add api & config

api/error.go

@@ -0,0 +1,45 @@
+package api
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+var (
+	ErrInvalid  = &Error{statusCode: http.StatusBadRequest, Code: 40001, Msg: "object invalid"}
+	ErrDup      = &Error{statusCode: http.StatusBadRequest, Code: 40002, Msg: "object duplicated"}
+	ErrCreate   = &Error{statusCode: http.StatusConflict, Code: 40003, Msg: "object creation failed"}
+	ErrNotFound = &Error{statusCode: http.StatusBadRequest, Code: 40004, Msg: "object not found"}
+	ErrSave     = &Error{statusCode: http.StatusInternalServerError, Code: 40005, Msg: "save config failed"}
+)
+
+// Error is an api error.
+type Error struct {
+	statusCode int
+	Code       int    `json:"code"`
+	Msg        string `json:"msg"`
+}
+
+func (e *Error) Error() string {
+	b, _ := json.Marshal(e)
+	return string(b)
+}
+
+func writeError(c *gin.Context, err error) {
+	// c.Set(HTTPResponseTag, err)
+	c.JSON(getStatusCode(err), err)
+}
+
+func getStatusCode(err error) int {
+	if err == nil {
+		return http.StatusOK
+	}
+	if e, ok := err.(*Error); ok {
+		if e.statusCode >= http.StatusOK && e.statusCode < 600 {
+			return e.statusCode
+		}
+	}
+	return http.StatusInternalServerError
+}