opencloud/ocs/pkg/service/v0/response/version.go

package response

import (
	"context"
	"net/http"

	"github.com/go-chi/chi"
	"github.com/go-chi/render"
	"github.com/owncloud/ocis/ocs/pkg/service/v0/data"
)

type key int

const (
	apiVersionKey key = iota
	ocsVersion1       = "1"
	ocsVersion2       = "2"
)

var (
	defaultStatusCodeMapper = OcsV2StatusCodes
)

// APIVersion retrieves the api version from the context.
func APIVersion(ctx context.Context) string {
	value := ctx.Value(apiVersionKey)
	if value != nil {
		return value.(string)
	}
	return ""
}

// OcsV1StatusCodes returns the http status codes for the OCS API v1.
func OcsV1StatusCodes(meta data.Meta) int {
	return http.StatusOK
}

// OcsV2StatusCodes maps the OCS codes to http status codes for the ocs API v2.
func OcsV2StatusCodes(meta data.Meta) int {
	sc := meta.StatusCode
	switch sc {
	case data.MetaNotFound.StatusCode:
		return http.StatusNotFound
	case data.MetaUnknownError.StatusCode:
		fallthrough
	case data.MetaServerError.StatusCode:
		return http.StatusInternalServerError
	case data.MetaUnauthorized.StatusCode:
		return http.StatusUnauthorized
	case 100:
		meta.StatusCode = http.StatusOK
		return http.StatusOK
	}
	// any 2xx, 4xx and 5xx will be used as is
	if sc >= 200 && sc < 600 {
		return sc
	}

	// any error codes > 100 are treated as client errors
	if sc > 100 && sc < 200 {
		return http.StatusBadRequest
	}

	// TODO change this status code?
	return http.StatusOK
}

// VersionCtx middleware is used to determine the response mapper from
// the URL parameters passed through as the request. In case
// the Version is unknown, we stop here and return a 404.
func VersionCtx(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		version := chi.URLParam(r, "version")
		if version == "" {
			render.Render(w, r, ErrRender(data.MetaBadRequest.StatusCode, "unknown ocs api version"))
			return
		}
		w.Header().Set("Ocs-Api-Version", version)

		// store version in context so handlers can access it
		ctx := context.WithValue(r.Context(), apiVersionKey, version)
		next.ServeHTTP(w, r.WithContext(ctx))
	})
}