add API boilerplate + /accounts/{accountID} and /accounts/@me endpoints

web/api/error.go

@@ -0,0 +1,166 @@
+package api
+
+import (
+	"fmt"
+	"net/http"
+
+	"emperror.dev/errors"
+	"github.com/go-chi/render"
+)
+
+// NoValue should be returned by functions that either:
+// - don't return any content for one or more code paths
+// - handle rendering content themselves
+const NoValue = errors.Sentinel("no content")
+
+// WrapHandlerT wraps a modified http.HandlerFunc into a stdlib-compatible one.
+// The inner HandlerFunc additionally returns a JSON response and an error.
+func WrapHandlerT[T any](hn func(w http.ResponseWriter, r *http.Request) (T, error)) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		v, err := hn(w, r)
+		if err == nil {
+			render.JSON(w, r, v)
+			return
+		} else if err == NoValue {
+			return
+		}
+
+		// if the function returned an API error, just render that verbatim
+		if apiErr, ok := err.(Error); ok {
+			apiErr.prepare()
+
+			render.Status(r, apiErr.Status)
+			render.JSON(w, r, apiErr)
+			return
+		}
+
+		// otherwise, we return an internal server error message
+		apiErr := Error{Code: ErrInternalServerError}
+		apiErr.prepare()
+
+		render.Status(r, apiErr.Status)
+		render.JSON(w, r, apiErr)
+	}
+}
+
+// WrapHandler wraps a modified http.HandlerFunc into a stdlib-compatible one.
+// The inner HandlerFunc additionally returns an error.
+func WrapHandler(hn func(w http.ResponseWriter, r *http.Request) error) http.HandlerFunc {
+	fn := func(w http.ResponseWriter, r *http.Request) (any, error) {
+		err := hn(w, r)
+		if err == nil {
+			return nil, NoValue
+		}
+		return nil, err
+	}
+
+	return WrapHandlerT(fn)
+
+	// return func(w http.ResponseWriter, r *http.Request) {
+	// 	err := hn(w, r)
+	// 	if err != nil {
+	// 		// if the function returned an API error, just render that verbatim
+	// 		// we can assume that it also logged the error (if that was needed)
+	// 		if apiErr, ok := err.(Error); ok {
+	// 			apiErr.prepare()
+
+	// 			render.Status(r, apiErr.Status)
+	// 			render.JSON(w, r, apiErr)
+	// 			return
+	// 		}
+
+	// 		// otherwise, we log the error and return an internal server error message
+	// 		log.Err(err).Msg("error in http handler")
+
+	// 		apiErr := Error{Code: ErrInternalServerError}
+	// 		apiErr.prepare()
+
+	// 		render.Status(r, apiErr.Status)
+	// 		render.JSON(w, r, apiErr)
+	// 	}
+	// }
+}
+
+type Error struct {
+	Code    int    `json:"code"`
+	Message string `json:"message,omitempty"`
+	Details string `json:"details,omitempty"`
+
+	// Status is set as the HTTP status code.
+	Status int `json:"-"`
+}
+
+func (e Error) Error() string {
+	if e.Message == "" {
+		e.Message = errCodeMessages[e.Code]
+	}
+
+	if e.Details != "" {
+		return fmt.Sprintf("%s (code: %d) (%s)", e.Message, e.Code, e.Details)
+	}
+
+	return fmt.Sprintf("%s (code: %d)", e.Message, e.Code)
+}
+
+func (e *Error) prepare() {
+	if e.Status == 0 {
+		e.Status = errCodeStatuses[e.Code]
+	}
+
+	if e.Message == "" {
+		e.Message = errCodeMessages[e.Code]
+	}
+}
+
+// Error code constants
+const (
+	ErrBadRequest          = 400
+	ErrForbidden           = 403
+	ErrNotFound            = 404
+	ErrMethodNotAllowed    = 405
+	ErrTooManyRequests     = 429
+	ErrInternalServerError = 500 // catch-all code for unknown errors
+
+	// Auth related
+	ErrInvalidToken = 1001
+	ErrMissingScope = 1002
+
+	// Account related
+	ErrAccountNotFound = 1003
+)
+
+func ErrCodeMessage(code int) string {
+	return errCodeMessages[code]
+}
+
+var errCodeMessages = map[int]string{
+	ErrBadRequest:          "Bad request",
+	ErrForbidden:           "Forbidden",
+	ErrInternalServerError: "Internal server error",
+	ErrNotFound:            "Not found",
+	ErrTooManyRequests:     "Rate limit reached",
+	ErrMethodNotAllowed:    "Method not allowed",
+
+	ErrInvalidToken: "No token supplied, or token is invalid",
+	ErrMissingScope: "Token is missing required scope for this endpoint",
+
+	ErrAccountNotFound: "Account not found",
+}
+
+func ErrCodeStatus(code int) int {
+	return errCodeStatuses[code]
+}
+
+var errCodeStatuses = map[int]int{
+	ErrBadRequest:          http.StatusBadRequest,
+	ErrForbidden:           http.StatusForbidden,
+	ErrInternalServerError: http.StatusInternalServerError,
+	ErrNotFound:            http.StatusNotFound,
+	ErrTooManyRequests:     http.StatusTooManyRequests,
+	ErrMethodNotAllowed:    http.StatusMethodNotAllowed,
+
+	ErrInvalidToken: http.StatusUnauthorized,
+	ErrMissingScope: http.StatusForbidden,
+
+	ErrAccountNotFound: http.StatusNotFound,
+}