storj/private/apigen/gogen.go
Egon Elbre 794a4cc365 private/apigen: make code compile with 1.16
Our Test Versions still requires 1.16 to be compatible with our oldest
uplink versions. These changes make the code compile with 1.16.

Also, it makes go generate work in private/apigen/example.

Change-Id: Ib2f7493941a16f361328fe01d2be293f26123719
2022-09-02 16:34:46 +03:00

386 lines
9.8 KiB
Go

// Copyright (C) 2022 Storj Labs, Inc.
// See LICENSE for copying information.
package apigen
import (
"fmt"
"go/format"
"os"
"reflect"
"sort"
"strings"
"time"
"github.com/zeebo/errs"
"golang.org/x/text/cases"
"golang.org/x/text/language"
"storj.io/common/uuid"
)
// DateFormat is the layout of dates passed into and out of the API.
const DateFormat = "2006-01-02T15:04:05.999Z"
// MustWriteGo writes generated Go code into a file.
func (a *API) MustWriteGo(path string) {
generated, err := a.generateGo()
if err != nil {
panic(errs.Wrap(err))
}
err = os.WriteFile(path, generated, 0644)
if err != nil {
panic(errs.Wrap(err))
}
}
// generateGo generates api code and returns an output.
func (a *API) generateGo() ([]byte, error) {
var result string
pf := func(format string, a ...interface{}) {
result += fmt.Sprintf(format+"\n", a...)
}
getPackageName := func(path string) string {
pathPackages := strings.Split(path, "/")
return pathPackages[len(pathPackages)-1]
}
imports := struct {
All map[string]bool
Standard []string
External []string
Internal []string
}{
All: make(map[string]bool),
}
i := func(paths ...string) {
for _, path := range paths {
if path == "" || getPackageName(path) == a.PackageName {
continue
}
if _, ok := imports.All[path]; ok {
continue
}
imports.All[path] = true
var slice *[]string
switch {
case !strings.Contains(path, "."):
slice = &imports.Standard
case strings.HasPrefix(path, "storj.io"):
slice = &imports.Internal
default:
slice = &imports.External
}
*slice = append(*slice, path)
}
}
for _, group := range a.EndpointGroups {
for _, method := range group.endpoints {
if method.Request != nil {
i(getElementaryType(reflect.TypeOf(method.Request)).PkgPath())
}
if method.Response != nil {
i(getElementaryType(reflect.TypeOf(method.Response)).PkgPath())
}
}
}
for _, group := range a.EndpointGroups {
i("github.com/zeebo/errs")
pf("var Err%sAPI = errs.Class(\"%s %s api\")", cases.Title(language.Und).String(group.Prefix), a.PackageName, group.Prefix)
}
pf("")
params := make(map[*fullEndpoint][]Param)
for _, group := range a.EndpointGroups {
pf("type %sService interface {", group.Name)
for _, e := range group.endpoints {
params[e] = append(e.PathParams, e.QueryParams...)
var paramStr string
for i, param := range params[e] {
paramStr += param.Name
if i == len(params[e])-1 || param.Type != params[e][i+1].Type {
paramStr += " " + param.Type.String()
}
paramStr += ", "
}
if e.Request != nil {
paramStr += "request " + reflect.TypeOf(e.Request).String() + ", "
}
i("context", "storj.io/storj/private/api")
if e.Response != nil {
responseType := reflect.TypeOf(e.Response)
returnParam := a.handleTypesPackage(responseType)
if responseType == getElementaryType(responseType) {
returnParam = "*" + returnParam
}
pf("%s(ctx context.Context, "+paramStr+") (%s, api.HTTPError)", e.MethodName, returnParam)
} else {
pf("%s(ctx context.Context, "+paramStr+") (api.HTTPError)", e.MethodName)
}
}
pf("}")
pf("")
}
for _, group := range a.EndpointGroups {
i("go.uber.org/zap", "github.com/spacemonkeygo/monkit/v3")
pf("// %sHandler is an api handler that exposes all %s related functionality.", group.Name, group.Prefix)
pf("type %sHandler struct {", group.Name)
pf("log *zap.Logger")
pf("mon *monkit.Scope")
pf("service %sService", group.Name)
pf("auth api.Auth")
pf("}")
pf("")
}
for _, group := range a.EndpointGroups {
i("github.com/gorilla/mux")
pf(
"func New%s(log *zap.Logger, mon *monkit.Scope, service %sService, router *mux.Router, auth api.Auth) *%sHandler {",
group.Name,
group.Name,
group.Name,
)
pf("handler := &%sHandler{", group.Name)
pf("log: log,")
pf("mon: mon,")
pf("service: service,")
pf("auth: auth,")
pf("}")
pf("")
pf("%sRouter := router.PathPrefix(\"/api/v0/%s\").Subrouter()", group.Prefix, group.Prefix)
for _, endpoint := range group.endpoints {
handlerName := "handle" + endpoint.MethodName
pf("%sRouter.HandleFunc(\"%s\", handler.%s).Methods(\"%s\")", group.Prefix, endpoint.Path, handlerName, endpoint.Method)
}
pf("")
pf("return handler")
pf("}")
pf("")
}
for _, group := range a.EndpointGroups {
for _, endpoint := range group.endpoints {
i("net/http")
pf("")
handlerName := "handle" + endpoint.MethodName
pf("func (h *%sHandler) %s(w http.ResponseWriter, r *http.Request) {", group.Name, handlerName)
pf("ctx := r.Context()")
pf("var err error")
pf("defer h.mon.Task()(&ctx)(&err)")
pf("")
pf("w.Header().Set(\"Content-Type\", \"application/json\")")
pf("")
if !endpoint.NoCookieAuth || !endpoint.NoAPIAuth {
pf("ctx, err = h.auth.IsAuthenticated(ctx, r, %v, %v)", !endpoint.NoCookieAuth, !endpoint.NoAPIAuth)
pf("if err != nil {")
if !endpoint.NoCookieAuth {
pf("h.auth.RemoveAuthCookie(w)")
}
pf("api.ServeError(h.log, w, http.StatusUnauthorized, err)")
pf("return")
pf("}")
pf("")
}
if err := handleParams(pf, i, endpoint.PathParams, endpoint.QueryParams); err != nil {
return nil, err
}
if endpoint.Request != nil {
handleBody(pf, endpoint.Request)
}
var methodFormat string
if endpoint.Response != nil {
methodFormat = "retVal, httpErr := h.service.%s(ctx, "
} else {
methodFormat = "httpErr := h.service.%s(ctx, "
}
for _, param := range params[endpoint] {
methodFormat += param.Name + ", "
}
if endpoint.Request != nil {
methodFormat += "payload"
}
methodFormat += ")"
pf(methodFormat, endpoint.MethodName)
pf("if httpErr.Err != nil {")
pf("api.ServeError(h.log, w, httpErr.Status, httpErr.Err)")
if endpoint.Response == nil {
pf("}")
pf("}")
continue
}
pf("return")
pf("}")
i("encoding/json")
pf("")
pf("err = json.NewEncoder(w).Encode(retVal)")
pf("if err != nil {")
pf("h.log.Debug(\"failed to write json %s response\", zap.Error(Err%sAPI.Wrap(err)))", endpoint.MethodName, cases.Title(language.Und).String(group.Prefix))
pf("}")
pf("}")
}
}
fileBody := result
result = ""
pf("// AUTOGENERATED BY private/apigen")
pf("// DO NOT EDIT.")
pf("")
pf("package %s", a.PackageName)
pf("")
pf("import (")
slices := [][]string{imports.Standard, imports.External, imports.Internal}
for sn, slice := range slices {
sort.Strings(slice)
for pn, path := range slice {
pf(`"%s"`, path)
if pn == len(slice)-1 && sn < len(slices)-1 {
pf("")
}
}
}
pf(")")
pf("")
if _, ok := imports.All["time"]; ok {
pf("const dateLayout = \"%s\"", DateFormat)
pf("")
}
result += fileBody
output, err := format.Source([]byte(result))
if err != nil {
return nil, err
}
return output, nil
}
// handleTypesPackage handles the way some type is used in generated code.
// If type is from the same package then we use only type's name.
// If type is from external package then we use type along with its appropriate package name.
func (a *API) handleTypesPackage(t reflect.Type) string {
if strings.HasPrefix(t.String(), a.PackageName) {
return t.Elem().Name()
}
return t.String()
}
// handleParams handles parsing of URL path parameters or query parameters.
func handleParams(pf func(format string, a ...interface{}), i func(paths ...string), pathParams, queryParams []Param) error {
pErrCheck := func() {
pf("if err != nil {")
pf("api.ServeError(h.log, w, http.StatusBadRequest, err)")
pf("return")
pf("}")
}
for _, params := range []*[]Param{&queryParams, &pathParams} {
for _, param := range *params {
varName := param.Name
if param.Type.Kind() != reflect.String {
varName += "Param"
}
switch params {
case &queryParams:
pf("%s := r.URL.Query().Get(\"%s\")", varName, param.Name)
pf("if %s == \"\" {", varName)
pf("api.ServeError(h.log, w, http.StatusBadRequest, errs.New(\"parameter '%s' can't be empty\"))", param.Name)
pf("return")
pf("}")
pf("")
case &pathParams:
pf("%s, ok := mux.Vars(r)[\"%s\"]", varName, param.Name)
pf("if !ok {")
pf("api.ServeError(h.log, w, http.StatusBadRequest, errs.New(\"missing %s route param\"))", param.Name)
pf("return")
pf("}")
pf("")
}
switch param.Type {
case reflect.TypeOf(uuid.UUID{}):
i("storj.io/common/uuid")
pf("%s, err := uuid.FromString(%s)", param.Name, varName)
pErrCheck()
case reflect.TypeOf(time.Time{}):
i("time")
pf("%s, err := time.Parse(dateLayout, %s)", param.Name, varName)
pErrCheck()
default:
switch param.Type.Kind() {
case reflect.String:
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
i("strconv")
convName := varName
if param.Type.Kind() != reflect.Uint64 {
convName += "U64"
}
bits := param.Type.Bits()
if param.Type.Kind() == reflect.Uint {
bits = 32
}
pf("%s, err := strconv.ParseUint(%s, 10, %d)", convName, varName, bits)
pErrCheck()
if param.Type.Kind() != reflect.Uint64 {
pf("%s := %s(%s)", param.Name, param.Type.String(), convName)
}
default:
return errs.New("Unsupported parameter type \"%s\"", param.Type)
}
}
pf("")
}
}
return nil
}
// handleBody handles request body.
func handleBody(pf func(format string, a ...interface{}), body interface{}) {
pf("payload := %s{}", reflect.TypeOf(body).String())
pf("if err = json.NewDecoder(r.Body).Decode(&payload); err != nil {")
pf("api.ServeError(h.log, w, http.StatusBadRequest, err)")
pf("return")
pf("}")
pf("")
}
// getElementaryType simplifies a Go type.
func getElementaryType(t reflect.Type) reflect.Type {
switch t.Kind() {
case reflect.Array, reflect.Chan, reflect.Map, reflect.Ptr, reflect.Slice:
return getElementaryType(t.Elem())
default:
return t
}
}