthCode(exchangeReq.ClientId, user.Email)
+	if err != nil {
+		utils.HttpResponse(c, 500, "", "code gen failed")
+		return
+	}
+
+	url, err := url.Parse(exchangeReq.RedirectUri)
+	if err != nil {
+		utils.HttpResponse(c, 400, "", "invalid redirect uri")
+		return
+	}
+	query := url.Query()
+	query.Set("code", code)
+	url.RawQuery = query.Encode()
+
+	exchangeResp := struct {
+		RedirectUri string `json:"redirect_uri"`
+	}{url.String()}
+
+	utils.HttpResponse(c, 200, "", "success", exchangeResp)
+}